gammaloop_api/commands/

generate.rs

// file: src/cmd/generate.rs
#![allow(clippy::too_many_arguments)]

use ahash::HashMap;
use color_eyre::owo_colors::OwoColorize;
use tracing::info;

use std::collections::{BTreeMap, BTreeSet};
use std::ffi::OsStr;
use std::fs;
use std::num::ParseIntError;
use std::ops::RangeInclusive;
use std::path::Path;
use std::str::FromStr;

use clap::{Args, Parser, Subcommand, ValueEnum};
use color_eyre::Result;
use regex::Regex;
use schemars::JsonSchema;
use serde::{Deserialize, Serialize};
use symbolica::parse;
use tabled::{
    builder::Builder,
    settings::{style::HorizontalLine, themes::Theme, Style},
};
use thiserror::Error;
use walkdir::WalkDir;

use eyre::{eyre, Context};
use gammalooprs::feyngen::{
    FeynGenFilter, FeynGenFilters, GenerationType, GraphGroupingOptions,
    NumeratorAwareGraphGroupingOption, SelfEnergyFilterOptions, SewedFilterOptions,
    SnailFilterOptions, TadpolesFilterOptions,
};
use gammalooprs::model::Model;
use gammalooprs::numerator::GlobalPrefactor;
use gammalooprs::processes::amplitude::Amplitude;
use gammalooprs::processes::{
    merge_generated_graph_reports, CrossSection, GeneratedGraphReport, GraphGenerationStats,
    Process, ProcessDefinition, ProcessList,
};
use gammalooprs::settings::{GlobalSettings, RuntimeSettings};

use crate::commands::set::KvPair;
use crate::completion::CompletionArgExt;
use crate::state::{GenerationResourceSummary, ProcessRef, State};

// =================== CLI containers (kept close to your structure) ===================

#[derive(Debug, Parser, Serialize, Deserialize, Clone, JsonSchema, PartialEq)]
/// Generate cross-section or amplitude integrands from a process specification.
pub struct Generate {
    /// Keep generated C++ source files after external compilation
    #[arg(long = "keep-sources", default_value_t = false, global = true)]
    #[serde(default)]
    pub keep_sources: bool,
    /// Selects cross-section, amplitude, or existing-process generation; when
    /// omitted, generates all integrands in the active state.
    #[command(subcommand)]
    pub mode: Option<GenerateCmd>,
}

#[derive(Debug, Subcommand, Serialize, Deserialize, Clone, JsonSchema, PartialEq)]
/// Select cross-section, amplitude, or existing-process integrand generation.
pub enum GenerateCmd {
    /// Generate a cross-section integrand through the forward-scattering construction.
    Xs(SpecArgs),

    /// Generate an amplitude integrand for the supplied process specification.
    #[command(alias = "amplitude")]
    Amp(SpecArgs),

    /// Create another integrand from an existing process without regenerating its graphs.
    Existing(ProcessArgs),
}

#[derive(Debug, Clone, Copy, Serialize, Deserialize, JsonSchema, PartialEq, Eq, ValueEnum)]
pub enum GroupingChoice {
    #[clap(name = "no_grouping")]
    NoGrouping,
    #[clap(name = "only_detect_zeroes")]
    OnlyDetectZeroes,
    #[clap(name = "group_identical_graphs_up_to_sign")]
    GroupIdenticalGraphsUpToSign,
    #[clap(name = "group_identical_graphs_up_to_scalar_rescaling")]
    GroupIdenticalGraphsUpToScalarRescaling,
}

impl GroupingChoice {
    fn to_strategy(
        self,
        seed: Option<u16>,
        num_samples: Option<usize>,
        differentiate_particle_masses_only: Option<bool>,
        fully_numerical_substitution_when_comparing_numerators: Option<bool>,
        test_canonized_numerator: Option<bool>,
        symmetric_polarizations: Option<bool>,
    ) -> NumeratorAwareGraphGroupingOption {
        let mut graph_grouping_options = GraphGroupingOptions::default();
        if let Some(seed) = seed {
            graph_grouping_options.numerical_sample_seed = seed;
        }
        if let Some(num_samples) = num_samples {
            graph_grouping_options.number_of_numerical_samples = num_samples;
        }
        if let Some(differentiate_particle_masses_only) = differentiate_particle_masses_only {
            graph_grouping_options.differentiate_particle_masses_only =
                differentiate_particle_masses_only;
        }
        if let Some(test_canonized_numerator) = test_canonized_numerator {
            graph_grouping_options.test_canonized_numerator = test_canonized_numerator;
        }
        if let Some(fully_numerical_substitution_when_comparing_numerators) =
            fully_numerical_substitution_when_comparing_numerators
        {
            graph_grouping_options.fully_numerical_substitution_when_comparing_numerators =
                fully_numerical_substitution_when_comparing_numerators;
        }
        if let Some(symmetric_polarizations) = symmetric_polarizations {
            graph_grouping_options.symmetric_polarizations = symmetric_polarizations;
        }
        match self {
            GroupingChoice::GroupIdenticalGraphsUpToScalarRescaling => {
                NumeratorAwareGraphGroupingOption::GroupIdenticalGraphUpToScalarRescaling(
                    graph_grouping_options,
                )
            }
            GroupingChoice::GroupIdenticalGraphsUpToSign => {
                NumeratorAwareGraphGroupingOption::GroupIdenticalGraphUpToSign(
                    graph_grouping_options,
                )
            }
            GroupingChoice::NoGrouping => NumeratorAwareGraphGroupingOption::NoGrouping,
            GroupingChoice::OnlyDetectZeroes => NumeratorAwareGraphGroupingOption::OnlyDetectZeroes,
        }
    }
}

#[derive(Args, Debug, Clone, Serialize, Deserialize, JsonSchema, PartialEq)]
pub struct SpecArgs {
    /// Quote-free spec.
    ///
    /// Grammar (unquoted): `INITIAL to FINAL [process_options] [generation_options]`
    /// Also accepts: `INITIAL > FINAL [ ... ]`
    ///
    /// Examples:
    ///   e+ e- to d d~ g veto u d xs QED^2==2 QCD^2<=4 pert loops=1 fsloops=2 QCD=2
    ///   e+ e- > { z z, a a } [ {1} {{2}} QCD=2 QED=1 ] / u d | g ghG QED==2 QCD>=2 QCD<=4
    ///
    /// Notes:
    /// - `veto` and `only` are synonyms for `/` and `|`.
    /// - The `[ ... ]` block holds perturbative spec: `{n}`, `{{n}}`, and orders `QCD=n` with shorthand `QCD`≡1.
    #[arg(value_name = "TOKENS", num_args = 1..)]
    pub tokens: Vec<String>,

    // --------- Generation options that influence FeynGenOptions ---------
    // Number of threads
    //#[arg(short = 'n', long = "num-threads")]
    //pub num_threads: Option<u32>, deprectaed in favor of global parallelisation settings
    /// Append the generated process instead of replacing the current process selection.
    #[arg(short = 'a', default_value_t = false)]
    pub append: bool,

    /// Clear pre-existing processes
    #[arg(
        long = "clear-existing-processes",
        short = 'c',
        alias = "clear",
        default_value_t = false
    )]
    pub clear_existing_processes: bool,

    /// Optional human-readable process name
    #[arg(long = "process-name", short = 'p')]
    pub process_name: Option<String>,

    /// Name assigned to the generated integrand; defaults to the generated process name.
    #[arg(
        long = "integrand-name",
        short = 'i',
        completion_disable_special_value()
    )]
    pub integrand_name: Option<String>,

    /// Stop after diagram generation without constructing an evaluable integrand.
    #[arg(long = "only-diagrams", short = 'o', default_value_t = false)]
    pub only_diagrams: bool,

    /// Include or exclude self-energy topologies; omission uses the generation-mode default.
    #[arg(long = "filter-selfenergies")]
    pub filter_selfenergies: Option<bool>,
    /// Include or exclude snail topologies; omission uses the generation-mode default.
    #[arg(long = "filter-snails")]
    pub filter_snails: Option<bool>,
    /// Include or exclude tadpole topologies; omission uses the generation-mode default.
    #[arg(long = "filter-tadpoles")]
    pub filter_tadpoles: Option<bool>,

    /// Exclude graphs containing any listed vertex-interaction name
    #[arg(long = "veto-vertex-interactions", num_args = 0..)]
    pub veto_vertex_interactions: Option<Vec<String>>,

    /// Restrict generation to an allow-list of vertex interactions
    #[arg(long = "allowed-vertex-interactions", num_args = 0..)]
    pub allowed_vertex_interactions: Option<Vec<String>>,

    /// Filter tadpoles formed while sewing amplitudes into a cross-section graph.
    #[arg(long = "filter-cross-section-tadpoles")]
    pub filter_cross_section_tadpoles: Option<bool>,

    /// Veto tadpoles attached to massive propagators.
    #[arg(long = "veto-tadpoles-attached-to-massive-lines")]
    pub veto_tadpoles_attached_to_massive_lines: Option<bool>,
    /// Veto tadpoles attached to massless propagators.
    #[arg(long = "veto-tadpoles-attached-to-massless-lines")]
    pub veto_tadpoles_attached_to_massless_lines: Option<bool>,
    /// Veto only tadpoles that are scaleless.
    #[arg(long = "veto-only-scaleless-tadpoles")]
    pub veto_only_scaleless_tadpoles: Option<bool>,

    /// Veto snail insertions attached to massive propagators.
    #[arg(long = "veto-snails-attached-to-massive-lines")]
    pub veto_snails_attached_to_massive_lines: Option<bool>,
    /// Veto snail insertions attached to massless propagators.
    #[arg(long = "veto-snails-attached-to-massless-lines")]
    pub veto_snails_attached_to_massless_lines: Option<bool>,
    /// Veto only snail insertions that are scaleless.
    #[arg(long = "veto-only-scaleless-snails")]
    pub veto_only_scaleless_snails: Option<bool>,

    /// Veto self-energy insertions on massive propagators.
    #[arg(long = "veto-self-energy-of-massive-lines")]
    pub veto_self_energy_of_massive_lines: Option<bool>,
    /// Veto self-energy insertions on massless propagators.
    #[arg(long = "veto-self-energy-of-massless-lines")]
    pub veto_self_energy_of_massless_lines: Option<bool>,
    /// Veto only self-energy insertions that are scaleless.
    #[arg(long = "veto-only-scaleless-self-energy")]
    pub veto_only_scaleless_self_energy: Option<bool>,

    /// Maximum number of bridges allowed in a generated graph; negative values disable the bound.
    #[arg(long = "max-n-bridges", short = 'b', allow_negative_numbers = true)]
    pub max_n_bridges: Option<i32>,
    /// Inclusive minimum and maximum number of factorized loop subtopologies.
    #[arg(
        long = "number-of-factorized-loop-subtopologies",
        short = 'f',
        alias = "nfactl",
        num_args = 2,
        allow_negative_numbers = true
    )]
    pub number_of_factorized_loop_subtopologies: Option<Vec<i32>>,
    /// Number of closed fermion loops, excluding ghosts; negative disables
    #[arg(
        long = "number-of-fermion-loops",
        short = 'L',
        num_args = 2,
        allow_negative_numbers = true
    )]
    pub number_of_fermion_loops: Option<Vec<i32>>,

    /// Inclusive minimum and maximum number of cut blobs on either side of a cross-section cut.
    #[arg(long = "n-cut-blobs", short = 'B', num_args = 2)]
    pub n_cut_blobs: Option<Vec<usize>>,
    /// Inclusive minimum and maximum number of spectators crossing a cross-section cut.
    #[arg(long = "n-cut-spectators", short = 'S', num_args = 2)]
    pub n_cut_spectators: Option<Vec<usize>>,

    /// Permit external fermion permutations when identifying equivalent amplitudes.
    #[arg(
        long = "allow-symmetrization-of-external-fermions-in-amplitudes",
        alias = "symferm"
    )]
    pub allow_symmetrization_of_external_fermions_in_amplitudes: Option<bool>,
    /// Identify graphs related by permutations of identical initial-state particles.
    #[arg(long = "symmetrize-initial-states")]
    pub symmetrize_initial_states: Option<bool>,
    /// Identify graphs related by permutations of identical final-state particles.
    #[arg(long = "symmetrize-final-states")]
    pub symmetrize_final_states: Option<bool>,
    /// Identify cross-section graphs under CP-based left/right exchange; requires CP symmetry.
    #[arg(long = "symmetrize-left-right-states")]
    pub symmetrize_left_right_states: Option<bool>,

    /// Numerator-aware grouping choice
    #[arg(long = "numerator-grouping", short = 'G', value_enum)]
    pub numerator_aware_isomorphism_grouping: Option<GroupingChoice>,

