//! Daily routine system (#88, #101, #243).
//!
//! Detects day-phase transitions (D-031) and issues PathRequests for NPCs
//! whose DailyRoutine has a location for the new phase. Tracks NPC activity
//! state when they arrive at their routine destination (#101).
//!
//! Routine deviation detection (#243): each tick, compares Active-tier NPCs'
//! current position and activity against their expected routine. Emits
//! `RoutineDeviationEvent` when an NPC deviates from their schedule. This is
//! the primary server-side detective mechanic per D-027 criterion 4.
//!
//! Pipeline: phase transition → PathRequest → pathfinder → path_follow →
//! NPC arrives → enter_activity sets ActivityState.
//!
//! Deviation pipeline: enter_activity runs → detect_routine_deviation compares
//! position/activity against schedule → emits RoutineDeviationEvent if mismatch.

use bevy_ecs::prelude::*;
use serde::{Deserialize, Serialize};

use crate::npc::{DailyRoutine, Npc};
use crate::simulation::movement::TilePosition;
use crate::simulation::pathfinding::{ComputedPath, PathRequest};
use crate::simulation::tier::ActiveSim;
use crate::simulation::time::{DayPhase, SimulationTime};

// ---------------------------------------------------------------------------
// ActivityState component (#101)
// ---------------------------------------------------------------------------

/// Tracks the activity an NPC is currently performing at their routine location.
///
/// Set by `enter_activity` when an NPC:
///   1. Has no active `ComputedPath` or `PathRequest` (finished walking)
///   2. Is at the location specified by their `DailyRoutine` for the current phase
///
/// Cleared on phase transitions (replaced with new activity or removed).
/// Feeds `TellTrigger::DuringActivity` and D-028 Layer 2 situation matching.
#[derive(Component, Debug, Clone, Serialize, Deserialize)]
pub struct ActivityState {
    /// Activity name from `RoutineEntry.activity` (e.g., "Work", "Bar", "Sleep").
    pub activity: String,
    /// The day phase this activity belongs to.
    pub phase: DayPhase,
    /// Tick when the NPC arrived and started this activity.
    pub started_tick: u64,
}

/// Resource tracking the previous day phase for transition detection.
#[derive(Resource, Debug, Clone)]
pub struct PreviousDayPhase {
    pub phase: DayPhase,
    pub day: u64,
}

impl Default for PreviousDayPhase {
    fn default() -> Self {
        Self {
            phase: DayPhase::Morning,
            day: 0,
        }
    }
}

/// System: detect day-phase transitions and issue PathRequests for NPC routines.
/// Runs after advance_tick so the current phase is up-to-date.
///
/// Scoped to `ActiveSim` NPCs — only active-tier NPCs receive routine-based
/// PathRequests on phase transitions (D-026, #94).
pub fn check_phase_transition(
    time: Res<SimulationTime>,
    mut previous: ResMut<PreviousDayPhase>,
    mut commands: Commands,
    npcs: Query<(Entity, &TilePosition, &DailyRoutine), (With<Npc>, With<ActiveSim>)>,
) {
    let current_phase = time.day_phase();
    let current_day = time.day();

    if current_phase == previous.phase && current_day == previous.day {
        return;
    }

    tracing::debug!(
        "Day phase transition: {:?} -> {:?} (day {} -> {})",
        previous.phase,
        current_phase,
        previous.day,
        current_day
    );

    previous.phase = current_phase;
    previous.day = current_day;

    for (entity, current_pos, routine) in npcs.iter() {
        // Clear stale activity on phase transition — will be re-evaluated by enter_activity
        commands.entity(entity).remove::<ActivityState>();

        if let Some(expected_location) = routine.expected_location(current_phase) {
            if *current_pos != expected_location {
                commands.entity(entity).insert(PathRequest {
                    goal: expected_location,
                });
                tracing::trace!(
                    "Entity {:?}: routine path request to {:?} for {:?}",
                    entity,
                    expected_location,
                    current_phase
                );
            }
        }
    }
}

// ---------------------------------------------------------------------------
// System: enter_activity (#101)
// ---------------------------------------------------------------------------

/// Set ActivityState when an NPC has arrived at their routine destination.
///
/// Runs after movement validation. Checks NPCs that:
///   - Have a DailyRoutine and ActiveSim tier
///   - Are NOT currently pathfinding (no ComputedPath or PathRequest)
///   - Are at the location specified for the current day phase
///   - Don't already have the correct ActivityState for the current phase
///
/// When conditions are met, inserts an ActivityState component. When an NPC
/// has a stale activity from a previous phase and isn't at the new phase's
/// destination, the stale activity is removed.
///
/// System ordering: after validate_movement, before compute_observer_snapshot.
pub fn enter_activity(
    mut commands: Commands,
    time: Res<SimulationTime>,
    npcs: Query<
        (Entity, &TilePosition, &DailyRoutine, Option<&ActivityState>),
        (
            With<Npc>,
            With<ActiveSim>,
            Without<ComputedPath>,
            Without<PathRequest>,
        ),
    >,
) {
    let current_phase = time.day_phase();

    for (entity, pos, routine, activity_opt) in npcs.iter() {
        // Already performing the correct activity for this phase
        if let Some(activity) = activity_opt {
            if activity.phase == current_phase {
                continue;
            }
        }

