use bevy::prelude::*;
use bevy::input::mouse::MouseMotion;
use bevy::window::PrimaryWindow;
use bevy::core_pipeline::bloom::{BloomCompositeMode, BloomSettings};
use bevy::core_pipeline::tonemapping::Tonemapping;
use bevy::transform::TransformSystem;
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.after(handle_input));
        app.add_systems(PostUpdate, sync_camera_to_player
            .after(PhysicsSet::Sync)
            .before(TransformSystem::TransformPropagate));
        app.add_systems(Update, update_fov);
        app.add_systems(PostUpdate, apply_input_to_player
            .after(PhysicsSet::Sync)
            .before(TransformSystem::TransformPropagate));
    }
}

// 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;

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

pub fn sync_camera_to_player(
    settings: Res<settings::Settings>,
    mut q_camera: Query<&mut Transform, With<Camera>>,
    q_playercam: Query<(&actor::Actor, &Transform), (With<actor::PlayerCamera>, Without<Camera>)>,
) {
    if q_camera.is_empty() || q_playercam.is_empty() {
        return;
    }
    let mut camera_transform = q_camera.get_single_mut().unwrap();
    let (actor, player_transform) = q_playercam.get_single().unwrap();

    // Rotation
    camera_transform.rotation = player_transform.rotation * Quat::from_array([0.0, -1.0, 0.0, 0.0]);

    // Translation
    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;
    }
}

pub fn update_fov(
    q_player: Query<&actor::LifeForm, With<actor::Player>>,
    mut q_camera: Query<&mut Projection, With<Camera>>,
) {
    if let (Ok(lifeform), Ok(mut projection)) = (q_player.get_single(), q_camera.get_single_mut())
    {
        let fov = (lifeform.adrenaline.powf(3.0) * 45.0 + 45.0).to_radians();
        *projection = Projection::Perspective(PerspectiveProjection { fov: fov, ..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 apply_input_to_player(
    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_playercam: Query<(
            &mut Transform,
            &mut actor::Engine,
            &mut AngularVelocity,
            &mut LinearVelocity,
        ), (With<actor::PlayerCamera>, Without<Camera>)>,
) {
    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 player_transform, mut engine, mut angularvelocity, mut v)) = q_playercam.get_single_mut() {

        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));

        // 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) {
                // Decelerate
                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() {
                        // Almost stopped, but we overshot v=0
                        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 and mouse-like key bindings
        let mut mouse_delta = Vec2::ZERO;
        let mut pitch_yaw_rot = Vec3::ZERO;
        let mouseless_sensitivity = 8.0;
        if key_input.pressed(settings.key_mouseup) {
            pitch_yaw_rot[0] -= mouseless_sensitivity;
        }
        if key_input.pressed(settings.key_mousedown) {
            pitch_yaw_rot[0] += mouseless_sensitivity;
        }
        if key_input.pressed(settings.key_mouseleft) {
            pitch_yaw_rot[1] += mouseless_sensitivity;
        }
        if key_input.pressed(settings.key_mouseright) {
            pitch_yaw_rot[1] -= mouseless_sensitivity;
        }
        if key_input.pressed(settings.key_rotateleft) {
            pitch_yaw_rot[2] -= mouseless_sensitivity;
        }
        if key_input.pressed(settings.key_rotateright) {
            pitch_yaw_rot[2] += mouseless_sensitivity;
        }
        for mouse_event in mouse_events.read() {
            mouse_delta += mouse_event.delta;
        }
        if mouse_delta != Vec2::ZERO {
            if key_input.pressed(settings.key_rotate) {
                pitch_yaw_rot[2] += mouse_delta.x;
            } else {
                pitch_yaw_rot[0] += mouse_delta.y;
                pitch_yaw_rot[1] -= mouse_delta.x;
            }
        }
        if pitch_yaw_rot.length_squared() > 0.0001 {
            pitch_yaw_rot *= RADIANS_PER_DOT * settings.mouse_sensitivity;
            player_transform.rotation *= Quat::from_euler(EulerRot::ZYX,
                pitch_yaw_rot[2], pitch_yaw_rot[1], pitch_yaw_rot[0]).normalize();
        }

        // Play sound effects
        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()
            }
        }
    }
}