    /// Deterministic random seed used for numerical numerator comparisons.
    #[arg(long = "numerical-samples-seed")]
    pub numerical_samples_seed: Option<u16>,
    /// Number of phase-space samples used to decide whether two numerators are equivalent.
    #[arg(long = "number-of-samples-for-numerator-comparisons")]
    pub number_of_samples_for_numerator_comparisons: Option<usize>,
    /// Distinguish mass parameters while ignoring other model-parameter labels during grouping.
    #[arg(long = "consider-internal-masses-only-in-numerator-isomorphisms")]
    pub consider_internal_masses_only_in_numerator_isomorphisms: Option<bool>,
    /// Numerically substitute every parameter when comparing candidate numerator isomorphisms.
    #[arg(long = "fully-numerical-substitution-when-comparing-numerators")]
    pub fully_numerical_substitution_when_comparing_numerators: Option<bool>,
    /// Compare canonicalized numerators in addition to graph topology when grouping.
    #[arg(long = "compare-canonized-numerator")]
    pub compare_canonized_numerator: Option<bool>,
    /// Treat left- and right-side polarization factors symmetrically during numerator grouping.
    #[arg(long = "symmetric-left-right-polarizations")]
    pub symmetric_left_right_polarizations: Option<bool>,

    /// Graph processing toggles
    ///
    /// Format:
    ///   --loop-momentum-bases "GL_12=7,10 GL_77=4,2"
    ///   --select-graphs "GL_12 GL_13"
    ///   --veto-graphs "GL_11 GL_15"
    #[arg(long = "loop-momentum-bases", value_name = "KEY=VALUE", num_args = 0.., value_parser = KvPair::from_str)]
    pub loop_momentum_bases: Option<Vec<KvPair>>,
    /// Generate only graphs whose names appear in this allow-list.
    #[arg(long = "select-graphs", num_args = 0..)]
    pub select_graphs: Option<Vec<String>>,
    /// Exclude graphs whose names appear in this deny-list.
    #[arg(long = "veto-graphs", num_args = 0..)]
    pub veto_graphs: Option<Vec<String>>,
    /// Prefix assigned to generated graph names; defaults to `GL`
    #[arg(long = "graph-prefix", short = 'g')]
    pub graph_prefix: Option<String>,

    /// Global prefactor projector (Symbolica atom string)
    #[arg(
        long = "global-prefactor-projector",
        value_name = "ATOM",
        allow_hyphen_values = true
    )]
    pub global_prefactor_projector: Option<String>,

    /// Global prefactor numerator (Symbolica atom string)
    #[arg(
        long = "global-prefactor-num",
        value_name = "ATOM",
        allow_hyphen_values = true
    )]
    pub global_prefactor_num: Option<String>,

    /// Fast cut filter switch multiplicity
    #[arg(
        long = "max-multiplicity-for-fast-cut-filter",
        short = 'M',
        default_value_t = 6usize
    )]
    pub max_multiplicity_for_fast_cut_filter: usize,

    /// Filter graph-theoretic self-loops explicitly; omission keeps them.
    #[arg(long = "filter-self-loop")]
    pub filter_self_loop: Option<bool>,

    /// Filter edges that carry zero momentum flow in the selected routing.
    #[arg(long = "filter-zero-flow-edges")]
    pub filter_zero_flow_edges: Option<bool>,
}

impl SpecArgs {
    pub(crate) fn from_process_spec_string(spec: impl Into<String>) -> Self {
        Self {
            tokens: vec![spec.into()],
            ..Self::default()
        }
    }
}

impl Default for SpecArgs {
    fn default() -> Self {
        Self {
            tokens: Vec::new(),
            append: false,
            clear_existing_processes: false,
            process_name: None,
            integrand_name: None,
            only_diagrams: false,
            filter_selfenergies: None,
            filter_snails: None,
            filter_tadpoles: None,
            veto_vertex_interactions: None,
            allowed_vertex_interactions: None,
            filter_cross_section_tadpoles: None,
            veto_tadpoles_attached_to_massive_lines: None,
            veto_tadpoles_attached_to_massless_lines: None,
            veto_only_scaleless_tadpoles: None,
            veto_snails_attached_to_massive_lines: None,
            veto_snails_attached_to_massless_lines: None,
            veto_only_scaleless_snails: None,
            veto_self_energy_of_massive_lines: None,
            veto_self_energy_of_massless_lines: None,
            veto_only_scaleless_self_energy: None,
            max_n_bridges: None,
            number_of_factorized_loop_subtopologies: None,
            number_of_fermion_loops: None,
            n_cut_blobs: None,
            n_cut_spectators: None,
            allow_symmetrization_of_external_fermions_in_amplitudes: None,
            symmetrize_initial_states: None,
            symmetrize_final_states: None,
            symmetrize_left_right_states: None,
            numerator_aware_isomorphism_grouping: None,
            numerical_samples_seed: None,
            number_of_samples_for_numerator_comparisons: None,
            consider_internal_masses_only_in_numerator_isomorphisms: None,
            fully_numerical_substitution_when_comparing_numerators: None,
            compare_canonized_numerator: None,
            symmetric_left_right_polarizations: None,
            loop_momentum_bases: None,
            select_graphs: None,
            veto_graphs: None,
            graph_prefix: None,
            global_prefactor_projector: None,
            global_prefactor_num: None,
            max_multiplicity_for_fast_cut_filter: 6,
            filter_self_loop: None,
            filter_zero_flow_edges: None,
        }
    }
}

// =================== Runner ===================

fn format_generation_duration(duration: std::time::Duration) -> String {
    if duration.as_secs() >= 60 {
        let minutes = duration.as_secs() / 60;
        let seconds = duration.as_secs_f64() - (minutes * 60) as f64;
        format!("{minutes}m {seconds:.1}s")
    } else if duration.as_secs_f64() >= 1.0 {
        format!("{:.2}s", duration.as_secs_f64())
    } else {
        format!("{}ms", duration.as_millis())
    }
}

fn format_generation_fraction(
    numerator: std::time::Duration,
    total: std::time::Duration,
) -> String {
    let percent = if total.is_zero() {
        0.0
    } else {
        (numerator.as_secs_f64() / total.as_secs_f64()) * 100.0
    };

    if percent >= 10.0 {
        format!("{percent:.0}%")
    } else if percent >= 1.0 {
        format!("{percent:.1}%")
    } else {
        format!("{percent:.2}%")
    }
}

fn format_generation_memory(bytes: u64) -> String {
    const KIB: f64 = 1024.0;
    const MIB: f64 = KIB * 1024.0;
    const GIB: f64 = MIB * 1024.0;
    const TIB: f64 = GIB * 1024.0;

    let value = bytes as f64;
    if value < KIB {
        format!("{bytes} B")
    } else if value < MIB {
        format!("{:.2} KiB", value / KIB)
    } else if value < GIB {
        format!("{:.2} MiB", value / MIB)
    } else if value < TIB {
        format!("{:.2} GiB", value / GIB)
    } else {
        format!("{:.2} TiB", value / TIB)
    }
}

pub(crate) fn render_generation_summary(
    reports: &[GeneratedGraphReport],
    peak_ram_bytes: u64,
    generation_cores: Option<usize>,
    title: Option<&str>,
) -> Option<String> {
    if reports.is_empty() {
        return None;
    }

    let mut sorted_reports = reports.to_vec();
    sorted_reports.sort_by(|left, right| {
        (
            left.process_id,
            left.integrand_name.as_str(),
            left.graph_name.as_str(),
        )
            .cmp(&(
                right.process_id,
                right.integrand_name.as_str(),
                right.graph_name.as_str(),
            ))
    });

    let mut builder = Builder::new();
    builder.push_record([
        "integrand".bold().blue().to_string(),
        "graph".bold().blue().to_string(),
        "# evals".bold().blue().to_string(),
        "expr build".bold().blue().to_string(),
        "spenso".bold().blue().to_string(),
        "symbolica eval".bold().blue().to_string(),
        "compile".bold().blue().to_string(),
    ]);

    let mut total_stats = GraphGenerationStats::default();
    for report in &sorted_reports {
        total_stats.merge_in_place(&report.stats);
        let expr_time = report.stats.expression_build_time();
        let total_time = report.stats.total_time;
        let expr_value = format!(
            "{} ({})",
            format_generation_duration(expr_time).magenta(),
            format_generation_fraction(expr_time, total_time).cyan()
        );
        let spenso_value = format!(
            "{} ({})",
            format_generation_duration(report.stats.evaluator_spenso_time).magenta(),
            format_generation_fraction(report.stats.evaluator_spenso_time, total_time).cyan()
        );
        let symbolica_value = format!(
            "{} ({})",
            format_generation_duration(report.stats.evaluator_symbolica_time).magenta(),
            format_generation_fraction(report.stats.evaluator_symbolica_time, total_time).cyan()
        );
        let compile_value = format!(
            "{} ({})",
            format_generation_duration(report.stats.evaluator_compile_time).magenta(),
            format_generation_fraction(report.stats.evaluator_compile_time, total_time).cyan()
        );

        builder.push_record([
            report.integrand_name.yellow().to_string(),
            report.graph_name.yellow().to_string(),
            report
                .stats
                .evaluator_count
                .to_string()
                .yellow()
                .to_string(),
            expr_value,
            spenso_value,
            symbolica_value,
            compile_value,
        ]);
    }

    let total_time = total_stats.total_time;
    let total_expr_time = total_stats.expression_build_time();
    let total_expr_value = format!(
        "{} ({})",
        format_generation_duration(total_expr_time).magenta(),
        format_generation_fraction(total_expr_time, total_time).cyan()
    );
    let total_spenso_value = format!(
        "{} ({})",
        format_generation_duration(total_stats.evaluator_spenso_time).magenta(),
        format_generation_fraction(total_stats.evaluator_spenso_time, total_time).cyan()
    );
    let total_symbolica_value = format!(
        "{} ({})",
        format_generation_duration(total_stats.evaluator_symbolica_time).magenta(),
        format_generation_fraction(total_stats.evaluator_symbolica_time, total_time).cyan()
    );
    let total_compile_value = format!(
        "{} ({})",
        format_generation_duration(total_stats.evaluator_compile_time).magenta(),
        format_generation_fraction(total_stats.evaluator_compile_time, total_time).cyan()
    );
    builder.push_record([
        "Total".bold().yellow().to_string(),
        String::new(),
        total_stats
            .evaluator_count
            .to_string()
            .bold()
            .yellow()
            .to_string(),
        total_expr_value,
        total_spenso_value,
        total_symbolica_value,
        total_compile_value,
    ]);

    let mut table = builder.build();
    let mut style = Theme::from_style(Style::rounded());
    style.insert_horizontal_line(
        sorted_reports.len() + 1,
        HorizontalLine::inherit(Style::modern()),
    );
    table.with(style);
    let mut sections = Vec::new();
    if let Some(title) = title {
        sections.push(title.bold().blue().to_string());
    }
    let resources = match generation_cores {
        Some(cores) => {
            format!(
                "{} {} | {} {}",
                "peak RAM".bold().blue(),
                format_generation_memory(peak_ram_bytes).yellow(),
                "cores".bold().blue(),
                cores.to_string().yellow(),
            )
        }
        None => format!(
            "{} {}",
            "peak RAM".bold().blue(),
            format_generation_memory(peak_ram_bytes).yellow(),
        ),
    };
    sections.push(resources);
    sections.push(table.to_string());
    Some(sections.join("\n"))
}

fn log_generation_summary_table(
    reports: &[GeneratedGraphReport],
    resources: GenerationResourceSummary,
) {
    if let Some(summary) = render_generation_summary(
        reports,
        resources.peak_ram_bytes,
        Some(resources.generation_cores),
        Some("Integrand generation summary"),
    ) {
        info!("\n{summary}");
    }
}

fn remove_compiled_cpp_sources(root: &Path) -> Result<usize> {
    let mut removed_count = 0usize;
    for entry in WalkDir::new(root) {
        let entry = entry?;
        if !entry.file_type().is_file() {
            continue;
        }

        let source_path = entry.path();
        if source_path.extension() != Some(OsStr::new("cpp")) {
            continue;
        }

        let library_path = source_path.with_extension("so");
        if !library_path.is_file() {
            continue;
        }

        fs::remove_file(source_path).with_context(|| {
            format!(
                "Trying to remove generated C++ source {} after compiling {}",
                source_path.display(),
                library_path.display()
            )
        })?;
        removed_count += 1;
    }

    Ok(removed_count)
}

fn compile_integrands_for_generation(
    state: &mut State,
    compile_folder: &Path,
    override_existing_compiled: bool,
    global_settings: &GlobalSettings,
    process_id: Option<usize>,
    integrand_name: Option<String>,
    keep_sources: bool,
) -> Result<Vec<GeneratedGraphReport>> {
    let reports = state.compile_integrands(
        compile_folder,
        override_existing_compiled,
        global_settings,
        process_id,
        integrand_name,
    )?;

    if !keep_sources {
        let removed_count = remove_compiled_cpp_sources(compile_folder)?;
        if removed_count > 0 {
            info!(
                "Removed {} generated C++ source file(s). Use '{}' to keep them.",
                removed_count,
                "--keep-sources".green()
            );
        }
    }