        // Check if at routine destination for current phase
        if let Some(entry) = routine.entry_for_phase(current_phase) {
            if *pos == entry.location {
                commands.entity(entity).insert(ActivityState {
                    activity: entry.activity.clone(),
                    phase: current_phase,
                    started_tick: time.tick,
                });
                tracing::trace!(
                    "Entity {:?}: entered activity '{}' for {:?}",
                    entity,
                    entry.activity,
                    current_phase,
                );
            } else {
                // Not at destination yet — remove stale activity
                commands.entity(entity).remove::<ActivityState>();
            }
        } else {
            // No routine entry for this phase — remove stale activity
            commands.entity(entity).remove::<ActivityState>();
        }
    }
}

// ---------------------------------------------------------------------------
// Routine deviation detection (#243)
// ---------------------------------------------------------------------------

/// Type of routine deviation detected.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
pub enum RoutineDeviationType {
    /// NPC is not at their expected location for the current day phase,
    /// and is not currently travelling there (no PathRequest or ComputedPath).
    /// Primary absence detection case — feeds the detective mechanic (D-027).
    WrongLocation,
    /// NPC is at their expected location for the current phase, but is
    /// performing a different activity (or ActivityState is absent).
    WrongActivity,
}

/// Event: an NPC has deviated from their scheduled routine.
///
/// Emitted once per deviation episode (not every tick while deviated).
/// Feeds `observe_anomaly` monologue triggers (#119, this sprint).
/// Primary detective mechanic per D-027 criterion 4.
#[derive(Debug, Clone)]
pub struct RoutineDeviationEvent {
    /// The NPC entity that deviated.
    pub entity: Entity,
    /// Type of deviation detected.
    pub deviation_type: RoutineDeviationType,
    /// Current day phase when deviation was detected.
    pub phase: DayPhase,
    /// Tick when deviation was first detected.
    pub tick: u64,
    /// Where the NPC should be (from their DailyRoutine).
    pub expected_location: TilePosition,
    /// Where the NPC actually is.
    pub actual_location: TilePosition,
    /// Activity NPC should be performing.
    pub expected_activity: String,
    /// Activity NPC is actually performing (None if ActivityState absent).
    pub actual_activity: Option<String>,
}

/// Resource: queue of routine deviation events.
///
/// Drained by the observation event generator (#239) which routes them to
/// `observe_anomaly` monologue triggers (#119).
#[derive(Resource, Default)]
pub struct RoutineDeviationEventQueue {
    pub events: Vec<RoutineDeviationEvent>,
}

impl RoutineDeviationEventQueue {
    pub fn push(&mut self, event: RoutineDeviationEvent) {
        self.events.push(event);
    }

    pub fn drain(&mut self) -> Vec<RoutineDeviationEvent> {
        std::mem::take(&mut self.events)
    }

    pub fn len(&self) -> usize {
        self.events.len()
    }

    pub fn is_empty(&self) -> bool {
        self.events.is_empty()
    }
}

/// Marker: NPC is currently deviating from their routine.
///
/// Inserted by `detect_routine_deviation` on first deviation detection.
/// Removed when NPC returns to their routine.
/// Guards against duplicate events on consecutive deviation ticks.
#[derive(Component, Debug, Clone, Copy)]
pub struct CurrentlyDeviating;

/// System: detect when Active-tier NPCs deviate from their scheduled routine.
///
/// Runs after `enter_activity` (so ActivityState is current). For each Active
/// NPC with a `DailyRoutine` entry for the current phase:
/// - If NPC is not at expected location AND not pathfinding: `WrongLocation`.
/// - If NPC is at expected location but activity is wrong/absent: `WrongActivity`.
/// - If on-schedule: clear `CurrentlyDeviating` marker.
///
/// NPCs with no routine entry for the current phase are not monitored.
/// Scoped to `ActiveSim` — Background-tier NPCs are not monitored (D-026).
pub fn detect_routine_deviation(
    mut commands: Commands,
    time: Res<SimulationTime>,
    mut queue: ResMut<RoutineDeviationEventQueue>,
    npcs: Query<
        (
            Entity,
            &TilePosition,
            &DailyRoutine,
            Option<&ActivityState>,
            Option<&PathRequest>,
            Option<&ComputedPath>,
            Option<&CurrentlyDeviating>,
        ),
        (With<Npc>, With<ActiveSim>),
    >,
) {
    let phase = time.day_phase();
    let tick = time.tick;

    for (entity, pos, routine, activity_opt, path_req, computed_path, deviating_opt) in npcs.iter()
    {
        let Some(entry) = routine.entry_for_phase(phase) else {
            // No routine entry for this phase — nothing to deviate from.
            // Clear any stale deviation marker from a previous phase.
            if deviating_opt.is_some() {
                commands.entity(entity).remove::<CurrentlyDeviating>();
            }
            continue;
        };

        let is_pathfinding = path_req.is_some() || computed_path.is_some();

