const EResult = require('../resources/EResult.js');

/**
 * Make sure that a provided input is a valid SteamID object.
 * @param {object} input
 * @returns {boolean}
 */
exports.isSteamID = function(input) {
	return ['universe', 'type', 'instance', 'accountid'].every(prop => typeof input[prop] == 'number' || typeof input[prop] == 'bigint');
};

exports.decodeSteamTime = function(time) {
	let date = new Date();

	if (time.includes('@')) {
		let parts = time.split('@');
		if (!parts[0].includes(',')) {
			// no year, assume current year
			parts[0] += ', ' + date.getFullYear();
		}

		date = new Date(parts.join('@').replace(/(am|pm)/, ' $1') + ' UTC');  // add a space so JS can decode it
	} else {
		// Relative date
		let amount = time.replace(/(\d) (minutes|hour|hours) ago/, '$1');

		if (time.includes('minutes')) {
			date.setMinutes(date.getMinutes() - amount);
		} else if (time.match(/hour|hours/)) {
			date.setHours(date.getHours() - amount);
		}
	}

	return date;
};

/**
 * Get an Error object for a particular EResult
 * @param {int|EResult} eresult
 * @param {string} [message] - If eresult is a failure code and message exists, this message will be used in the Error object instead
 * @returns {null|Error}
 */
exports.eresultError = function(eresult, message) {
	if (eresult == EResult.OK) {
		// no error
		return null;
	}

	let err = new Error(message || EResult[eresult] || `Error ${eresult}`);
	err.eresult = eresult;
	return err;
};

exports.decodeJwt = function(jwt) {
	let parts = jwt.split('.');
	if (parts.length != 3) {
		throw new Error('Invalid JWT');
	}

	let standardBase64 = parts[1].replace(/-/g, '+')
		.replace(/_/g, '/');

	return JSON.parse(Buffer.from(standardBase64, 'base64').toString('utf8'));
};