use std::collections::BTreeSet;

use serde::{Deserialize, Serialize};

use crate::{
    RuntimeCompanyControllerKind, RuntimeCompanyMetric, RuntimeCompanyTarget, RuntimeCondition,
    RuntimeConditionComparator, RuntimeEffect, RuntimeEventRecordTemplate, RuntimePlayerTarget,
    RuntimeState, RuntimeSummary, RuntimeTerritoryMetric, RuntimeTerritoryTarget,
    RuntimeTrackMetric, RuntimeTrackPieceCounts, calendar::BoundaryEventKind,
};

const PERIODIC_TRIGGER_KIND_ORDER: [u8; 6] = [1, 0, 3, 2, 5, 4];

#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
#[serde(tag = "kind", rename_all = "snake_case")]
pub enum StepCommand {
    AdvanceTo { calendar: crate::CalendarPoint },
    StepCount { steps: u32 },
    ServiceTriggerKind { trigger_kind: u8 },
    ServicePeriodicBoundary,
}

impl StepCommand {
    pub fn validate(&self) -> Result<(), String> {
        match self {
            Self::AdvanceTo { calendar } => calendar.validate(),
            Self::StepCount { steps } => {
                if *steps == 0 {
                    return Err("step_count command requires steps > 0".to_string());
                }
                Ok(())
            }
            Self::ServiceTriggerKind { .. } | Self::ServicePeriodicBoundary => Ok(()),
        }
    }
}

#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub struct BoundaryEvent {
    pub kind: String,
    pub calendar: crate::CalendarPoint,
}

#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub struct ServiceEvent {
    pub kind: String,
    pub trigger_kind: Option<u8>,
    pub serviced_record_ids: Vec<u32>,
    pub applied_effect_count: u32,
    pub mutated_company_ids: Vec<u32>,
    pub mutated_player_ids: Vec<u32>,
    pub appended_record_ids: Vec<u32>,
    pub activated_record_ids: Vec<u32>,
    pub deactivated_record_ids: Vec<u32>,
    pub removed_record_ids: Vec<u32>,
    pub dirty_rerun: bool,
}

#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub struct StepResult {
    pub initial_summary: RuntimeSummary,
    pub final_summary: RuntimeSummary,
    pub steps_executed: u64,
    pub boundary_events: Vec<BoundaryEvent>,
    pub service_events: Vec<ServiceEvent>,
}

#[derive(Debug, Clone, PartialEq, Eq)]
enum EventGraphMutation {
    Append(RuntimeEventRecordTemplate),
    Activate { record_id: u32 },
    Deactivate { record_id: u32 },
    Remove { record_id: u32 },
}

#[derive(Debug, Default)]
struct AppliedEffectsSummary {
    applied_effect_count: u32,
    appended_record_ids: Vec<u32>,
    activated_record_ids: Vec<u32>,
    deactivated_record_ids: Vec<u32>,
    removed_record_ids: Vec<u32>,
}

#[derive(Debug, Default)]
struct ResolvedConditionContext {
    matching_company_ids: BTreeSet<u32>,
    matching_player_ids: BTreeSet<u32>,
}

pub fn execute_step_command(
    state: &mut RuntimeState,
    command: &StepCommand,
) -> Result<StepResult, String> {
    state.validate()?;
    command.validate()?;

    let initial_summary = RuntimeSummary::from_state(state);
    let mut boundary_events = Vec::new();
    let mut service_events = Vec::new();
    let steps_executed = match command {
        StepCommand::AdvanceTo { calendar } => {
            advance_to_target_calendar_point(state, *calendar, &mut boundary_events)?
        }
        StepCommand::StepCount { steps } => step_count(state, *steps, &mut boundary_events),
        StepCommand::ServiceTriggerKind { trigger_kind } => {
            service_trigger_kind(state, *trigger_kind, &mut service_events)?;
            0
        }
        StepCommand::ServicePeriodicBoundary => {
            service_periodic_boundary(state, &mut service_events)?;
            0
        }
    };
    let final_summary = RuntimeSummary::from_state(state);

    Ok(StepResult {
        initial_summary,
        final_summary,
        steps_executed,
        boundary_events,
        service_events,
    })
}

fn advance_to_target_calendar_point(
    state: &mut RuntimeState,
    target: crate::CalendarPoint,
    boundary_events: &mut Vec<BoundaryEvent>,
) -> Result<u64, String> {
    target.validate()?;
    if target < state.calendar {
        return Err(format!(
            "advance_to target {:?} is earlier than current calendar {:?}",
            target, state.calendar
        ));
    }

    let mut steps = 0_u64;
    while state.calendar < target {
        step_once(state, boundary_events);
        steps += 1;
    }
    Ok(steps)
}

fn step_count(
    state: &mut RuntimeState,
    steps: u32,
    boundary_events: &mut Vec<BoundaryEvent>,
) -> u64 {
    for _ in 0..steps {
        step_once(state, boundary_events);
    }
    steps.into()
}

fn step_once(state: &mut RuntimeState, boundary_events: &mut Vec<BoundaryEvent>) {
    let boundary = state.calendar.step_forward();
    if boundary != BoundaryEventKind::Tick {
        boundary_events.push(BoundaryEvent {
            kind: boundary_kind_label(boundary).to_string(),
            calendar: state.calendar,
        });
    }
}

fn boundary_kind_label(boundary: BoundaryEventKind) -> &'static str {
    match boundary {
        BoundaryEventKind::Tick => "tick",
        BoundaryEventKind::PhaseRollover => "phase_rollover",
        BoundaryEventKind::MonthRollover => "month_rollover",
        BoundaryEventKind::YearRollover => "year_rollover",
    }
}

fn service_periodic_boundary(
    state: &mut RuntimeState,
    service_events: &mut Vec<ServiceEvent>,
) -> Result<(), String> {
    state.service_state.periodic_boundary_calls += 1;

    for trigger_kind in PERIODIC_TRIGGER_KIND_ORDER {
        service_trigger_kind(state, trigger_kind, service_events)?;
    }

    Ok(())
}

fn service_trigger_kind(
    state: &mut RuntimeState,
    trigger_kind: u8,
    service_events: &mut Vec<ServiceEvent>,
) -> Result<(), String> {
    let eligible_indices = state
        .event_runtime_records
        .iter()
        .enumerate()
        .filter(|(_, record)| {
            record.active
                && record.trigger_kind == trigger_kind
                && !(record.one_shot && record.has_fired)
        })
        .map(|(index, _)| index)
        .collect::<Vec<_>>();

    let mut serviced_record_ids = Vec::new();
    let mut applied_effect_count = 0_u32;
    let mut mutated_company_ids = BTreeSet::new();
    let mut mutated_player_ids = BTreeSet::new();
    let mut appended_record_ids = Vec::new();
    let mut activated_record_ids = Vec::new();
    let mut deactivated_record_ids = Vec::new();
    let mut removed_record_ids = Vec::new();
    let mut staged_event_graph_mutations = Vec::new();
    let mut dirty_rerun = false;

    *state
        .service_state
        .trigger_dispatch_counts
        .entry(trigger_kind)
        .or_insert(0) += 1;

    for index in eligible_indices {
        let (
            record_id,
            record_conditions,
            record_effects,
            record_marks_collection_dirty,
            record_one_shot,
        ) = {
            let record = &state.event_runtime_records[index];
            (
                record.record_id,
                record.conditions.clone(),
                record.effects.clone(),
                record.marks_collection_dirty,
                record.one_shot,
            )
        };

        let Some(condition_context) = evaluate_record_conditions(state, &record_conditions)? else {
            continue;
        };

        let effect_summary = apply_runtime_effects(
            state,
            &record_effects,
            &condition_context,
            &mut mutated_company_ids,
            &mut mutated_player_ids,
            &mut staged_event_graph_mutations,
        )?;
        applied_effect_count += effect_summary.applied_effect_count;
        appended_record_ids.extend(effect_summary.appended_record_ids);
        activated_record_ids.extend(effect_summary.activated_record_ids);
        deactivated_record_ids.extend(effect_summary.deactivated_record_ids);
        removed_record_ids.extend(effect_summary.removed_record_ids);

        {
            let record = &mut state.event_runtime_records[index];
            record.service_count += 1;
            if record_one_shot {
                record.has_fired = true;
            }
        }

        serviced_record_ids.push(record_id);
        state.service_state.total_event_record_services += 1;
        if trigger_kind != 0x0a && record_marks_collection_dirty {
            dirty_rerun = true;
        }
    }

    commit_staged_event_graph_mutations(state, &staged_event_graph_mutations)?;

    service_events.push(ServiceEvent {
        kind: "trigger_dispatch".to_string(),
        trigger_kind: Some(trigger_kind),
        serviced_record_ids,
        applied_effect_count,
        mutated_company_ids: mutated_company_ids.into_iter().collect(),
        mutated_player_ids: mutated_player_ids.into_iter().collect(),
        appended_record_ids,
        activated_record_ids,
        deactivated_record_ids,
        removed_record_ids,
        dirty_rerun,
    });

    if dirty_rerun {
        state.service_state.dirty_rerun_count += 1;
        service_trigger_kind(state, 0x0a, service_events)?;
    }