    Ok(reports)
}

fn finish_generation(
    state: &mut State,
    reports: &[GeneratedGraphReport],
    resources: GenerationResourceSummary,
) {
    state.record_generation_summary(reports, resources);
    log_generation_summary_table(reports, resources);
}

impl Generate {
    pub fn run(
        &self,
        state: &mut State,
        compile_folder: impl AsRef<Path>,
        override_existing_compiled: bool,
        global_settings: &GlobalSettings,
        runtime_settings: &RuntimeSettings,
    ) -> Result<()> {
        let compile_folder = compile_folder.as_ref();
        let generation_mode = match &self.mode {
            Some(GenerateCmd::Xs(a)) => Some((GenerationType::CrossSection, a)),
            Some(GenerateCmd::Amp(a)) => Some((GenerationType::Amplitude, a)),
            _ => None,
        };
        if let Some((generation_type, args)) = generation_mode.as_ref() {
            global_settings
                .generation
                .validate_for_process(*generation_type)?;
            if !state.process_list.processes.is_empty() && args.clear_existing_processes {
                info!(
                    "Clearing all {} existing processes as requested.",
                    state.process_list.processes.len()
                );
                state.process_list = ProcessList::default();
            }
        }
        let generation_info = if let Some((gen_mode, args)) = generation_mode {
            let mut spec = parse_spec_with_model(args, gen_mode, &state.model)?;
            spec.process_definition.process_id = state.process_list.processes.len();

            let mut existing_process = None;
            if let Some(ep) = state
                .process_list
                .processes
                .iter_mut()
                .find(|p| p.definition.folder_name == spec.process_definition.folder_name)
            {
                if ep.definition != spec.process_definition {
                    if !args.append {
                        return Err(eyre!(
                            "Process with name '{}' already exists.\n> Use 'existing' subcommand to continue generation of this process.\n> Use '--clear-existing-processes' to remove all existing ones.\n> Or specify a different process name with '--process-name <chosen_process_name>'.",
                            spec.process_definition.folder_name
                        ));
                    }
                } else {
                    info!(
                        "Identical process definition, with name '{}', already exists. Gammaloop will recycle it.",
                        spec.process_definition.folder_name
                    );
                    return Ok(());
                }
                spec.process_definition.process_id = ep.definition.process_id;
                existing_process = Some(ep);
            }
            Some((spec, existing_process))
        } else {
            None
        };
        match &self.mode {
            Some(GenerateCmd::Amp(args)) | Some(GenerateCmd::Xs(args)) => {
                let generation_type = generation_mode.as_ref().unwrap().0;
                let model: &Model = &state.model;
                let (spec, existing_process) = generation_info.unwrap();
                let this_process_id = spec.process_definition.process_id;
                // TODO handle existing process and continue
                let graphs = spec.process_definition.generate(model, global_settings)?;
                info!(
                    "Generated {} {} graphs.",
                    if matches!(self.mode, Some(GenerateCmd::Amp(_))) {
                        "amplitude"
                    } else {
                        "cross-section"
                    },
                    graphs.len()
                );
                // Keep the possibility of changing default name for the two modes
                let integrand_base_name = matches!(self.mode, Some(GenerateCmd::Amp(_)))
                    .then(|| args.integrand_name.clone().unwrap_or("default".to_string()))
                    .unwrap_or_else(|| {
                        args.integrand_name.clone().unwrap_or("default".to_string())
                    });
                let generated_integrand_name = if let Some(p) = existing_process {
                    let existing_names = p.collection.get_integrand_names();
                    let integrand_name = if existing_names.contains(&integrand_base_name.as_str()) {
                        let mut integrand_i = 0;
                        while existing_names
                            .iter()
                            .any(|ce| *ce == format!("{}_{}", integrand_base_name, integrand_i))
                        {
                            integrand_i += 1;
                        }
                        format!("{}_{}", integrand_base_name, integrand_i)
                    } else {
                        integrand_base_name
                    };
                    match &self.mode {
                        Some(GenerateCmd::Amp(_)) => {
                            p.collection.add_amplitude(Amplitude::from_graph_list(
                                integrand_name.clone(),
                                graphs,
                            )?);
                        }
                        Some(GenerateCmd::Xs(_)) => {
                            p.collection
                                .add_cross_section(CrossSection::from_graph_list(
                                    integrand_name.clone(),
                                    graphs,
                                    model,
                                )?);
                        }
                        _ => unreachable!(),
                    }
                    integrand_name
                } else {
                    let process = Process::from_graph_list(
                        spec.process_definition.folder_name.clone(),
                        integrand_base_name.clone(),
                        graphs,
                        generation_type,
                        Some(spec.process_definition),
                        None,
                        model,
                    )?;
                    state.process_list.add_process(process);
                    integrand_base_name
                };
                if !args.only_diagrams {
                    let generated_integrand_name_for_compile = generated_integrand_name.clone();
                    let generation = state.generate_integrand(
                        global_settings,
                        runtime_settings.into(),
                        this_process_id,
                        Some(generated_integrand_name),
                    )?;
                    let mut reports = generation.reports;
                    if global_settings.generation.evaluator.compile
                        && global_settings
                            .generation
                            .compile
                            .requires_external_compilation()
                    {
                        merge_generated_graph_reports(
                            &mut reports,
                            compile_integrands_for_generation(
                                state,
                                compile_folder,
                                override_existing_compiled,
                                global_settings,
                                Some(this_process_id),
                                Some(generated_integrand_name_for_compile),
                                self.keep_sources,
                            )?,
                        );
                    }
                    finish_generation(state, &reports, generation.resources);
                    Ok(())
                } else {
                    info!(
                        "Only diagram generation was requested, skipping integrand generation. You can generate integrands later using the '{}' command.",
                        "generate existing <options>".green()
                    );
                    Ok(())
                }
            }
            Some(GenerateCmd::Existing(process_args)) => {
                let process_id = state.resolve_process_ref(process_args.process.as_ref())?;

                let generation = state.generate_integrand(
                    global_settings,
                    runtime_settings.into(),
                    process_id,
                    process_args.integrand_name.clone(),
                )?;
                let mut reports = generation.reports;
                if global_settings.generation.evaluator.compile
                    && global_settings
                        .generation
                        .compile
                        .requires_external_compilation()
                {
                    merge_generated_graph_reports(
                        &mut reports,
                        compile_integrands_for_generation(
                            state,
                            compile_folder,
                            override_existing_compiled,
                            global_settings,
                            Some(process_id),
                            process_args.integrand_name.clone(),
                            self.keep_sources,
                        )?,
                    );
                }
                finish_generation(state, &reports, generation.resources);
                Ok(())
            }
            None => {
                let generation =
                    state.generate_integrands(global_settings, runtime_settings.into())?;
                let mut reports = generation.reports;
                if global_settings.generation.evaluator.compile
                    && global_settings
                        .generation
                        .compile
                        .requires_external_compilation()
                {
                    merge_generated_graph_reports(
                        &mut reports,
                        compile_integrands_for_generation(
                            state,
                            compile_folder,
                            override_existing_compiled,
                            global_settings,
                            None,
                            None,
                            self.keep_sources,
                        )?,
                    );
                }
                finish_generation(state, &reports, generation.resources);
                Ok(())
            }
        }
    }
}

#[derive(Args, Debug, Clone, Serialize, Deserialize, JsonSchema, PartialEq)]
pub struct ProcessArgs {
    /// Process reference: `#<id>`, `name:<name>`, or `<id>/<name>`
    #[arg(
        long = "process",
        short = 'p',
        value_name = "PROCESS",
        completion_process_selector(crate::completion::SelectorKind::Any)
    )]
    pub process: Option<ProcessRef>,

    /// Optional human-readable integrand name used to disambiguate the process
    #[arg(
        long = "integrand-name",
        short = 'i',
        completion_integrand_selector(crate::completion::SelectorKind::Any)
    )]
    pub integrand_name: Option<String>,
}

// =================== Domain structs ===================

#[derive(Debug, Clone, Serialize, Deserialize, JsonSchema, PartialEq, Eq, Default)]
pub struct OrderRange {
    pub eq: Option<u32>,
    pub min: Option<u32>,
    pub max: Option<u32>,
}
impl OrderRange {
    fn set(&mut self, op: &str, v: u32) {
        match op {
            "==" => self.eq = Some(v),
            ">=" => self.min = Some(v),
            "<=" => self.max = Some(v),
            _ => {}
        }
    }
}

#[derive(Debug, Clone, Serialize, Deserialize, JsonSchema, PartialEq, Eq, PartialOrd, Ord)]
pub struct CouplingKey {
    pub name: String,
    pub power: u32, // parsed, but dropped when building FeynGenFilter::CouplingOrders
}

#[derive(Debug, Clone, Default, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
pub struct Perturbative {
    /// {n}
    pub loops_sum_amp_or_sum: Option<u32>,
    /// {{n}}
    pub loops_forward_graph: Option<u32>,
    /// QCD=2, QED=1; shorthand "QCD"≡1
    pub orders: BTreeMap<String, u32>,
}

#[derive(Debug, Clone, Serialize, Deserialize, JsonSchema, PartialEq)]
pub struct ProcessSpec {
    pub initial: Vec<String>,
    pub final_: Vec<String>,
    pub empty_initial: bool,
    pub empty_final: bool,

    /// `/ ...`
    pub veto: BTreeSet<String>,
    /// `| ...`
    pub only: Option<BTreeSet<String>>,

    /// AMP amplitude coupling ranges: QED==2, QCD>=2, QCD<=4
    pub amp_couplings: BTreeMap<String, OrderRange>,
    /// XS graph-level coupling ranges: QED^2==2, QCD^2<=4  (power is dropped when building filters)
    pub xs_couplings: BTreeMap<CouplingKey, OrderRange>,

    /// For example, `[{1} {{2}} QCD=2 QED=1]` or `[QCD]`.
    pub pert: Perturbative,

    /// XS-only: final-state alternative sets `{ A, B, ... }`
    pub final_sets: Vec<Vec<String>>,

    /// Generation options captured alongside the spec
    pub process_definition: ProcessDefinition,

    /// Parsed numerator-aware grouping mode (not part of FeynGenOptions)
    pub numerator_grouping: NumeratorAwareGraphGroupingOption,
}

impl ProcessSpec {
    /// Canonical shell-friendly name. Deterministic and lexicographically ordered.
    pub fn process_shell_name(&self, short: bool) -> String {
        // sanitize within a piece so '-' separators between pieces are preserved
        let sanitize_piece = |s: &str| s.replace('~', "x").replace('+', "p").replace('-', "m");
        let lower = |s: &str| s.to_ascii_lowercase();

        // base slug: "<init>_<final or sets joined by _or_>"
        let init_slug = if self.initial.is_empty() {
            "empty".to_string()
        } else {
            self.initial.iter().map(|p| lower(p)).collect::<String>()
        };

        let finals_lists: Vec<Vec<String>> = if self.final_sets.is_empty() {
            vec![self.final_.clone()]
        } else {
            self.final_sets.clone()
        };
        let finals_slugs: Vec<String> = finals_lists
            .iter()
            .map(|lst| {
                if lst.is_empty() {
                    "empty".to_string()
                } else {
                    lst.iter().map(|p| lower(p)).collect::<String>()
                }
            })
            .collect();

        let mut pieces: Vec<String> = vec![sanitize_piece(&format!(
            "{}_{}",
            init_slug,
            finals_slugs.join("_or_")
        ))];

        if !short {
            // particle vetoes (sorted)
            if !self.veto.is_empty() {
                let mut veto_list: Vec<String> = self.veto.iter().map(|v| lower(v)).collect();
                veto_list.sort();
                pieces.push(sanitize_piece(&format!("no__{}", veto_list.join("_"))));
            }

            // amplitude coupling orders (sorted by coupling name)
            if !self.amp_couplings.is_empty() {
                let mut keys: Vec<&String> = self.amp_couplings.keys().collect();
                keys.sort();
                let mut parts: Vec<String> = Vec::new();
                for k in keys {
                    let r = &self.amp_couplings[k];
                    if let Some(eq) = r.eq {
                        parts.push(format!("{}_eq_{}", k, eq));
                    } else {
                        if let Some(min) = r.min {
                            if min > 0 {
                                parts.push(format!("{}_ge_{}", k, min));
                            }
                        }
                        if let Some(max) = r.max {
                            parts.push(format!("{}_le_{}", k, max));
                        }
                    }
                }
                if !parts.is_empty() {
                    pieces.push(parts.join("__"));
                }
            }

