//! Generate MessagePack fixture files for cross-language testing (D-030 Layer 1).
//! Run with: cargo test --test gen_fixtures -- --ignored

use settled_reach_server::bridge::types::*;
use settled_reach_server::simulation::time::{DayPhase, TickRate};
use std::fs;
use std::path::Path;

fn write_fixture(name: &str, bytes: &[u8]) {
    // Write directly into the Godot project's test fixtures (single source of truth)
    let dir = Path::new("../client/tests/fixtures/msgpack");
    fs::create_dir_all(dir).expect("create fixture dir");
    let path = dir.join(format!("{}.msgpack", name));
    fs::write(&path, bytes).expect("write fixture");
    eprintln!("Wrote {} ({} bytes)", path.display(), bytes.len());
}

/// Helper to create a minimal v2 snapshot for fixtures
fn fixture_snapshot(tick: u64, entities: Vec<VisibleEntity>) -> ObserverSnapshot {
    ObserverSnapshot {
        version: PROTOCOL_VERSION,
        tick,
        game_time: GameTime {
            day: 0,
            time_of_day: 0,
            day_phase: DayPhase::Morning,
            tick_rate: TickRate::Full,
        },
        player_facing: FacingDirection::North,
        player_stance: MovementStance::default(),
        player_inventory: vec![],
        entities,
        visible_tiles: vec![],
        nearby_interactions: vec![],
        current_monologue: None,
        pending_recognitions: vec![],
        dialogue_response: None,
        blocked_entities: vec![],
        scan_events: vec![],
        sound_events: vec![],
        conversation_events: vec![],
        conversation_ended: vec![],
        rng_seed: None,
    }
}

#[test]
#[ignore] // Run manually: cargo test --test gen_fixtures -- --ignored
fn generate_msgpack_fixtures() {
    // Snapshot with one NPC entity
    let snapshot = fixture_snapshot(
        42,
        vec![VisibleEntity {
            entity_id: 1,
            x: 10.0,
            y: 20.0,
            z: 0,
            kind: EntityKind::Npc,
            visibility: VisibilitySector::Forward,
            relationship: RelationshipState::Unknown,
            observation: EntityVisibility::Visible,
        }],
    );
    write_fixture(
        "snapshot_one_npc",
        &rmp_serde::to_vec_named(&snapshot).unwrap(),
    );

    // Empty snapshot
    let empty = fixture_snapshot(0, vec![]);
    write_fixture("snapshot_empty", &rmp_serde::to_vec_named(&empty).unwrap());

    // PlayerInput: MoveNorth
    let input_north = PlayerInput {
        tick: 100,
        action: PlayerAction::MoveNorth,
    };
    write_fixture(
        "input_move_north",
        &rmp_serde::to_vec_named(&input_north).unwrap(),
    );

    // PlayerInput: UsePerceptionMode
    let input_perception = PlayerInput {
        tick: 200,
        action: PlayerAction::UsePerceptionMode("thermal".to_string()),
    };
    write_fixture(
        "input_perception_mode",
        &rmp_serde::to_vec_named(&input_perception).unwrap(),
    );

    // Snapshot with Player entity
    let snapshot_player = fixture_snapshot(
        1,
        vec![VisibleEntity {
            entity_id: 100,
            x: 16.5,
            y: 16.5,
            z: 0,
            kind: EntityKind::Player,
            visibility: VisibilitySector::Forward,
            relationship: RelationshipState::Unknown,
            observation: EntityVisibility::Visible,
        }],
    );
    write_fixture(
        "snapshot_player",
        &rmp_serde::to_vec_named(&snapshot_player).unwrap(),
    );

    // Snapshot with multiple entities and all EntityKind variants
    let snapshot_multi = fixture_snapshot(
        999,
        vec![
            VisibleEntity {
                entity_id: 1,
                x: 16.5,
                y: 16.5,
                z: 0,
                kind: EntityKind::Player,
                visibility: VisibilitySector::Forward,
                relationship: RelationshipState::Known,
                observation: EntityVisibility::Visible,
            },
            VisibleEntity {
                entity_id: 2,
                x: 5.0,
                y: 10.0,
                z: 0,
                kind: EntityKind::Npc,
                visibility: VisibilitySector::Peripheral,
                relationship: RelationshipState::Unknown,
                observation: EntityVisibility::Visible,
            },
            VisibleEntity {
                entity_id: 3,
                x: 15.5,
                y: 3.0,
                z: 1,
                kind: EntityKind::Object,
                visibility: VisibilitySector::Forward,
                relationship: RelationshipState::Unknown,
                observation: EntityVisibility::Visible,
            },
            VisibleEntity {
                entity_id: 4,
                x: 0.0,
                y: 0.0,
                z: -1,
                kind: EntityKind::Terrain,
                visibility: VisibilitySector::Forward,
                relationship: RelationshipState::Unknown,
                observation: EntityVisibility::Visible,
            },
        ],
    );
    write_fixture(
        "snapshot_multi_entity",
        &rmp_serde::to_vec_named(&snapshot_multi).unwrap(),
    );

