use bevy::{
    core::{Time, Timer},
    diagnostic::{Diagnostics, FrameTimeDiagnosticsPlugin, LogDiagnosticsPlugin},
    ecs::prelude::*,
    input::Input,
    math::Vec3,
    prelude::{info, App, AssetServer, Handle, MouseButton, Transform},
    render2::{camera::OrthographicCameraBundle, color::Color, texture::Image},
    sprite2::{PipelinedSpriteBundle, Sprite},
    window::WindowDescriptor,
    PipelinedDefaultPlugins,
};
use rand::{random, Rng};

const BIRDS_PER_SECOND: u32 = 10000;
const _BASE_COLOR: Color = Color::rgb(5.0, 5.0, 5.0);
const GRAVITY: f32 = -9.8 * 100.0;
const MAX_VELOCITY: f32 = 750.;
const BIRD_SCALE: f32 = 0.15;
const HALF_BIRD_SIZE: f32 = 256. * BIRD_SCALE * 0.5;

struct BevyCounter {
    pub count: u128,
    pub color: Color,
}

struct Bird {
    velocity: Vec3,
}

// struct BirdMaterial(Handle<ColorMaterial>);

// impl FromWorld for BirdMaterial {
//     fn from_world(world: &mut World) -> Self {
//         let world = world.cell();
//         let mut color_materials = world.get_resource_mut::<Assets<ColorMaterial>>().unwrap();
//         let asset_server = world.get_resource_mut::<AssetServer>().unwrap();
//         BirdMaterial(color_materials.add(asset_server.load("branding/icon.png").into()))
//     }
// }

fn main() {
    App::new()
        .insert_resource(WindowDescriptor {
            title: "BevyMark".to_string(),
            width: 800.,
            height: 600.,
            vsync: false,
            resizable: true,
            ..Default::default()
        })
        .add_plugins(PipelinedDefaultPlugins)
        .add_plugin(FrameTimeDiagnosticsPlugin::default())
        .add_plugin(LogDiagnosticsPlugin::default())
        // .add_plugin(WgpuResourceDiagnosticsPlugin::default())
        .insert_resource(BevyCounter {
            count: 0,
            color: Color::WHITE,
        })
        // .init_resource::<BirdMaterial>()
        .add_startup_system(setup)
        .add_system(mouse_handler)
        .add_system(movement_system)
        .add_system(collision_system)
        .add_system(counter_system)
        .run();
}

struct BirdTexture(Handle<Image>);

fn setup(
    mut commands: Commands,
    window: Res<WindowDescriptor>,
    mut counter: ResMut<BevyCounter>,
    asset_server: Res<AssetServer>,
) {
    let texture = asset_server.load("branding/icon.png");
    if let Some(initial_count) = std::env::args()
        .nth(1)
        .and_then(|arg| arg.parse::<u128>().ok())
    {
        spawn_birds(
            &mut commands,
            &window,
            &mut counter,
            initial_count,
            texture.clone_weak(),
        );
    }
    commands.spawn_bundle(OrthographicCameraBundle::new_2d());
    // commands.spawn_bundle(UiCameraBundle::default());
    // commands.spawn_bundle(TextBundle {
    //     text: Text {
    //         sections: vec![
    //             TextSection {
    //                 value: "Bird Count: ".to_string(),
    //                 style: TextStyle {
    //                     font: asset_server.load("fonts/FiraSans-Bold.ttf"),
    //                     font_size: 40.0,
    //                     color: Color::rgb(0.0, 1.0, 0.0),
    //                 },
    //             },
    //             TextSection {
    //                 value: "".to_string(),
    //                 style: TextStyle {
    //                     font: asset_server.load("fonts/FiraSans-Bold.ttf"),
    //                     font_size: 40.0,
    //                     color: Color::rgb(0.0, 1.0, 1.0),
    //                 },
    //             },
    //             TextSection {
    //                 value: "\nAverage FPS: ".to_string(),
    //                 style: TextStyle {
    //                     font: asset_server.load("fonts/FiraSans-Bold.ttf"),
    //                     font_size: 40.0,
    //                     color: Color::rgb(0.0, 1.0, 0.0),
    //                 },
    //             },
    //             TextSection {
    //                 value: "".to_string(),
    //                 style: TextStyle {
    //                     font: asset_server.load("fonts/FiraSans-Bold.ttf"),
    //                     font_size: 40.0,
    //                     color: Color::rgb(0.0, 1.0, 1.0),
    //                 },
    //             },
    //         ],
    //         ..Default::default()
    //     },
    //     style: Style {
    //         position_type: PositionType::Absolute,
    //         position: Rect {
    //             top: Val::Px(5.0),
    //             left: Val::Px(5.0),
    //             ..Default::default()
    //         },
    //         ..Default::default()
    //     },
    //     ..Default::default()
    // });