        // Determine deviation type
        let deviation = if *pos != entry.location {
            if is_pathfinding {
                // Still travelling to destination — not deviated yet.
                if deviating_opt.is_some() {
                    commands.entity(entity).remove::<CurrentlyDeviating>();
                }
                continue;
            }
            // Not at expected location, not en route → WrongLocation
            Some(RoutineDeviationType::WrongLocation)
        } else {
            // At expected location — check activity
            let correct = match activity_opt {
                Some(state) => state.activity == entry.activity && state.phase == phase,
                None => false, // No ActivityState when at location → WrongActivity
            };
            if correct {
                None // On schedule
            } else {
                Some(RoutineDeviationType::WrongActivity)
            }
        };

        match (deviation, deviating_opt) {
            (Some(dev_type), None) => {
                // New deviation — insert marker and emit event
                commands.entity(entity).insert(CurrentlyDeviating);
                queue.push(RoutineDeviationEvent {
                    entity,
                    deviation_type: dev_type,
                    phase,
                    tick,
                    expected_location: entry.location,
                    actual_location: *pos,
                    expected_activity: entry.activity.clone(),
                    actual_activity: activity_opt.map(|a| a.activity.clone()),
                });
                tracing::debug!(
                    "Entity {:?}: routine deviation {:?} at phase {:?} tick {}",
                    entity,
                    dev_type,
                    phase,
                    tick
                );
            }
            (None, Some(_)) => {
                // Returned to routine — clear marker
                commands.entity(entity).remove::<CurrentlyDeviating>();
                tracing::debug!(
                    "Entity {:?}: returned to routine at phase {:?} tick {}",
                    entity,
                    phase,
                    tick
                );
            }
            // (Some, Some): still deviated — no duplicate event
            // (None, None): on schedule — no action
            _ => {}
        }
    }
}

// ---------------------------------------------------------------------------

#[cfg(test)]
mod tests {
    use super::*;
    use crate::npc::RoutineEntry;
    use crate::simulation::time::{MINUTES_PER_PHASE, TICKS_PER_GAME_MINUTE};

    fn setup_world() -> bevy_ecs::world::World {
        let mut world = bevy_ecs::world::World::new();
        world.insert_resource(SimulationTime::default());
        world.init_resource::<PreviousDayPhase>();
        world
    }

    #[test]
    fn phase_transition_generates_path_request() {
        let mut world = setup_world();

        let afternoon_loc = TilePosition::new(10, 10, 0);
        let entity = world
            .spawn((
                Npc,
                crate::simulation::tier::ActiveSim, // system requires With<ActiveSim> (#94)
                TilePosition::new(5, 5, 0),         // Not at afternoon location
                DailyRoutine {
                    entries: vec![RoutineEntry {
                        phase: DayPhase::Afternoon,
                        location: afternoon_loc,
                        activity: "Work".into(),
                    }],
                    description: "Test".into(),
                },
            ))
            .id();

        // Advance time to Afternoon boundary
        world.resource_mut::<SimulationTime>().tick = MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE;

        let mut schedule = bevy_ecs::schedule::Schedule::default();
        schedule.add_systems(check_phase_transition);
        schedule.run(&mut world);

        let request = world.get::<PathRequest>(entity).unwrap();
        assert_eq!(request.goal, afternoon_loc);
    }

    #[test]
    fn no_transition_no_request() {
        let mut world = setup_world();

        let entity = world
            .spawn((
                Npc,
                ActiveSim,
                TilePosition::new(5, 5, 0),
                DailyRoutine {
                    entries: vec![RoutineEntry {
                        phase: DayPhase::Afternoon,
                        location: TilePosition::new(10, 10, 0),
                        activity: "Work".into(),
                    }],
                    description: "Test".into(),
                },
            ))
            .id();

        // Time still at Morning (tick 0), same as PreviousDayPhase default
        let mut schedule = bevy_ecs::schedule::Schedule::default();
        schedule.add_systems(check_phase_transition);
        schedule.run(&mut world);

        assert!(world.get::<PathRequest>(entity).is_none());
    }

    #[test]
    fn npc_already_at_destination_no_request() {
        let mut world = setup_world();

        let loc = TilePosition::new(10, 10, 0);
        let entity = world
            .spawn((
                Npc,
                ActiveSim,
                loc, // Already at afternoon location
                DailyRoutine {
                    entries: vec![RoutineEntry {
                        phase: DayPhase::Afternoon,
                        location: loc,
                        activity: "Work".into(),
                    }],
                    description: "Test".into(),
                },
            ))
            .id();

