zuma-like/src/states/level/system_cannon.rs

use bevy::prelude::*;
use crate::states::level::*;
use bevy::window::PrimaryWindow;

pub fn setup_cannon(mut commands: Commands, asset_server: Res<AssetServer>) {
    let texture: Handle<Image> = asset_server.load("cannon/cannon.png");

    commands.spawn((
        LevelMarker,
        Cannon,
        Transform::from_xyz(579.0 - (1280.0 / 2.0), (768.0 / 2.0) - 150.0, CANNON_Z_INDEX),
        Sprite::from_image(texture),
        Visibility::Visible,
    ));
    println!("Cannon visuals is set up");
}

pub fn rotate_cannon(
    mut query: Query<&mut Transform, With<Cannon>>,
    window_query: Query<&Window, With<PrimaryWindow>>,
    camera_query: Query<(&Camera, &GlobalTransform)>,
) {
    let Ok(mut cannon_tf) = query.single_mut() else {
        return;
    };
    let Ok(window) = window_query.single() else {
        return;
    };
    let Some(cursor_pos) = window.cursor_position() else {
        return;
    };
    let Ok((camera, camera_tf)) = camera_query.single() else {
        return;
    };

    // Конвертируем экранные координаты курсора в мировые
    let Ok(world_cursor_pos) = camera.viewport_to_world_2d(camera_tf, cursor_pos) else {
        return;
    };

    // Вектор направления от пушки к курсору
    let cannon_pos = Vec2::new(cannon_tf.translation.x, cannon_tf.translation.y);
    let direction = world_cursor_pos - cannon_pos;

    // Применяем вращение по оси Z
    let angle = direction.to_angle() - std::f32::consts::FRAC_PI_2;
    cannon_tf.rotation = Quat::from_rotation_z(angle);
}

pub fn spawn_projectile_from_cannon(
    mut commands: Commands,
    cannon_query: Query<&Transform, With<Cannon>>,
    mouse_input: Res<ButtonInput<MouseButton>>,
    asset_server: Res<AssetServer>,
    mut cannon_state: ResMut<CannonState>
) {
    if !mouse_input.just_pressed(MouseButton::Left) {
        return;
    }

    let Ok(cannon_tf) = cannon_query.single() else {
        return;
    };

    let ball_type = cannon_state.current_type;
    let image = asset_server.load(ball_type.asset_path());

    let offset = 100.0; // сдвиг от центра к дулу пушки
    let direction = cannon_tf.rotation.mul_vec3(Vec3::Y).truncate().normalize();
    let spawn_pos_2d = cannon_tf.translation.truncate() + direction * offset;
    let spawn_pos = spawn_pos_2d.extend(PROJECTILE_Z_INDEX);

    commands.spawn((
        LevelMarker,
        Transform::from_translation(spawn_pos),
        Sprite {
            image,
            custom_size: Some(Vec2::splat(SLOT_SIZE)),
            ..default()
        },
        Visibility::Visible,
        BallProjectile {
            velocity: direction * 800.0,
            previous_position: spawn_pos_2d,
            ball_type,
        },
    ));
    cannon_state.fire();
}

pub fn move_projectiles(
    mut commands: Commands,
    mut projectiles: Query<(Entity, &mut BallProjectile, &mut Transform)>,
    time: Res<Time>,
) {
    for (entity, mut proj, mut transform) in projectiles.iter_mut() {
        // Обновляем позицию
        let delta = proj.velocity * time.delta_secs();
        let new_pos = proj.previous_position + delta;

        transform.translation = new_pos.extend(transform.translation.z);
        proj.previous_position = new_pos;

        // Опционально: удаляем снаряды, улетевшие за экран
        if new_pos.x.abs() > 2000.0 || new_pos.y.abs() > 2000.0 {
            commands.entity(entity).despawn();
        }
    }
}

pub fn detect_projectile_hit(
    mut commands: Commands,
    track: Res<TrackPath>,
    mut wave: ResMut<WaveState>,
    mut projectiles: Query<(Entity, &mut BallProjectile)>,
    mut balls: Query<(Entity, &mut Ball)>,
) {
    // пока идёт структурное изменение, спавн и другие мутации ждут
    if wave.is_queue_locked {
        return;
    }

    for (proj_entity, proj) in projectiles.iter_mut() {
        let mut min_dist_any = f32::MAX;
        let mut nearest_idx_any = 0;

        for (idx, &slot_pos) in track.points.iter().enumerate() {
            let dist = proj.previous_position.distance(slot_pos);
            if dist < min_dist_any {
                min_dist_any = dist;
                nearest_idx_any = idx;
            }
        }

