use bevy::prelude::*;
use bevy::input::mouse::MouseMotion;
use bevy::window::PrimaryWindow;
use bevy::core_pipeline::bloom::{BloomCompositeMode, BloomSettings};
use bevy_xpbd_3d::prelude::*;
use std::f32::consts::*;
use crate::{settings, audio, actor};

pub struct CameraControllerPlugin;

impl Plugin for CameraControllerPlugin {
    fn build(&self, app: &mut App) {
        app.add_systems(Startup, setup_camera);
        app.add_systems(Update, handle_input);
        app.add_systems(Update, manage_player_actor);
        app.add_systems(Update, run_camera_controller);
    }
}

// Based on Valorant's default sensitivity, not entirely sure why it is exactly 1.0 / 180.0,
// but I'm guessing it is a misunderstanding between degrees/radians and then sticking with
// it because it felt nice.
pub const RADIANS_PER_DOT: f32 = 1.0 / 180.0;

#[derive(Component)]
pub struct CameraController {
    pub enabled: bool,
    pub initialized: bool,
    pub sensitivity: f32,
    pub pitch: f32,
    pub yaw: f32,
}

impl Default for CameraController {
    fn default() -> Self {
        Self {
            enabled: true,
            initialized: false,
            sensitivity: 0.5,
            pitch: 1.0, // pitch=0/yaw=0 -> face sun
            yaw: 0.3,
        }
    }
}

fn setup_camera(
    mut commands: Commands,
) {
    // Add player
    commands.spawn((
        Camera3dBundle {
            camera: Camera {
                hdr: true, // HDR is required for bloom
                ..default()
            },
            transform: Transform::from_xyz(0.0, 0.0, 8.0).looking_at(Vec3::ZERO, Vec3::Y),
            ..default()
        },
        CameraController::default(),
        BloomSettings {
            composite_mode: BloomCompositeMode::EnergyConserving,
            ..default()
        },
    ));
}

pub fn handle_input(
    keyboard_input: Res<ButtonInput<KeyCode>>,
    mut settings: ResMut<settings::Settings>,
) {
    if keyboard_input.just_pressed(settings.key_camera) {
        settings.third_person ^= true;
    }
}

fn manage_player_actor(
    settings: Res<settings::Settings>,
    mut q_playercam: Query<&mut Visibility, With<actor::PlayerCamera>>,
    mut q_hiddenplayer: Query<&mut Visibility, (With<actor::Player>, Without<actor::PlayerCamera>)>,
) {
    for mut vis in &mut q_playercam {
        if settings.third_person {
            *vis = Visibility::Inherited;
        }
        else {
            *vis = Visibility::Hidden;
        }
    }
    for mut vis in &mut q_hiddenplayer {
        *vis = Visibility::Hidden;
    }
}

#[allow(clippy::too_many_arguments)]
fn run_camera_controller(
    time: Res<Time>,
    settings: Res<settings::Settings>,
    mut windows: Query<&mut Window, With<PrimaryWindow>>,
    mut mouse_events: EventReader<MouseMotion>,
    key_input: Res<ButtonInput<KeyCode>>,
    thruster_sound_controller: Query<&AudioSink, With<audio::ComponentThrusterSound>>,
    rocket_sound_controller: Query<&AudioSink, With<audio::ComponentRocketSound>>,
    ion_sound_controller: Query<&AudioSink, With<audio::ComponentIonSound>>,
    mut q_engine: Query<&mut actor::Engine, With<actor::PlayerDrivesThis>>,
    mut q_camera: Query<(&mut Transform, &mut CameraController, &mut Projection)>,
    q_player: Query<&actor::LifeForm, With<actor::Player>>,
    mut q_playercam: Query<(
            &actor::Actor,
            &mut Transform,
            &mut actor::Engine,
            &mut AngularVelocity,
            &mut LinearVelocity,
        ), (With<actor::PlayerCamera>, Without<actor::PlayerDrivesThis>, Without<CameraController>)>,
) {
    let dt = time.delta_seconds();
    let mut play_thruster_sound = false;

    let window_result = windows.get_single_mut();
    let mut focused = true;
    if window_result.is_ok() {
        focused = window_result.unwrap().focused;
    }

    if let (
        Ok((mut camera_transform, mut controller, mut projection)),
        Ok(lifeform),
        Ok((actor, mut player_transform, player_engine, mut angularvelocity, mut v)),
    ) = (q_camera.get_single_mut(), q_player.get_single(), q_playercam.get_single_mut()) {
        if !controller.enabled {
            mouse_events.clear();
            return;
        }

        if angularvelocity.length_squared() > 0.0001 {
            angularvelocity.x *= 0.98;
            angularvelocity.y *= 0.98;
            angularvelocity.z *= 0.98;
        }
        else {
            angularvelocity.0 = Vec3::splat(0.0);
        }