    Ok(())
}

fn apply_runtime_effects(
    state: &mut RuntimeState,
    effects: &[RuntimeEffect],
    condition_context: &ResolvedConditionContext,
    mutated_company_ids: &mut BTreeSet<u32>,
    mutated_player_ids: &mut BTreeSet<u32>,
    staged_event_graph_mutations: &mut Vec<EventGraphMutation>,
) -> Result<AppliedEffectsSummary, String> {
    let mut summary = AppliedEffectsSummary::default();

    for effect in effects {
        match effect {
            RuntimeEffect::SetWorldFlag { key, value } => {
                state.world_flags.insert(key.clone(), *value);
            }
            RuntimeEffect::SetEconomicStatusCode { value } => {
                state.world_restore.economic_status_code = Some(*value);
            }
            RuntimeEffect::SetCompanyCash { target, value } => {
                let company_ids = resolve_company_target_ids(state, target, condition_context)?;
                for company_id in company_ids {
                    let company = state
                        .companies
                        .iter_mut()
                        .find(|company| company.company_id == company_id)
                        .ok_or_else(|| {
                            format!("missing company_id {company_id} while applying cash effect")
                        })?;
                    company.current_cash = *value;
                    mutated_company_ids.insert(company_id);
                }
            }
            RuntimeEffect::SetPlayerCash { target, value } => {
                let player_ids = resolve_player_target_ids(state, target, condition_context)?;
                for player_id in player_ids {
                    let player = state
                        .players
                        .iter_mut()
                        .find(|player| player.player_id == player_id)
                        .ok_or_else(|| {
                            format!("missing player_id {player_id} while applying cash effect")
                        })?;
                    player.current_cash = *value;
                    mutated_player_ids.insert(player_id);
                }
            }
            RuntimeEffect::SetCompanyTerritoryAccess {
                target,
                territory,
                value,
            } => {
                let company_ids = resolve_company_target_ids(state, target, condition_context)?;
                let territory_ids = resolve_territory_target_ids(state, territory)?;
                set_company_territory_access_pairs(
                    &mut state.company_territory_access,
                    &company_ids,
                    &territory_ids,
                    *value,
                );
                mutated_company_ids.extend(company_ids);
            }
            RuntimeEffect::ConfiscateCompanyAssets { target } => {
                let company_ids = resolve_company_target_ids(state, target, condition_context)?;
                for company_id in company_ids.iter().copied() {
                    let company = state
                        .companies
                        .iter_mut()
                        .find(|company| company.company_id == company_id)
                        .ok_or_else(|| {
                            format!(
                                "missing company_id {company_id} while applying confiscate effect"
                            )
                        })?;
                    company.current_cash = 0;
                    company.debt = 0;
                    company.active = false;
                    mutated_company_ids.insert(company_id);
                    if state.selected_company_id == Some(company_id) {
                        state.selected_company_id = None;
                    }
                }
                retire_matching_trains(&mut state.trains, Some(&company_ids), None, None);
            }
            RuntimeEffect::DeactivateCompany { target } => {
                let company_ids = resolve_company_target_ids(state, target, condition_context)?;
                for company_id in company_ids {
                    let company = state
                        .companies
                        .iter_mut()
                        .find(|company| company.company_id == company_id)
                        .ok_or_else(|| {
                            format!(
                                "missing company_id {company_id} while applying deactivate effect"
                            )
                        })?;
                    company.active = false;
                    mutated_company_ids.insert(company_id);
                    if state.selected_company_id == Some(company_id) {
                        state.selected_company_id = None;
                    }
                }
            }
            RuntimeEffect::SetCompanyTrackLayingCapacity { target, value } => {
                let company_ids = resolve_company_target_ids(state, target, condition_context)?;
                for company_id in company_ids {
                    let company = state
                        .companies
                        .iter_mut()
                        .find(|company| company.company_id == company_id)
                        .ok_or_else(|| {
                            format!(
                                "missing company_id {company_id} while applying track capacity effect"
                            )
                        })?;
                    company.available_track_laying_capacity = *value;
                    mutated_company_ids.insert(company_id);
                }
            }
            RuntimeEffect::RetireTrains {
                company_target,
                territory_target,
                locomotive_name,
            } => {
                let company_ids = company_target
                    .as_ref()
                    .map(|target| resolve_company_target_ids(state, target, condition_context))
                    .transpose()?;
                let territory_ids = territory_target
                    .as_ref()
                    .map(|target| resolve_territory_target_ids(state, target))
                    .transpose()?;
                retire_matching_trains(
                    &mut state.trains,
                    company_ids.as_ref(),
                    territory_ids.as_ref(),
                    locomotive_name.as_deref(),
                );
            }
            RuntimeEffect::AdjustCompanyCash { target, delta } => {
                let company_ids = resolve_company_target_ids(state, target, condition_context)?;
                for company_id in company_ids {
                    let company = state
                        .companies
                        .iter_mut()
                        .find(|company| company.company_id == company_id)
                        .ok_or_else(|| {
                            format!("missing company_id {company_id} while applying cash effect")
                        })?;
                    company.current_cash =
                        company.current_cash.checked_add(*delta).ok_or_else(|| {
                            format!("company_id {company_id} cash adjustment overflow")
                        })?;
                    mutated_company_ids.insert(company_id);
                }
            }
            RuntimeEffect::AdjustCompanyDebt { target, delta } => {
                let company_ids = resolve_company_target_ids(state, target, condition_context)?;
                for company_id in company_ids {
                    let company = state
                        .companies
                        .iter_mut()
                        .find(|company| company.company_id == company_id)
                        .ok_or_else(|| {
                            format!("missing company_id {company_id} while applying debt effect")
                        })?;
                    company.debt = apply_u64_delta(company.debt, *delta, company_id)?;
                    mutated_company_ids.insert(company_id);
                }
            }
            RuntimeEffect::SetCandidateAvailability { name, value } => {
                state.candidate_availability.insert(name.clone(), *value);
            }
            RuntimeEffect::SetSpecialCondition { label, value } => {
                state.special_conditions.insert(label.clone(), *value);
            }
            RuntimeEffect::AppendEventRecord { record } => {
                staged_event_graph_mutations.push(EventGraphMutation::Append((**record).clone()));
                summary.appended_record_ids.push(record.record_id);
            }
            RuntimeEffect::ActivateEventRecord { record_id } => {
                staged_event_graph_mutations.push(EventGraphMutation::Activate {
                    record_id: *record_id,
                });
                summary.activated_record_ids.push(*record_id);
            }
            RuntimeEffect::DeactivateEventRecord { record_id } => {
                staged_event_graph_mutations.push(EventGraphMutation::Deactivate {
                    record_id: *record_id,
                });
                summary.deactivated_record_ids.push(*record_id);
            }
            RuntimeEffect::RemoveEventRecord { record_id } => {
                staged_event_graph_mutations.push(EventGraphMutation::Remove {
                    record_id: *record_id,
                });
                summary.removed_record_ids.push(*record_id);
            }
        }

        summary.applied_effect_count += 1;
    }

    Ok(summary)
}

fn commit_staged_event_graph_mutations(
    state: &mut RuntimeState,
    staged_event_graph_mutations: &[EventGraphMutation],
) -> Result<(), String> {
    for mutation in staged_event_graph_mutations {
        match mutation {
            EventGraphMutation::Append(record) => {
                if state
                    .event_runtime_records
                    .iter()
                    .any(|existing| existing.record_id == record.record_id)
                {
                    return Err(format!(
                        "cannot append duplicate event record_id {}",
                        record.record_id
                    ));
                }
                state
                    .event_runtime_records
                    .push(record.clone().into_runtime_record());
            }
            EventGraphMutation::Activate { record_id } => {
                let record = state
                    .event_runtime_records
                    .iter_mut()
                    .find(|record| record.record_id == *record_id)
                    .ok_or_else(|| {
                        format!("cannot activate missing event record_id {record_id}")
                    })?;
                record.active = true;
            }
            EventGraphMutation::Deactivate { record_id } => {
                let record = state
                    .event_runtime_records
                    .iter_mut()
                    .find(|record| record.record_id == *record_id)
                    .ok_or_else(|| {
                        format!("cannot deactivate missing event record_id {record_id}")
                    })?;
                record.active = false;
            }
            EventGraphMutation::Remove { record_id } => {
                let index = state
                    .event_runtime_records
                    .iter()
                    .position(|record| record.record_id == *record_id)
                    .ok_or_else(|| format!("cannot remove missing event record_id {record_id}"))?;
                state.event_runtime_records.remove(index);
            }
        }
    }

    state.validate()
}

fn evaluate_record_conditions(
    state: &RuntimeState,
    conditions: &[RuntimeCondition],
) -> Result<Option<ResolvedConditionContext>, String> {
    if conditions.is_empty() {
        return Ok(Some(ResolvedConditionContext::default()));
    }

