api: flatten code directories, better filenames, remove old files

api/src/processing/services/bilibili.js

@@ -0,0 +1,105 @@
+import { genericUserAgent, env } from "../../config.js";
+
+// TO-DO: higher quality downloads (currently requires an account)
+
+function com_resolveShortlink(shortId) {
+    return fetch(`https://b23.tv/${shortId}`, { redirect: 'manual' })
+            .then(r => r.status > 300 && r.status < 400 && r.headers.get('location'))
+            .then(url => {
+                if (!url) return;
+                const path = new URL(url).pathname;
+                if (path.startsWith('/video/'))
+                    return path.split('/')[2];
+            })
+            .catch(() => {})
+}
+
+function getBest(content) {
+    return content?.filter(v => v.baseUrl || v.url)
+                .map(v => (v.baseUrl = v.baseUrl || v.url, v))
+                .reduce((a, b) => a?.bandwidth > b?.bandwidth ? a : b);
+}
+
+function extractBestQuality(dashData) {
+    const bestVideo = getBest(dashData.video),
+          bestAudio = getBest(dashData.audio);
+
+    if (!bestVideo || !bestAudio) return [];
+    return [ bestVideo, bestAudio ];
+}
+
+async function com_download(id) {
+    let html = await fetch(`https://bilibili.com/video/${id}`, {
+        headers: { "user-agent": genericUserAgent }
+    }).then(r => r.text()).catch(() => {});
+    if (!html) return { error: 'ErrorCouldntFetch' };
+
+    if (!(html.includes('<script>window.__playinfo__=') && html.includes('"video_codecid"'))) {
+        return { error: 'ErrorEmptyDownload' };
+    }
+
+    let streamData = JSON.parse(html.split('<script>window.__playinfo__=')[1].split('</script>')[0]);
+    if (streamData.data.timelength > env.durationLimit * 1000) {
+        return { error: ['ErrorLengthLimit', env.durationLimit / 60] };
+    }
+
+    const [ video, audio ] = extractBestQuality(streamData.data.dash);
+    if (!video || !audio) {
+        return { error: 'ErrorEmptyDownload' };
+    }
+
+    return {
+        urls: [video.baseUrl, audio.baseUrl],
+        audioFilename: `bilibili_${id}_audio`,
+        filename: `bilibili_${id}_${video.width}x${video.height}.mp4`
+    };
+}
+
+async function tv_download(id) {
+    const url = new URL(
+        'https://api.bilibili.tv/intl/gateway/web/playurl'
+        + '?s_locale=en_US&platform=web&qn=64&type=0&device=wap'
+        + '&tf=0&spm_id=bstar-web.ugc-video-detail.0.0&from_spm_id='
+    );
+
+    url.searchParams.set('aid', id);
+
+    const { data } = await fetch(url).then(a => a.json());
+    if (!data?.playurl?.video) {
+        return { error: 'ErrorEmptyDownload' };
+    }
+
+    const [ video, audio ] = extractBestQuality({
+        video: data.playurl.video.map(s => s.video_resource)
+                                 .filter(s => s.codecs.includes('avc1')),
+        audio: data.playurl.audio_resource
+    });
+
+    if (!video || !audio) {
+        return { error: 'ErrorEmptyDownload' };
+    }
+
+    if (video.duration > env.durationLimit * 1000) {
+        return { error: ['ErrorLengthLimit', env.durationLimit / 60] };
+    }
+
+    return {
+        urls: [video.url, audio.url],
+        audioFilename: `bilibili_tv_${id}_audio`,
+        filename: `bilibili_tv_${id}.mp4`
+    };
+}
+
+export default async function({ comId, tvId, comShortLink }) {
+    if (comShortLink) {
+        comId = await com_resolveShortlink(comShortLink);
+    }
+
+    if (comId) {
+        return com_download(comId);
+    } else if (tvId) {
+        return tv_download(tvId);
+    }
+
+    return { error: 'ErrorCouldntFetch' };
+}