feat: Add last played timestamp to video data

backend/src/controllers/videoController.ts

@@ -657,7 +657,10 @@ export const incrementViewCount = (req: Request, res: Response): any => {
     }
 
     const currentViews = video.viewCount || 0;
-    const updatedVideo = storageService.updateVideo(id, { viewCount: currentViews + 1 });
+    const updatedVideo = storageService.updateVideo(id, { 
+      viewCount: currentViews + 1,
+      lastPlayedAt: Date.now()
+    });
 
     res.status(200).json({
       success: true,
@@ -679,7 +682,10 @@ export const updateProgress = (req: Request, res: Response): any => {
       return res.status(400).json({ error: "Progress must be a number" });
     }
 
-    const updatedVideo = storageService.updateVideo(id, { progress });
+    const updatedVideo = storageService.updateVideo(id, { 
+      progress,
+      lastPlayedAt: Date.now()
+    });
 
     if (!updatedVideo) {
       return res.status(404).json({ error: "Video not found" });

backend/src/db/schema.ts

@@ -27,6 +27,7 @@ export const videos = sqliteTable('videos', {
   tags: text('tags'), // JSON stringified array of strings
   progress: integer('progress'), // Playback progress in seconds
   fileSize: text('file_size'),
+  lastPlayedAt: integer('last_played_at'), // Timestamp when video was last played
 });
 
 export const collections = sqliteTable('collections', {

backend/src/services/storageService.ts

@@ -143,6 +143,12 @@ export function initializeStorage(): void {
       console.log("Migration successful: file_size added.");
     }
 
+    if (!columns.includes('last_played_at')) {
+      console.log("Migrating database: Adding last_played_at column to videos table...");
+      sqlite.prepare("ALTER TABLE videos ADD COLUMN last_played_at INTEGER").run();
+      console.log("Migration successful: last_played_at added.");
+    }
+
     // Populate fileSize for existing videos
     const allVideos = db.select().from(videos).all();
     let updatedCount = 0;

frontend/src/pages/VideoPlayer.tsx

@@ -13,7 +13,7 @@ import {
 } from '@mui/material';
 import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
 import axios from 'axios';
-import { useEffect, useRef, useState } from 'react';
+import { useEffect, useMemo, useRef, useState } from 'react';
 import { useNavigate, useParams } from 'react-router-dom';
 import ConfirmationModal from '../components/ConfirmationModal';
 import CollectionModal from '../components/VideoPlayer/CollectionModal';
@@ -25,6 +25,7 @@ import { useLanguage } from '../contexts/LanguageContext';
 import { useSnackbar } from '../contexts/SnackbarContext';
 import { useVideo } from '../contexts/VideoContext';
 import { Collection, Video } from '../types';
+import { getRecommendations } from '../utils/recommendations';
 
 const API_URL = import.meta.env.VITE_API_URL;
 const BACKEND_URL = import.meta.env.VITE_BACKEND_URL;
@@ -343,8 +344,15 @@ const VideoPlayer: React.FC = () => {
         );
     }
 
-    // Get related videos (exclude current video)
-    const relatedVideos = videos.filter(v => v.id !== id).slice(0, 10);
+    // Get related videos using recommendation algorithm
+    const relatedVideos = useMemo(() => {
+        if (!video) return [];
+        return getRecommendations({
+            currentVideo: video,
+            allVideos: videos,
+            collections: collections
+        }).slice(0, 10);
+    }, [video, videos, collections]);
 
     return (
         <Container maxWidth="xl" sx={{ py: 4 }}>

frontend/src/types.ts

@@ -20,6 +20,7 @@ export interface Video {
   progress?: number;
   duration?: string;
   fileSize?: string; // Size in bytes as string
+  lastPlayedAt?: number;
   [key: string]: any;
 }
 

