#!/usr/bin/env node

if (process.argv.length != 7) {
	console.log("Usage: ./run_tour.js <seed_file> <num_turns> <num_workers> <output_file> <logs_dir>");
	console.log("<seed_file> should contain a 32-hex-digit seed on each line. One game will be run for each seed. The games will all have <num_turns> turns.");
	console.log("The tournament will be run using <num_workers> parallel workers.")
	console.log("Output results will be written to <output_file>.")
	console.log("Game log files will be written to the directory <logs_dir>.");
	process.exit(1);
}

const fs = require("fs");
const child_process = require("child_process");
const mkdirp = require("mkdirp");

const seed_file = process.argv[2];
const num_turns = +process.argv[3];
const num_workers = +process.argv[4];
const output_file = process.argv[5];
const logs_dir = process.argv[6];

mkdirp.sync(logs_dir);

const output_stream = fs.createWriteStream(output_file);

const seeds =
	fs.readFileSync(seed_file).toString()
		.split("\n").filter(s => s.length > 0);


console.log(seeds.length + " games to play using " + num_workers + " workers.");

function register_result(result) {
	output_stream.write(result + "\n");

	const seed = result.split(" ", 1)[0];
	console.log("Finished game with seed " + seed);
}

const workers = [];
const current_seed = new Array(num_workers).fill(null);
const start_at = new Array(num_workers).fill(null);

function distribute_work() {
	if (seeds.length == 0) return;

	for (let i = 0; i < num_workers; i++) {
		if (current_seed[i] == null) {
			const seed = seeds.shift();
			current_seed[i] = seed;
			start_at[i] = new Date();
			workers[i].stdin.write(seed + "\n");

			console.log("Started game with seed " + seed);
		}
	}
}

function check_finished() {
	for (let i = 0; i < num_workers; i++) {
		if (current_seed[i] != null) return false;
	}

	console.log("\nFINISHED! Shutting down...");

	output_stream.end();
	for (const worker of workers) {
		worker.stdin.end();
	}

	console.log("All done.");
	setTimeout(() => process.exit(0), 500);
}

function spawn_worker(index) {
	const worker = child_process.spawn(
		"node",
		["tour_worker.js", num_turns.toString(), logs_dir],
		{ stdio: ["pipe", "pipe", "inherit"] }
	);

	let buffer = "";
	worker.stdout.on("data", (data) => {
		buffer += data;
		let idx = buffer.indexOf("\n");
		while (idx != -1) {
			const line = buffer.slice(0, idx);
			buffer = buffer.slice(idx + 1);
			idx = buffer.indexOf("\n");

			register_result(line);
			current_seed[index] = null;
			start_at[index] = null;
			distribute_work();
			if (check_finished()) return;
		}
	});

	return worker;
}

for (let i = 0; i < num_workers; i++) {
	workers.push(spawn_worker(workers.length));
}

distribute_work();

// Check for stuck games once in a while
setInterval(function() {
	const max_game_time = 1350 * num_turns;
	const now = new Date();

	for (let i = 0; i < num_workers; i++) {
		if (current_seed[i] != null && now - start_at[i] > max_game_time) {
			console.log("Game for seed " + current_seed[i] + " is taking too long, KILLING!");
			workers[i].kill("SIGKILL");

			console.log("Spawning new worker and hoping everything's fine...");
			workers[i] = spawn_worker(i);
		}
	}
}, 60 * 1000);