        world.resource_mut::<SimulationTime>().tick = MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE;

        let mut schedule = bevy_ecs::schedule::Schedule::default();
        schedule.add_systems(check_phase_transition);
        schedule.run(&mut world);

        assert!(world.get::<PathRequest>(entity).is_none());
    }

    #[test]
    fn npc_without_routine_entry_ignored() {
        let mut world = setup_world();

        let entity = world
            .spawn((
                Npc,
                ActiveSim,
                TilePosition::new(5, 5, 0),
                DailyRoutine {
                    entries: vec![RoutineEntry {
                        phase: DayPhase::Morning,
                        location: TilePosition::new(5, 5, 0),
                        activity: "Sleep".into(),
                    }],
                    description: "Test".into(),
                },
            ))
            .id();

        // Transition to Afternoon, but NPC only has Morning entry
        world.resource_mut::<SimulationTime>().tick = MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE;

        let mut schedule = bevy_ecs::schedule::Schedule::default();
        schedule.add_systems(check_phase_transition);
        schedule.run(&mut world);

        assert!(world.get::<PathRequest>(entity).is_none());
    }

    #[test]
    fn day_rollover_triggers_morning_routine() {
        let mut world = setup_world();

        // Start at Night
        let night_tick = 1080 * TICKS_PER_GAME_MINUTE;
        world.resource_mut::<SimulationTime>().tick = night_tick;
        world.resource_mut::<PreviousDayPhase>().phase = DayPhase::Night;
        world.resource_mut::<PreviousDayPhase>().day = 0;

        let morning_loc = TilePosition::new(3, 3, 0);
        let entity = world
            .spawn((
                Npc,
                crate::simulation::tier::ActiveSim, // system requires With<ActiveSim> (#94)
                TilePosition::new(20, 20, 0),
                DailyRoutine {
                    entries: vec![RoutineEntry {
                        phase: DayPhase::Morning,
                        location: morning_loc,
                        activity: "Wake up".into(),
                    }],
                    description: "Test".into(),
                },
            ))
            .id();

        // Advance to next day's Morning (day 1, tick 0 of new day)
        world.resource_mut::<SimulationTime>().tick = 1440 * TICKS_PER_GAME_MINUTE;

        let mut schedule = bevy_ecs::schedule::Schedule::default();
        schedule.add_systems(check_phase_transition);
        schedule.run(&mut world);

        let request = world.get::<PathRequest>(entity).unwrap();
        assert_eq!(request.goal, morning_loc);
    }

    // -- enter_activity tests (#101) ------------------------------------------

    #[test]
    fn npc_at_routine_destination_gets_activity_state() {
        let mut world = setup_world();
        // Time = Afternoon
        world.resource_mut::<SimulationTime>().tick = MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE;

        let loc = TilePosition::new(10, 10, 0);
        let entity = world
            .spawn((
                Npc,
                ActiveSim,
                loc, // Already at afternoon destination
                DailyRoutine {
                    entries: vec![RoutineEntry {
                        phase: DayPhase::Afternoon,
                        location: loc,
                        activity: "Work".into(),
                    }],
                    description: "Test".into(),
                },
            ))
            .id();

        let mut schedule = bevy_ecs::schedule::Schedule::default();
        schedule.add_systems(enter_activity);
        schedule.run(&mut world);
        world.flush();

        let state = world.get::<ActivityState>(entity).unwrap();
        assert_eq!(state.activity, "Work");
        assert_eq!(state.phase, DayPhase::Afternoon);
        assert_eq!(
            state.started_tick,
            MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE
        );
    }

    #[test]
    fn npc_not_at_destination_no_activity_state() {
        let mut world = setup_world();
        world.resource_mut::<SimulationTime>().tick = MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE;

        let entity = world
            .spawn((
                Npc,
                ActiveSim,
                TilePosition::new(5, 5, 0), // NOT at afternoon location
                DailyRoutine {
                    entries: vec![RoutineEntry {
                        phase: DayPhase::Afternoon,
                        location: TilePosition::new(10, 10, 0),
                        activity: "Work".into(),
                    }],
                    description: "Test".into(),
                },
            ))
            .id();

        let mut schedule = bevy_ecs::schedule::Schedule::default();
        schedule.add_systems(enter_activity);
        schedule.run(&mut world);
        world.flush();

        assert!(world.get::<ActivityState>(entity).is_none());
    }

    #[test]
    fn npc_with_computed_path_excluded() {
        let mut world = setup_world();
        world.resource_mut::<SimulationTime>().tick = MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE;

        let loc = TilePosition::new(10, 10, 0);
        let entity = world
            .spawn((
                Npc,
                ActiveSim,
                loc, // At destination but still has a path
                DailyRoutine {
                    entries: vec![RoutineEntry {
                        phase: DayPhase::Afternoon,
                        location: loc,
                        activity: "Work".into(),
                    }],
                    description: "Test".into(),
                },
                ComputedPath {
                    steps: vec![],
                    current_index: 0,
                },
            ))
            .id();

        let mut schedule = bevy_ecs::schedule::Schedule::default();
        schedule.add_systems(enter_activity);
        schedule.run(&mut world);
        world.flush();

        assert!(
            world.get::<ActivityState>(entity).is_none(),
            "NPC with ComputedPath should not get ActivityState"
        );
    }