    let mut company_matches: Option<BTreeSet<u32>> = None;

    for condition in conditions {
        match condition {
            RuntimeCondition::CompanyNumericThreshold {
                target,
                metric,
                comparator,
                value,
            } => {
                let resolved = resolve_company_target_ids(
                    state,
                    target,
                    &ResolvedConditionContext::default(),
                )?;
                let matching = resolved
                    .into_iter()
                    .filter(|company_id| {
                        state
                            .companies
                            .iter()
                            .find(|company| company.company_id == *company_id)
                            .is_some_and(|company| {
                                compare_condition_value(
                                    company_metric_value(company, *metric),
                                    *comparator,
                                    *value,
                                )
                            })
                    })
                    .collect::<BTreeSet<_>>();
                if matching.is_empty() {
                    return Ok(None);
                }
                intersect_company_matches(&mut company_matches, matching);
                if company_matches.as_ref().is_some_and(BTreeSet::is_empty) {
                    return Ok(None);
                }
            }
            RuntimeCondition::TerritoryNumericThreshold {
                target,
                metric,
                comparator,
                value,
            } => {
                let territory_ids = resolve_territory_target_ids(state, target)?;
                let actual = territory_metric_value(state, &territory_ids, *metric);
                if !compare_condition_value(actual, *comparator, *value) {
                    return Ok(None);
                }
            }
            RuntimeCondition::CompanyTerritoryNumericThreshold {
                target,
                territory,
                metric,
                comparator,
                value,
            } => {
                let territory_ids = resolve_territory_target_ids(state, territory)?;
                let resolved = resolve_company_target_ids(
                    state,
                    target,
                    &ResolvedConditionContext::default(),
                )?;
                let matching = resolved
                    .into_iter()
                    .filter(|company_id| {
                        compare_condition_value(
                            company_territory_metric_value(
                                state,
                                *company_id,
                                &territory_ids,
                                *metric,
                            ),
                            *comparator,
                            *value,
                        )
                    })
                    .collect::<BTreeSet<_>>();
                if matching.is_empty() {
                    return Ok(None);
                }
                intersect_company_matches(&mut company_matches, matching);
                if company_matches.as_ref().is_some_and(BTreeSet::is_empty) {
                    return Ok(None);
                }
            }
        }
    }

    Ok(Some(ResolvedConditionContext {
        matching_company_ids: company_matches.unwrap_or_default(),
        matching_player_ids: BTreeSet::new(),
    }))
}

fn intersect_company_matches(company_matches: &mut Option<BTreeSet<u32>>, next: BTreeSet<u32>) {
    match company_matches {
        Some(existing) => {
            existing.retain(|company_id| next.contains(company_id));
        }
        None => {
            *company_matches = Some(next);
        }
    }
}

fn resolve_company_target_ids(
    state: &RuntimeState,
    target: &RuntimeCompanyTarget,
    condition_context: &ResolvedConditionContext,
) -> Result<Vec<u32>, String> {
    match target {
        RuntimeCompanyTarget::AllActive => Ok(state
            .companies
            .iter()
            .filter(|company| company.active)
            .map(|company| company.company_id)
            .collect()),
        RuntimeCompanyTarget::Ids { ids } => {
            let known_ids = state
                .companies
                .iter()
                .map(|company| company.company_id)
                .collect::<BTreeSet<_>>();
            for company_id in ids {
                if !known_ids.contains(company_id) {
                    return Err(format!("target references unknown company_id {company_id}"));
                }
            }
            Ok(ids.clone())
        }
        RuntimeCompanyTarget::HumanCompanies => {
            if state
                .companies
                .iter()
                .any(|company| company.controller_kind == RuntimeCompanyControllerKind::Unknown)
            {
                return Err(
                    "target requires company role context but at least one company has unknown controller_kind"
                        .to_string(),
                );
            }
            Ok(state
                .companies
                .iter()
                .filter(|company| {
                    company.active && company.controller_kind == RuntimeCompanyControllerKind::Human
                })
                .map(|company| company.company_id)
                .collect())
        }
        RuntimeCompanyTarget::AiCompanies => {
            if state
                .companies
                .iter()
                .any(|company| company.controller_kind == RuntimeCompanyControllerKind::Unknown)
            {
                return Err(
                    "target requires company role context but at least one company has unknown controller_kind"
                        .to_string(),
                );
            }
            Ok(state
                .companies
                .iter()
                .filter(|company| {
                    company.active && company.controller_kind == RuntimeCompanyControllerKind::Ai
                })
                .map(|company| company.company_id)
                .collect())
        }
        RuntimeCompanyTarget::SelectedCompany => {
            let selected_company_id = state
                .selected_company_id
                .ok_or_else(|| "target requires selected_company_id context".to_string())?;
            if state
                .companies
                .iter()
                .any(|company| company.company_id == selected_company_id && company.active)
            {
                Ok(vec![selected_company_id])
            } else {
                Err(
                    "target requires selected_company_id to reference an active company"
                        .to_string(),
                )
            }
        }
        RuntimeCompanyTarget::ConditionTrueCompany => {
            if condition_context.matching_company_ids.is_empty() {
                Err("target requires condition-evaluation context".to_string())
            } else {
                Ok(condition_context
                    .matching_company_ids
                    .iter()
                    .copied()
                    .collect())
            }
        }
    }
}

fn resolve_player_target_ids(
    state: &RuntimeState,
    target: &RuntimePlayerTarget,
    condition_context: &ResolvedConditionContext,
) -> Result<Vec<u32>, String> {
    match target {
        RuntimePlayerTarget::AllActive => Ok(state
            .players
            .iter()
            .filter(|player| player.active)
            .map(|player| player.player_id)
            .collect()),
        RuntimePlayerTarget::Ids { ids } => {
            let known_ids = state
                .players
                .iter()
                .map(|player| player.player_id)
                .collect::<BTreeSet<_>>();
            for player_id in ids {
                if !known_ids.contains(player_id) {
                    return Err(format!("target references unknown player_id {player_id}"));
                }
            }
            Ok(ids.clone())
        }
        RuntimePlayerTarget::HumanPlayers => {
            if state
                .players
                .iter()
                .any(|player| player.controller_kind == RuntimeCompanyControllerKind::Unknown)
            {
                return Err(
                    "target requires player role context but at least one player has unknown controller_kind"
                        .to_string(),
                );
            }
            Ok(state
                .players
                .iter()
                .filter(|player| {
                    player.active && player.controller_kind == RuntimeCompanyControllerKind::Human
                })
                .map(|player| player.player_id)
                .collect())
        }
        RuntimePlayerTarget::AiPlayers => {
            if state
                .players
                .iter()
                .any(|player| player.controller_kind == RuntimeCompanyControllerKind::Unknown)
            {
                return Err(
                    "target requires player role context but at least one player has unknown controller_kind"
                        .to_string(),
                );
            }
            Ok(state
                .players
                .iter()
                .filter(|player| {
                    player.active && player.controller_kind == RuntimeCompanyControllerKind::Ai
                })
                .map(|player| player.player_id)
                .collect())
        }
        RuntimePlayerTarget::SelectedPlayer => {
            let selected_player_id = state
                .selected_player_id
                .ok_or_else(|| "target requires selected_player_id context".to_string())?;
            if state
                .players
                .iter()
                .any(|player| player.player_id == selected_player_id && player.active)
            {
                Ok(vec![selected_player_id])
            } else {
                Err("target requires selected_player_id to reference an active player".to_string())
            }
        }
        RuntimePlayerTarget::ConditionTruePlayer => {
            if condition_context.matching_player_ids.is_empty() {
                Err("target requires player condition-evaluation context".to_string())
            } else {
                Ok(condition_context
                    .matching_player_ids
                    .iter()
                    .copied()
                    .collect())
            }
        }
    }
}

fn resolve_territory_target_ids(
    state: &RuntimeState,
    target: &RuntimeTerritoryTarget,
) -> Result<Vec<u32>, String> {
    match target {
        RuntimeTerritoryTarget::AllTerritories => Ok(state
            .territories
            .iter()
            .map(|territory| territory.territory_id)
            .collect()),
        RuntimeTerritoryTarget::Ids { ids } => {
            let known_ids = state
                .territories
                .iter()
                .map(|territory| territory.territory_id)
                .collect::<BTreeSet<_>>();
            for territory_id in ids {
                if !known_ids.contains(territory_id) {
                    return Err(format!(
                        "territory target references unknown territory_id {territory_id}"
                    ));
                }
            }
            Ok(ids.clone())
        }
    }
}