    commands.insert_resource(BirdTexture(texture));
}

#[allow(clippy::too_many_arguments)]
fn mouse_handler(
    mut commands: Commands,
    _asset_server: Res<AssetServer>,
    time: Res<Time>,
    mouse_button_input: Res<Input<MouseButton>>,
    window: Res<WindowDescriptor>,
    bird_texture: Res<BirdTexture>,
    // mut bird_material: ResMut<BirdMaterial>,
    mut counter: ResMut<BevyCounter>,
    // mut materials: ResMut<Assets<ColorMaterial>>,
) {
    // if mouse_button_input.just_pressed(MouseButton::Left) {
    //     let mut rnd = rand::thread_rng();
    //     let color = gen_color(&mut rnd);

    //     let texture_handle = asset_server.load("branding/icon.png");

    //     bird_material.0 = materials.add(ColorMaterial {
    //         color: BASE_COLOR * color,
    //         texture: Some(texture_handle),
    //     });
    // }
    if mouse_button_input.just_released(MouseButton::Left) {
        counter.color = Color::rgb(random(), random(), random());
    }

    if mouse_button_input.pressed(MouseButton::Left) {
        let spawn_count = (BIRDS_PER_SECOND as f64 * time.delta_seconds_f64()) as u128;
        spawn_birds(
            &mut commands,
            &window,
            &mut counter,
            spawn_count,
            bird_texture.0.clone(),
        );
    }
}

fn spawn_birds(
    commands: &mut Commands,
    window: &WindowDescriptor,
    counter: &mut BevyCounter,
    spawn_count: u128,
    texture: Handle<Image>,
) {
    let bird_x = (window.width / -2.) + HALF_BIRD_SIZE;
    let bird_y = (window.height / 2.) - HALF_BIRD_SIZE;
    for count in 0..spawn_count {
        let bird_z = (counter.count + count) as f32 * 0.00001;
        commands
            .spawn_bundle(PipelinedSpriteBundle {
                // material: bird_material.0.clone(),
                texture: texture.clone(),
                transform: Transform {
                    translation: Vec3::new(bird_x, bird_y, bird_z),
                    scale: Vec3::splat(BIRD_SCALE),
                    ..Default::default()
                },
                sprite: Sprite {
                    color: counter.color,
                    ..Default::default()
                },
                ..Default::default()
            })
            .insert(Bird {
                velocity: Vec3::new(
                    rand::random::<f32>() * MAX_VELOCITY - (MAX_VELOCITY * 0.5),
                    0.,
                    0.,
                ),
            });
    }
    counter.count += spawn_count;
}

fn movement_system(time: Res<Time>, mut bird_query: Query<(&mut Bird, &mut Transform)>) {
    for (mut bird, mut transform) in bird_query.iter_mut() {
        transform.translation.x += bird.velocity.x * time.delta_seconds();
        transform.translation.y += bird.velocity.y * time.delta_seconds();
        bird.velocity.y += GRAVITY * time.delta_seconds();
    }
}

fn collision_system(window: Res<WindowDescriptor>, mut bird_query: Query<(&mut Bird, &Transform)>) {
    let half_width = window.width as f32 * 0.5;
    let half_height = window.height as f32 * 0.5;

    for (mut bird, transform) in bird_query.iter_mut() {
        let x_vel = bird.velocity.x;
        let y_vel = bird.velocity.y;
        let x_pos = transform.translation.x;
        let y_pos = transform.translation.y;

        if (x_vel > 0. && x_pos + HALF_BIRD_SIZE > half_width)
            || (x_vel <= 0. && x_pos - HALF_BIRD_SIZE < -(half_width))
        {
            bird.velocity.x = -x_vel;
        }
        if y_vel < 0. && y_pos - HALF_BIRD_SIZE < -half_height {
            bird.velocity.y = -y_vel;
        }
    }
}

struct CountTimer {
    timer: Timer,
}

impl Default for CountTimer {
    fn default() -> Self {
        Self {
            timer: Timer::from_seconds(1.0, true),
        }
    }
}

fn counter_system(
    mut timer: Local<CountTimer>,
    _diagnostics: Res<Diagnostics>,
    time: Res<Time>,
    counter: Res<BevyCounter>,
) {
    if timer.timer.tick(time.delta()).finished() {
        info!("counter: {}", counter.count);
    }
}

/// Generate a color modulation
///
/// Because there is no `Mul<Color> for Color` instead `[f32; 3]` is
/// used.
fn _gen_color(rng: &mut impl Rng) -> [f32; 3] {
    let r = rng.gen_range(0.2..1.0);
    let g = rng.gen_range(0.2..1.0);
    let b = rng.gen_range(0.2..1.0);
    let v = Vec3::new(r, g, b);
    v.normalize().into()
}