修复前端不显示下载进度的问题

server.js

@@ -480,21 +480,83 @@ app.get('/api/hls/playlist.m3u8', async (req, res) => {
     const auth = extractS3Credentials(req);
     const s3Client = createS3Client(auth);
     let totalBytes = 0;
+    const progressKey = getProgressKey(key);
+    const streamSessionId = createStreamSessionId();
+    let downloadedBytes = 0;
     
     if (!fs.existsSync(tmpInputPath)) {
         try {
             const command = new GetObjectCommand({ Bucket: bucket, Key: key });
             const response = await s3Client.send(command);
             totalBytes = response.ContentLength;
+            const s3Stream = response.Body;
+
+            progressMap[progressKey] = {
+                status: 'downloading',
+                percent: 0,
+                downloadedBytes: 0,
+                totalBytes,
+                streamSessionId,
+                details: 'Downloading full source before streaming...',
+                mp4Url: null
+            };
+            broadcastWs(progressKey, { type: 'progress', key, progress: progressMap[progressKey] });
+
             await new Promise((resolve, reject) => {
                 const writeStream = fs.createWriteStream(tmpInputPath);
-                response.Body.pipe(writeStream);
+                
+                s3Stream.on('data', (chunk) => {
+                    downloadedBytes += chunk.length;
+                    const percent = totalBytes ? Math.min(100, Math.round((downloadedBytes / totalBytes) * 100)) : 0;
+                    
+                    const downloadState = {
+                        status: 'downloading',
+                        percent,
+                        downloadedBytes,
+                        totalBytes,
+                        streamSessionId,
+                        details: totalBytes ? `Downloading source ${percent}%` : 'Downloading source...',
+                        mp4Url: null
+                    };
+                    progressMap[progressKey] = downloadState;
+                    broadcastWs(progressKey, { type: 'progress', key, progress: downloadState });
+                });
+
+                s3Stream.on('error', reject);
                 writeStream.on('error', reject);
                 writeStream.on('finish', resolve);
+                s3Stream.pipe(writeStream);
             });
+
+            progressMap[progressKey] = {
+                status: 'downloaded',
+                percent: 100,
+                downloadedBytes,
+                totalBytes,
+                streamSessionId,
+                details: 'Source download complete, parsing for HLS...',
+                mp4Url: null
+            };
+            broadcastWs(progressKey, { type: 'progress', key, progress: progressMap[progressKey] });
+
         } catch(err) {
+            console.error('S3 Download Failed:', err);
             return res.status(500).send('S3 Download Failed');
         }
+    } else {
+        const stats = fs.statSync(tmpInputPath);
+        totalBytes = stats.size;
+        downloadedBytes = totalBytes;
+        progressMap[progressKey] = {
+            status: 'downloaded',
+            percent: 100,
+            downloadedBytes,
+            totalBytes,
+            streamSessionId,
+            details: 'Source already downloaded locally, parsing for HLS...',
+            mp4Url: null
+        };
+        broadcastWs(progressKey, { type: 'progress', key, progress: progressMap[progressKey] });
     }
     
     let duration = 0;