    #[test]
    fn npc_with_path_request_excluded() {
        let mut world = setup_world();
        world.resource_mut::<SimulationTime>().tick = MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE;

        let loc = TilePosition::new(10, 10, 0);
        let entity = world
            .spawn((
                Npc,
                ActiveSim,
                loc,
                DailyRoutine {
                    entries: vec![RoutineEntry {
                        phase: DayPhase::Afternoon,
                        location: loc,
                        activity: "Work".into(),
                    }],
                    description: "Test".into(),
                },
                PathRequest { goal: loc },
            ))
            .id();

        let mut schedule = bevy_ecs::schedule::Schedule::default();
        schedule.add_systems(enter_activity);
        schedule.run(&mut world);
        world.flush();

        assert!(
            world.get::<ActivityState>(entity).is_none(),
            "NPC with PathRequest should not get ActivityState"
        );
    }

    #[test]
    fn existing_activity_same_phase_not_overwritten() {
        let mut world = setup_world();
        let tick = MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE;
        world.resource_mut::<SimulationTime>().tick = tick + 100;

        let loc = TilePosition::new(10, 10, 0);
        let entity = world
            .spawn((
                Npc,
                ActiveSim,
                loc,
                DailyRoutine {
                    entries: vec![RoutineEntry {
                        phase: DayPhase::Afternoon,
                        location: loc,
                        activity: "Work".into(),
                    }],
                    description: "Test".into(),
                },
                ActivityState {
                    activity: "Work".into(),
                    phase: DayPhase::Afternoon,
                    started_tick: tick, // Set earlier
                },
            ))
            .id();

        let mut schedule = bevy_ecs::schedule::Schedule::default();
        schedule.add_systems(enter_activity);
        schedule.run(&mut world);
        world.flush();

        let state = world.get::<ActivityState>(entity).unwrap();
        assert_eq!(
            state.started_tick, tick,
            "started_tick should be preserved, not updated"
        );
    }

    #[test]
    fn stale_activity_replaced_on_phase_change() {
        let mut world = setup_world();
        // Time = Evening (after Afternoon)
        let evening_tick = 2 * MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE;
        world.resource_mut::<SimulationTime>().tick = evening_tick;

        let evening_loc = TilePosition::new(20, 20, 0);
        let entity = world
            .spawn((
                Npc,
                ActiveSim,
                evening_loc, // Already at evening location
                DailyRoutine {
                    entries: vec![
                        RoutineEntry {
                            phase: DayPhase::Afternoon,
                            location: TilePosition::new(10, 10, 0),
                            activity: "Work".into(),
                        },
                        RoutineEntry {
                            phase: DayPhase::Evening,
                            location: evening_loc,
                            activity: "Bar".into(),
                        },
                    ],
                    description: "Test".into(),
                },
                // Stale activity from previous phase
                ActivityState {
                    activity: "Work".into(),
                    phase: DayPhase::Afternoon,
                    started_tick: 1000,
                },
            ))
            .id();

        let mut schedule = bevy_ecs::schedule::Schedule::default();
        schedule.add_systems(enter_activity);
        schedule.run(&mut world);
        world.flush();

        let state = world.get::<ActivityState>(entity).unwrap();
        assert_eq!(state.activity, "Bar");
        assert_eq!(state.phase, DayPhase::Evening);
        assert_eq!(state.started_tick, evening_tick);
    }

    #[test]
    fn no_routine_for_phase_clears_stale_activity() {
        let mut world = setup_world();
        // Time = Night
        let night_tick = 3 * MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE;
        world.resource_mut::<SimulationTime>().tick = night_tick;

        let entity = world
            .spawn((
                Npc,
                ActiveSim,
                TilePosition::new(10, 10, 0),
                DailyRoutine {
                    entries: vec![RoutineEntry {
                        phase: DayPhase::Evening,
                        location: TilePosition::new(10, 10, 0),
                        activity: "Bar".into(),
                    }],
                    description: "Test".into(),
                },
                // Stale activity from Evening, no Night entry
                ActivityState {
                    activity: "Bar".into(),
                    phase: DayPhase::Evening,
                    started_tick: 1000,
                },
            ))
            .id();

        let mut schedule = bevy_ecs::schedule::Schedule::default();
        schedule.add_systems(enter_activity);
        schedule.run(&mut world);
        world.flush();

        assert!(
            world.get::<ActivityState>(entity).is_none(),
            "Stale activity should be cleared when no routine entry for current phase"
        );
    }