            // cross-section coupling orders (sorted by name, then power)
            if !self.xs_couplings.is_empty() {
                let mut entries: Vec<(&CouplingKey, &OrderRange)> =
                    self.xs_couplings.iter().collect();
                entries.sort_by(|(ka, _), (kb, _)| {
                    use std::cmp::Ordering;
                    match ka.name.cmp(&kb.name) {
                        Ordering::Equal => ka.power.cmp(&kb.power),
                        other => other,
                    }
                });
                let mut parts: Vec<String> = Vec::new();
                for (k, r) in entries {
                    let base = format!("{}sq", k.name);
                    if let Some(eq) = r.eq {
                        parts.push(format!("{}_eq_{}", base, eq));
                    } else {
                        if let Some(min) = r.min {
                            if min > 0 {
                                parts.push(format!("{}_ge_{}", base, min));
                            }
                        }
                        if let Some(max) = r.max {
                            parts.push(format!("{}_le_{}", base, max));
                        }
                    }
                }
                if !parts.is_empty() {
                    pieces.push(parts.join("__"));
                }
            }

            // perturbative coupling orders (sorted by key)
            if !self.pert.orders.is_empty() {
                let mut ords: Vec<(&String, &u32)> = self.pert.orders.iter().collect();
                ords.sort_by(|a, b| a.0.cmp(b.0));
                let parts: Vec<String> = ords
                    .into_iter()
                    .map(|(k, v)| format!("{}loop_eq_{}", k, v))
                    .collect();
                if !parts.is_empty() {
                    pieces.push(parts.join("__"));
                }
            }
        }

        pieces.join("-")
    }

    /// Canonical human-readable representation. Deterministic and lexicographically ordered.
    pub fn repr_str(&self) -> String {
        let lower = |s: &str| s.to_ascii_lowercase();

        let mut out: Vec<String> = Vec::new();

        // initial states
        if self.initial.is_empty() {
            out.push("{}".to_string());
        } else {
            for p in &self.initial {
                out.push(lower(p));
            }
        }

        // arrow
        out.push(">".to_string());

        // final states or sets
        if self.final_sets.is_empty() {
            if self.final_.is_empty() {
                out.push("{}".to_string());
            } else {
                for p in &self.final_ {
                    out.push(lower(p));
                }
            }
        } else {
            // sets with deterministic inner ordering as given; outer order is as parsed
            let sets_str = self
                .final_sets
                .iter()
                .map(|set| {
                    if set.is_empty() {
                        "empty".to_string()
                    } else {
                        set.iter().map(|p| lower(p)).collect::<Vec<_>>().join(" ")
                    }
                })
                .collect::<Vec<_>>()
                .join(", ");
            out.push(format!("{{ {} }}", sets_str));
        }

        // particle vetoes (sorted)
        if !self.veto.is_empty() {
            out.push("/".to_string());
            let mut veto_list: Vec<String> = self.veto.iter().map(|v| lower(v)).collect();
            veto_list.sort();
            out.extend(veto_list);
        }

        // amplitude coupling orders (sorted by coupling name)
        if !self.amp_couplings.is_empty() {
            let mut keys: Vec<&String> = self.amp_couplings.keys().collect();
            keys.sort();
            for k in keys {
                let r = &self.amp_couplings[k];
                if let Some(eq) = r.eq {
                    out.push(format!("{}=={}", k, eq));
                } else {
                    if let Some(min) = r.min {
                        if min > 0 {
                            out.push(format!("{}>={}", k, min));
                        }
                    }
                    if let Some(max) = r.max {
                        out.push(format!("{}<={}", k, max));
                    }
                }
            }
        }

        // perturbative block if any
        let has_pert_block = self.pert.loops_sum_amp_or_sum.is_some()
            || self.pert.loops_forward_graph.is_some()
            || !self.pert.orders.is_empty();
        if has_pert_block {
            out.push("[".to_string());
            if let Some(n) = self.pert.loops_sum_amp_or_sum {
                out.push(format!("{{{}}}", n));
            }
            if let Some(n) = self.pert.loops_forward_graph {
                out.push(format!("{{{{{}}}}}", n));
            }
            if !self.pert.orders.is_empty() {
                let mut ords: Vec<(&String, &u32)> = self.pert.orders.iter().collect();
                ords.sort_by(|a, b| a.0.cmp(b.0));
                for (k, v) in ords {
                    if *v > 0 {
                        if *v == 1 {
                            out.push(k.clone());
                        } else {
                            out.push(format!("{}={}", k, v));
                        }
                    }
                }
            }
            out.push("]".to_string());
        }

        // cross-section coupling orders (sorted by name, then power)
        if !self.xs_couplings.is_empty() {
            let mut entries: Vec<(&CouplingKey, &OrderRange)> = self.xs_couplings.iter().collect();
            entries.sort_by(|(ka, _), (kb, _)| {
                use std::cmp::Ordering;
                match ka.name.cmp(&kb.name) {
                    Ordering::Equal => ka.power.cmp(&kb.power),
                    other => other,
                }
            });
            for (k, r) in entries {
                if let Some(eq) = r.eq {
                    out.push(format!("{}^{}=={}", k.name, k.power, eq));
                } else {
                    if let Some(min) = r.min {
                        if min > 0 {
                            out.push(format!("{}^{}>={}", k.name, k.power, min));
                        }
                    }
                    if let Some(max) = r.max {
                        out.push(format!("{}^{}<={}", k.name, k.power, max));
                    }
                }
            }
        }

        out.join(" ")
    }
}

// =================== Parsing ===================

#[derive(Debug, Error, PartialEq, Eq)]
pub enum ParseError {
    #[error("expected 'to' or '>' between initial and final states")]
    MissingArrow,
    #[error("unbalanced brackets/braces")]
    Unbalanced,
    #[error("invalid token '{0}'")]
    InvalidToken(String),
    #[error("unknown particle '{name}'. Valid choices: {choices}")]
    UnknownParticle { name: String, choices: String },
    #[error("unknown coupling '{name}'. Valid choices: {choices}")]
    UnknownCoupling { name: String, choices: String },
    #[error("invalid lmb specification: {0}")]
    InvalidLmbSpec(ParseIntError),
}

pub fn parse_spec_with_model(
    args: &SpecArgs,
    generation_type: GenerationType,
    model: &Model,
) -> std::result::Result<ProcessSpec, ParseError> {
    let raw = args.tokens.join(" ");
    let (lhs, rhs0) = split_top_level_arrow(&raw).ok_or(ParseError::MissingArrow)?;
    let (rhs_wo_bracket, pert) = extract_perturbative(rhs0.trim())?;

    // LHS initial states
    let lhs = lhs.trim();
    let (initial_names, empty_initial) = if lhs == "{}" || lhs.eq_ignore_ascii_case("empty-initial")
    {
        (Vec::new(), true)
    } else {
        (split_ws(lhs), false)
    };

    // Tokenize RHS outside the perturbative block
    let tokens = tokenize(rhs_wo_bracket)?;
    let (final_spec, empty_final, rest) = parse_final_states(tokens)?;
    let (veto_names, only, amp_couplings, xs_couplings) = parse_process_options(rest)?;

    // Validate coupling orders against model
    validate_coupling_names(model, &amp_couplings, &xs_couplings, &pert)?;

    // Convert names → PDGs using the model
    let initial_pdgs = resolve_pdgs(model, &initial_names)?;
    let primary_final_pdgs = resolve_pdgs(model, &final_spec.primary)?;
    let final_sets_pdgs = final_spec
        .sets
        .iter()
        .map(|set| resolve_pdgs(model, set))
        .collect::<Result<Vec<_>, _>>()?;

    // Resolve vetoed particles to PDGs and validate they exist
    let mut veto_pdgs = resolve_pdgs(model, &veto_names.iter().cloned().collect::<Vec<_>>())?;
    if let Some(o) = only.clone() {
        let only_vec = o.iter().cloned().collect::<Vec<_>>();
        if !only_vec.is_empty() {
            let only_pdgs = resolve_pdgs(model, &only_vec)?
                .iter()
                .map(|pdg| pdg.abs())
                .collect::<Vec<_>>();

            let all_pdgs = model
                .particles
                .iter()
                .map(|p| p.pdg_code.abs() as i64)
                .filter(|pdg| !only_pdgs.contains(pdg))
                .collect::<Vec<_>>();

            veto_pdgs.extend(all_pdgs);
            veto_pdgs.sort_unstable();
            veto_pdgs.dedup();
        }
    }

    // Build FeynGenOptions with filters and PDGs
    let numerator_grouping = build_grouping_option(args);
    let process_definition = feyngen_from_spec_args(
        args,
        generation_type,
        &pert,
        &amp_couplings,
        &xs_couplings,
        &initial_pdgs,
        &primary_final_pdgs,
        &final_sets_pdgs,
        &veto_pdgs,
    );

    let mut spec = ProcessSpec {
        initial: initial_names,
        final_: final_spec.primary.clone(),
        empty_initial,
        empty_final,
        veto: veto_names,
        only,
        amp_couplings,
        xs_couplings,
        pert,
        final_sets: final_spec.sets,
        process_definition,
        numerator_grouping,
    };

    if let Some(process_name) = &args.process_name {
        spec.process_definition.folder_name = process_name.clone();
    } else {
        spec.process_definition.folder_name = spec.process_shell_name(true);
    }
    spec.process_definition.numerator_grouping = spec.numerator_grouping.clone();
    spec.process_definition.filter_self_loop = args.filter_self_loop.unwrap_or(false);
    spec.process_definition.filter_zero_flow_edges = args.filter_zero_flow_edges.unwrap_or(true);

    spec.process_definition.graph_prefix = args
        .graph_prefix
        .clone()
        .unwrap_or_else(|| "GL".to_string());
    // spec.process_definition.selected_graphs =
    //     args.select_graphs.as_ref().map(|s| parse_csv_list(s));
    // spec.process_definition.vetoed_graphs = args.veto_graphs.as_ref().map(|s| parse_csv_list(s));
    spec.process_definition.selected_graphs = args.select_graphs.clone();
    spec.process_definition.vetoed_graphs = args.veto_graphs.clone();
    spec.process_definition.loop_momentum_bases = args
        .loop_momentum_bases
        .as_deref()
        .map(|kvs| {
            kvs.iter()
                .map(|kv| {
                    parse_csv_list(&kv.value)
                        .into_iter()
                        .map(|s| s.parse::<usize>())
                        .collect::<core::result::Result<Vec<_>, _>>()
                        .map(|lst| (kv.key.clone(), lst))
                })
                .collect::<core::result::Result<HashMap<_, _>, _>>()
        })
        .transpose()
        .map_err(ParseError::InvalidLmbSpec)?;
    let mut prefactor = GlobalPrefactor::default();
    if let Some(projector) = &args.global_prefactor_projector {
        prefactor.projector = parse!(projector);
    }
    if let Some(num) = &args.global_prefactor_num {
        prefactor.num = parse!(num);
    }
    spec.process_definition.prefactor = prefactor;

    Ok(spec)
}

pub(crate) fn parse_process_spec_string(
    spec: &str,
    generation_type: GenerationType,
    model: &Model,
) -> std::result::Result<ProcessSpec, ParseError> {
    let args = SpecArgs::from_process_spec_string(spec);
    parse_spec_with_model(&args, generation_type, model)
}

