'use strict';

const config = require('config');
const timers = require('timers/promises');
const { decode } = require('html-entities');

const questions = require('../../assets/jeopardy.json');
const shuffle = require('../utils/shuffle');

const settings = { ...config.trivia };
const help = {
	mode: '\'first\' or \'timeout\'',
	rounds: 'rounds per game as a number',
	timeout: 'seconds as a number',
};

let game = null;

function scoreRound(context, round) {
	if (game.answers.length === 0) {
		return `No one scored in round ${round + 1}, better luck next time!`;
	}

	return game.answers.map(({ user }) => {
		if (user) {
			context.setPoints(user, 1);
			game.points[user.username] = (game.points[user.username] || 0) + 1;

			return `**@${user.username}** gets a point`;
		}

		return null;
	}).filter(Boolean).join(', ');
}

async function playRound(context, round = 0) {
	const ac = new AbortController(); // eslint-disable-line no-undef
	const now = new Date();

	game.answers = [];
	game.round = round;
	game.ac = ac;

	const question = game.questions[round];

	context.sendMessage(`**Question ${round + 1}/${game.questions.length}** (${question.category}): ${question.question}`, context.room.id);
	context.logger.info(`Trivia asked "${question.question}" with answer: ${question.answer}`);

	try {
		await timers.setTimeout((game.timeout / 3) * 1000, null, {
			signal: ac.signal,
		});

		// replace space with U+2003 Em Space to separate words, since a single space separates the placeholders, and double spaces are removed during Markdown render
		context.sendMessage(`**${Math.floor(game.timeout / 3) * 2} seconds** left, first hint for **question ${round + 1}/${game.questions.length}**: **${question.answer.slice(0, 1)} ${question.answer.slice(1).replace(/\s/g, ' ').replace(/[^\s]/g, '_ ').trim()}**`, context.room.id);

		await timers.setTimeout((game.timeout / 3) * 1000, null, {
			signal: ac.signal,
		});

		if (question.answer.length > 3) {
			context.sendMessage(`**${Math.floor(game.timeout / 3)} seconds** left, second hint for **question ${round + 1}/${game.questions.length}**: **${question.answer.slice(0, 1)} ${question.answer.slice(1, -1).replace(/\s/g, ' ').replace(/[^\s]/g, '_ ')}${question.answer.slice(-1)}**`, context.room.id);
		}

		await timers.setTimeout((game.timeout / 3) * 1000, null, {
			signal: ac.signal,
		});
	} catch (error) {
		// abort expected, probably not an error
	}

	if (!ac.signal.aborted) {
		ac.abort();
	}

	if (game.stopped) {
		context.sendMessage(`The game was stopped by @${game.stopped.username}. The answer to the last question was: **${question.answer}**`, context.room.id);
		game = null;

		return;
	}

	if (game.answers.length === 0) {
		context.sendMessage(`**TIME'S UP!** No one guessed the answer: **${question.answer}**`, context.room.id);
	} else {
		const scores = scoreRound(context, round);

		if (game.mode === 'first') {
			context.sendMessage(`**${question.fullAnswer || question.answer}** is the right answer, played in **${((new Date() - now) / 1000).toFixed(3)}s**! ${scores}`, context.room.id);
		}

		if (game.mode === 'timeout') {
			context.sendMessage(`**STOP!** The correct answer is **${question.fullAnswer || question.answer}**. ${scores}`, context.room.id);
		}
	}

	if (round < game.questions.length - 1) {
		await timers.setTimeout(5000);

		if (game.stopped) {
			context.sendMessage(`The game was stopped by ${game.stopped.username}`, context.room.id);
			game = null;

			return;
		}

		playRound(context, round + 1);
		return;
	}

	await timers.setTimeout(2000);

	const leaders = Object.entries(game.points).sort(([, scoreA], [, scoreB]) => scoreB - scoreA).map(([username, score], index) => {
		if (index === 0) {
			return `**@${username}** with **${score}** points`;
		}

		return `**@${username}** with **${score}** points`;
	}).join(', ');

	context.sendMessage(`That's the end of the game! Best players: ${leaders}`, context.room.id);

	game = null;
}

async function start(context) {
	const roundQuestions = shuffle(questions, settings.rounds);

	game = {
		round: 0,
		questions: roundQuestions,
		answers: [],
		points: {},
		...settings,
	};

	playRound(context, 0);
}

async function stop(context) {
	game.stopped = context.user;
	game.ac.abort();
}

function onCommand(args, context) {
	if (!context.subcommand && !game) {
		start(context);
		return;
	}

	if (!context.subcommand && game) {
		context.sendMessage(`There is already a game going on! Use ${config.prefix}trivia:stop to reset. The current question for round ${game.round + 1} is: ${game.questions[game.round].question}`, context.room.id);
		return;
	}

	if (context.subcommand === 'stop' && game) {
		stop(context);
	}

	if (context.subcommand === 'stop' && !game) {
		context.sendMessage(`There is no game going on at the moment. Start one with ${config.prefix}trivia!`, context.room.id);
	}

	if (['help', 'commands'].includes(context.subcommand)) {
		context.sendMessage(`Available subcommands for ${config.prefix}trivia are :stop, :mode, :rounds and :timeout`, context.room.id);
	}

	const subcommand = context.subcommand?.toLowerCase();

	if (subcommand && settings[subcommand]) {
		if (args[0]) {
			settings[subcommand] = typeof settings[subcommand] === 'number' ? (Number(args[0]) || settings[subcommand]) : args[0];

			context.sendMessage(`${subcommand} set to ${settings[subcommand]}`, context.room.id);
		} else if (help[subcommand]) {
			context.sendMessage(`Please give ${help[subcommand]}`, context.room.id);
		}
	}
}

async function onMessage(message, context) {
	if (!game || context.user?.id === config.user?.id) {
		return;
	}

	const { answer, fullAnswer } = game.questions[game.round];

	if (new RegExp(answer, 'i').test(decode(message.originalBody || message.body))) { // resolve HTML entities in case original body is not available, such as &amp; to &
		game.answers.push({
			user: context.user,
			answer: message.body,
		});

		if (settings.mode === 'first') {
			game.ac.abort();
		}

		if (settings.mode === 'timeout' && !game.ac.signal.aborted) {
			if (message.type === 'message') {
				context.sendMessage(`**${fullAnswer || answer}** is the correct answer! You might want to **/whisper** the answer to me instead, so others can't leech off your impeccable knowledge. You will receive a point at the end of the round.`, context.room.id, null, context.user.username);
			} else {
				context.sendMessage(`**${fullAnswer || answer}** is the correct answer! You will receive a point at the end of the round.`, context.room.id, null, context.user.username);
			}
		}
	}
}

module.exports = {
	name: 'Trivia',
	onCommand,
	onMessage,
};