    #[test]
    fn phase_transition_clears_activity_state() {
        let mut world = setup_world();

        let loc = TilePosition::new(10, 10, 0);
        let entity = world
            .spawn((
                Npc,
                ActiveSim,
                loc,
                DailyRoutine {
                    entries: vec![
                        RoutineEntry {
                            phase: DayPhase::Morning,
                            location: loc,
                            activity: "Work".into(),
                        },
                        RoutineEntry {
                            phase: DayPhase::Afternoon,
                            location: TilePosition::new(20, 20, 0),
                            activity: "Lunch".into(),
                        },
                    ],
                    description: "Test".into(),
                },
                ActivityState {
                    activity: "Work".into(),
                    phase: DayPhase::Morning,
                    started_tick: 0,
                },
            ))
            .id();

        // Trigger phase transition to Afternoon
        world.resource_mut::<SimulationTime>().tick = MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE;

        let mut schedule = bevy_ecs::schedule::Schedule::default();
        schedule.add_systems(check_phase_transition);
        schedule.run(&mut world);
        world.flush();

        // ActivityState should be cleared by phase transition
        assert!(
            world.get::<ActivityState>(entity).is_none(),
            "Phase transition should clear ActivityState"
        );
        // PathRequest should be set for the new phase location
        assert!(world.get::<PathRequest>(entity).is_some());
    }

    // -- detect_routine_deviation tests (#243) --------------------------------

    fn setup_deviation_world() -> World {
        let mut world = World::new();
        world.init_resource::<SimulationTime>();
        world.init_resource::<RoutineDeviationEventQueue>();
        world.init_resource::<PreviousDayPhase>();
        world
    }

    fn run_deviation_system(world: &mut World) {
        let mut schedule = bevy_ecs::schedule::Schedule::default();
        schedule.add_systems(detect_routine_deviation);
        schedule.run(world);
        world.flush();
    }

    #[test]
    fn deviation_event_emitted_wrong_location() {
        let mut world = setup_deviation_world();
        // Time = Afternoon
        world.resource_mut::<SimulationTime>().tick = MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE;

        let expected_loc = TilePosition::new(10, 10, 0);
        let entity = world
            .spawn((
                Npc,
                ActiveSim,
                TilePosition::new(5, 5, 0), // Wrong location, not pathfinding
                DailyRoutine {
                    entries: vec![RoutineEntry {
                        phase: DayPhase::Afternoon,
                        location: expected_loc,
                        activity: "Work".into(),
                    }],
                    description: "Test".into(),
                },
                // No PathRequest, no ComputedPath — NPC is just absent
            ))
            .id();

        run_deviation_system(&mut world);

        let queue = world.resource::<RoutineDeviationEventQueue>();
        assert_eq!(queue.len(), 1, "should emit one deviation event");
        let evt = &queue.events[0];
        assert_eq!(evt.entity, entity);
        assert_eq!(evt.deviation_type, RoutineDeviationType::WrongLocation);
        assert_eq!(evt.expected_location, expected_loc);
        assert_eq!(evt.actual_location, TilePosition::new(5, 5, 0));
        assert_eq!(evt.expected_activity, "Work");
        assert!(evt.actual_activity.is_none());
    }

    #[test]
    fn no_deviation_when_at_correct_location_and_activity() {
        let mut world = setup_deviation_world();
        world.resource_mut::<SimulationTime>().tick = MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE;

        let loc = TilePosition::new(10, 10, 0);
        world.spawn((
            Npc,
            ActiveSim,
            loc,
            DailyRoutine {
                entries: vec![RoutineEntry {
                    phase: DayPhase::Afternoon,
                    location: loc,
                    activity: "Work".into(),
                }],
                description: "Test".into(),
            },
            ActivityState {
                activity: "Work".into(),
                phase: DayPhase::Afternoon,
                started_tick: MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE,
            },
        ));

        run_deviation_system(&mut world);

        let queue = world.resource::<RoutineDeviationEventQueue>();
        assert!(
            queue.is_empty(),
            "on-schedule NPC should not emit a deviation event"
        );
    }

    #[test]
    fn no_deviation_when_pathfinding_to_destination() {
        let mut world = setup_deviation_world();
        world.resource_mut::<SimulationTime>().tick = MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE;

        let expected_loc = TilePosition::new(10, 10, 0);
        world.spawn((
            Npc,
            ActiveSim,
            TilePosition::new(5, 5, 0), // Not there yet
            DailyRoutine {
                entries: vec![RoutineEntry {
                    phase: DayPhase::Afternoon,
                    location: expected_loc,
                    activity: "Work".into(),
                }],
                description: "Test".into(),
            },
            PathRequest { goal: expected_loc }, // En route
        ));

        run_deviation_system(&mut world);

        let queue = world.resource::<RoutineDeviationEventQueue>();
        assert!(
            queue.is_empty(),
            "NPC with PathRequest is en route — not yet deviated"
        );
    }