        // если снаряд далеко от трека - промах
        if min_dist_any > HIT_THRESHOLD {
            // commands.entity(proj_entity).despawn();
            continue;
        }

        let insert_idx;
        let target_progress;

        if let Some((_, target_ball)) = balls.iter().find(|(_, b)| b.slot_index == nearest_idx_any) {
            // Копируем значения в локальные переменные
            target_progress = target_ball.slot_progress;

            // Определяем индекс вставки
            insert_idx = if target_progress <= 0.5 { //TODO check correction
                nearest_idx_any - 1
            } else {
                nearest_idx_any
            };
        } else {
            // Слот пуст — снаряд пролетает мимо
            // commands.entity(proj_entity).despawn();
            continue;
        }

        wave.is_queue_locked = true;

        // сдвигаем очередь
        let max_idx = track.points.len() - 1;
        let mut to_despawn = Vec::new();


        for (entity, mut ball) in balls.iter_mut() {
            if ball.slot_index >= insert_idx {
                if ball.slot_index < max_idx {
                    ball.slot_index += 1;
                } else {
                    to_despawn.push(entity);
                };
            }
        }

        for entity in to_despawn {
            commands.entity(entity).despawn();
        }

        commands.entity(proj_entity).insert({
            Ball {
                ball_type: proj.ball_type,
                slot_index: insert_idx,
                slot_progress: target_progress,
            }
        }).remove::<BallProjectile>();

        if let Some(&curr_pos) = track.points.get(insert_idx) {
            // Вычисляем позицию: интерполяция или центр слота
            let visual_pos = if let Some(&next_pos) = track.points.get(insert_idx + 1) {
                curr_pos.lerp(next_pos, target_progress)
            } else {
                curr_pos
            };

            // Обновляем Transform: ставим на трек и выравниваем Z (10.0), 
            // чтобы шарик не висел «над» очередью (PROJECTILE_Z_INDEX)
            commands.entity(proj_entity).insert(
                Transform::from_translation(visual_pos.extend(10.0))
            );
        }
        // запоминаем индекс слота, куда попали
        wave.last_insert_index = Some(insert_idx);
    }

    // Разблокировка (структурные изменения завершены)
    wave.is_queue_locked = false;
}

pub fn cycle_cannon_type(
    mut cannon_state: ResMut<CannonState>,
    mouse_input: Res<ButtonInput<MouseButton>>,
) {
    if mouse_input.just_pressed(MouseButton::Right) {
        cannon_state.cycle_next();
    }
}

pub fn update_cannon_preview(
    mut commands: Commands,
    cannon_state: Res<CannonState>,
    asset_server: Res<AssetServer>,
    cannon_query: Query<Entity, With<Cannon>>,
    muzzle_query: Query<Entity, With<CurrentPreviewMarker>>,
    next_query: Query<Entity, With<NextPreviewMarker>>,
) {
    let Ok(cannon_entity) = cannon_query.single() else { return };

    let muzzle_image = asset_server.load(cannon_state.current_type.asset_path());

    if let Ok(muzzle_entity) = muzzle_query.single() {
        // усли шарик у дула есть, то обновляем спрайт
        commands.entity(muzzle_entity).insert(Sprite::from_image(muzzle_image));
    } else {
        //иначе создаем
        let preview_entity = commands.spawn((
            CurrentPreviewMarker,
            Sprite{
                image: muzzle_image,
                custom_size: Some(Vec2::splat(SLOT_SIZE)),
                ..default()
            },
            Transform::from_xyz(0.0, 100.0, CURRENT_SHOT_Z_INDEX),
            Visibility::Visible,
        )).id();
        commands.entity(cannon_entity).add_child(preview_entity);
    }

    let next_image = asset_server.load(cannon_state.next_type.asset_path());

    if let Ok(next_entity) = next_query.single() {
        commands.entity(next_entity).insert(Sprite::from_image(next_image));
    } else {
        let preview_entity = commands.spawn((
            NextPreviewMarker,
            Sprite{
                image: next_image,
                custom_size: Some(Vec2::splat(SLOT_SIZE)),
                ..default()
            },
            Transform::from_xyz(0.0, -50.0, NEXT_SHOT_Z_INDEX),
            Visibility::Visible,
        )).id();
        commands.entity(cannon_entity).add_child(preview_entity);
    }
}

pub fn build_cannon_state() -> CannonState {
    CannonState {
        current_type: BallType::random(),
        next_type: BallType::random(),
    }
}