import { AssetManager } from "./assets.ts";
import { Client } from "./client.ts";
import { InputManager } from "./input_manager.ts";
import { Connection, get_player_name } from "./network.ts";
import { connect, HandshakeError, is_trusted, join, load_atlas, remember_trust, server_address } from "./handshake.ts";
import { confirm_mods } from "./confirm_mods.ts";
import { ModLoadError } from "$/common/mod_loader.ts";
import { begin_drawing, clear_background, end_drawing, init_font, init_window, load_texture } from "./renderer/mod.ts";
import { is_stopped, show_fatal_error } from "./fatal.ts";
import { load_client_mods, set_mods_client } from "./mods.ts";

export class ClientLoop {
	running = false;
	last_time = 0;
	client: Client;

	frame_count = 0;
	last_fps_time = 0;

	constructor(client: Client) {
		this.client = client;
	}

	start() {
		document.addEventListener("visibilitychange", () => {
			if (!document.hidden) {
				this.last_time = performance.now();
			}
		});

		this.running = true;
		const now = performance.now();
		this.last_time = now;
		this.frame_count = 0;
		this.last_fps_time = this.last_time;
		requestAnimationFrame((time) => this.loop(time));
	}

	stop() {
		this.running = false;
	}

	loop(time: number) {
		if (!this.running || is_stopped()) {
			return;
		}

		const delta = (time - this.last_time) / 1000;

		begin_drawing();
		clear_background(0.69, 0.8, 1, 1.0);
		this.client.run_frame(delta);
		end_drawing();

		this.frame_count += 1;
		const now = performance.now();
		if (now - this.last_fps_time >= 1000) {
			const fps = (this.frame_count * 1000) / (now - this.last_fps_time);
			console.log(`FPS: ${fps.toFixed(2)}`);
			this.frame_count = 0;
			this.last_fps_time = now;
		}

		InputManager.update();

		this.last_time = time;
		requestAnimationFrame((time) => this.loop(time));
	}
}

const canvas = document.getElementById("game") as HTMLCanvasElement;
if (!canvas) {
	throw Error("Canvas was not found");
}

await init_window(canvas);

InputManager.initialize(canvas);

AssetManager.instance.load("bworld:assets_text", "/assets/ASSETS.md");

AssetManager.instance.load("bworld:player", "/assets/sprites/player.png");
AssetManager.instance.load("bworld:roguelike", "/assets/sprites/roguelike.png");
AssetManager.instance.load("bworld:ui", "/assets/sprites/ui.png");

AssetManager.instance.load("bworld:m6x11", "/assets/fonts/m6x11.png");
AssetManager.instance.load("bworld:m6x11_fnt", "/assets/fonts/m6x11.fnt");

await AssetManager.instance.load_all();

init_font();

// the game only runs against a server, it owns the world and everything in it. see "Delivery to clients" in MODS.md
async function join_server(): Promise<Connection> {
	const address = server_address();
	const { socket, welcome } = await connect(address, get_player_name());
	console.log(`Connected to ${address.ws_url}`);

	try {
		if (address.cross_origin && !is_trusted(address, welcome)) {
			if (!await confirm_mods(address, welcome)) {
				throw new HandshakeError(`You didn't join ${address.base.host}`);
			}
			remember_trust(address, welcome);
		}

		// textures, blocks and items all come from the server's mods, so this happens before anything else
		const atlas = await load_atlas(address, welcome.atlas);
		AssetManager.instance.assets["bworld:textures"] = load_texture(atlas.image);
		AssetManager.instance.assets["bworld:textures_info"] = atlas.regions;
		await load_client_mods(welcome.mods, address.base);
		console.log(`Mods: ${welcome.mods.map((mod) => `${mod.id} ${mod.version}`).join(", ") || "none"}`);

		const joined = await join(socket);
		return new Connection(socket, welcome, joined);
	} catch (e) {
		socket.close();
		throw e;
	}
}

try {
	const connection = await join_server();
	const client = new Client(connection);
	set_mods_client(client);
	client.chat.add("Connected to the server");

	const loop = new ClientLoop(client);
	loop.start();

	console.log("Game started");
} catch (e) {
	console.error(e);
	const message = e instanceof HandshakeError
		? e.message
		: e instanceof ModLoadError
		? `Couldn't load the server's mods: ${e.message}`
		: `Something went wrong joining the server: ${e instanceof Error ? e.message : e}`;
	show_fatal_error(message);
}