    #[test]
    fn no_deviation_when_computed_path_active() {
        let mut world = setup_deviation_world();
        world.resource_mut::<SimulationTime>().tick = MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE;

        let expected_loc = TilePosition::new(10, 10, 0);
        world.spawn((
            Npc,
            ActiveSim,
            TilePosition::new(5, 5, 0),
            DailyRoutine {
                entries: vec![RoutineEntry {
                    phase: DayPhase::Afternoon,
                    location: expected_loc,
                    activity: "Work".into(),
                }],
                description: "Test".into(),
            },
            ComputedPath {
                steps: vec![TilePosition::new(6, 5, 0)],
                current_index: 0,
            },
        ));

        run_deviation_system(&mut world);

        let queue = world.resource::<RoutineDeviationEventQueue>();
        assert!(
            queue.is_empty(),
            "NPC with ComputedPath is walking — not yet deviated"
        );
    }

    #[test]
    fn deviation_event_emitted_wrong_activity() {
        let mut world = setup_deviation_world();
        world.resource_mut::<SimulationTime>().tick = MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE;

        let loc = TilePosition::new(10, 10, 0);
        let entity = world
            .spawn((
                Npc,
                ActiveSim,
                loc, // At correct location
                DailyRoutine {
                    entries: vec![RoutineEntry {
                        phase: DayPhase::Afternoon,
                        location: loc,
                        activity: "Work".into(),
                    }],
                    description: "Test".into(),
                },
                ActivityState {
                    activity: "Idle".into(), // Wrong activity
                    phase: DayPhase::Afternoon,
                    started_tick: 100,
                },
            ))
            .id();

        run_deviation_system(&mut world);

        let queue = world.resource::<RoutineDeviationEventQueue>();
        assert_eq!(queue.len(), 1);
        let evt = &queue.events[0];
        assert_eq!(evt.entity, entity);
        assert_eq!(evt.deviation_type, RoutineDeviationType::WrongActivity);
        assert_eq!(evt.expected_activity, "Work");
        assert_eq!(evt.actual_activity.as_deref(), Some("Idle"));
    }

    #[test]
    fn wrong_activity_when_activity_state_absent_at_location() {
        let mut world = setup_deviation_world();
        world.resource_mut::<SimulationTime>().tick = MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE;

        let loc = TilePosition::new(10, 10, 0);
        let entity = world
            .spawn((
                Npc,
                ActiveSim,
                loc, // At correct location
                DailyRoutine {
                    entries: vec![RoutineEntry {
                        phase: DayPhase::Afternoon,
                        location: loc,
                        activity: "Work".into(),
                    }],
                    description: "Test".into(),
                },
                // No ActivityState — NPC is at location but hasn't settled
            ))
            .id();

        run_deviation_system(&mut world);

        let queue = world.resource::<RoutineDeviationEventQueue>();
        assert_eq!(queue.len(), 1);
        let evt = &queue.events[0];
        assert_eq!(evt.entity, entity);
        assert_eq!(evt.deviation_type, RoutineDeviationType::WrongActivity);
        assert!(evt.actual_activity.is_none());
    }

    #[test]
    fn no_duplicate_events_while_deviated() {
        let mut world = setup_deviation_world();
        world.resource_mut::<SimulationTime>().tick = MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE;

        let expected_loc = TilePosition::new(10, 10, 0);
        world.spawn((
            Npc,
            ActiveSim,
            TilePosition::new(5, 5, 0),
            DailyRoutine {
                entries: vec![RoutineEntry {
                    phase: DayPhase::Afternoon,
                    location: expected_loc,
                    activity: "Work".into(),
                }],
                description: "Test".into(),
            },
            CurrentlyDeviating, // Already marked as deviating
        ));

        run_deviation_system(&mut world);

        let queue = world.resource::<RoutineDeviationEventQueue>();
        assert!(
            queue.is_empty(),
            "no duplicate deviation event while already marked as deviating"
        );
    }

    #[test]
    fn deviation_marker_cleared_when_npc_returns_to_routine() {
        let mut world = setup_deviation_world();
        world.resource_mut::<SimulationTime>().tick = MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE;

        let loc = TilePosition::new(10, 10, 0);
        let entity = world
            .spawn((
                Npc,
                ActiveSim,
                loc, // Now at correct location
                DailyRoutine {
                    entries: vec![RoutineEntry {
                        phase: DayPhase::Afternoon,
                        location: loc,
                        activity: "Work".into(),
                    }],
                    description: "Test".into(),
                },
                ActivityState {
                    activity: "Work".into(),
                    phase: DayPhase::Afternoon,
                    started_tick: 100,
                },
                CurrentlyDeviating, // Was deviating, now returned
            ))
            .id();

        run_deviation_system(&mut world);

        assert!(
            world.get::<CurrentlyDeviating>(entity).is_none(),
            "CurrentlyDeviating marker should be removed when NPC returns to routine"
        );
        let queue = world.resource::<RoutineDeviationEventQueue>();
        assert!(queue.is_empty(), "no event on deviation resolution");
    }

