feat: Implement HLS video segment preloading and caching using a service worker.

lib/hooks/useHistoryDownloader.ts

@@ -0,0 +1,61 @@
+/**
+ * History Downloader Hook
+ * Downloads all segments for videos in watch history
+ */
+
+'use client';
+
+import { useEffect, useRef } from 'react';
+import { useHistoryStore } from '@/lib/store/history-store';
+import { parseHLSManifest } from '@/lib/utils/hlsManifestParser';
+import { downloadSegmentQueue } from '@/lib/utils/segmentDownloader';
+
+export function useHistoryDownloader() {
+    const viewingHistory = useHistoryStore((state) => state.viewingHistory);
+    const processedUrlsRef = useRef<Set<string>>(new Set());
+
+    useEffect(() => {
+        if (viewingHistory.length === 0) return;
+
+        const downloadHistoryVideos = async () => {
+            for (const item of viewingHistory) {
+                const { url } = item;
+
+                // Skip if already processed
+                if (processedUrlsRef.current.has(url)) continue;
+
+                // Skip if not m3u8
+                if (!url.endsWith('.m3u8')) continue;
+
+                console.log(`[HistoryDownloader] Queueing background download for: ${item.title}`);
+                processedUrlsRef.current.add(url);
+
+                try {
+                    const segments = await parseHLSManifest(url);
+                    const controller = new AbortController();
+
+                    // Download all segments (not just from playback position)
+                    downloadSegmentQueue({
+                        segments,
+                        startIndex: 0,
+                        signal: controller.signal,
+                        onProgress: (current, total) => {
+                            if (current % 50 === 0) {
+                                console.log(`[HistoryDownloader] ${item.title}: ${current}/${total}`);
+                            }
+                        }
+                    });
+                } catch (error) {
+                    console.error(`[HistoryDownloader] Failed to download ${item.title}:`, error);
+                }
+            }
+        };
+
+        downloadHistoryVideos();
+    }, [viewingHistory]);
+}
+
+export function HistoryDownloader() {
+    useHistoryDownloader();
+    return null;
+}