// ---- helpers ----

fn split_top_level_arrow(s: &str) -> Option<(&str, &str)> {
    // Accept either "to" token or '>' outside any [...] or {...}
    let mut depth_brace = 0i32;
    let mut depth_bracket = 0i32;
    let bytes = s.as_bytes();
    let mut i = 0usize;
    while i < bytes.len() {
        let c = bytes[i] as char;
        match c {
            '{' => depth_brace += 1,
            '}' => depth_brace -= 1,
            '[' => depth_bracket += 1,
            ']' => depth_bracket -= 1,
            '>' if depth_brace == 0 && depth_bracket == 0 => {
                return Some((&s[..i], &s[i + 1..]));
            }
            _ => {
                if depth_brace == 0
                    && depth_bracket == 0
                    && i + 2 < bytes.len()
                    && (c == 't' || c == 'T')
                    && &s[i..].to_ascii_lowercase().as_str()[..2] == "to"
                {
                    let before = if i == 0 {
                        ' '
                    } else {
                        s.as_bytes()[i - 1] as char
                    };
                    let after = if i + 2 >= s.len() {
                        ' '
                    } else {
                        s.as_bytes()[i + 2] as char
                    };
                    if before.is_whitespace() && after.is_whitespace() {
                        return Some((&s[..i], &s[i + 2..]));
                    }
                }
            }
        }
        i += 1;
    }
    None
}

fn extract_perturbative(rhs: &str) -> Result<(String, Perturbative), ParseError> {
    let mut out = rhs.to_string();
    let mut spec = Perturbative::default();
    if let Some((start, end)) = find_top_level_block(rhs, '[', ']') {
        let inside = &rhs[start + 1..end];
        spec = parse_perturbative_block(inside.trim())?;
        out.replace_range(start..=end, "");
    }
    Ok((out, spec))
}

fn parse_perturbative_block(s: &str) -> Result<Perturbative, ParseError> {
    if s.is_empty() {
        return Ok(Perturbative::default());
    }
    let re_amp = Regex::new(r"^\{(\d+)\}$").unwrap();
    let re_fwd = Regex::new(r"^\{\{(\d+)\}\}$").unwrap();
    let re_order = Regex::new(r"^([A-Za-z_][A-Za-z0-9_]*)=(\d+)$").unwrap();

    let mut spec = Perturbative::default();
    for tok in split_ws(s) {
        if let Some(c) = re_amp.captures(&tok) {
            spec.loops_sum_amp_or_sum = Some(c[1].parse().unwrap());
            continue;
        }
        if let Some(c) = re_fwd.captures(&tok) {
            spec.loops_forward_graph = Some(c[1].parse().unwrap());
            continue;
        }
        if let Some(c) = re_order.captures(&tok) {
            let n: u32 = c[2].parse().unwrap();
            spec.orders.insert(c[1].to_string(), n);
            continue;
        }
        if tok.chars().all(|ch| ch.is_ascii_alphabetic()) {
            spec.orders.insert(tok, 1);
            continue;
        }
        return Err(ParseError::InvalidToken(tok));
    }
    Ok(spec)
}

fn tokenize(s: String) -> Result<Vec<String>, ParseError> {
    let mut out = Vec::new();
    let mut cur = String::new();
    let mut depth = 0i32;
    for ch in s.chars() {
        match ch {
            '{' => {
                depth += 1;
                cur.push(ch);
            }
            '}' => {
                depth -= 1;
                cur.push(ch);
                if depth < 0 {
                    return Err(ParseError::Unbalanced);
                }
            }
            c if c.is_whitespace() && depth == 0 => {
                if !cur.trim().is_empty() {
                    out.push(cur.trim().to_string());
                }
                cur.clear();
            }
            _ => cur.push(ch),
        }
    }
    if !cur.trim().is_empty() {
        out.push(cur.trim().to_string());
    }
    if depth != 0 {
        return Err(ParseError::Unbalanced);
    }
    Ok(out)
}

fn parse_final_states(tokens: Vec<String>) -> Result<(FinalSpec, bool, Vec<String>), ParseError> {
    if tokens.is_empty() {
        return Ok((FinalSpec::default(), false, vec![]));
    }
    let mut t = tokens;
    let mut finals = Vec::<String>::new();
    let mut empty_final = false;

    if t[0].eq_ignore_ascii_case("empty-final") || t[0] == "{}" {
        empty_final = true;
        t.remove(0);
        return Ok((FinalSpec::default(), empty_final, t));
    }

    if t[0].starts_with('{') {
        let raw = t.remove(0);
        let sets = parse_alt_sets(&raw)?;
        return Ok((
            FinalSpec {
                primary: vec![],
                sets,
            },
            empty_final,
            t,
        ));
    }

    while !t.is_empty() {
        if is_option_token(&t[0]) {
            break;
        }
        finals.push(t.remove(0));
    }
    Ok((
        FinalSpec {
            primary: finals,
            sets: vec![],
        },
        empty_final,
        t,
    ))
}

#[derive(Default)]
struct FinalSpec {
    primary: Vec<String>,
    sets: Vec<Vec<String>>,
}

fn parse_alt_sets(s: &str) -> Result<Vec<Vec<String>>, ParseError> {
    let trimmed = s.trim();
    if !(trimmed.starts_with('{') && trimmed.ends_with('}')) {
        return Err(ParseError::InvalidToken(s.to_string()));
    }
    let inner = &trimmed[1..trimmed.len() - 1];
    let mut out: Vec<Vec<String>> = Vec::new();
    let mut cur = String::new();
    let mut depth = 0i32;
    for ch in inner.chars() {
        match ch {
            '{' => {
                depth += 1;
                cur.push(ch);
            }
            '}' => {
                depth -= 1;
                if depth < 0 {
                    return Err(ParseError::Unbalanced);
                }
                cur.push(ch);
            }
            ',' if depth == 0 => {
                let items = split_ws(cur.trim());
                if !items.is_empty() {
                    out.push(items);
                } else {
                    out.push(vec![]);
                }
                cur.clear();
            }
            _ => cur.push(ch),
        }
    }
    if !cur.trim().is_empty() {
        out.push(split_ws(cur.trim()));
    }
    Ok(out)
}

fn is_option_token(tok: &str) -> bool {
    matches!(
        tok,
        "/" | "|" | "veto" | "only" | "amp" | "xs" | "pert" | "sets" | "empty-final"
    ) || tok.starts_with('[')
        || Regex::new(r"^[A-Za-z_][A-Za-z0-9_]*(?:\^\d+)?(==|>=|<=)\d+$")
            .unwrap()
            .is_match(tok)
}

#[allow(clippy::type_complexity)]
fn parse_process_options(
    tokens: Vec<String>,
) -> Result<
    (
        BTreeSet<String>,
        Option<BTreeSet<String>>,
        BTreeMap<String, OrderRange>,
        BTreeMap<CouplingKey, OrderRange>,
    ),
    ParseError,
> {
    let mut veto = BTreeSet::<String>::new();
    let mut only: Option<BTreeSet<String>> = None;
    let mut amp = BTreeMap::<String, OrderRange>::new();
    let mut xs = BTreeMap::<CouplingKey, OrderRange>::new();

    let re = Regex::new(r"^([A-Za-z_][A-Za-z0-9_]*)(?:\^(\d+))?(==|>=|<=)(\d+)$").unwrap();

    let mut i = 0usize;
    while i < tokens.len() {
        match tokens[i].as_str() {
            "/" | "veto" => {
                i += 1;
                while i < tokens.len() && !is_option_token(&tokens[i]) {
                    veto.insert(tokens[i].clone());
                    i += 1;
                }
            }
            "|" | "only" => {
                i += 1;
                let mut s = only.take().unwrap_or_default();
                while i < tokens.len() && !is_option_token(&tokens[i]) {
                    s.insert(tokens[i].clone());
                    i += 1;
                }
                only = Some(s);
            }
            "amp" | "xs" | "pert" | "sets" | "empty-final" => {
                return Err(ParseError::InvalidToken(tokens[i].clone()));
            }
            other => {
                if let Some(c) = re.captures(other) {
                    let name = c[1].to_string();
                    let power: u32 = c.get(2).map(|m| m.as_str().parse().unwrap()).unwrap_or(1);
                    let op = c.get(3).unwrap().as_str();
                    let val: u32 = c.get(4).unwrap().as_str().parse().unwrap();
                    if power == 1 {
                        let e = amp.entry(name).or_default();
                        e.set(op, val);
                    } else {
                        let key = CouplingKey { name, power };
                        let e = xs.entry(key).or_default();
                        e.set(op, val);
                    }
                } else {
                    return Err(ParseError::InvalidToken(other.to_string()));
                }
                i += 1;
            }
        }
    }
    Ok((veto, only, amp, xs))
}

fn find_top_level_block(s: &str, open: char, close: char) -> Option<(usize, usize)> {
    let mut depth = 0i32;
    let mut start: Option<usize> = None;
    for (i, ch) in s.char_indices() {
        if ch == open {
            if depth == 0 {
                start = Some(i);
            }
            depth += 1;
        } else if ch == close {
            depth -= 1;
            if depth == 0 {
                return start.map(|st| (st, i));
            }
        }
    }
    None
}

fn split_ws(s: &str) -> Vec<String> {
    s.split_whitespace().map(|t| t.to_string()).collect()
}

// =================== Build Feyngen options and filters ===================

fn feyngen_from_spec_args(
    a: &SpecArgs,
    generation_type: GenerationType,
    pert: &Perturbative,
    amp_couplings: &BTreeMap<String, OrderRange>,
    xs_couplings: &BTreeMap<CouplingKey, OrderRange>,
    initial_pdgs: &[i64],
    primary_final_pdgs: &[i64],
    final_sets_pdgs: &[Vec<i64>],
    veto_pdgs: &[i64],
) -> ProcessDefinition {
    // Decide vacuum-like topology from PDGs
    let is_vacuum = if initial_pdgs.is_empty() {
        match generation_type {
            GenerationType::CrossSection => true,
            GenerationType::Amplitude => {
                primary_final_pdgs.is_empty()
                    && (final_sets_pdgs
                        .first()
                        .map(|v| v.is_empty())
                        .unwrap_or(true))
            }
        }
    } else {
        false
    };

    // Smart defaults influenced by vacuum
    let filter_tadpoles_default = !is_vacuum;
    let filter_snails_default = !is_vacuum;
    let filter_selfenergies_default = !is_vacuum;

    // Normalize filter toggles
    let filter_tadpoles = a.filter_tadpoles.unwrap_or(filter_tadpoles_default);
    let filter_snails = a.filter_snails.unwrap_or(filter_snails_default);
    let filter_selfenergies = a.filter_selfenergies.unwrap_or(filter_selfenergies_default);

    // Normalize numeric toggles with the vacuum defaults
    let number_of_factorized_loop_subtopologies = a
        .number_of_factorized_loop_subtopologies
        .clone()
        .or(if is_vacuum {
            Some(vec![1_i32, 1_i32])
        } else {
            None
        })
        .and_then(|v| {
            if v[0] < 0 && v[1] < 0 {
                None
            } else {
                Some((v[0].max(0) as usize, v[1].max(0) as usize))
            }
        });

    let max_n_bridges = a
        .max_n_bridges
        .or(if is_vacuum { Some(0) } else { None })
        .and_then(|n| if n < 0 { None } else { Some(n as usize) });

    let number_of_fermion_loops = a
        .number_of_fermion_loops
        .as_ref()
        .map(|v| (v[0].max(0) as usize, v[1].max(0) as usize));

    // Cut ranges (XS)
    let blob_range: RangeInclusive<usize> = {
        let (lo, hi) = a
            .n_cut_blobs
            .as_ref()
            .map(|v| (v[0], v[1]))
            .unwrap_or((1, 1));
        lo..=hi
    };
    let spectator_range: RangeInclusive<usize> = {
        let (lo, hi) = a
            .n_cut_spectators
            .as_ref()
            .map(|v| (v[0], v[1]))
            .unwrap_or((0, 0));
        lo..=hi
    };

    // Symmetrization defaults depend on generation type (mirror python logic)
    let sym_left_right = a.symmetrize_left_right_states.unwrap_or(false);
    let (sym_init, sym_final) = match generation_type {
        GenerationType::Amplitude => {
            // LR is the amplitude shorthand; explicit side options take precedence.
            let s_init = a.symmetrize_initial_states.unwrap_or(sym_left_right);
            let s_final = a.symmetrize_final_states.unwrap_or(sym_left_right);
            (s_init, s_final)
        }
        GenerationType::CrossSection => {
            let s_init = a.symmetrize_initial_states.unwrap_or(false);
            let s_final = a.symmetrize_final_states.unwrap_or(true);
            (s_init, s_final)
        }
    };
    let allow_symferm = a
        .allow_symmetrization_of_external_fermions_in_amplitudes
        .unwrap_or(false);

    // Base options
    let mut fg = ProcessDefinition {
        generation_type,
        initial_pdgs: initial_pdgs.to_vec(),
        final_pdgs_lists: if final_sets_pdgs.is_empty() {
            vec![primary_final_pdgs.to_vec()]
        } else if !primary_final_pdgs.is_empty() {
            let mut sets = vec![primary_final_pdgs.to_vec()];
            sets.extend_from_slice(final_sets_pdgs);
            sets
        } else {
            final_sets_pdgs.to_vec()
        },
        loop_count_range: (1, 1), // may be overridden below
        // (Blob/Spectator ranges are expressed through filters below)
        symmetrize_initial_states: sym_init,
        symmetrize_final_states: sym_final,
        symmetrize_left_right_states: sym_left_right,
        allow_symmetrization_of_external_fermions_in_amplitudes: allow_symferm,
        max_multiplicity_for_fast_cut_filter: a.max_multiplicity_for_fast_cut_filter,
        amplitude_filters: FeynGenFilters(vec![]),
        cross_section_filters: FeynGenFilters(vec![]),
        ..Default::default()
    };

    // Build filters
    let mut amp_filters: Vec<FeynGenFilter> = Vec::new();
    let mut xs_filters: Vec<FeynGenFilter> = Vec::new();

