import { mts } from "../../common/mod.ts";
import { range } from "../../common/utils.ts";
import { log_from, v2, Vec2 } from "../../common/utils.ts";
import { CompDisplay } from "../components/display.ts";
import { sys_find_free_pos } from "../components/world.ts";
import { CompPos, query_in_rect } from "../components/world.ts";
import { Engine, Entity } from "../engine.ts";
import { ClientInterface } from "../network.ts";
const log = log_from(import.meta);

export class Session {
	client;
	engine;
	entity;

	constructor(client: ClientInterface, engine: Engine, entity: Entity) {
		this.client = client;
		this.engine = engine;
		this.entity = entity;
	}

	static init(client: ClientInterface, engine: Engine) {
		const spawn_pos = engine.run(sys_find_free_pos(v2(0, 0)));
		const entity = engine.run(sys_spawn_player(spawn_pos));
		const self = new Session(client, engine, entity);
		return self;
	}

	async start() {
		try {
			for await (const input of this.client.inputs.iter()) {
				if (input.kind !== "request_display") log("Received", input);

				if (input.kind === "ping") this.client.outputs.send({ kind: "ping_response", content: input.content });
				if (input.kind === "request_display") this.send_display(input.content.width, input.content.height);
				if (input.kind === "input") this.handle_input(input);
				if (input.kind === "exit") this.engine.delete(this.entity.identifier);
			}
		} catch (error) {
			console.error("Session loop failed, ", error);
			this.engine.delete(this.entity.identifier);
		}
	}

	handle_input(input: mts.MsgInput) {
		if (input.content.control === "up") this.move(v2(0, 1));
		if (input.content.control === "down") this.move(v2(0, -1));
		if (input.content.control === "left") this.move(v2(-1, 0));
		if (input.content.control === "right") this.move(v2(1, 0));
	}

	send_display(width: number, height: number) {
		const raw = this.engine.run(sys_render_world(this.entity.get_force(CompPos).position, v2(width, height)));
		this.client.outputs.send({ kind: "display", content: { raw } });
	}

	move(direction: Vec2) {
		const pos = this.entity.get_force(CompPos);
		pos.move_collide(this.engine, direction);
	}
}

export function sys_render_world(center: Vec2, size: Vec2) {
	return (engine: Engine) => {
		const radius = size.scale(0.5);
		const result = Array.from(range(0, size.y())).map(() => Array.from(range(0, size.x())).map(() => "  "));
		const min = center.sub(radius);
		const max = center.add(radius);
		for (const entity of engine.query_all(query_in_rect(min, max).with(CompDisplay))) {
			const local_pos = entity.get_force(CompPos).position.sub(min);
			result[local_pos.y()][local_pos.x()] = entity.get_force(CompDisplay).display;
		}
		return result.map((line) => line.join("")).toReversed().join("\n");
	};
}

export function sys_spawn_player(position: Vec2) {
	return (engine: Engine) => {
		return engine.spawn((entity) =>
			entity.insert(
				new CompPlayer(),
				new CompPos(entity, position),
				new CompDisplay("`/"),
			)
		);
	};
}

class CompPlayer {
	life;
	constructor() {
		this.life = 10;
	}
}