const Command = require('../../framework/Command');
const request = require('node-superfetch');
const { list, today, tomorrow } = require('../../util/Util');
const { GOOGLE_KEY, PERSONAL_GOOGLE_CALENDAR_ID } = process.env;
const holidayCals = {
	USA: 'en.usa#holiday@group.v.calendar.google.com',
	Japan: 'en.japanese#holiday@group.v.calendar.google.com',
	UK: 'en.uk#holiday@group.v.calendar.google.com',
	Australia: 'en.australian#holiday@group.v.calendar.google.com',
	Canada: 'en.canadian#holiday@group.v.calendar.google.com'
};

module.exports = class HolidaysCommand extends Command {
	constructor(client) {
		super(client, {
			name: 'holidays',
			aliases: ['events', 'google-calendar'],
			group: 'events',
			memberName: 'holidays',
			description: 'Responds with today\'s holidays.',
			credit: [
				{
					name: 'Google',
					url: 'https://www.google.com/',
					reason: 'Calendar API',
					reasonURL: 'https://developers.google.com/calendar/'
				}
			]
		});
	}

	async run(msg) {
		try {
			const events = [];
			for (const [country, calID] of Object.entries(holidayCals)) {
				const standardEvents = await this.fetchHolidays(calID);
				if (standardEvents) {
					const mapped = standardEvents.map(event => `${event} (${country})`);
					events.push(...mapped);
				}
			}
			if (PERSONAL_GOOGLE_CALENDAR_ID) {
				const personalEvents = await this.fetchHolidays(PERSONAL_GOOGLE_CALENDAR_ID);
				if (personalEvents) events.push(...personalEvents);
			}
			if (!events.length) return msg.say('There are no holidays today...');
			const holidays = list(events.map(event => `**${event}**`));
			return msg.say(`Today${events.length === 1 ? ' is' : `'s holidays are`} ${holidays}!`);
		} catch (err) {
			return msg.reply(`Oh no, an error occurred: \`${err.message}\`. Try again later!`);
		}
	}

	async fetchHolidays(id) {
		try {
			const { body } = await request
				.get(`https://www.googleapis.com/calendar/v3/calendars/${encodeURIComponent(id)}/events`)
				.query({
					maxResults: 20,
					orderBy: 'startTime',
					singleEvents: true,
					timeMax: tomorrow().toISOString(),
					timeMin: today().toISOString(),
					timeZone: 'UTC',
					key: GOOGLE_KEY
				});
			if (!body.items.length) return null;
			return body.items.map(holiday => holiday.summary);
		} catch (err) {
			if (err.status === 404) return null;
			throw err;
		}
	}
};