    // Loop counts
    if let Some(n) = pert.loops_sum_amp_or_sum {
        amp_filters.push(FeynGenFilter::LoopCountRange((n as usize, n as usize)));
        if fg.generation_type == GenerationType::Amplitude {
            fg.loop_count_range = (n as usize, n as usize);
        }
    }
    if let Some(n) = pert.loops_forward_graph {
        xs_filters.push(FeynGenFilter::LoopCountRange((n as usize, n as usize)));
        if fg.generation_type == GenerationType::CrossSection {
            fg.loop_count_range = (n as usize, n as usize);
        }
    }

    // Perturbative orders (only to matching container)
    if !pert.orders.is_empty() {
        let map: HashMap<String, usize> = pert
            .orders
            .iter()
            .map(|(k, v)| (k.clone(), *v as usize))
            .collect();
        if fg.generation_type == GenerationType::Amplitude {
            amp_filters.push(FeynGenFilter::PerturbativeOrders(map));
        } else {
            xs_filters.push(FeynGenFilter::PerturbativeOrders(map));
        }
    }

    // CouplingOrders
    if !amp_couplings.is_empty() {
        let cmap = coupling_orders_from_order_ranges_amp(amp_couplings);
        amp_filters.push(FeynGenFilter::CouplingOrders(cmap));
    }
    if !xs_couplings.is_empty() {
        let cmap = coupling_orders_from_order_ranges_xs(xs_couplings);
        xs_filters.push(FeynGenFilter::CouplingOrders(cmap));
    }

    // Factorized loop topologies → FactorizedLoopTopologiesCountRange((n,n))
    if let Some((n_min, n_max)) = number_of_factorized_loop_subtopologies {
        let filt = FeynGenFilter::FactorizedLoopTopologiesCountRange((n_min, n_max));
        if fg.generation_type == GenerationType::Amplitude {
            amp_filters.push(filt);
        } else {
            xs_filters.push(filt);
        }
    }

    // Fermion loop count → FermionLoopCountRange((n,n))
    if let Some((n_min, n_max)) = number_of_fermion_loops {
        let filt = FeynGenFilter::FermionLoopCountRange((n_min, n_max));
        if fg.generation_type == GenerationType::Amplitude {
            amp_filters.push(filt);
        } else {
            xs_filters.push(filt);
        }
    }

    // MaxNumberOfBridges
    if let Some(n) = max_n_bridges {
        let filt = FeynGenFilter::MaxNumberOfBridges(n);
        if fg.generation_type == GenerationType::Amplitude {
            amp_filters.push(filt);
        } else {
            xs_filters.push(filt);
        }
    }

    // Particle vetoes
    if !veto_pdgs.is_empty() {
        let filt = FeynGenFilter::ParticleVeto(veto_pdgs.to_vec());
        if fg.generation_type == GenerationType::Amplitude {
            amp_filters.push(filt);
        } else {
            xs_filters.push(filt);
        }
    }

    // XS cut ranges
    if fg.generation_type == GenerationType::CrossSection {
        xs_filters.push(FeynGenFilter::BlobRange(blob_range));
        xs_filters.push(FeynGenFilter::SpectatorRange(spectator_range));
    }

    // Self-energy / snails / tadpoles with detailed veto flags:
    if filter_selfenergies {
        let mut se = SelfEnergyFilterOptions::default();
        if let Some(opt) = a.veto_self_energy_of_massive_lines {
            se.veto_self_energy_of_massive_lines = opt;
        }
        if let Some(opt) = a.veto_self_energy_of_massless_lines {
            se.veto_self_energy_of_massless_lines = opt;
        }
        if let Some(opt) = a.veto_only_scaleless_self_energy {
            se.veto_only_scaleless_self_energy = opt;
        }
        let filt = FeynGenFilter::SelfEnergyFilter(se);
        if fg.generation_type == GenerationType::Amplitude {
            amp_filters.push(filt);
        } else {
            xs_filters.push(filt);
        }
    }
    if filter_snails {
        let mut sn = SnailFilterOptions::default();
        if let Some(opt) = a.veto_snails_attached_to_massive_lines {
            sn.veto_snails_attached_to_massive_lines = opt;
        }
        if let Some(opt) = a.veto_snails_attached_to_massless_lines {
            sn.veto_snails_attached_to_massless_lines = opt;
        }
        if let Some(opt) = a.veto_only_scaleless_snails {
            sn.veto_only_scaleless_snails = opt;
        }
        let filt = FeynGenFilter::ZeroSnailsFilter(sn);
        if fg.generation_type == GenerationType::Amplitude {
            amp_filters.push(filt);
        } else {
            xs_filters.push(filt);
        }
    }
    if filter_tadpoles {
        let mut td = TadpolesFilterOptions::default();
        if let Some(opt) = a.veto_tadpoles_attached_to_massive_lines {
            td.veto_tadpoles_attached_to_massive_lines = opt;
        }
        if let Some(opt) = a.veto_tadpoles_attached_to_massless_lines {
            td.veto_tadpoles_attached_to_massless_lines = opt;
        }
        if let Some(opt) = a.veto_only_scaleless_tadpoles {
            td.veto_only_scaleless_tadpoles = opt;
        }
        let filt = FeynGenFilter::TadpolesFilter(td);
        if fg.generation_type == GenerationType::Amplitude {
            amp_filters.push(filt);
        } else {
            xs_filters.push(filt);
        }
    }

    // XS-only: sewed filter controlled separately
    if fg.generation_type == GenerationType::CrossSection
        && a.filter_cross_section_tadpoles.unwrap_or(false)
    {
        if let Some(opt) = a.filter_cross_section_tadpoles {
            xs_filters.push(FeynGenFilter::SewedFilter(SewedFilterOptions {
                filter_tadpoles: opt,
            }));
        }
    }

    if let Some(vertex_interactions_allowed) = a.allowed_vertex_interactions.as_ref() {
        if !vertex_interactions_allowed.is_empty() {
            let filt = FeynGenFilter::VertexAllow(vertex_interactions_allowed.clone());
            if fg.generation_type == GenerationType::Amplitude {
                amp_filters.push(filt);
            } else {
                xs_filters.push(filt);
            }
        }
    }
    if let Some(vertex_interactions_vetoed) = a.veto_vertex_interactions.as_ref() {
        let filt = FeynGenFilter::VertexVeto(vertex_interactions_vetoed.clone());
        if fg.generation_type == GenerationType::Amplitude {
            amp_filters.push(filt);
        } else {
            xs_filters.push(filt);
        }
    }

    fg.amplitude_filters = FeynGenFilters(amp_filters);
    fg.cross_section_filters = FeynGenFilters(xs_filters);

    fg
}

fn coupling_orders_from_order_ranges_amp(
    orders: &BTreeMap<String, OrderRange>,
) -> HashMap<String, (usize, Option<usize>)> {
    let mut out = HashMap::default();
    for (name, r) in orders {
        if let Some(eq) = r.eq {
            out.insert(name.clone(), (eq as usize, Some(eq as usize)));
        } else {
            let minv = r.min.unwrap_or(0) as usize;
            let maxv = r.max.map(|m| m as usize);
            out.insert(name.clone(), (minv, maxv));
        }
    }
    out
}

fn coupling_orders_from_order_ranges_xs(
    orders: &BTreeMap<CouplingKey, OrderRange>,
) -> HashMap<String, (usize, Option<usize>)> {
    // Drop the power and merge constraints per name.
    let mut merged: BTreeMap<String, OrderRange> = BTreeMap::new();
    for (k, r) in orders {
        let e = merged.entry(k.name.clone()).or_default();
        if let Some(eq) = r.eq {
            e.eq = Some(eq);
        }
        if let Some(min) = r.min {
            e.min = Some(e.min.map_or(min, |m| m.max(min)));
        }
        if let Some(max) = r.max {
            e.max = Some(e.max.map_or(max, |m| m.min(max)));
        }
    }
    coupling_orders_from_order_ranges_amp(&merged)
}

fn build_grouping_option(a: &SpecArgs) -> NumeratorAwareGraphGroupingOption {
    a.numerator_aware_isomorphism_grouping
        .unwrap_or(GroupingChoice::GroupIdenticalGraphsUpToScalarRescaling)
        .to_strategy(
            a.numerical_samples_seed,
            a.number_of_samples_for_numerator_comparisons,
            a.consider_internal_masses_only_in_numerator_isomorphisms,
            a.fully_numerical_substitution_when_comparing_numerators,
            a.compare_canonized_numerator,
            a.symmetric_left_right_polarizations,
        )
}

// ---- Model-backed validation and resolution ----

fn all_particle_names(model: &Model) -> Vec<String> {
    model
        .particles
        .iter()
        .map(|p| p.name.clone().to_string())
        .collect::<Vec<_>>()
}

fn resolve_pdgs(model: &Model, names: &[String]) -> Result<Vec<i64>, ParseError> {
    let all_particles = all_particle_names(model);
    let mut out = Vec::with_capacity(names.len());
    'outer: for n in names {
        // Accept numeric PDG directly
        if let Ok(p) = n.parse::<i64>() {
            out.push(p);
            continue;
        }
        // Try exact name lookup via model
        if let Ok(p) = model.try_get_particle(n) {
            out.push(p.pdg_code as i64);
            continue;
        }
        // Case-insensitive fallback against both names and antinames
        for part in model.particles.iter() {
            if part.name.eq_ignore_ascii_case(n) || part.antiname.eq_ignore_ascii_case(n) {
                out.push(part.pdg_code as i64);
                continue 'outer;
            }
        }
        // Unknown
        return Err(ParseError::UnknownParticle {
            name: n.clone(),
            choices: all_particles.join(", "),
        });
    }
    Ok(out)
}

fn validate_coupling_names(
    model: &Model,
    amp: &BTreeMap<String, OrderRange>,
    xs: &BTreeMap<CouplingKey, OrderRange>,
    pert: &Perturbative,
) -> Result<(), ParseError> {
    // If the model has no coupling metadata, skip validation entirely.
    let has_orders_info = !model.orders.is_empty();

    if !has_orders_info {
        return Ok(());
    }

    // Collect all mentioned coupling names
    let mut names = BTreeSet::<String>::new();
    for k in amp.keys() {
        names.insert(k.clone());
    }
    for k in xs.keys() {
        names.insert(k.name.clone());
    }
    for k in pert.orders.keys() {
        names.insert(k.clone());
    }

    if names.is_empty() {
        return Ok(());
    }

    // Known couplings (case-insensitive compare)
    let known: Vec<String> = model
        .orders
        .iter()
        .map(|o| o.name.to_string())
        .collect::<Vec<_>>();
    let known_lower: BTreeSet<String> = known.iter().map(|s| s.to_ascii_lowercase()).collect();

    for n in names {
        if !known_lower.contains(&n.to_ascii_lowercase()) {
            return Err(ParseError::UnknownCoupling {
                name: n,
                choices: known.join(", "),
            });
        }
    }
    Ok(())
}

// ---- parsing of structured CLI fields ----

fn parse_csv_list(s: &str) -> Vec<String> {
    s.split(',')
        .flat_map(|x| x.split_whitespace())
        .filter(|t| !t.is_empty())
        .map(|t| t.to_string())
        .collect()
}

#[allow(dead_code)]
fn parse_loop_momentum_bases(s: &str) -> Option<HashMap<String, Vec<String>>> {
    // Format: "B1=p1,p2;B2=q1,q2"
    let mut out: HashMap<String, Vec<String>> = HashMap::default();
    for kv in s.split(';') {
        let kv = kv.trim();
        if kv.is_empty() {
            continue;
        }
        if let Some((k, v)) = kv.split_once('=') {
            let key = k.trim().to_string();
            let vals = v
                .split(',')
                .map(|x| x.trim().to_string())
                .filter(|x| !x.is_empty())
                .collect::<Vec<_>>();
            if !key.is_empty() {
                out.insert(key, vals);
            }
        } else {
            // single name without '=' is allowed but ignored
        }
    }
    if out.is_empty() {
        None
    } else {
        Some(out)
    }
}

// =================== Tests ===================

#[cfg(test)]
mod tests {
    use super::*;
    use crate::{commands::Commands, Repl};
    use clap::Parser;
    use gammalooprs::utils::load_generic_model;
    use gammalooprs::{feyngen::GenerationType, initialisation::test_initialise};
    use std::time::Duration;