fn company_metric_value(company: &crate::RuntimeCompany, metric: RuntimeCompanyMetric) -> i64 {
    match metric {
        RuntimeCompanyMetric::CurrentCash => company.current_cash,
        RuntimeCompanyMetric::TotalDebt => company.debt as i64,
        RuntimeCompanyMetric::CreditRating => company.credit_rating_score.unwrap_or(0),
        RuntimeCompanyMetric::PrimeRate => company.prime_rate.unwrap_or(0),
        RuntimeCompanyMetric::TrackPiecesTotal => i64::from(company.track_piece_counts.total),
        RuntimeCompanyMetric::TrackPiecesSingle => i64::from(company.track_piece_counts.single),
        RuntimeCompanyMetric::TrackPiecesDouble => i64::from(company.track_piece_counts.double),
        RuntimeCompanyMetric::TrackPiecesTransition => {
            i64::from(company.track_piece_counts.transition)
        }
        RuntimeCompanyMetric::TrackPiecesElectric => i64::from(company.track_piece_counts.electric),
        RuntimeCompanyMetric::TrackPiecesNonElectric => {
            i64::from(company.track_piece_counts.non_electric)
        }
    }
}

fn territory_metric_value(
    state: &RuntimeState,
    territory_ids: &[u32],
    metric: RuntimeTerritoryMetric,
) -> i64 {
    state
        .territories
        .iter()
        .filter(|territory| territory_ids.contains(&territory.territory_id))
        .map(|territory| {
            track_piece_metric_value(
                territory.track_piece_counts,
                territory_metric_to_track_metric(metric),
            )
        })
        .sum()
}

fn company_territory_metric_value(
    state: &RuntimeState,
    company_id: u32,
    territory_ids: &[u32],
    metric: RuntimeTrackMetric,
) -> i64 {
    state
        .company_territory_track_piece_counts
        .iter()
        .filter(|entry| {
            entry.company_id == company_id && territory_ids.contains(&entry.territory_id)
        })
        .map(|entry| track_piece_metric_value(entry.track_piece_counts, metric))
        .sum()
}

fn track_piece_metric_value(counts: RuntimeTrackPieceCounts, metric: RuntimeTrackMetric) -> i64 {
    match metric {
        RuntimeTrackMetric::Total => i64::from(counts.total),
        RuntimeTrackMetric::Single => i64::from(counts.single),
        RuntimeTrackMetric::Double => i64::from(counts.double),
        RuntimeTrackMetric::Transition => i64::from(counts.transition),
        RuntimeTrackMetric::Electric => i64::from(counts.electric),
        RuntimeTrackMetric::NonElectric => i64::from(counts.non_electric),
    }
}

fn territory_metric_to_track_metric(metric: RuntimeTerritoryMetric) -> RuntimeTrackMetric {
    match metric {
        RuntimeTerritoryMetric::TrackPiecesTotal => RuntimeTrackMetric::Total,
        RuntimeTerritoryMetric::TrackPiecesSingle => RuntimeTrackMetric::Single,
        RuntimeTerritoryMetric::TrackPiecesDouble => RuntimeTrackMetric::Double,
        RuntimeTerritoryMetric::TrackPiecesTransition => RuntimeTrackMetric::Transition,
        RuntimeTerritoryMetric::TrackPiecesElectric => RuntimeTrackMetric::Electric,
        RuntimeTerritoryMetric::TrackPiecesNonElectric => RuntimeTrackMetric::NonElectric,
    }
}

fn compare_condition_value(
    actual: i64,
    comparator: RuntimeConditionComparator,
    expected: i64,
) -> bool {
    match comparator {
        RuntimeConditionComparator::Ge => actual >= expected,
        RuntimeConditionComparator::Le => actual <= expected,
        RuntimeConditionComparator::Gt => actual > expected,
        RuntimeConditionComparator::Lt => actual < expected,
        RuntimeConditionComparator::Eq => actual == expected,
        RuntimeConditionComparator::Ne => actual != expected,
    }
}

fn apply_u64_delta(current: u64, delta: i64, company_id: u32) -> Result<u64, String> {
    if delta >= 0 {
        current
            .checked_add(delta as u64)
            .ok_or_else(|| format!("company_id {company_id} debt adjustment overflow"))
    } else {
        current
            .checked_sub(delta.unsigned_abs())
            .ok_or_else(|| format!("company_id {company_id} debt adjustment underflow"))
    }
}

fn retire_matching_trains(
    trains: &mut [crate::RuntimeTrain],
    company_ids: Option<&Vec<u32>>,
    territory_ids: Option<&Vec<u32>>,
    locomotive_name: Option<&str>,
) {
    for train in trains.iter_mut() {
        if !train.active || train.retired {
            continue;
        }
        if company_ids.is_some_and(|company_ids| !company_ids.contains(&train.owner_company_id)) {
            continue;
        }
        if territory_ids.is_some_and(|territory_ids| {
            !train
                .territory_id
                .is_some_and(|territory_id| territory_ids.contains(&territory_id))
        }) {
            continue;
        }
        if locomotive_name.is_some_and(|name| train.locomotive_name.as_deref() != Some(name)) {
            continue;
        }
        train.active = false;
        train.retired = true;
    }
}

fn set_company_territory_access_pairs(
    access_entries: &mut Vec<crate::RuntimeCompanyTerritoryAccess>,
    company_ids: &[u32],
    territory_ids: &[u32],
    value: bool,
) {
    if value {
        for company_id in company_ids {
            for territory_id in territory_ids {
                if !access_entries.iter().any(|entry| {
                    entry.company_id == *company_id && entry.territory_id == *territory_id
                }) {
                    access_entries.push(crate::RuntimeCompanyTerritoryAccess {
                        company_id: *company_id,
                        territory_id: *territory_id,
                    });
                }
            }
        }
    } else {
        access_entries.retain(|entry| {
            !(company_ids.contains(&entry.company_id) && territory_ids.contains(&entry.territory_id))
        });
    }
}

#[cfg(test)]
mod tests {
    use std::collections::BTreeMap;

    use super::*;
    use crate::{
        CalendarPoint, RuntimeCompany, RuntimeCompanyControllerKind, RuntimeCompanyTarget,
        RuntimeEffect, RuntimeEventRecord, RuntimeEventRecordTemplate, RuntimeSaveProfileState,
        RuntimeServiceState, RuntimeTerritory, RuntimeTerritoryTarget, RuntimeTrackPieceCounts,
        RuntimeTrain, RuntimeWorldRestoreState,
    };

    fn state() -> RuntimeState {
        RuntimeState {
            calendar: CalendarPoint {
                year: 1830,
                month_slot: 0,
                phase_slot: 0,
                tick_slot: 0,
            },
            world_flags: BTreeMap::new(),
            save_profile: RuntimeSaveProfileState::default(),
            world_restore: RuntimeWorldRestoreState::default(),
            metadata: BTreeMap::new(),
            companies: vec![RuntimeCompany {
                company_id: 1,
                controller_kind: RuntimeCompanyControllerKind::Unknown,
                current_cash: 10,
                debt: 0,
                credit_rating_score: None,
                prime_rate: None,
                track_piece_counts: RuntimeTrackPieceCounts::default(),
                active: true,
                available_track_laying_capacity: None,
            }],
            selected_company_id: None,
            players: Vec::new(),
            selected_player_id: None,
            trains: Vec::new(),
            territories: Vec::new(),
            company_territory_track_piece_counts: Vec::new(),
            company_territory_access: Vec::new(),
            packed_event_collection: None,
            event_runtime_records: Vec::new(),
            candidate_availability: BTreeMap::new(),
            special_conditions: BTreeMap::new(),
            service_state: RuntimeServiceState::default(),
        }
    }

    #[test]
    fn advances_to_target() {
        let mut state = state();
        let result = execute_step_command(
            &mut state,
            &StepCommand::AdvanceTo {
                calendar: CalendarPoint {
                    year: 1830,
                    month_slot: 0,
                    phase_slot: 0,
                    tick_slot: 5,
                },
            },
        )
        .expect("advance_to should succeed");

        assert_eq!(result.steps_executed, 5);
        assert_eq!(state.calendar.tick_slot, 5);
    }

