import type { Request, Response } from 'express';
import type { Metadata, Twt } from 'twtxt-lib';

import {
	generateEtag,
	getQueryParameterArray,
	getValueOrFirstEntry,
} from '../../lib/utils.js';
import dayjs from 'dayjs';
import utc from 'dayjs/plugin/utc.js';
import NodeCache from '@cacheable/node-cache';
import { QueryParameters } from '../../types.js';

dayjs.extend(utc);

/**
 *
 * @param req
 * @param res
 * @param twts
 * @param twtParameter
 * @param twtsParameter
 * @returns
 */
export default function twtHandler(
	req: Request,
	res: Response,
	twts: Twt[] = [],
	twtParameter: QueryParameters['twt'],
	twtsParameter: QueryParameters['twts']
) {
	const twtsToMatch = getQueryParameterArray(req.query[twtsParameter]);
	const showLastTwt = getQueryParameterArray(req.query[twtParameter]);
	const hashesToMatch = getQueryParameterArray(req.query.hash);
	const searchTermsToMatch = [
		...getQueryParameterArray(req.query.search),
		...getQueryParameterArray(req.query.s),
	];

	const createdDatesToMatch = getQueryParameterArray(req.query.created_date);
	const createdUTCStartDatesToMatch = getQueryParameterArray(
		req.query.created_date_start
	).map((val) => dayjs.utc(val));
	const createdUTCEndDatesToMatch = getQueryParameterArray(
		req.query.created_date_end
	).map((val) => dayjs.utc(val));

	const wantsJson =
		req.is('json') ||
		getValueOrFirstEntry(getQueryParameterArray(req.query.format)) === 'json';
	if (wantsJson) res.set('content-type', 'application/json');
	else res.set('content-type', 'text/plain');

	if (showLastTwt.length === 1 && showLastTwt[0] === '') {
		const lastTwt = twts.reduce((matched, curr) =>
			matched?.createdUTC > curr.createdUTC ? matched : curr
		);
		let result = 'No results';

		if (lastTwt) {
			result = wantsJson
				? JSON.stringify(lastTwt)
				: `${lastTwt?.created || ''}\t${lastTwt?.content || ''}\n`;
		}

		res.set('etag', generateEtag(result)).send(result);
		return;
	}

	const matchedTwts = twts.filter(({ content, created, createdUTC, hash }) => {
		return (
			(!twtsToMatch.length ||
				(twtsToMatch.length === 1 && twtsToMatch[0] === '') ||
				twtsToMatch.includes(created) ||
				(hash &&
					(twtsToMatch.includes(hash) || twtsToMatch.includes(`#${hash}`)))) &&
			(!hashesToMatch.length ||
				(hash &&
					(hashesToMatch.includes(hash) ||
						hashesToMatch.includes(`#${hash}`)))) &&
			(!createdDatesToMatch.length ||
				createdDatesToMatch.some((date) => created.includes(date))) &&
			(!createdUTCStartDatesToMatch.length ||
				createdUTCStartDatesToMatch.some(
					(date) => date.diff(createdUTC) < 0
				)) &&
			(!createdUTCEndDatesToMatch.length ||
				createdUTCEndDatesToMatch.some((date) => date.diff(createdUTC) > 0)) &&
			(!searchTermsToMatch.length ||
				searchTermsToMatch.some((term) => content.includes(term)))
		);
	});

	const result = wantsJson
		? JSON.stringify(matchedTwts)
		: matchedTwts
				.map(({ content, created }) => `${created}\t${content}`)
				.join('\n');

	res.set('etag', generateEtag(result)).send(result);
}