use crate::client::network::*;
use crate::protocol::*;
use crate::shared::imperative::*;
use crate::shared::projectile::*;
use crate::shared::*;
use bevy::input::mouse::MouseButton;
use bevy::prelude::*;
use bevy::sprite::{MaterialMesh2dBundle, Mesh2dHandle};
use lightyear::client::input::InputSystemSet;
use lightyear::prelude::*;

mod network;

const PLAYER_RADIUS: f32 = 10.;
const PLAYER_HOVER_INDICATOR_RADIUS: f32 = 13.;
const PLAYER_HOVER_RADIUS: f32 = 20.;

pub fn main(transport: TransportConfig) {
    App::new()
        .add_plugins(DefaultPlugins)
        .add_plugins(ClientPlugin { transport })
        .run();
}

struct ClientPlugin {
    pub transport: TransportConfig,
}

impl Plugin for ClientPlugin {
    fn build(&self, app: &mut App) {
        app.add_plugins(NetworkPlugin {
            transport: self.transport.clone(),
        })
        .add_systems(Startup, setup)
        .add_systems(Update, render_players)
        .add_systems(Update, render_projectiles)
        .add_systems(Update, move_players)
        .add_systems(Update, move_projectiles)
        .add_systems(
            FixedPreUpdate,
            buffer_input.in_set(InputSystemSet::BufferInputs),
        )
        .add_systems(Last, gizmos_hover_indicator);
    }
}

fn setup(mut client: ClientMut, mut commands: Commands) {
    commands.spawn(Camera2dBundle::default());
    client.connect().unwrap();
}

fn render_players(
    mut commands: Commands,
    mut materials: ResMut<Assets<ColorMaterial>>,
    mut meshes: ResMut<Assets<Mesh>>,
    players: Query<(Entity, &PlayerPosition, &PlayerColor), Added<PlayerId>>,
) {
    for (entity, position, color) in players.iter() {
        commands.entity(entity).insert(MaterialMesh2dBundle {
            mesh: Mesh2dHandle(meshes.add(Circle {
                radius: PLAYER_RADIUS,
            })),
            material: materials.add(color.0),
            transform: Transform::from_xyz(position.0.x, position.0.y, 0.),
            ..Default::default()
        });
    }
}

fn render_projectiles(
    mut commands: Commands,
    mut materials: ResMut<Assets<ColorMaterial>>,
    mut meshes: ResMut<Assets<Mesh>>,
    projectiles: Query<(Entity, &ProjectilePosition), Added<Projectile>>,
) {
    for (entity, position) in projectiles.iter() {
        commands.entity(entity).insert(MaterialMesh2dBundle {
            mesh: Mesh2dHandle(meshes.add(Circle { radius: 2. })),
            material: materials.add(Color::RED),
            transform: Transform::from_xyz(position.0.x, position.0.y, 1.),
            ..Default::default()
        });
    }
}

fn move_projectiles(
    mut projectiles: Query<(&mut Transform, &ProjectilePosition), Changed<ProjectilePosition>>,
) {
    for (mut transform, projectile_position) in projectiles.iter_mut() {
        transform.translation = Vec3::new(projectile_position.0.x, projectile_position.0.y, 0.);
    }
}

fn move_players(mut players: Query<(&mut Transform, &PlayerPosition), Changed<PlayerPosition>>) {
    for (mut transform, player_position) in players.iter_mut() {
        transform.translation = Vec3::new(player_position.0.x, player_position.0.y, 0.);
    }
}

fn buffer_input(
    attackables: Query<(&PlayerId, &PlayerPosition)>,
    cameras: Query<(&Camera, &GlobalTransform)>,
    mouse_input: Res<ButtonInput<MouseButton>>,
    mut client: ClientMut,
    windows: Query<&Window>,
) {
    if mouse_input.just_pressed(MouseButton::Left) {
        if let Some((target_player, _)) = hovered_player(&windows, &cameras, &attackables) {
            client.add_input(Inputs::Imperative(Imperative::Attack(target_player)));
        } else {
            if let Some(world_position) = cursor_world_position(&windows, &cameras) {
                client.add_input(Inputs::Imperative(Imperative::WalkTo(world_position)));
            }
        }
    }
}

fn gizmos_hover_indicator(
    mut gizmos: Gizmos,
    hoverables: Query<(&PlayerId, &PlayerPosition)>,
    cameras: Query<(&Camera, &GlobalTransform)>,
    windows: Query<&Window>,
) {
    let Some((_, position)) = hovered_player(&windows, &cameras, &hoverables) else {
        return;
    };
    gizmos.circle_2d(position.0, PLAYER_HOVER_INDICATOR_RADIUS, Color::GREEN);
}

fn cursor_world_position(
    windows: &Query<&Window>,
    cameras: &Query<(&Camera, &GlobalTransform)>,
) -> Option<Vec2> {
    let window = windows.single();
    let (camera, camera_transform) = cameras.single();
    let Some(cursor_position) = window.cursor_position() else {
        return None;
    };
    camera.viewport_to_world_2d(camera_transform, cursor_position)
}

fn hovered_player(
    windows: &Query<&Window>,
    cameras: &Query<(&Camera, &GlobalTransform)>,
    hoverables: &Query<(&PlayerId, &PlayerPosition)>,
) -> Option<(PlayerId, PlayerPosition)> {
    let Some(world_position) = cursor_world_position(&windows, &cameras) else {
        return None;
    };
    let mut hovered_player = None;
    for (id, position) in hoverables.iter() {
        if position.0.distance(world_position) < PLAYER_HOVER_RADIUS {
            hovered_player = Some((*id, *position));
        }
    }
    hovered_player
}