    #[test]
    fn rejects_backward_target() {
        let mut state = state();
        state.calendar.tick_slot = 3;

        let result = execute_step_command(
            &mut state,
            &StepCommand::AdvanceTo {
                calendar: CalendarPoint {
                    year: 1830,
                    month_slot: 0,
                    phase_slot: 0,
                    tick_slot: 2,
                },
            },
        );

        assert!(result.is_err());
    }

    #[test]
    fn services_periodic_trigger_order_and_dirty_rerun() {
        let mut state = RuntimeState {
            event_runtime_records: vec![
                RuntimeEventRecord {
                    record_id: 1,
                    trigger_kind: 1,
                    active: true,
                    service_count: 0,
                    marks_collection_dirty: true,
                    one_shot: false,
                    has_fired: false,
                    conditions: Vec::new(),
                    effects: vec![RuntimeEffect::SetWorldFlag {
                        key: "runtime.effect_fired".to_string(),
                        value: true,
                    }],
                },
                RuntimeEventRecord {
                    record_id: 2,
                    trigger_kind: 4,
                    active: true,
                    service_count: 0,
                    marks_collection_dirty: false,
                    one_shot: false,
                    has_fired: false,
                    conditions: Vec::new(),
                    effects: vec![RuntimeEffect::AdjustCompanyCash {
                        target: RuntimeCompanyTarget::AllActive,
                        delta: 5,
                    }],
                },
                RuntimeEventRecord {
                    record_id: 3,
                    trigger_kind: 0x0a,
                    active: true,
                    service_count: 0,
                    marks_collection_dirty: false,
                    one_shot: false,
                    has_fired: false,
                    conditions: Vec::new(),
                    effects: vec![RuntimeEffect::SetSpecialCondition {
                        label: "Dirty rerun fired".to_string(),
                        value: 1,
                    }],
                },
            ],
            ..state()
        };

        let result = execute_step_command(&mut state, &StepCommand::ServicePeriodicBoundary)
            .expect("periodic boundary service should succeed");

        assert_eq!(result.steps_executed, 0);
        assert_eq!(state.service_state.periodic_boundary_calls, 1);
        assert_eq!(state.service_state.total_event_record_services, 3);
        assert_eq!(state.service_state.dirty_rerun_count, 1);
        assert_eq!(state.event_runtime_records[0].service_count, 1);
        assert_eq!(state.event_runtime_records[1].service_count, 1);
        assert_eq!(state.event_runtime_records[2].service_count, 1);
        assert_eq!(state.world_flags.get("runtime.effect_fired"), Some(&true));
        assert_eq!(state.companies[0].current_cash, 15);
        assert_eq!(state.special_conditions.get("Dirty rerun fired"), Some(&1));
        assert_eq!(
            state.service_state.trigger_dispatch_counts.get(&1),
            Some(&1)
        );
        assert_eq!(
            state.service_state.trigger_dispatch_counts.get(&4),
            Some(&1)
        );
        assert_eq!(
            state.service_state.trigger_dispatch_counts.get(&0x0a),
            Some(&1)
        );
        assert_eq!(result.service_events.len(), 7);
        assert_eq!(result.service_events[0].applied_effect_count, 1);
        assert_eq!(
            result
                .service_events
                .iter()
                .find(|event| event.trigger_kind == Some(4))
                .expect("trigger kind 4 event should be present")
                .applied_effect_count,
            1
        );
        assert_eq!(
            result
                .service_events
                .iter()
                .find(|event| event.trigger_kind == Some(0x0a))
                .expect("trigger kind 0x0a event should be present")
                .applied_effect_count,
            1
        );
        assert_eq!(
            result
                .service_events
                .iter()
                .find(|event| event.trigger_kind == Some(4))
                .expect("trigger kind 4 event should be present")
                .mutated_company_ids,
            vec![1]
        );
    }

    #[test]
    fn applies_company_effects_for_specific_targets() {
        let mut state = RuntimeState {
            companies: vec![
                RuntimeCompany {
                    company_id: 1,
                    controller_kind: RuntimeCompanyControllerKind::Unknown,
                    current_cash: 10,
                    debt: 5,
                    credit_rating_score: None,
                    prime_rate: None,
                    track_piece_counts: RuntimeTrackPieceCounts::default(),
                    active: true,
                    available_track_laying_capacity: None,
                },
                RuntimeCompany {
                    company_id: 2,
                    controller_kind: RuntimeCompanyControllerKind::Unknown,
                    current_cash: 20,
                    debt: 8,
                    credit_rating_score: None,
                    prime_rate: None,
                    track_piece_counts: RuntimeTrackPieceCounts::default(),
                    active: true,
                    available_track_laying_capacity: None,
                },
            ],
            event_runtime_records: vec![RuntimeEventRecord {
                record_id: 10,
                trigger_kind: 7,
                active: true,
                service_count: 0,
                marks_collection_dirty: false,
                one_shot: false,
                has_fired: false,
                conditions: Vec::new(),
                effects: vec![
                    RuntimeEffect::AdjustCompanyCash {
                        target: RuntimeCompanyTarget::Ids { ids: vec![2] },
                        delta: 4,
                    },
                    RuntimeEffect::AdjustCompanyDebt {
                        target: RuntimeCompanyTarget::Ids { ids: vec![2] },
                        delta: -3,
                    },
                ],
            }],
            ..state()
        };

        let result = execute_step_command(
            &mut state,
            &StepCommand::ServiceTriggerKind { trigger_kind: 7 },
        )
        .expect("targeted company effects should succeed");

        assert_eq!(state.companies[0].current_cash, 10);
        assert_eq!(state.companies[1].current_cash, 24);
        assert_eq!(state.companies[1].debt, 5);
        assert_eq!(result.service_events[0].applied_effect_count, 2);
        assert_eq!(result.service_events[0].mutated_company_ids, vec![2]);
    }

    #[test]
    fn resolves_symbolic_company_targets() {
        let mut state = RuntimeState {
            companies: vec![
                RuntimeCompany {
                    company_id: 1,
                    controller_kind: RuntimeCompanyControllerKind::Human,
                    current_cash: 10,
                    debt: 0,
                    credit_rating_score: None,
                    prime_rate: None,
                    track_piece_counts: RuntimeTrackPieceCounts::default(),
                    active: true,
                    available_track_laying_capacity: None,
                },
                RuntimeCompany {
                    company_id: 2,
                    controller_kind: RuntimeCompanyControllerKind::Ai,
                    current_cash: 20,
                    debt: 2,
                    credit_rating_score: None,
                    prime_rate: None,
                    track_piece_counts: RuntimeTrackPieceCounts::default(),
                    active: true,
                    available_track_laying_capacity: None,
                },
            ],
            selected_company_id: Some(1),
            event_runtime_records: vec![
                RuntimeEventRecord {
                    record_id: 11,
                    trigger_kind: 7,
                    active: true,
                    service_count: 0,
                    marks_collection_dirty: false,
                    one_shot: false,
                    has_fired: false,
                    conditions: Vec::new(),
                    effects: vec![RuntimeEffect::AdjustCompanyCash {
                        target: RuntimeCompanyTarget::HumanCompanies,
                        delta: 5,
                    }],
                },
                RuntimeEventRecord {
                    record_id: 12,
                    trigger_kind: 7,
                    active: true,
                    service_count: 0,
                    marks_collection_dirty: false,
                    one_shot: false,
                    has_fired: false,
                    conditions: Vec::new(),
                    effects: vec![RuntimeEffect::AdjustCompanyDebt {
                        target: RuntimeCompanyTarget::AiCompanies,
                        delta: 3,
                    }],
                },
                RuntimeEventRecord {
                    record_id: 13,
                    trigger_kind: 7,
                    active: true,
                    service_count: 0,
                    marks_collection_dirty: false,
                    one_shot: false,
                    has_fired: false,
                    conditions: Vec::new(),
                    effects: vec![RuntimeEffect::AdjustCompanyCash {
                        target: RuntimeCompanyTarget::SelectedCompany,
                        delta: 7,
                    }],
                },
            ],
            ..state()
        };

        let result = execute_step_command(
            &mut state,
            &StepCommand::ServiceTriggerKind { trigger_kind: 7 },
        )
        .expect("symbolic target effects should succeed");

        assert_eq!(state.companies[0].current_cash, 22);
        assert_eq!(state.companies[0].debt, 0);
        assert_eq!(state.companies[1].current_cash, 20);
        assert_eq!(state.companies[1].debt, 5);
        assert_eq!(result.service_events[0].mutated_company_ids, vec![1, 2]);
    }

    #[test]
    fn rejects_selected_company_target_without_selection_context() {
        let mut state = RuntimeState {
            event_runtime_records: vec![RuntimeEventRecord {
                record_id: 14,
                trigger_kind: 7,
                active: true,
                service_count: 0,
                marks_collection_dirty: false,
                one_shot: false,
                has_fired: false,
                conditions: Vec::new(),
                effects: vec![RuntimeEffect::AdjustCompanyCash {
                    target: RuntimeCompanyTarget::SelectedCompany,
                    delta: 1,
                }],
            }],
            ..state()
        };

        let error = execute_step_command(
            &mut state,
            &StepCommand::ServiceTriggerKind { trigger_kind: 7 },
        )
        .expect_err("selected company target should require selection context");

        assert!(error.contains("selected_company_id"));
    }

    #[test]
    fn rejects_human_or_ai_targets_without_role_context() {
        let mut state = RuntimeState {
            event_runtime_records: vec![RuntimeEventRecord {
                record_id: 15,
                trigger_kind: 7,
                active: true,
                service_count: 0,
                marks_collection_dirty: false,
                one_shot: false,
                has_fired: false,
                conditions: Vec::new(),
                effects: vec![RuntimeEffect::AdjustCompanyCash {
                    target: RuntimeCompanyTarget::HumanCompanies,
                    delta: 1,
                }],
            }],
            ..state()
        };

        let error = execute_step_command(
            &mut state,
            &StepCommand::ServiceTriggerKind { trigger_kind: 7 },
        )
        .expect_err("human target should require controller metadata");