frontend/src/utils/recommendations.ts

@@ -0,0 +1,135 @@
+import { Collection, Video } from '../types';
+
+export interface RecommendationWeights {
+    recency: number;
+    frequency: number;
+    collection: number;
+    tags: number;
+    author: number;
+    filename: number;
+    sequence: number;
+}
+
+export const DEFAULT_WEIGHTS: RecommendationWeights = {
+    recency: 0.2,
+    frequency: 0.1,
+    collection: 0.4,
+    tags: 0.2,
+    author: 0.1,
+    filename: 0.0, // Used as tie-breaker mostly
+    sequence: 0.5, // Boost for the immediate next file
+};
+
+export interface RecommendationContext {
+    currentVideo: Video;
+    allVideos: Video[];
+    collections: Collection[];
+    weights?: Partial<RecommendationWeights>;
+}
+
+export const getRecommendations = (context: RecommendationContext): Video[] => {
+    const { currentVideo, allVideos, collections, weights } = context;
+    const finalWeights = { ...DEFAULT_WEIGHTS, ...weights };
+
+    // Filter out current video
+    const candidates = allVideos.filter(v => v.id !== currentVideo.id);
+
+    // Pre-calculate collection membership for current video
+    const currentVideoCollections = collections.filter(c => c.videos.includes(currentVideo.id)).map(c => c.id);
+
+    // Calculate max values for normalization
+    const maxViewCount = Math.max(...allVideos.map(v => v.viewCount || 0), 1);
+    const now = Date.now();
+    // Normalize recency: 1.0 for now, 0.0 for very old (e.g. 1 year ago)
+    const ONE_YEAR_MS = 365 * 24 * 60 * 60 * 1000;
+
+    // Determine natural sequence
+    // Sort all videos by filename/title to find the "next" one naturally
+    const sortedAllVideos = [...allVideos].sort((a, b) => {
+        const nameA = a.videoFilename || a.title;
+        const nameB = b.videoFilename || b.title;
+        return nameA.localeCompare(nameB, undefined, { numeric: true, sensitivity: 'base' });
+    });
+    const currentIndex = sortedAllVideos.findIndex(v => v.id === currentVideo.id);
+    const nextInSequenceId = currentIndex !== -1 && currentIndex < sortedAllVideos.length - 1 
+        ? sortedAllVideos[currentIndex + 1].id 
+        : null;
+
+    const scoredCandidates = candidates.map(video => {
+        let score = 0;
+
+        // 1. Recency (lastPlayedAt)
+        // Higher score for more recently played.
+        // If never played, score is 0.
+        if (video.lastPlayedAt) {
+            const age = Math.max(0, now - video.lastPlayedAt);
+            const recencyScore = Math.max(0, 1 - (age / ONE_YEAR_MS));
+            score += recencyScore * finalWeights.recency;
+        }
+
+        // 2. Frequency (viewCount)
+        const frequencyScore = (video.viewCount || 0) / maxViewCount;
+        score += frequencyScore * finalWeights.frequency;
+
+        // 3. Collection/Series
+        // Check if video is in the same collection as current video
+        const videoCollections = collections.filter(c => c.videos.includes(video.id)).map(c => c.id);
+        const inSameCollection = currentVideoCollections.some(id => videoCollections.includes(id));
+        
+        // Also check seriesTitle if available
+        const sameSeriesTitle = currentVideo.seriesTitle && video.seriesTitle && currentVideo.seriesTitle === video.seriesTitle;
+
+        if (inSameCollection || sameSeriesTitle) {
+            score += 1.0 * finalWeights.collection;
+        }
+
+        // 4. Tags
+        // Jaccard index or simple overlap
+        const currentTags = currentVideo.tags || [];
+        const videoTags = video.tags || [];
+        if (currentTags.length > 0 && videoTags.length > 0) {
+            const intersection = currentTags.filter(t => videoTags.includes(t));
+            const union = new Set([...currentTags, ...videoTags]);
+            const tagScore = intersection.length / union.size;
+            score += tagScore * finalWeights.tags;
+        }
+
+        // 5. Author
+        if (currentVideo.author && video.author && currentVideo.author === video.author) {
+            score += 1.0 * finalWeights.author;
+        }
+        
+        // 6. Sequence (Natural Order)
+        if (video.id === nextInSequenceId) {
+            score += 1.0 * finalWeights.sequence;
+        }
+        
+        return {
+            video,
+            score,
+            inSameCollection
+        };
+    });
+
+    // Sort by score descending
+    scoredCandidates.sort((a, b) => {
+        if (Math.abs(a.score - b.score) > 0.001) {
+            return b.score - a.score;
+        }
+
+        // Tie-breakers
+        
+        // 1. Same collection
+        if (a.inSameCollection !== b.inSameCollection) {
+            return a.inSameCollection ? -1 : 1;
+        }
+
+        // 2. Filename natural order
+        const nameA = a.video.videoFilename || a.video.title;
+        const nameB = b.video.videoFilename || b.video.title;
+        
+        return nameA.localeCompare(nameB, undefined, { numeric: true, sensitivity: 'base' });
+    });
+
+    return scoredCandidates.map(item => item.video);
+};