    #[test]
    fn thermal_xs_generation_is_rejected_before_changing_processes() -> Result<()> {
        use gammalooprs::{processes::ProcessCollection, settings::global::MediumMode};

        let mut state = State::new_test();
        let mut cross_sections = BTreeMap::new();
        cross_sections.insert(
            "default".to_string(),
            CrossSection::from_graph_list("default".to_string(), vec![], &state.model)?,
        );
        state.process_list.add_process(Process {
            definition: ProcessDefinition {
                generation_type: GenerationType::CrossSection,
                ..ProcessDefinition::default()
            },
            settings_history: None,
            collection: ProcessCollection::CrossSections(cross_sections),
        });
        let mut settings = GlobalSettings::default();
        let runtime = RuntimeSettings::default();
        let temp = tempfile::tempdir()?;

        for mode in [
            MediumMode::ThermodynamicEquilibrium,
            MediumMode::ZeroTemperatureEquilibrium,
        ] {
            settings.generation.medium.mode = mode;
            for command in [
                "generate xs a > d d~ --clear-existing-processes",
                "generate xs a > d d~ --only-diagrams --clear-existing-processes",
                "generate existing -p 0",
                "generate existing -p 0 --integrand-name default",
                "generate",
            ] {
                let repl = Repl::try_parse_from(
                    std::iter::once("gammaloop").chain(command.split_whitespace()),
                )?;
                let Commands::Generate(generate) = repl.command else {
                    unreachable!();
                };
                let error = generate
                    .run(&mut state, temp.path(), false, &settings, &runtime)
                    .unwrap_err();
                assert!(error.to_string().contains("`xs`"), "{command}: {error}");
                assert!(error.to_string().contains("not supported"));
                assert_eq!(state.process_list.processes.len(), 1);
                assert!(state.process_list.processes[0].settings_history.is_none());
            }
        }
        // The amplitude must remain untouched when a later cross section
        // rejects the batch settings. Empty graphs isolate preprocessing order.
        let vacuum_settings = GlobalSettings::default();
        state.process_list.processes.insert(
            0,
            Process {
                definition: ProcessDefinition {
                    generation_type: GenerationType::Amplitude,
                    folder_name: "amplitude".to_string(),
                    ..ProcessDefinition::default()
                },
                settings_history: Some(vacuum_settings.clone()),
                collection: ProcessCollection::Amplitudes(BTreeMap::from([(
                    "default".to_string(),
                    Amplitude::from_graph_list("default", vec![])?,
                )])),
            },
        );
        state.process_list.processes[1].definition.process_id = 1;
        settings.generation.threshold_subtraction.enable_thresholds = false;
        for mode in [
            MediumMode::ThermodynamicEquilibrium,
            MediumMode::ZeroTemperatureEquilibrium,
        ] {
            settings.generation.medium.mode = mode;
            let error = Generate {
                keep_sources: false,
                mode: None,
            }
            .run(&mut state, temp.path(), false, &settings, &runtime)
            .unwrap_err();
            assert!(error.to_string().contains("`xs`"), "{mode:?}: {error}");
            assert!(error.to_string().contains("not supported"));
            assert_eq!(state.process_list.processes.len(), 2);
            assert!(
                state.process_list.processes[0].settings_history.as_ref() == Some(&vacuum_settings),
                "failed batch generation changed the preceding amplitude's settings in {mode:?}"
            );
            assert!(state.process_list.processes[1].settings_history.is_none());
        }
        assert_eq!(std::fs::read_dir(temp.path())?.count(), 0);
        Ok(())
    }

    #[test]
    fn remove_compiled_cpp_sources_only_removes_sources_with_matching_libraries() -> Result<()> {
        let temp = tempfile::tempdir()?;
        let compiled_source = temp.path().join("integrand.cpp");
        let compiled_library = temp.path().join("integrand.so");
        let uncompiled_source = temp.path().join("orphan.cpp");
        std::fs::write(&compiled_source, "compiled source")?;
        std::fs::write(&compiled_library, "compiled library")?;
        std::fs::write(&uncompiled_source, "orphan source")?;

        let removed_count = remove_compiled_cpp_sources(temp.path())?;

        assert_eq!(removed_count, 1);
        assert!(!compiled_source.exists());
        assert!(compiled_library.is_file());
        assert!(uncompiled_source.is_file());
        Ok(())
    }

    #[test]
    fn parse_generate_keep_sources_after_subcommand() {
        let repl =
            Repl::try_parse_from(["gammaloop", "generate", "existing", "--keep-sources"]).unwrap();

        match repl.command {
            Commands::Generate(generate) => {
                assert!(generate.keep_sources);
                assert!(matches!(generate.mode, Some(GenerateCmd::Existing(_))));
            }
            other => panic!("Expected generate command, got {other:?}"),
        }
    }

    #[test]
    fn generation_summary_includes_separator_and_total_row() {
        let reports = vec![
            GeneratedGraphReport {
                process_id: 0,
                integrand_name: "itg".to_string(),
                graph_name: "GL01".to_string(),
                stats: GraphGenerationStats {
                    evaluator_count: 2,
                    total_time: Duration::from_secs(4),
                    evaluator_spenso_time: Duration::from_secs(1),
                    evaluator_symbolica_time: Duration::from_secs(1),
                    evaluator_compile_time: Duration::from_secs(1),
                    ..GraphGenerationStats::default()
                },
            },
            GeneratedGraphReport {
                process_id: 0,
                integrand_name: "itg".to_string(),
                graph_name: "GL02".to_string(),
                stats: GraphGenerationStats {
                    evaluator_count: 3,
                    total_time: Duration::from_secs(6),
                    evaluator_spenso_time: Duration::from_secs(2),
                    evaluator_symbolica_time: Duration::ZERO,
                    evaluator_compile_time: Duration::from_secs(3),
                    ..GraphGenerationStats::default()
                },
            },
        ];

        let summary = render_generation_summary(&reports, 0, Some(4), None).unwrap();
        let plain = Regex::new(r"\x1b\[[0-9;]*m")
            .unwrap()
            .replace_all(&summary, "")
            .into_owned();

        assert!(plain.contains("Total"));
        assert!(plain.contains("5"));
        assert!(plain.contains("20%"));
        assert!(plain.contains("30%"));
        assert!(plain.contains("10%"));
        assert!(plain.contains("40%"));

        let lines = plain.lines().collect::<Vec<_>>();
        let total_line_index = lines
            .iter()
            .position(|line| line.contains("Total"))
            .expect("missing Total row");
        let separator_line = lines[..total_line_index]
            .iter()
            .rev()
            .find(|line| !line.trim().is_empty())
            .expect("missing line before Total row");
        assert!(
            separator_line.chars().any(|ch| "┼╪╫┿├┤".contains(ch)),
            "missing horizontal separator before Total row: {separator_line}"
        );
    }

    fn base_args(tokens: &str) -> SpecArgs {
        SpecArgs {
            tokens: tokens.split_whitespace().map(|x| x.to_string()).collect(),
            clear_existing_processes: false,
            filter_selfenergies: None,
            filter_snails: None,
            filter_tadpoles: None,
            filter_cross_section_tadpoles: None,
            veto_tadpoles_attached_to_massive_lines: None,
            veto_tadpoles_attached_to_massless_lines: None,
            veto_only_scaleless_tadpoles: None,
            veto_snails_attached_to_massive_lines: None,
            veto_snails_attached_to_massless_lines: None,
            veto_only_scaleless_snails: None,
            veto_self_energy_of_massive_lines: None,
            veto_self_energy_of_massless_lines: None,
            veto_only_scaleless_self_energy: None,
            max_n_bridges: None,
            number_of_factorized_loop_subtopologies: None,
            number_of_fermion_loops: None,
            symmetric_left_right_polarizations: None,
            n_cut_blobs: None,
            n_cut_spectators: None,
            allow_symmetrization_of_external_fermions_in_amplitudes: None,
            symmetrize_initial_states: None,
            symmetrize_final_states: None,
            symmetrize_left_right_states: None,
            numerator_aware_isomorphism_grouping: None,
            numerical_samples_seed: None,
            number_of_samples_for_numerator_comparisons: None,
            consider_internal_masses_only_in_numerator_isomorphisms: None,
            fully_numerical_substitution_when_comparing_numerators: None,
            compare_canonized_numerator: None,
            loop_momentum_bases: None,
            select_graphs: None,
            veto_graphs: None,
            graph_prefix: None,
            max_multiplicity_for_fast_cut_filter: 6,
            filter_self_loop: None,
            filter_zero_flow_edges: None,
            process_name: None,
            append: false,
            integrand_name: None,
            only_diagrams: true,
            allowed_vertex_interactions: None,
            veto_vertex_interactions: None,
            global_prefactor_num: None,
            global_prefactor_projector: None,
        }
    }

    // Test helpers using a real generic model shipped with the crate
    fn parse_ok_amp(s: &str) -> ProcessSpec {
        let model = &load_generic_model("sm");
        let a = base_args(s);
        parse_spec_with_model(&a, GenerationType::Amplitude, model).unwrap()
    }

    fn parse_ok_xs(s: &str) -> ProcessSpec {
        let model = &load_generic_model("sm");
        let a = base_args(s);
        parse_spec_with_model(&a, GenerationType::CrossSection, model).unwrap()
    }

    #[test]
    fn cp_symmetrization_option_defaults_false_and_roundtrips() {
        let model = load_generic_model("sm");
        for option in [None, Some(false), Some(true)] {
            let mut command = vec!["gammaloop", "generate", "xs", "a", ">", "d", "d~"];
            if let Some(enabled) = option {
                command.extend([
                    "--symmetrize-left-right-states",
                    if enabled { "true" } else { "false" },
                ]);
            }
            let repl = Repl::try_parse_from(command).unwrap();
            let Commands::Generate(Generate {
                mode: Some(GenerateCmd::Xs(args)),
                ..
            }) = repl.command
            else {
                panic!("expected a cross-section generation command");
            };
            assert_eq!(args.symmetrize_left_right_states, option);
            let serialized = serde_json::to_value(&args).unwrap();
            assert_eq!(
                serialized["symmetrize_left_right_states"],
                serde_json::json!(option)
            );
            let decoded: SpecArgs = serde_json::from_value(serialized).unwrap();
            assert_eq!(decoded, args);
            let spec =
                parse_spec_with_model(&decoded, GenerationType::CrossSection, &model).unwrap();
            assert_eq!(
                spec.process_definition.symmetrize_left_right_states,
                option.unwrap_or(false)
            );
        }
    }

    #[test]
    fn amplitude_left_right_shorthand_respects_explicit_side_options() {
        let model = load_generic_model("sm");
        let mut args = base_args("e+ e- > d d~");
        for (left_right, initial, final_state, expected) in [
            (None, None, None, (false, false)),
            (Some(true), None, None, (true, true)),
            (Some(true), Some(false), None, (false, true)),
            (Some(true), None, Some(false), (true, false)),
        ] {
            args.symmetrize_left_right_states = left_right;
            args.symmetrize_initial_states = initial;
            args.symmetrize_final_states = final_state;
            let definition = parse_spec_with_model(&args, GenerationType::Amplitude, &model)
                .unwrap()
                .process_definition;
            assert_eq!(
                (
                    definition.symmetrize_initial_states,
                    definition.symmetrize_final_states
                ),
                expected
            );
            assert_eq!(
                definition.symmetrize_left_right_states,
                left_right.unwrap_or(false)
            );
        }
    }

    #[test]
    fn fermion_loop_filter_is_added_in_both_generation_modes() {
        let model = &load_generic_model("sm");
        let repl = Repl::try_parse_from([
            "gammaloop",
            "generate",
            "amp",
            "e+",
            "e-",
            ">",
            "d",
            "d~",
            "--number-of-fermion-loops",
            "1",
            "2",
        ])
        .unwrap();
        let Commands::Generate(Generate {
            mode: Some(GenerateCmd::Amp(args)),
            ..
        }) = repl.command
        else {
            panic!("expected an amplitude generation command");
        };
        for mode in [GenerationType::Amplitude, GenerationType::CrossSection] {
            let spec = parse_spec_with_model(&args, mode, model).unwrap();
            let filters = if mode == GenerationType::Amplitude {
                &spec.process_definition.amplitude_filters
            } else {
                &spec.process_definition.cross_section_filters
            };
            assert!(filters
                .0
                .iter()
                .any(|filter| matches!(filter, FeynGenFilter::FermionLoopCountRange((1, 2)))));
        }
    }

    #[test]
    fn allowed_vertex_interactions_are_added_to_generation_filters() {
        let model = &load_generic_model("sm");
        let mut args = base_args("e+ e- > d d~");
        args.allowed_vertex_interactions = Some(vec!["V_6".to_string(), "V_9".to_string()]);

        let spec = parse_spec_with_model(&args, GenerationType::Amplitude, model).unwrap();

        assert!(spec
            .process_definition
            .amplitude_filters
            .0
            .iter()
            .any(|filter| matches!(
                filter,
                FeynGenFilter::VertexAllow(vertex_names)
                    if vertex_names == &vec!["V_6".to_string(), "V_9".to_string()]
            )));
    }

    #[test]
    fn basic_process_list_arrow() {
        test_initialise().unwrap();
        let ps = parse_ok_amp("e+ e- > d d~ g");
        assert_eq!(ps.initial, vec!["e+", "e-"]);
        assert_eq!(ps.final_, vec!["d", "d~", "g"]);
        assert!(!ps.empty_initial && !ps.empty_final);
    }