        assert!(error.contains("controller_kind"));
    }

    #[test]
    fn all_active_and_role_targets_exclude_inactive_companies() {
        let mut state = RuntimeState {
            companies: vec![
                RuntimeCompany {
                    company_id: 1,
                    controller_kind: RuntimeCompanyControllerKind::Human,
                    current_cash: 10,
                    debt: 1,
                    credit_rating_score: None,
                    prime_rate: None,
                    track_piece_counts: RuntimeTrackPieceCounts::default(),
                    active: true,
                    available_track_laying_capacity: None,
                },
                RuntimeCompany {
                    company_id: 2,
                    controller_kind: RuntimeCompanyControllerKind::Human,
                    current_cash: 20,
                    debt: 2,
                    credit_rating_score: None,
                    prime_rate: None,
                    track_piece_counts: RuntimeTrackPieceCounts::default(),
                    active: false,
                    available_track_laying_capacity: None,
                },
                RuntimeCompany {
                    company_id: 3,
                    controller_kind: RuntimeCompanyControllerKind::Ai,
                    current_cash: 30,
                    debt: 3,
                    credit_rating_score: None,
                    prime_rate: None,
                    track_piece_counts: RuntimeTrackPieceCounts::default(),
                    active: true,
                    available_track_laying_capacity: None,
                },
            ],
            event_runtime_records: vec![
                RuntimeEventRecord {
                    record_id: 16,
                    trigger_kind: 7,
                    active: true,
                    service_count: 0,
                    marks_collection_dirty: false,
                    one_shot: false,
                    has_fired: false,
                    conditions: Vec::new(),
                    effects: vec![RuntimeEffect::AdjustCompanyCash {
                        target: RuntimeCompanyTarget::AllActive,
                        delta: 5,
                    }],
                },
                RuntimeEventRecord {
                    record_id: 17,
                    trigger_kind: 7,
                    active: true,
                    service_count: 0,
                    marks_collection_dirty: false,
                    one_shot: false,
                    has_fired: false,
                    conditions: Vec::new(),
                    effects: vec![RuntimeEffect::AdjustCompanyDebt {
                        target: RuntimeCompanyTarget::HumanCompanies,
                        delta: 4,
                    }],
                },
                RuntimeEventRecord {
                    record_id: 18,
                    trigger_kind: 7,
                    active: true,
                    service_count: 0,
                    marks_collection_dirty: false,
                    one_shot: false,
                    has_fired: false,
                    conditions: Vec::new(),
                    effects: vec![RuntimeEffect::AdjustCompanyDebt {
                        target: RuntimeCompanyTarget::AiCompanies,
                        delta: 6,
                    }],
                },
            ],
            ..state()
        };

        execute_step_command(
            &mut state,
            &StepCommand::ServiceTriggerKind { trigger_kind: 7 },
        )
        .expect("active-company filtering should succeed");

        assert_eq!(state.companies[0].current_cash, 15);
        assert_eq!(state.companies[1].current_cash, 20);
        assert_eq!(state.companies[2].current_cash, 35);
        assert_eq!(state.companies[0].debt, 5);
        assert_eq!(state.companies[1].debt, 2);
        assert_eq!(state.companies[2].debt, 9);
    }

    #[test]
    fn deactivating_selected_company_clears_selection() {
        let mut state = RuntimeState {
            companies: vec![RuntimeCompany {
                company_id: 1,
                controller_kind: RuntimeCompanyControllerKind::Human,
                current_cash: 10,
                debt: 0,
                credit_rating_score: None,
                prime_rate: None,
                track_piece_counts: RuntimeTrackPieceCounts::default(),
                active: true,
                available_track_laying_capacity: Some(8),
            }],
            selected_company_id: Some(1),
            event_runtime_records: vec![RuntimeEventRecord {
                record_id: 19,
                trigger_kind: 7,
                active: true,
                service_count: 0,
                marks_collection_dirty: false,
                one_shot: false,
                has_fired: false,
                conditions: Vec::new(),
                effects: vec![RuntimeEffect::DeactivateCompany {
                    target: RuntimeCompanyTarget::SelectedCompany,
                }],
            }],
            ..state()
        };

        let result = execute_step_command(
            &mut state,
            &StepCommand::ServiceTriggerKind { trigger_kind: 7 },
        )
        .expect("deactivate company effect should succeed");

        assert!(!state.companies[0].active);
        assert_eq!(state.selected_company_id, None);
        assert_eq!(result.service_events[0].mutated_company_ids, vec![1]);
    }

    #[test]
    fn sets_track_laying_capacity_for_resolved_targets() {
        let mut state = RuntimeState {
            companies: vec![
                RuntimeCompany {
                    company_id: 1,
                    controller_kind: RuntimeCompanyControllerKind::Human,
                    current_cash: 10,
                    debt: 0,
                    credit_rating_score: None,
                    prime_rate: None,
                    track_piece_counts: RuntimeTrackPieceCounts::default(),
                    active: true,
                    available_track_laying_capacity: None,
                },
                RuntimeCompany {
                    company_id: 2,
                    controller_kind: RuntimeCompanyControllerKind::Ai,
                    current_cash: 20,
                    debt: 0,
                    credit_rating_score: None,
                    prime_rate: None,
                    track_piece_counts: RuntimeTrackPieceCounts::default(),
                    active: true,
                    available_track_laying_capacity: None,
                },
            ],
            event_runtime_records: vec![RuntimeEventRecord {
                record_id: 20,
                trigger_kind: 7,
                active: true,
                service_count: 0,
                marks_collection_dirty: false,
                one_shot: false,
                has_fired: false,
                conditions: Vec::new(),
                effects: vec![RuntimeEffect::SetCompanyTrackLayingCapacity {
                    target: RuntimeCompanyTarget::Ids { ids: vec![2] },
                    value: Some(14),
                }],
            }],
            ..state()
        };

        let result = execute_step_command(
            &mut state,
            &StepCommand::ServiceTriggerKind { trigger_kind: 7 },
        )
        .expect("track capacity effect should succeed");

        assert_eq!(state.companies[0].available_track_laying_capacity, None);
        assert_eq!(state.companies[1].available_track_laying_capacity, Some(14));
        assert_eq!(result.service_events[0].mutated_company_ids, vec![2]);
    }

    #[test]
    fn sets_and_clears_company_territory_access_for_resolved_targets() {
        let mut state = RuntimeState {
            companies: vec![
                RuntimeCompany {
                    company_id: 1,
                    controller_kind: RuntimeCompanyControllerKind::Human,
                    current_cash: 10,
                    debt: 0,
                    credit_rating_score: None,
                    prime_rate: None,
                    track_piece_counts: RuntimeTrackPieceCounts::default(),
                    active: true,
                    available_track_laying_capacity: None,
                },
                RuntimeCompany {
                    company_id: 2,
                    controller_kind: RuntimeCompanyControllerKind::Ai,
                    current_cash: 20,
                    debt: 0,
                    credit_rating_score: None,
                    prime_rate: None,
                    track_piece_counts: RuntimeTrackPieceCounts::default(),
                    active: true,
                    available_track_laying_capacity: None,
                },
            ],
            territories: vec![
                RuntimeTerritory {
                    territory_id: 7,
                    name: Some("Appalachia".to_string()),
                    track_piece_counts: RuntimeTrackPieceCounts::default(),
                },
                RuntimeTerritory {
                    territory_id: 8,
                    name: Some("Great Plains".to_string()),
                    track_piece_counts: RuntimeTrackPieceCounts::default(),
                },
            ],
            event_runtime_records: vec![
                RuntimeEventRecord {
                    record_id: 21,
                    trigger_kind: 7,
                    active: true,
                    service_count: 0,
                    marks_collection_dirty: false,
                    one_shot: true,
                    has_fired: false,
                    conditions: Vec::new(),
                    effects: vec![RuntimeEffect::SetCompanyTerritoryAccess {
                        target: RuntimeCompanyTarget::SelectedCompany,
                        territory: RuntimeTerritoryTarget::Ids { ids: vec![7, 8] },
                        value: true,
                    }],
                },
                RuntimeEventRecord {
                    record_id: 22,
                    trigger_kind: 8,
                    active: true,
                    service_count: 0,
                    marks_collection_dirty: false,
                    one_shot: true,
                    has_fired: false,
                    conditions: Vec::new(),
                    effects: vec![RuntimeEffect::SetCompanyTerritoryAccess {
                        target: RuntimeCompanyTarget::SelectedCompany,
                        territory: RuntimeTerritoryTarget::Ids { ids: vec![8] },
                        value: false,
                    }],
                },
            ],
            selected_company_id: Some(1),
            ..state()
        };

        let first = execute_step_command(
            &mut state,
            &StepCommand::ServiceTriggerKind { trigger_kind: 7 },
        )
        .expect("territory access grant should succeed");

        assert_eq!(
            state.company_territory_access,
            vec![
                crate::RuntimeCompanyTerritoryAccess {
                    company_id: 1,
                    territory_id: 7,
                },
                crate::RuntimeCompanyTerritoryAccess {
                    company_id: 1,
                    territory_id: 8,
                },
            ]
        );
        assert_eq!(first.service_events[0].mutated_company_ids, vec![1]);

        execute_step_command(
            &mut state,
            &StepCommand::ServiceTriggerKind { trigger_kind: 8 },
        )
        .expect("territory access clear should succeed");

        assert_eq!(
            state.company_territory_access,
            vec![crate::RuntimeCompanyTerritoryAccess {
                company_id: 1,
                territory_id: 7,
            }]
        );
    }