        // Handle key input
        let mut axis_input = Vec3::ZERO;
        if focused {
            if key_input.pressed(settings.key_forward) {
                axis_input.z += 1.2;
            }
            if key_input.pressed(settings.key_back) {
                axis_input.z -= 1.2;
            }
            if key_input.pressed(settings.key_right) {
                axis_input.x -= 1.2;
            }
            if key_input.pressed(settings.key_left) {
                axis_input.x += 1.2;
            }
            if key_input.pressed(settings.key_up) {
                axis_input.y += 1.2;
            }
            if key_input.pressed(settings.key_down) {
                axis_input.y -= 1.2;
            }
            if key_input.pressed(settings.key_stop) {
                let stop_direction = -v.normalize();
                if stop_direction.length_squared() > 0.3 {
                    axis_input += 1.0 * (player_transform.rotation.inverse() * stop_direction);
                }
            }
        }
        // In typical games we would normalize the input vector so that diagonal movement is as
        // fast as forward or sideways movement.  But here, we merely clamp each direction to an
        // absolute maximum of 1, since every thruster can be used separately. If the forward
        // thrusters and the leftward thrusters are active at the same time, then of course the
        // total diagonal acceleration is faster than the forward acceleration alone.
        axis_input = axis_input.clamp(Vec3::splat(-1.0), Vec3::splat(1.0));

        let mut engine = if let Ok(engine) = q_engine.get_single_mut() { engine } else { player_engine };

        // Apply movement update
        let forward_factor = engine.current_warmup * (if axis_input.z < 0.0 {
            engine.thrust_forward
        } else {
            engine.thrust_back
        });
        let right_factor = engine.thrust_sideways * engine.current_warmup;
        let up_factor = engine.thrust_sideways * engine.current_warmup;
        let factor = Vec3::new(right_factor, up_factor, forward_factor);

        if axis_input.length_squared() > 0.003 {
            let acceleration_global = player_transform.rotation * (axis_input * factor);
            let mut acceleration_total = actor::ENGINE_SPEED_FACTOR * dt * acceleration_global;
            let threshold = 1e-5;
            if key_input.pressed(settings.key_stop) {
                for i in 0..3 {
                    if v[i].abs() < threshold {
                        v[i] = 0.0;
                    }
                    else if v[i].signum() != (v[i] + acceleration_total[i]).signum() {
                        // Overshoot
                        v[i] = 0.0;
                        acceleration_total[i] = 0.0;
                    }
                }
            }
            v.0 += acceleration_total;
            engine.current_warmup = (engine.current_warmup + dt / engine.warmup_seconds).clamp(0.0, 1.0);
            play_thruster_sound = !settings.mute_sfx;
        }
        else {
            engine.current_warmup = (engine.current_warmup - dt / engine.warmup_seconds).clamp(0.0, 1.0);
        }

        // Handle mouse input
        let mut mouse_delta = Vec2::ZERO;
        for mouse_event in mouse_events.read() {
            mouse_delta += mouse_event.delta;
        }

        if mouse_delta != Vec2::ZERO {
            // Apply look update
            controller.pitch = (controller.pitch
                + mouse_delta.y * RADIANS_PER_DOT * controller.sensitivity)
                .clamp(-PI / 2., PI / 2.);
            controller.yaw += mouse_delta.x * RADIANS_PER_DOT * controller.sensitivity;
            player_transform.rotation = Quat::from_euler(EulerRot::ZYX, 0.0, -controller.yaw, controller.pitch).normalize();
            camera_transform.rotation = Quat::from_euler(EulerRot::ZYX, 0.0, PI-controller.yaw, -controller.pitch).normalize();
        }

        if settings.third_person {
            camera_transform.translation = player_transform.translation + camera_transform.rotation * (actor.camdistance * Vec3::new(0.0, 0.2, 1.0));
        }
        else {
            camera_transform.translation = player_transform.translation;
        }

        let fov = (lifeform.adrenaline * lifeform.adrenaline * lifeform.adrenaline * 45.0 + 45.0).to_radians();
        *projection = Projection::Perspective(PerspectiveProjection { fov: fov, ..default() });

        if let Ok(sink) = thruster_sound_controller.get_single() {
            if play_thruster_sound && engine.engine_type == actor::EngineType::Monopropellant {
                sink.play()
            } else {
                sink.pause()
            }
        }
        if let Ok(sink) = rocket_sound_controller.get_single() {
            if play_thruster_sound && engine.engine_type == actor::EngineType::Rocket {
                sink.play()
            } else {
                sink.pause()
            }
        }
        if let Ok(sink) = ion_sound_controller.get_single() {
            if play_thruster_sound && engine.engine_type == actor::EngineType::Ion {
                sink.play()
            } else {
                sink.pause()
            }
        }
    }
}