    #[test]
    fn basic_process_list_to() {
        test_initialise().unwrap();
        let ps = parse_ok_amp("e+ e- to d d~ g");
        assert_eq!(ps.initial, vec!["e+", "e-"]);
        assert_eq!(ps.final_, vec!["d", "d~", "g"]);
    }

    #[test]
    fn empty_sets_allowed() {
        test_initialise().unwrap();
        let ps = parse_ok_xs("{} to {}");
        assert!(ps.empty_initial);
        assert!(ps.empty_final);
    }

    #[test]
    fn alternatives_in_final_states() {
        test_initialise().unwrap();
        let ps = parse_ok_xs("e+ e- > { Z Z, a a }");
        assert!(ps.final_.is_empty());
        assert_eq!(ps.final_sets.len(), 2);
        assert_eq!(ps.final_sets[0], vec!["Z", "Z"]);
        assert_eq!(ps.final_sets[1], vec!["a", "a"]);
    }

    #[test]
    fn veto_and_only() {
        test_initialise().unwrap();
        let ps = parse_ok_xs("e+ e- > mu+ mu- / u d c g ghG e- | u g ghG");
        assert!(ps.veto.contains("u"));
        assert!(ps.veto.contains("e-"));
        let sel = ps.only.as_ref().unwrap();
        assert!(sel.contains("u"));
        assert!(sel.contains("g"));
        assert!(sel.contains("ghG"));
    }

    #[test]
    fn amp_order_constraints() {
        test_initialise().unwrap();
        let ps = parse_ok_amp("e+ e- > mu+ mu- QED==2 QCD>=2 QCD<=4");
        let qcd = ps.amp_couplings.get("QCD").unwrap();
        assert_eq!(qcd.min, Some(2));
        assert_eq!(qcd.max, Some(4));
        let qed = ps.amp_couplings.get("QED").unwrap();
        assert_eq!(qed.eq, Some(2));
    }

    #[test]
    fn xs_order_constraints_powered() {
        test_initialise().unwrap();
        let ps = parse_ok_xs("e+ e- > mu+ mu- QED^2==2 QCD^2>=2 QCD^2<=4");
        let key = CouplingKey {
            name: "QCD".into(),
            power: 2,
        };
        let qcd2 = ps.xs_couplings.get(&key).unwrap();
        assert_eq!(qcd2.min, Some(2));
        assert_eq!(qcd2.max, Some(4));
        let keyq = CouplingKey {
            name: "QED".into(),
            power: 2,
        };
        let qed2 = ps.xs_couplings.get(&keyq).unwrap();
        assert_eq!(qed2.eq, Some(2));
    }

    #[test]
    fn perturbative_block_all_forms() {
        test_initialise().unwrap();
        let ps = parse_ok_xs("e+ e- > z [ {1} {{2}} QCD=2 QED=1 ]");
        assert_eq!(ps.pert.loops_sum_amp_or_sum, Some(1));
        assert_eq!(ps.pert.loops_forward_graph, Some(2));
        assert_eq!(ps.pert.orders.get("QCD"), Some(&2));
        assert_eq!(ps.pert.orders.get("QED"), Some(&1));
    }

    #[test]
    fn perturbative_block_shorthand() {
        test_initialise().unwrap();
        let ps = parse_ok_xs("e+ e- > z [ QCD ]");
        assert_eq!(ps.pert.orders.get("QCD"), Some(&1));
    }

    #[test]
    fn amplitude_generation_type_is_set() {
        test_initialise().unwrap();
        let ps = parse_ok_amp("e+ e- > mu+ mu-");
        assert_eq!(
            ps.process_definition.generation_type,
            GenerationType::Amplitude
        );
    }

    #[test]
    fn rejects_malformed_tokens() {
        test_initialise().unwrap();
        let model = &load_generic_model("sm");

        let args = base_args("e+ > z [ {{}} ]");
        let err = parse_spec_with_model(&args, GenerationType::CrossSection, model).unwrap_err();
        assert_eq!(err, ParseError::InvalidToken("{{}}".into()));
    }

    #[test]
    fn missing_arrow_detected() {
        test_initialise().unwrap();
        let model = &load_generic_model("sm");

        let args = base_args("e+ e-  z z");
        let err = parse_spec_with_model(&args, GenerationType::CrossSection, model).unwrap_err();
        assert!(matches!(err, ParseError::MissingArrow));
    }

    #[test]
    fn vacuum_defaults_and_filters_xs() {
        test_initialise().unwrap();
        let ps = parse_ok_xs("{} to {}");
        assert_eq!(
            ps.process_definition.generation_type,
            GenerationType::CrossSection
        );

        let xs_filters = &ps.process_definition.cross_section_filters.0;

        // Smart defaults for vacuum-like graphs
        assert!(xs_filters
            .iter()
            .any(|f| matches!(f, FeynGenFilter::MaxNumberOfBridges(0))));
        assert!(xs_filters
            .iter()
            .any(|f| matches!(f, FeynGenFilter::FactorizedLoopTopologiesCountRange((1, 1)))));

        // Default cut ranges present
        assert!(xs_filters
            .iter()
            .any(|f| matches!(f, FeynGenFilter::BlobRange(r) if r.clone()==(1..=1))));
        assert!(xs_filters
            .iter()
            .any(|f| matches!(f, FeynGenFilter::SpectatorRange(r) if r.clone()==(0..=0))));
    }

    #[test]
    fn particle_veto_resolution_cross_section() {
        use std::collections::BTreeSet;
        test_initialise().unwrap();
        // Veto both particles and anti-particles, plus a charged lepton
        let ps = parse_ok_xs("e+ e- > mu+ mu- / u d u~ e+");
        let xs_filters = &ps.process_definition.cross_section_filters.0;

        let veto_pdgs = xs_filters
            .iter()
            .find_map(|f| match f {
                FeynGenFilter::ParticleVeto(v) => Some(v.clone()),
                _ => None,
            })
            .expect("ParticleVeto filter not found");
        let set: BTreeSet<i64> = veto_pdgs.into_iter().collect();

        // u=2, d=1, u~=-2, e+=-11
        for pdg in [2_i64, 1_i64, -2_i64, -11_i64] {
            assert!(set.contains(&pdg), "missing PDG {pdg} in veto");
        }
    }

    #[test]
    fn particle_inclusion_resolution_cross_section() {
        use std::collections::BTreeSet;
        test_initialise().unwrap();
        // Veto both particles and anti-particles, plus a charged lepton
        let ps = parse_ok_xs("e+ e- > mu+ mu- | u d u~ e+");
        let xs_filters = &ps.process_definition.cross_section_filters.0;

        let veto_pdgs = xs_filters
            .iter()
            .find_map(|f| match f {
                FeynGenFilter::ParticleVeto(v) => Some(v.clone()),
                _ => None,
            })
            .expect("ParticleVeto filter not found");
        let set: BTreeSet<i64> = veto_pdgs.into_iter().collect();

        for pdg in [
            3, 4, 5, 6, 12, 13, 14, 15, 16, 21, 22, 23, 24, 25, 250, 251, 9000001, 9000002,
            9000003, 9000004, 9000005,
        ] {
            assert!(set.contains(&pdg), "missing PDG {pdg} in veto");
        }
    }

    #[test]
    fn final_sets_and_orders_and_loops_cross_section() {
        test_initialise().unwrap();
        // Cross-section with final-state alternatives and perturbative block
        let ps = parse_ok_xs("e+ e- > { Z Z, a a, H H } [ {{3}} QCD=2 QED=1 ]");

        // Final-state alternatives captured
        assert_eq!(ps.final_sets.len(), 3);
        assert_eq!(
            ps.process_definition.generation_type,
            GenerationType::CrossSection
        );

        // XS loop count from {{3}}
        assert_eq!(ps.process_definition.loop_count_range, (3, 3));

        // Perturbative orders end up in XS filters
        let xs_filters = &ps.process_definition.cross_section_filters.0;
        assert!(xs_filters.iter().any(|f| {
            if let FeynGenFilter::PerturbativeOrders(m) = f {
                m.get("QCD") == Some(&2usize) && m.get("QED") == Some(&1usize)
            } else {
                false
            }
        }));
    }

    #[test]
    fn amplitude_with_powered_xs_constraints_and_only() {
        test_initialise().unwrap();
        // AMP spec including "only" and XS-style powered coupling constraints
        let ps = parse_ok_amp("e+ e- > mu+ mu- | g ghG QED^2==2 QCD^2>=2 QCD^2<=4 [ {1} QCD ]");

        // AMP-side perturbative bits
        assert_eq!(ps.pert.loops_sum_amp_or_sum, Some(1));
        assert_eq!(ps.pert.orders.get("QCD"), Some(&1));

        // XS-style powered constraints recorded
        let key_qed2 = CouplingKey {
            name: "QED".into(),
            power: 2,
        };
        let key_qcd2 = CouplingKey {
            name: "QCD".into(),
            power: 2,
        };
        let qed2 = ps.xs_couplings.get(&key_qed2).unwrap();
        assert_eq!(qed2.eq, Some(2));
        let qcd2 = ps.xs_couplings.get(&key_qcd2).unwrap();
        assert_eq!(qcd2.min, Some(2));
        assert_eq!(qcd2.max, Some(4));

        // "only" selection recorded
        let only = ps.only.as_ref().expect("missing only-set");
        assert!(only.contains("g"));
        assert!(only.contains("ghG"));
    }

    #[test]
    fn amplitude_case_insensitive_and_anti_in_veto() {
        use std::collections::BTreeSet;
        test_initialise().unwrap();
        // Mixed case names and anti-particles in veto; ensure AMP-side veto filter present
        let ps = parse_ok_amp("E+ e- to Z Z / u~ d~ A");

        let amp_filters = &ps.process_definition.amplitude_filters.0;
        let veto_pdgs = amp_filters
            .iter()
            .find_map(|f| match f {
                FeynGenFilter::ParticleVeto(v) => Some(v.clone()),
                _ => None,
            })
            .expect("AMP ParticleVeto filter not found");

        let set: BTreeSet<i64> = veto_pdgs.into_iter().collect();
        // u~=-2, d~=-1, A(=a)=22
        for pdg in [-2_i64, -1_i64, 22_i64] {
            assert!(set.contains(&pdg), "missing PDG {pdg} in AMP veto");
        }
    }

    #[test]
    fn shell_name_long_with_sets_veto_orders_pert_and_xs() {
        test_initialise().unwrap();
        let model = &load_generic_model("sm");

        // Intentionally scrambled input order; output must be canonical.
        let args =
            base_args("e+ e- > { Z Z, a a } / u d QED==2 QCD>=1 QED^2<=4 QCD^2>=2 [ QED=1 QCD=2 ]");
        let ps = parse_spec_with_model(&args, GenerationType::Amplitude, model).unwrap();

        let long = ps.process_shell_name(false);

        let expected = "epem_zz_or_aa-\
                    no__d_u-\
                    QCD_ge_1__QED_eq_2-\
                    QCDsq_ge_2__QEDsq_le_4-\
                    QCDloop_eq_2__QEDloop_eq_1";

        assert_eq!(long, expected);
    }

    #[test]
    fn repr_str_canonical_with_amp_xs_veto_loops_orders() {
        test_initialise().unwrap();
        let model = &load_generic_model("sm");

        // Mixed options with non-canonical input ordering.
        let args = base_args(
            "mu+ mu- > g g / ghg gha QED==1 QCD<=3 [ {2} QED=0 QCD=1 ] QED^2==0 QCD^2>=2",
        );
        let ps = parse_spec_with_model(&args, GenerationType::Amplitude, model).unwrap();

        let r = ps.repr_str();

        let expected = "mu+ mu- > g g / gha ghg QCD<=3 QED==1 [ {2} QCD ] QCD^2>=2 QED^2==0";

        assert_eq!(r, expected);
    }

    #[test]
    fn repr_str_with_both_loop_counts_and_sorted_orders() {
        test_initialise().unwrap();
        let model = &load_generic_model("sm");

        let args = base_args("e+ e- > z z [ {{2}} QED=2 QCD=1 {1} ]");
        let ps = parse_spec_with_model(&args, GenerationType::CrossSection, model).unwrap();

        let r = ps.repr_str();

        let expected = "e+ e- > z z [ {1} {{2}} QCD QED=2 ]";

        assert_eq!(r, expected);
    }

    #[test]
    fn shell_name_short_canonical_and_sanitization() {
        test_initialise().unwrap();
        let model = &load_generic_model("sm");

        let args = base_args("W+ W- > {}");
        let ps = parse_spec_with_model(&args, GenerationType::CrossSection, model).unwrap();

        // Short form uses only the base slug and sanitizes +/- and ~.
        let short = ps.process_shell_name(true);
        let expected = "wpwm_empty";

        assert_eq!(short, expected);
    }
}