    #[test]
    fn rejects_condition_true_company_target_without_condition_context() {
        let mut state = RuntimeState {
            event_runtime_records: vec![RuntimeEventRecord {
                record_id: 16,
                trigger_kind: 7,
                active: true,
                service_count: 0,
                marks_collection_dirty: false,
                one_shot: false,
                has_fired: false,
                conditions: Vec::new(),
                effects: vec![RuntimeEffect::AdjustCompanyCash {
                    target: RuntimeCompanyTarget::ConditionTrueCompany,
                    delta: 1,
                }],
            }],
            ..state()
        };

        let error = execute_step_command(
            &mut state,
            &StepCommand::ServiceTriggerKind { trigger_kind: 7 },
        )
        .expect_err("condition-relative target should remain blocked");

        assert!(error.contains("condition-evaluation context"));
    }

    #[test]
    fn one_shot_record_only_fires_once() {
        let mut state = RuntimeState {
            event_runtime_records: vec![RuntimeEventRecord {
                record_id: 20,
                trigger_kind: 2,
                active: true,
                service_count: 0,
                marks_collection_dirty: false,
                one_shot: true,
                has_fired: false,
                conditions: Vec::new(),
                effects: vec![RuntimeEffect::SetWorldFlag {
                    key: "one_shot".to_string(),
                    value: true,
                }],
            }],
            ..state()
        };

        execute_step_command(
            &mut state,
            &StepCommand::ServiceTriggerKind { trigger_kind: 2 },
        )
        .expect("first one-shot service should succeed");
        let second = execute_step_command(
            &mut state,
            &StepCommand::ServiceTriggerKind { trigger_kind: 2 },
        )
        .expect("second one-shot service should succeed");

        assert_eq!(state.event_runtime_records[0].service_count, 1);
        assert!(state.event_runtime_records[0].has_fired);
        assert_eq!(
            second.service_events[0].serviced_record_ids,
            Vec::<u32>::new()
        );
        assert_eq!(second.service_events[0].applied_effect_count, 0);
    }

    #[test]
    fn rejects_debt_underflow() {
        let mut state = RuntimeState {
            companies: vec![RuntimeCompany {
                company_id: 1,
                controller_kind: RuntimeCompanyControllerKind::Unknown,
                current_cash: 10,
                debt: 2,
                credit_rating_score: None,
                prime_rate: None,
                track_piece_counts: RuntimeTrackPieceCounts::default(),
                active: true,
                available_track_laying_capacity: None,
            }],
            event_runtime_records: vec![RuntimeEventRecord {
                record_id: 30,
                trigger_kind: 3,
                active: true,
                service_count: 0,
                marks_collection_dirty: false,
                one_shot: false,
                has_fired: false,
                conditions: Vec::new(),
                effects: vec![RuntimeEffect::AdjustCompanyDebt {
                    target: RuntimeCompanyTarget::AllActive,
                    delta: -3,
                }],
            }],
            ..state()
        };

        let result = execute_step_command(
            &mut state,
            &StepCommand::ServiceTriggerKind { trigger_kind: 3 },
        );

        assert!(result.is_err());
    }

    #[test]
    fn appended_record_waits_until_later_pass_without_dirty_rerun() {
        let mut state = RuntimeState {
            event_runtime_records: vec![RuntimeEventRecord {
                record_id: 40,
                trigger_kind: 5,
                active: true,
                service_count: 0,
                marks_collection_dirty: false,
                one_shot: true,
                has_fired: false,
                conditions: Vec::new(),
                effects: vec![RuntimeEffect::AppendEventRecord {
                    record: Box::new(RuntimeEventRecordTemplate {
                        record_id: 41,
                        trigger_kind: 5,
                        active: true,
                        marks_collection_dirty: false,
                        one_shot: false,
                        conditions: Vec::new(),
                        effects: vec![RuntimeEffect::SetWorldFlag {
                            key: "follow_on_later_pass".to_string(),
                            value: true,
                        }],
                    }),
                }],
            }],
            ..state()
        };

        let first = execute_step_command(
            &mut state,
            &StepCommand::ServiceTriggerKind { trigger_kind: 5 },
        )
        .expect("first pass should succeed");

        assert_eq!(first.service_events.len(), 1);
        assert_eq!(first.service_events[0].serviced_record_ids, vec![40]);
        assert_eq!(first.service_events[0].appended_record_ids, vec![41]);
        assert_eq!(state.world_flags.get("follow_on_later_pass"), None);
        assert_eq!(state.event_runtime_records.len(), 2);
        assert_eq!(state.event_runtime_records[1].service_count, 0);

        let second = execute_step_command(
            &mut state,
            &StepCommand::ServiceTriggerKind { trigger_kind: 5 },
        )
        .expect("second pass should succeed");

        assert_eq!(second.service_events[0].serviced_record_ids, vec![41]);
        assert_eq!(state.world_flags.get("follow_on_later_pass"), Some(&true));
        assert!(state.event_runtime_records[0].has_fired);
        assert_eq!(state.event_runtime_records[1].service_count, 1);
    }

    #[test]
    fn appended_record_runs_in_dirty_rerun_after_commit() {
        let mut state = RuntimeState {
            event_runtime_records: vec![RuntimeEventRecord {
                record_id: 50,
                trigger_kind: 1,
                active: true,
                service_count: 0,
                marks_collection_dirty: true,
                one_shot: false,
                has_fired: false,
                conditions: Vec::new(),
                effects: vec![RuntimeEffect::AppendEventRecord {
                    record: Box::new(RuntimeEventRecordTemplate {
                        record_id: 51,
                        trigger_kind: 0x0a,
                        active: true,
                        marks_collection_dirty: false,
                        one_shot: false,
                        conditions: Vec::new(),
                        effects: vec![RuntimeEffect::SetWorldFlag {
                            key: "dirty_rerun_follow_on".to_string(),
                            value: true,
                        }],
                    }),
                }],
            }],
            ..state()
        };

        let result = execute_step_command(
            &mut state,
            &StepCommand::ServiceTriggerKind { trigger_kind: 1 },
        )
        .expect("dirty rerun with follow-on should succeed");

        assert_eq!(result.service_events.len(), 2);
        assert_eq!(result.service_events[0].serviced_record_ids, vec![50]);
        assert_eq!(result.service_events[0].appended_record_ids, vec![51]);
        assert_eq!(result.service_events[1].trigger_kind, Some(0x0a));
        assert_eq!(result.service_events[1].serviced_record_ids, vec![51]);
        assert_eq!(state.service_state.dirty_rerun_count, 1);
        assert_eq!(state.event_runtime_records.len(), 2);
        assert_eq!(state.event_runtime_records[1].service_count, 1);
        assert_eq!(state.world_flags.get("dirty_rerun_follow_on"), Some(&true));
    }

    #[test]
    fn lifecycle_mutations_commit_between_passes() {
        let mut state = RuntimeState {
            event_runtime_records: vec![
                RuntimeEventRecord {
                    record_id: 60,
                    trigger_kind: 7,
                    active: true,
                    service_count: 0,
                    marks_collection_dirty: false,
                    one_shot: true,
                    has_fired: false,
                    conditions: Vec::new(),
                    effects: vec![
                        RuntimeEffect::AppendEventRecord {
                            record: Box::new(RuntimeEventRecordTemplate {
                                record_id: 64,
                                trigger_kind: 7,
                                active: true,
                                marks_collection_dirty: false,
                                one_shot: false,
                                conditions: Vec::new(),
                                effects: vec![RuntimeEffect::SetCandidateAvailability {
                                    name: "Appended Industry".to_string(),
                                    value: 1,
                                }],
                            }),
                        },
                        RuntimeEffect::DeactivateEventRecord { record_id: 61 },
                        RuntimeEffect::ActivateEventRecord { record_id: 62 },
                        RuntimeEffect::RemoveEventRecord { record_id: 63 },
                    ],
                },
                RuntimeEventRecord {
                    record_id: 61,
                    trigger_kind: 7,
                    active: true,
                    service_count: 0,
                    marks_collection_dirty: false,
                    one_shot: false,
                    has_fired: false,
                    conditions: Vec::new(),
                    effects: vec![RuntimeEffect::SetWorldFlag {
                        key: "deactivated_after_first_pass".to_string(),
                        value: true,
                    }],
                },
                RuntimeEventRecord {
                    record_id: 62,
                    trigger_kind: 7,
                    active: false,
                    service_count: 0,
                    marks_collection_dirty: false,
                    one_shot: false,
                    has_fired: false,
                    conditions: Vec::new(),
                    effects: vec![RuntimeEffect::SetSpecialCondition {
                        label: "Activated On Second Pass".to_string(),
                        value: 1,
                    }],
                },
                RuntimeEventRecord {
                    record_id: 63,
                    trigger_kind: 7,
                    active: true,
                    service_count: 0,
                    marks_collection_dirty: false,
                    one_shot: false,
                    has_fired: false,
                    conditions: Vec::new(),
                    effects: vec![RuntimeEffect::SetWorldFlag {
                        key: "removed_after_first_pass".to_string(),
                        value: true,
                    }],
                },
            ],
            ..state()
        };

