/* eslint-disable promise/prefer-await-to-then */

import { useEffect, useMemo, useState } from 'react';
import { Emoji, fetchEmojis, fetchMessages, Locale } from 'emojibase';
import { LATEST_DATASET_VERSION } from './constants';
import { EmojiDataManager } from './EmojiDataManager';
import { CanonicalEmoji, Source, UseEmojiDataOptions } from './types';

export function determinePresets(locale: string, shortcodes: string[]): string[] {
	const presets: string[] = [];

	if (shortcodes.length === 0) {
		presets.push('emojibase');
	} else {
		presets.push(...shortcodes);
	}

	if (
		!locale.startsWith('en') &&
		presets.includes('emojibase') &&
		!presets.includes('en/emojibase')
	) {
		presets.push('en/emojibase');
	}

	return presets;
}

const promises = new Map<string, Promise<CanonicalEmoji[]>>();

export function resetLoaded() {
	if (__DEV__) {
		promises.clear();
	}
}

async function loadEmojis(
	locale: Locale,
	version: string,
	shortcodes: string[],
	compact: boolean,
): Promise<CanonicalEmoji[]> {
	const key = `${locale}:${version}:${compact ? 'compact' : 'data'}`;
	const instance = EmojiDataManager.getInstance(locale, version);

	// Return as we're currently loading data
	if (promises.has(key)) {
		return promises.get(key)!;
	}

	// Data has been loaded elsewhere
	if (instance.data.length > 0) {
		return instance.getData();
	}

	// Otherwise, start loading emoji data from the CDN
	// eslint-disable-next-line compat/compat
	const request = Promise.all([
		// @ts-expect-error Mismatched types
		fetchEmojis(locale, { compact, flat: false, shortcodes, version }) as Emoji[],
		fetchMessages(locale, { version }),
	]);

	promises.set(
		key,
		request.then(([emojis, messages]) => {
			instance.parseEmojiData(emojis);
			instance.parseMessageData(messages);

			return instance.getData();
		}),
	);

	return promises.get(key)!;
}

export function useEmojiData({
	avoidFetch = false,
	compact = false,
	locale = 'en',
	shortcodes = ['emojibase'],
	throwErrors = false,
	version = LATEST_DATASET_VERSION,
}: UseEmojiDataOptions = {}): [CanonicalEmoji[], Source, EmojiDataManager] {
	// eslint-disable-next-line react-hooks/exhaustive-deps
	const shortcodePresets = useMemo(() => determinePresets(locale, shortcodes), shortcodes);
	const [emojis, setEmojis] = useState<CanonicalEmoji[]>([]);
	const [error, setError] = useState<Error>();

	useEffect(() => {
		let mounted = true;

		if (!avoidFetch) {
			loadEmojis(locale, version, shortcodePresets, compact)
				.then((loadedEmojis) => {
					if (mounted) {
						setEmojis(loadedEmojis);
					}

					return loadedEmojis;
				})
				.catch(setError);
		}

		return () => {
			mounted = false;
		};
	}, [avoidFetch, compact, locale, shortcodePresets, version]);

	if (error && throwErrors) {
		throw error;
	}

	return [
		emojis,
		{
			compact,
			error,
			locale,
			version,
		},
		EmojiDataManager.getInstance(locale, version),
	];
}