Updated to use mimetype instead of file extension

Also fixed everything that Tom asked, i hope.

gulp/res/js/ptchina-playlist.js

@@ -1,26 +1,26 @@
 //https://github.com/ussaohelcim/ptchina-playlist/tree/bookmarklet-let
-'use strict';
 async function threadToPlaylist(board, postId) {
 	async function getThread() {
 		let link = `${window.location.origin}/${board}/thread/${postId}.json`;
-		return await fetch(link).then(async (res) => {
-			const thread = await res.json();
-			return thread;
-		});
+		return await fetch(link).then(res => res.json());
+	}
+	function isAudioOrVideo(file) {
+		const mimeTypes = ['video', 'audio'];
+		const fileType = file.mimetype.split('/')[0];
+		return fileType === mimeTypes[0] || fileType === mimeTypes[1];
 	}
 	async function getMedia(thread) {
-		const fileTypes = ['.mp4', '.mp3', '.webm'];
 		const files = [];
-		thread.files?.forEach((f) => {
-			if (fileTypes.includes(f.extension)) {
-				files.push(f);
+		thread.files.forEach((file) => {
+			if (isAudioOrVideo(file)) {
+				files.push(file);
 			}
 		});
 		for (let i = 0; i < thread.replies.length; i++) {
-			const element = thread.replies[i].files;
-			element?.forEach((f) => {
-				if (fileTypes.includes(f.extension)) {
-					files.push(f);
+			const replyFiles = thread.replies[i].files;
+			replyFiles.forEach((file) => {
+				if (isAudioOrVideo(file)) {
+					files.push(file);
 				}
 			});
 		}
@@ -49,17 +49,21 @@ async function threadToPlaylist(board, postId) {
 		a.click();
 		document.body.removeChild(a);
 	}
-	const thread = await getThread();
-	const files = await getMedia(thread);
-	const playlist = await createPlaylist(files);
-	if (playlist.split('\n').length > 1) { //playlist.split('\n').length === 1 means only "#EXTM3U" inside the string
-		downloadPlaylist(`${thread.board}-${thread.postId}.m3u`, playlist);
+	try {
+		const thread = await getThread();
+		const files = await getMedia(thread);
+		const playlist = await createPlaylist(files);
+		if (playlist.split('\n').length > 1) {
+			downloadPlaylist(`${thread.board}-${thread.postId}.m3u`, playlist);
+		}
+		else {
+			console.log('No video/audio files in this thread.');
+		}
 	}
-	else {
-		console.log('No video/audio files in this thread.');
+	catch (error) {
+		console.log(error);
 	}
 }
-
-window.addEventListener('createPlaylist',(e)=>{
-	threadToPlaylist(e.detail.board,e.detail.postId);
+window.addEventListener('createPlaylist', (e) => {
+	threadToPlaylist(e.detail.board, e.detail.postId);
 });