const { createCanvas, loadImage } = require('@napi-rs/canvas');
const path = require('path');
const holidayList = require('../assets/json/holiday-list');

module.exports = class AvatarChanger {
	constructor(client) {
		Object.defineProperty(this, 'client', { value: client });

		this.isWearingHat = false;
	}

	async editAvatar(hat) {
		const base = await loadImage(path.join(__dirname, '..', 'assets', 'images', 'Xiao.png'));
		const hatImg = await loadImage(path.join(__dirname, '..', 'assets', 'images', 'hat', `${hat}.png`));
		const canvas = createCanvas(base.width, base.height);
		const ctx = canvas.getContext('2d');
		ctx.drawImage(base, 0, 0);
		ctx.drawImage(hatImg, 0, 0, base.width, base.height);
		return canvas.toBuffer('image/png');
	}

	async setAvatar(hat) {
		if (!hat) {
			this.isWearingHat = false;
			await this.client.user.setAvatar(path.join(__dirname, '..', 'assets', 'images', 'Xiao.png'));
			return;
		}
		this.isWearingHat = true;
		const image = await this.editAvatar(hat);
		await this.client.user.setAvatar(image);
		return;
	}

	setInterval() {
		const now = new Date();
		const midnight = new Date(Date.UTC(
			now.getUTCFullYear(),
			now.getUTCMonth(),
			now.getUTCDate() + 1,
			0 ,0, 0, 0
		));
		const msUntilNext = midnight - now;
		setTimeout(() => {
			const today = new Date();
			const holiday = this.isHoliday(today);
			if (holiday) {
				let hat = holiday.hat;
				if (Array.isArray(hat)) hat = hat[Math.floor(Math.random() * hat.length)];
				this.setAvatar(hat)
					.then(() => this.client.logger.info(`[AVATAR] Updated avatar to ${hat}!`))
					.catch(err => this.client.logger.error(`[AVATAR] Failed to update avatar.\n${err.stack}`));
			} else if (this.isWearingHat) {
				this.setAvatar()
					.then(() => this.client.logger.info('[AVATAR] Reset avatar to default.'))
					.catch(err => this.client.logger.error(`[AVATAR] Failed to update avatar.\n${err.stack}`));
			}
			this.setInterval();
		}, msUntilNext);
	}

	isHoliday(day) {
		for (const holiday of holidayList) {
			if (day.getUTCDate() === holiday.day && day.getUTCMonth() === holiday.month - 1) return holiday;
		}
		if (this.isThanksgiving(day)) {
			return {
				hat: 'pilgrim'
			};
		}
		return false;
	}

	isThanksgiving(day) {
		const thanksgiving = this.getThanksgiving(day.getUTCFullYear());
	  	return (
    		day.getUTCFullYear() === thanksgiving.getUTCFullYear() &&
    		day.getUTCMonth() === thanksgiving.getUTCMonth() &&
    		day.getUTCDate() === thanksgiving.getUTCDate()
  		);	
	}

	getThanksgiving(year) {
  		const date = new Date(Date.UTC(year, 10, 1));
  		const day = date.getUTCDay();
  		const offset = ((4 - day) + 7) % 7;
  		const firstThursday = 1 + offset;
  		const thanksgiving = firstThursday + 21;
		return new Date(Date.UTC(year, 10, thanksgiving));
	}
};