use bevy::prelude::*;
use shared::{resources::TileUnderCursor, sets::GameplaySet, states::AssetLoadState};

use crate::components::{LandUnit, Path, Target, Unit};

pub struct UnitsDebugPlugin;

impl Plugin for UnitsDebugPlugin {
	fn build(&self, app: &mut App) {
		app.add_systems(Update, init.run_if(in_state(AssetLoadState::Loading)));

		app.add_systems(Update, (spawn_test_unit, set_unit_target).in_set(GameplaySet));
		app.add_systems(FixedUpdate, (visualize_paths).in_set(GameplaySet));
	}
}

#[derive(Resource)]
struct TestUnit(pub Handle<Mesh>);

fn init(mut meshes: ResMut<Assets<Mesh>>, mut commands: Commands) {
	let mesh_handle = meshes.add(Cuboid::from_length(1.0));
	commands.insert_resource(TestUnit(mesh_handle));
}

fn spawn_test_unit(
	mut commands: Commands,
	input: Res<ButtonInput<KeyCode>>,
	tile_under_cursor: Res<TileUnderCursor>,
	unit: Res<TestUnit>,
) {
	if !input.just_pressed(KeyCode::KeyT) {
		return;
	}
	if let Some(contact) = tile_under_cursor.0 {
		info!("Spawning Test Unit");
		commands.spawn((
			PbrBundle {
				transform: Transform::from_translation(contact.surface),
				mesh: unit.0.clone(),
				..default()
			},
			Unit,
			LandUnit,
		));
	}
}

fn set_unit_target(
	mut commands: Commands,
	units: Query<Entity, With<Unit>>,
	input: Res<ButtonInput<MouseButton>>,
	tile_under_cursor: Res<TileUnderCursor>,
) {
	if !input.just_pressed(MouseButton::Right) {
		return;
	}
	if let Some(contact) = tile_under_cursor.0 {
		for e in units.iter() {
			info!("Setting Target");
			let mut e = commands.entity(e);
			e.insert(Target(contact.tile));
		}
	}
}

fn visualize_paths(units: Query<&Path, With<Unit>>, mut gizmos: Gizmos) {
	for path in units.iter() {
		if path.1 > path.0.len() {
			continue;
		}
		for node in 1..path.0.len() {
			let from = path.0[node];
			let to = path.0[node - 1];
			let color = if node > path.1 {
				LinearRgba::rgb(1.0, 0.5, 0.0)
			} else {
				LinearRgba::rgb(1.0, 0.5, 1.5)
			};
			gizmos.line(from + Vec3::Y * 0.1, to + Vec3::Y * 0.1, color);
		}
	}
}