    #[test]
    fn no_routine_for_phase_clears_deviation_marker() {
        let mut world = setup_deviation_world();
        // Night phase — NPC has no routine entry
        world.resource_mut::<SimulationTime>().tick = 3 * MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE;

        let entity = world
            .spawn((
                Npc,
                ActiveSim,
                TilePosition::new(5, 5, 0),
                DailyRoutine {
                    entries: vec![RoutineEntry {
                        phase: DayPhase::Morning,
                        location: TilePosition::new(5, 5, 0),
                        activity: "Sleep".into(),
                    }],
                    description: "Test".into(),
                },
                CurrentlyDeviating, // Stale marker from previous phase
            ))
            .id();

        run_deviation_system(&mut world);

        // No entry for Night → marker cleared, no event
        assert!(
            world.get::<CurrentlyDeviating>(entity).is_none(),
            "stale deviation marker cleared when NPC has no routine for current phase"
        );
        let queue = world.resource::<RoutineDeviationEventQueue>();
        assert!(queue.is_empty());
    }

    #[test]
    fn background_npc_not_monitored_for_deviation() {
        let mut world = setup_deviation_world();
        world.resource_mut::<SimulationTime>().tick = MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE;

        world.spawn((
            Npc,
            crate::simulation::tier::BackgroundSim,
            TilePosition::new(5, 5, 0), // Wrong location
            DailyRoutine {
                entries: vec![RoutineEntry {
                    phase: DayPhase::Afternoon,
                    location: TilePosition::new(10, 10, 0),
                    activity: "Work".into(),
                }],
                description: "Test".into(),
            },
        ));

        run_deviation_system(&mut world);

        let queue = world.resource::<RoutineDeviationEventQueue>();
        assert!(
            queue.is_empty(),
            "Background-tier NPCs must not generate deviation events"
        );
    }

    #[test]
    fn multiple_npcs_deviated_independently() {
        let mut world = setup_deviation_world();
        world.resource_mut::<SimulationTime>().tick = MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE;

        let expected_loc = TilePosition::new(10, 10, 0);

        // NPC 1: wrong location (will deviate)
        let e1 = world
            .spawn((
                Npc,
                ActiveSim,
                TilePosition::new(1, 1, 0),
                DailyRoutine {
                    entries: vec![RoutineEntry {
                        phase: DayPhase::Afternoon,
                        location: expected_loc,
                        activity: "Work".into(),
                    }],
                    description: "Test".into(),
                },
            ))
            .id();

        // NPC 2: on schedule (no deviation)
        let loc2 = TilePosition::new(20, 20, 0);
        world.spawn((
            Npc,
            ActiveSim,
            loc2,
            DailyRoutine {
                entries: vec![RoutineEntry {
                    phase: DayPhase::Afternoon,
                    location: loc2,
                    activity: "Bar".into(),
                }],
                description: "Test".into(),
            },
            ActivityState {
                activity: "Bar".into(),
                phase: DayPhase::Afternoon,
                started_tick: MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE,
            },
        ));

        // NPC 3: wrong activity (will deviate)
        let loc3 = TilePosition::new(30, 30, 0);
        let e3 = world
            .spawn((
                Npc,
                ActiveSim,
                loc3,
                DailyRoutine {
                    entries: vec![RoutineEntry {
                        phase: DayPhase::Afternoon,
                        location: loc3,
                        activity: "Inspect".into(),
                    }],
                    description: "Test".into(),
                },
                ActivityState {
                    activity: "Loiter".into(), // Wrong
                    phase: DayPhase::Afternoon,
                    started_tick: 100,
                },
            ))
            .id();

        run_deviation_system(&mut world);

        let queue = world.resource::<RoutineDeviationEventQueue>();
        assert_eq!(queue.len(), 2, "two NPCs should deviate independently");

        let deviated: Vec<Entity> = queue.events.iter().map(|e| e.entity).collect();
        assert!(deviated.contains(&e1));
        assert!(deviated.contains(&e3));
    }

    #[test]
    fn deviation_event_records_current_tick_and_phase() {
        let mut world = setup_deviation_world();
        let tick = MINUTES_PER_PHASE * TICKS_PER_GAME_MINUTE + 42;
        world.resource_mut::<SimulationTime>().tick = tick;

        world.spawn((
            Npc,
            ActiveSim,
            TilePosition::new(5, 5, 0),
            DailyRoutine {
                entries: vec![RoutineEntry {
                    phase: DayPhase::Afternoon,
                    location: TilePosition::new(10, 10, 0),
                    activity: "Work".into(),
                }],
                description: "Test".into(),
            },
        ));

        run_deviation_system(&mut world);

        let queue = world.resource::<RoutineDeviationEventQueue>();
        let evt = &queue.events[0];
        assert_eq!(evt.tick, tick);
        assert_eq!(evt.phase, DayPhase::Afternoon);
    }
}