// starts a game server with its mods: registers their data, then imports worldgen and server scripts.
// the worker loads built mods, tests can load mods straight from their source folders
import { register_mod_data } from "$/common/mod_loader.ts";
import type { ModData, ModListing } from "$/common/mod_loader.ts";
import { load_worldgen } from "$/common/worldgen_loader.ts";
import { add_base_item_hooks } from "./blocks.ts";
import { GameHost, GameServer } from "./game_server.ts";
import { ModRuntime } from "./mod_runtime.ts";

export interface ServerModSource {
	listing: ModListing;
	data: ModData;
	// importable urls of the scripts: data: urls in the worker, file urls in tests
	server_url?: string;
	worldgen_url?: string;
}

export async function start_game(
	host: GameHost,
	save: string | undefined,
	default_seed: string,
	mods: ServerModSource[],
): Promise<GameServer> {
	const recipes = register_mod_data(mods.map((mod) => ({ id: mod.listing.id, data: mod.data })));
	add_base_item_hooks();

	const worldgen_scripts = mods.flatMap((mod) =>
		mod.worldgen_url ? [{ mod: mod.listing.id, url: mod.worldgen_url }] : []
	);
	const worldgen = await load_worldgen(worldgen_scripts, recipes.ores);

	const runtime = new ModRuntime();
	const game = new GameServer(host, save, default_seed, {
		listings: mods.map((mod) => mod.listing),
		recipes,
		worldgen,
		runtime,
	});

	await runtime.load_scripts(
		game,
		mods.flatMap((mod) =>
			mod.server_url ? [{ mod: mod.listing.id, version: mod.listing.version, url: mod.server_url }] : []
		),
	);
	runtime.finish_setup();
	runtime.after.server_start.emit({});

	return game;
}

export function data_url(code: string) {
	const bytes = new TextEncoder().encode(code);
	let binary = "";
	for (let i = 0; i < bytes.length; i += 0x8000) {
		binary += String.fromCharCode(...bytes.subarray(i, i + 0x8000));
	}
	return `data:application/javascript;base64,${btoa(binary)}`;
}