import { error } from '@sveltejs/kit';
import type { RequestHandler } from './$types';
import { getYouTubeMetadata, streamYouTube, ytdl } from '$lib/server/ytdlp';
import { contentTypeFromFormat, isURLValid, mimeTypeMap } from '$lib/server/helpers';

const validateRequest = (url) => {
	// Get query params
	const link = url.searchParams.get('link');
	const format = url.searchParams.get('format'); // mp3, mp4
	const source = url.searchParams.get('source'); // youtube or spotify
	const metadata = url.searchParams.get('metadata');

	// Validate input
	if (!link || !format || !source) {
		throw error(400, 'Missing required query parameters: link, format, or source');
	}

	if (source !== 'youtube') {
		throw error(400, 'Currently, only YouTube is supported');
	}

	if (!isURLValid(link)) {
		throw error(400, 'URL not valid');
	}

	if (!mimeTypeMap.get(format)) {
		throw error(400, 'format not valid');
	}

	return {
		link, format, source, metadata
	}
}
export const GET: RequestHandler = async ({ url }) => {
	const { format, source, metadata, link } = validateRequest(url)
	let filename = `you-clicked-no-metadata-so-i-cant-put-a-correct-name.${format}`;

	if (metadata) {
		try {
			// Fetch metadata for filename
			const metadata = await getYouTubeMetadata(link);
			const { title, uploader } = metadata;
			const safeTitle = `${uploader} - ${title}`;
			filename = `${safeTitle}.${format}`;
		} catch (err) {
			console.error(err)
			console.error('Error fetching metadata:');
			throw error(500, 'Failed to fetch video metadata');
		}
	}

	try {

		// Stream video/audio
		return new Response(streamYouTube(link, format), {
			headers: {
				'Content-Type': contentTypeFromFormat(format),
				'Content-Disposition': `attachment; filename="${filename}"`,
				'Set-Cookie': 'downloading=0'
			}
		});

	} catch (err) {
		console.error(err)
		console.error('Filed to stream file');
		throw error(500, 'Failed to stream file');
	}
};