        let first = execute_step_command(
            &mut state,
            &StepCommand::ServiceTriggerKind { trigger_kind: 7 },
        )
        .expect("first lifecycle pass should succeed");

        assert_eq!(
            first.service_events[0].serviced_record_ids,
            vec![60, 61, 63]
        );
        assert_eq!(first.service_events[0].appended_record_ids, vec![64]);
        assert_eq!(first.service_events[0].activated_record_ids, vec![62]);
        assert_eq!(first.service_events[0].deactivated_record_ids, vec![61]);
        assert_eq!(first.service_events[0].removed_record_ids, vec![63]);
        assert_eq!(
            state
                .event_runtime_records
                .iter()
                .map(|record| (record.record_id, record.active))
                .collect::<Vec<_>>(),
            vec![(60, true), (61, false), (62, true), (64, true)]
        );

        let second = execute_step_command(
            &mut state,
            &StepCommand::ServiceTriggerKind { trigger_kind: 7 },
        )
        .expect("second lifecycle pass should succeed");

        assert_eq!(second.service_events[0].serviced_record_ids, vec![62, 64]);
        assert_eq!(
            state.special_conditions.get("Activated On Second Pass"),
            Some(&1)
        );
        assert_eq!(
            state.candidate_availability.get("Appended Industry"),
            Some(&1)
        );
        assert_eq!(
            state.world_flags.get("deactivated_after_first_pass"),
            Some(&true)
        );
        assert_eq!(
            state.world_flags.get("removed_after_first_pass"),
            Some(&true)
        );
    }

    #[test]
    fn rejects_duplicate_appended_record_id() {
        let mut state = RuntimeState {
            event_runtime_records: vec![
                RuntimeEventRecord {
                    record_id: 70,
                    trigger_kind: 4,
                    active: true,
                    service_count: 0,
                    marks_collection_dirty: false,
                    one_shot: false,
                    has_fired: false,
                    conditions: Vec::new(),
                    effects: vec![RuntimeEffect::AppendEventRecord {
                        record: Box::new(RuntimeEventRecordTemplate {
                            record_id: 71,
                            trigger_kind: 4,
                            active: true,
                            marks_collection_dirty: false,
                            one_shot: false,
                            conditions: Vec::new(),
                            effects: Vec::new(),
                        }),
                    }],
                },
                RuntimeEventRecord {
                    record_id: 71,
                    trigger_kind: 4,
                    active: true,
                    service_count: 0,
                    marks_collection_dirty: false,
                    one_shot: false,
                    has_fired: false,
                    conditions: Vec::new(),
                    effects: Vec::new(),
                },
            ],
            ..state()
        };

        let result = execute_step_command(
            &mut state,
            &StepCommand::ServiceTriggerKind { trigger_kind: 4 },
        );

        assert!(result.is_err());
    }

    #[test]
    fn rejects_missing_lifecycle_mutation_target() {
        let mut state = RuntimeState {
            event_runtime_records: vec![RuntimeEventRecord {
                record_id: 80,
                trigger_kind: 6,
                active: true,
                service_count: 0,
                marks_collection_dirty: false,
                one_shot: false,
                has_fired: false,
                conditions: Vec::new(),
                effects: vec![RuntimeEffect::ActivateEventRecord { record_id: 999 }],
            }],
            ..state()
        };

        let result = execute_step_command(
            &mut state,
            &StepCommand::ServiceTriggerKind { trigger_kind: 6 },
        );

        assert!(result.is_err());
    }

    #[test]
    fn applies_economic_status_code_effect() {
        let mut state = RuntimeState {
            event_runtime_records: vec![RuntimeEventRecord {
                record_id: 90,
                trigger_kind: 6,
                active: true,
                service_count: 0,
                marks_collection_dirty: false,
                one_shot: false,
                has_fired: false,
                conditions: Vec::new(),
                effects: vec![RuntimeEffect::SetEconomicStatusCode { value: 3 }],
            }],
            ..state()
        };

        execute_step_command(
            &mut state,
            &StepCommand::ServiceTriggerKind { trigger_kind: 6 },
        )
        .expect("economic-status effect should succeed");

        assert_eq!(state.world_restore.economic_status_code, Some(3));
    }

    #[test]
    fn confiscate_company_assets_zeros_company_and_retires_owned_trains() {
        let mut state = RuntimeState {
            companies: vec![
                RuntimeCompany {
                    company_id: 1,
                    controller_kind: RuntimeCompanyControllerKind::Human,
                    current_cash: 50,
                    debt: 7,
                    credit_rating_score: None,
                    prime_rate: None,
                    track_piece_counts: RuntimeTrackPieceCounts::default(),
                    active: true,
                    available_track_laying_capacity: None,
                },
                RuntimeCompany {
                    company_id: 2,
                    controller_kind: RuntimeCompanyControllerKind::Ai,
                    current_cash: 80,
                    debt: 9,
                    credit_rating_score: None,
                    prime_rate: None,
                    track_piece_counts: RuntimeTrackPieceCounts::default(),
                    active: true,
                    available_track_laying_capacity: None,
                },
            ],
            selected_company_id: Some(1),
            trains: vec![
                RuntimeTrain {
                    train_id: 10,
                    owner_company_id: 1,
                    territory_id: None,
                    locomotive_name: Some("Mikado".to_string()),
                    active: true,
                    retired: false,
                },
                RuntimeTrain {
                    train_id: 11,
                    owner_company_id: 2,
                    territory_id: None,
                    locomotive_name: Some("Orca".to_string()),
                    active: true,
                    retired: false,
                },
            ],
            event_runtime_records: vec![RuntimeEventRecord {
                record_id: 91,
                trigger_kind: 6,
                active: true,
                service_count: 0,
                marks_collection_dirty: false,
                one_shot: false,
                has_fired: false,
                conditions: Vec::new(),
                effects: vec![RuntimeEffect::ConfiscateCompanyAssets {
                    target: RuntimeCompanyTarget::SelectedCompany,
                }],
            }],
            ..state()
        };

        execute_step_command(
            &mut state,
            &StepCommand::ServiceTriggerKind { trigger_kind: 6 },
        )
        .expect("confiscation effect should succeed");

        assert_eq!(state.companies[0].current_cash, 0);
        assert_eq!(state.companies[0].debt, 0);
        assert!(!state.companies[0].active);
        assert_eq!(state.selected_company_id, None);
        assert!(state.trains[0].retired);
        assert!(!state.trains[1].retired);
    }

    #[test]
    fn retire_trains_respects_company_territory_and_locomotive_filters() {
        let mut state = RuntimeState {
            territories: vec![
                RuntimeTerritory {
                    territory_id: 7,
                    name: Some("Appalachia".to_string()),
                    track_piece_counts: RuntimeTrackPieceCounts::default(),
                },
                RuntimeTerritory {
                    territory_id: 8,
                    name: Some("Great Plains".to_string()),
                    track_piece_counts: RuntimeTrackPieceCounts::default(),
                },
            ],
            trains: vec![
                RuntimeTrain {
                    train_id: 10,
                    owner_company_id: 1,
                    territory_id: Some(7),
                    locomotive_name: Some("Mikado".to_string()),
                    active: true,
                    retired: false,
                },
                RuntimeTrain {
                    train_id: 11,
                    owner_company_id: 1,
                    territory_id: Some(7),
                    locomotive_name: Some("Orca".to_string()),
                    active: true,
                    retired: false,
                },
                RuntimeTrain {
                    train_id: 12,
                    owner_company_id: 1,
                    territory_id: Some(8),
                    locomotive_name: Some("Mikado".to_string()),
                    active: true,
                    retired: false,
                },
            ],
            event_runtime_records: vec![RuntimeEventRecord {
                record_id: 92,
                trigger_kind: 6,
                active: true,
                service_count: 0,
                marks_collection_dirty: false,
                one_shot: false,
                has_fired: false,
                conditions: Vec::new(),
                effects: vec![RuntimeEffect::RetireTrains {
                    company_target: Some(RuntimeCompanyTarget::SelectedCompany),
                    territory_target: Some(RuntimeTerritoryTarget::Ids { ids: vec![7] }),
                    locomotive_name: Some("Mikado".to_string()),
                }],
            }],
            selected_company_id: Some(1),
            ..state()
        };

        execute_step_command(
            &mut state,
            &StepCommand::ServiceTriggerKind { trigger_kind: 6 },
        )
        .expect("retire-trains effect should succeed");

        assert!(state.trains[0].retired);
        assert!(!state.trains[1].retired);
        assert!(!state.trains[2].retired);
    }
}