    // v2 snapshot with visible_tiles and game_time populated
    let snapshot_v2_full = ObserverSnapshot {
        version: PROTOCOL_VERSION,
        tick: 500,
        game_time: GameTime {
            day: 1,
            time_of_day: 720,
            day_phase: DayPhase::Evening,
            tick_rate: TickRate::Full,
        },
        player_facing: FacingDirection::Southeast,
        player_stance: MovementStance::default(),
        player_inventory: vec![],
        entities: vec![VisibleEntity {
            entity_id: 1,
            x: 10.5,
            y: 10.5,
            z: 0,
            kind: EntityKind::Player,
            visibility: VisibilitySector::Forward,
            relationship: RelationshipState::Unknown,
            observation: EntityVisibility::Visible,
        }],
        visible_tiles: vec![
            VisibleTile {
                x: 10,
                y: 10,
                z: 0,
                visibility: VisibilitySector::Forward,
                tile_kind: TileKind::Floor,
                zone_id: Some(1),
            },
            VisibleTile {
                x: 11,
                y: 10,
                z: 0,
                visibility: VisibilitySector::Peripheral,
                tile_kind: TileKind::Floor,
                zone_id: Some(1),
            },
            VisibleTile {
                x: 10,
                y: 9,
                z: 0,
                visibility: VisibilitySector::Forward,
                tile_kind: TileKind::Floor,
                zone_id: None,
            },
        ],
        nearby_interactions: vec![],
        current_monologue: None,
        pending_recognitions: vec![],
        dialogue_response: None,
        blocked_entities: vec![],
        scan_events: vec![],
        sound_events: vec![],
        conversation_events: vec![],
        conversation_ended: vec![],
        rng_seed: None,
    };
    write_fixture(
        "snapshot_v2_full",
        &rmp_serde::to_vec_named(&snapshot_v2_full).unwrap(),
    );

    // Batch input: Vec<PlayerInput> with two actions (D-030 Layer 1 bidirectional symmetry)
    let input_batch = vec![
        PlayerInput {
            tick: 0,
            action: PlayerAction::MoveNorth,
        },
        PlayerInput {
            tick: 0,
            action: PlayerAction::Interact {
                target_entity_id: None,
                verb: None,
            },
        },
    ];
    write_fixture(
        "input_batch_two",
        &rmp_serde::to_vec_named(&input_batch).unwrap(),
    );

    // Diagonal movement fixtures (clockwise: NE, SE, SW, NW)
    for (name, action) in [
        ("input_move_northeast", PlayerAction::MoveNortheast),
        ("input_move_southeast", PlayerAction::MoveSoutheast),
        ("input_move_southwest", PlayerAction::MoveSouthwest),
        ("input_move_northwest", PlayerAction::MoveNorthwest),
    ] {
        let input = PlayerInput { tick: 100, action };
        write_fixture(name, &rmp_serde::to_vec_named(&input).unwrap());
    }

    // === Boundary value fixtures (#472) ===
    // 14 raw integer values at encoding format boundaries (Appendix C).
    // These are Rust-encoded MessagePack that GDScript must decode correctly.
    // Covers every encoding format transition and the int16/int32 asymmetry zones.

    let boundary_raw: [(u64, &str); 14] = [
        // pos fixint boundaries
        (0, "boundary_raw_0"),
        (127, "boundary_raw_127"),
        // uint 8 boundaries
        (128, "boundary_raw_128"),
        (255, "boundary_raw_255"),
        // int16/uint16 asymmetry zone (GDScript: int_16, Rust: uint_16)
        (256, "boundary_raw_256"),
        (32767, "boundary_raw_32767"),
        // uint 16 boundaries
        (32768, "boundary_raw_32768"),
        (65535, "boundary_raw_65535"),
        // int32/uint32 asymmetry zone (GDScript: int_32, Rust: uint_32)
        (65536, "boundary_raw_65536"),
        (2147483647, "boundary_raw_2147483647"),
        // uint 32 boundaries
        (2147483648, "boundary_raw_2147483648"),
        (4294967295, "boundary_raw_4294967295"),
        // int 64 boundaries
        (4294967296, "boundary_raw_4294967296"),
        (u64::MAX >> 1, "boundary_raw_i64_max"), // 2^63-1 = i64::MAX
    ];

    for (value, name) in &boundary_raw {
        // Encode as u64 (matches how entity_id/tick are encoded in snapshots)
        let bytes = rmp_serde::to_vec(value).expect("encode boundary value");
        write_fixture(name, &bytes);
    }

    // 5 snapshot fixtures at boundary tick values.
    // Tests that GDScript can decode full ObserverSnapshot structs when the tick
    // field crosses encoding format boundaries.
    let boundary_snapshots: [(u64, &str); 5] = [
        (0, "snapshot_boundary_tick_0"),               // pos fixint
        (127, "snapshot_boundary_tick_127"),           // pos fixint max
        (32767, "snapshot_boundary_tick_32767"),       // int16/uint16 asymmetry
        (2147483647, "snapshot_boundary_tick_2b31m1"), // int32/uint32 asymmetry
        (4294967296, "snapshot_boundary_tick_2b32"),   // int64 minimum
    ];

    for (tick, name) in &boundary_snapshots {
        let snapshot = fixture_snapshot(*tick, vec![]);
        write_fixture(name, &rmp_serde::to_vec_named(&snapshot).unwrap());
    }
}