feat(miruro): attempt to retrieve quality from stream playlist

src/miruro/extractor.js

@@ -2,10 +2,11 @@
  * Resolve TMDB media to AniList, then retrieve Miruro episode sources.
  */
 
-import { BASE_URL, fetchJson, HEADERS, secureGet } from './http.js';
+import { BASE_URL, fetchJson, fetchText, HEADERS, secureGet } from './http.js';
 
 const ANIMAP_URL = 'https://animap.id/api/map';
 const ANILIST_URL = 'https://graphql.anilist.co';
+const HLS_QUALITY_TIMEOUT_MS = 4000;
 
 // Miruro's visible native-player providers and their preferred subtitle mode.
 const PROVIDERS = [
@@ -270,15 +271,71 @@ function getOrigin(url) {
     return match ? match[1] : BASE_URL;
 }
 
-function getQuality(stream) {
-    const value = String(stream.quality || stream.server || 'HD');
+function getDeclaredQuality(stream) {
+    const value = `${stream.quality || ''} ${stream.resolution || ''} ${stream.server || ''}`;
     const resolution = value.match(/(2160|1440|1080|720|480|360)p?/i);
 
     if (resolution) {
         return `${resolution[1]}p`;
     }
 
-    return /4k/i.test(value) ? '4K' : 'HD';
+    return /4k/i.test(value) ? '4K' : null;
+}
+
+function getHlsQuality(manifest) {
+    const heights = [];
+    const pattern = /\bRESOLUTION\s*=\s*\d+\s*x\s*(\d+)\b/gi;
+    let match;
+
+    while ((match = pattern.exec(manifest)) !== null) {
+        const height = Number(match[1]);
+
+        if (height > 0) {
+            heights.push(height);
+        }
+    }
+
+    return heights.length > 0 ? `${Math.max(...heights)}p` : null;
+}
+
+function isHlsStream(stream) {
+    const type = String(stream && stream.type || '').toLowerCase();
+    return type === 'hls' || type === 'm3u8' || type === 'application/x-mpegurl';
+}
+
+async function resolveQuality(stream, headers) {
+    const declaredQuality = getDeclaredQuality(stream);
+
+    if (declaredQuality) {
+        return declaredQuality;
+    }
+
+    if (isHlsStream(stream)) {
+        let timeoutId;
+
+        try {
+            const manifest = await Promise.race([
+                fetchText(stream.url, { headers }),
+                new Promise((resolve) => {
+                    timeoutId = setTimeout(() => resolve(null), HLS_QUALITY_TIMEOUT_MS);
+                })
+            ]);
+            const hlsQuality = typeof manifest === 'string' ? getHlsQuality(manifest) : null;
+
+            if (hlsQuality) {
+                return hlsQuality;
+            }
+        } catch (_) {
+            // A stream can still be playable when its manifest rejects this
+            // metadata request, so retain it with an unknown HD quality.
+        } finally {
+            if (timeoutId != null) {
+                clearTimeout(timeoutId);
+            }
+        }
+    }
+
+    return 'HD';
 }
 
 function isPlayableStream(stream) {
@@ -291,14 +348,26 @@ function isPlayableStream(stream) {
     );
 }
 
-function normalizeStreams(sourcePayload, provider, variant) {
+async function normalizeStreams(sourcePayload, provider, variant) {
     const subtitleCount = Array.isArray(sourcePayload.subtitles) ? sourcePayload.subtitles.length : 0;
     const language = variant === 'dub' ? 'DUB' : 'SUB';
 
-    return (sourcePayload.streams || []).filter(isPlayableStream).map((stream) => {
-        const referer = stream.referer || BASE_URL;
-        const server = stream.server || getQuality(stream);
+    return Promise.all((sourcePayload.streams || []).filter(isPlayableStream).map(async (stream) => {
+        const streamHeaders = stream.headers && typeof stream.headers === 'object'
+            ? stream.headers
+            : {};
+        const referer = stream.referer || streamHeaders.Referer || streamHeaders.referer || BASE_URL;
         const subtitleLabel = subtitleCount > 0 && variant !== 'dub' ? ' · CC' : '';
+        const headers = {
+            ...streamHeaders,
+            'Referer': referer,
+            'Origin': getOrigin(referer),
+            'User-Agent': HEADERS['User-Agent']
+        };
+        const quality = await resolveQuality(stream, headers);
+        const server = !stream.server || /^(?:HD|auto)$/i.test(stream.server)
+            ? quality
+            : stream.server;
 
         return {
             // Nuvio's source picker prominently displays `name`, so include the
@@ -306,14 +375,10 @@ function normalizeStreams(sourcePayload, provider, variant) {
             name: `Miruro · ${provider.label} · ${language}`,
             title: `[${language}] ${provider.label} · ${server}${subtitleLabel}`,
             url: stream.url,
-            quality: getQuality(stream),
-            headers: {
-                'Referer': referer,
-                'Origin': getOrigin(referer),
-                'User-Agent': HEADERS['User-Agent']
-            }
+            quality,
+            headers
         };
-    });
+    }));
 }
 
 async function getProviderStreams(provider, providerPayload, anilistId, episodeNumber) {