import { assert } from "https://deno.land/std@0.221.0/assert/assert.ts";
import { v2 } from "../../common/utils.ts";
import { Vec2 } from "../../common/utils.ts";
import { CompDisplay } from "../components/display.ts";
import { query_in_rect } from "../components/world.ts";
import { CompPos } from "../components/world.ts";
import { CompId, Query } from "../engine.ts";
import { Engine } from "../engine.ts";
import { CompPlayer } from "./player.ts";

export class CompEnemy {
	target;
	life;

	constructor() {
		this.target = null as number | null;
		this.life = 10;
	}

	find_target_from(engine: Engine, pos: Vec2, range: number) {
		const radius = v2(range, range);
		const found = engine.one(Query.with(CompPlayer).with(CompId).and(query_in_rect(pos.sub(radius), pos.add(radius))));
		if (found === null) {
			this.target = null;
			return;
		}
		const [_, id, __] = found;
		this.target = id.id;
	}

	get_target_pos(engine: Engine) {
		if (this.target === null) return null;
		const result = engine.one(Query.with(CompId).filter(([c]) => c.id === this.target).with(CompPos));
		if (result === null) {
			this.target = null;
			return null;
		}
		const [_, pos] = result;
		return pos.pos;
	}
}

export function sys_spawn_enemy(pos: Vec2) {
	return (engine: Engine) => {
		return engine.spawn((entity) =>
			entity.insert(
				new CompEnemy(),
				new CompPos(entity, pos),
				new CompDisplay("èé"),
			)
		);
	};
}

export function sys_update_enemy() {
	const trigger_range = 5;
	const forget_range = 10;
	return (engine: Engine) => {
		for (const [enemy, enemy_pos] of engine.all(Query.with(CompEnemy).with(CompPos))) {
			if (enemy.target === null) enemy.find_target_from(engine, enemy_pos.pos, trigger_range);
			const pos = enemy.get_target_pos(engine);
			if (pos === null) continue;
			const direction = pos.sub(enemy_pos.pos);
			if (direction.len() <= forget_range) {
				const displacement = direction.normalize();
				const moved = enemy_pos.move_collide(engine, displacement);
				if (!moved) {
					enemy_pos.move_collide(engine, v2(displacement.x(), 0));
					enemy_pos.move_collide(engine, v2(0, displacement.y()));
				}
			} else enemy.target = null;
		}
	};
}

export function enemy_plugin(engine: Engine) {
	engine.global_system_loop(sys_update_enemy(), 500);
}