feat: add video watch progress tracking with resume functionality

Implements a complete watch progress system that allows users to:
- Save playback position automatically every 5 seconds while watching
- Resume from last position when returning to a video
- Save progress on page leave using sendBeacon for reliability

Also includes:
- Optimized slug generation in projects and workspaces APIs (single query vs loop)
- Added isActive filter to version queries across all video endpoints
- Added pagination support for video and comment queries
- Enhanced database pool management with connection limits and graceful shutdown
- New WatchProgress Prisma model with user-version relations

app/api/projects/[projectId]/route.ts

@@ -52,6 +52,11 @@ export async function GET(request: NextRequest, { params }: RouteParams) {
     try {
         const session = await auth();
         const { projectId } = await params;
+        
+        // Parse pagination params
+        const searchParams = request.nextUrl.searchParams;
+        const limit = Math.min(parseInt(searchParams.get('limit') || '20'), 100);
+        const offset = parseInt(searchParams.get('offset') || '0');
 
         const project = await db.project.findUnique({
             where: { id: projectId },
@@ -64,10 +69,20 @@ export async function GET(request: NextRequest, { params }: RouteParams) {
                 },
                 videos: {
                     orderBy: { position: 'asc' },
+                    skip: offset,
+                    take: limit,
                     include: {
                         versions: {
+                            where: { isActive: true },
                             orderBy: { versionNumber: 'desc' },
                             take: 1,
+                            select: {
+                                id: true,
+                                thumbnailUrl: true,
+                                duration: true,
+                                versionNumber: true,
+                                _count: { select: { comments: true } },
+                            },
                         },
                         _count: { select: { versions: true } },
                     },

app/api/projects/[projectId]/videos/[videoId]/route.ts

@@ -15,25 +15,37 @@ export async function GET(request: NextRequest, { params }: RouteParams) {
         const session = await auth();
         const { projectId, videoId } = await params;
 
+        // Parse query params for pagination and options
+        const searchParams = request.nextUrl.searchParams;
+        const commentLimit = Math.min(parseInt(searchParams.get('commentLimit') || '50'), 100);
+        const commentOffset = parseInt(searchParams.get('commentOffset') || '0');
+        const includeReplies = searchParams.get('includeReplies') === 'true';
+
         const video = await db.video.findFirst({
             where: { id: videoId, projectId },
             include: {
                 project: true,
                 versions: {
+                    where: { isActive: true },
                     orderBy: { versionNumber: 'desc' },
+                    take: 1,
                     include: {
                         comments: {
                             orderBy: { timestamp: 'asc' },
+                            skip: commentOffset,
+                            take: commentLimit,
                             include: {
                                 author: { select: { id: true, name: true, image: true } },
                                 tag: { select: { id: true, name: true, color: true } },
-                                replies: {
-                                    orderBy: { createdAt: 'asc' },
-                                    include: {
-                                        author: { select: { id: true, name: true, image: true } },
-                                        tag: { select: { id: true, name: true, color: true } },
+                                ...(includeReplies ? {
+                                    replies: {
+                                        orderBy: { createdAt: 'asc' },
+                                        include: {
+                                            author: { select: { id: true, name: true, image: true } },
+                                            tag: { select: { id: true, name: true, color: true } },
+                                        },
                                     },
-                                },
+                                } : {}),
                             },
                             where: { parentId: null }, // Only top-level comments
                         },

app/api/projects/[projectId]/videos/route.ts

@@ -38,8 +38,14 @@ export async function GET(request: NextRequest, { params }: RouteParams) {
             orderBy: { position: 'asc' },
             include: {
                 versions: {
+                    where: { isActive: true },
                     orderBy: { versionNumber: 'desc' },
-                    include: {
+                    take: 1,
+                    select: {
+                        id: true,
+                        thumbnailUrl: true,
+                        duration: true,
+                        versionNumber: true,
                         _count: { select: { comments: true } },
                     },
                 },

app/api/projects/route.ts

@@ -105,14 +105,19 @@ export async function POST(request: NextRequest) {
             .replace(/\s+/g, '-')
             .replace(/-+/g, '-');
 
-        // Ensure uniqueness by appending random suffix if needed
+        // Find all existing slugs with the same prefix in a single query
+        const existingProjects = await db.project.findMany({
+            where: { slug: { startsWith: baseSlug } },
+            select: { slug: true },
+        });
+
+        // Generate unique slug from the results
+        const usedSlugs = new Set(existingProjects.map(p => p.slug));
         let slug = baseSlug;
-        let attempts = 0;
-        while (attempts < 10) {
-            const existing = await db.project.findUnique({ where: { slug } });
-            if (!existing) break;
-            slug = `${baseSlug}-${Math.random().toString(36).substring(2, 6)}`;
-            attempts++;
+        let counter = 1;
+        while (usedSlugs.has(slug)) {
+            slug = `${baseSlug}-${counter}`;
+            counter++;
         }
 
         // Verify user has access to the workspace

app/api/watch/[videoId]/progress/route.ts

@@ -0,0 +1,138 @@
+import { NextRequest } from 'next/server';
+import { db } from '@/lib/db';
+import { auth } from '@/lib/auth';
+import { apiErrors, successResponse } from '@/lib/api-response';
+
+type RouteParams = { params: Promise<{ videoId: string }> };
+
+// GET /api/watch/[videoId]/progress - Get watch progress for the current user
+export async function GET(request: NextRequest, { params }: RouteParams) {
+    try {
+        const session = await auth();
+        
+        if (!session?.user?.id) {
+            return apiErrors.unauthorized('Authentication required');
+        }
+
+        const { videoId } = await params;
+
+        // Get the video and its active version
+        const video = await db.video.findUnique({
+            where: { id: videoId },
+            include: {
+                versions: {
+                    where: { isActive: true },
+                    take: 1,
+                },
+            },
+        });
+
+        if (!video) {
+            return apiErrors.notFound('Video');
+        }
+
+        const activeVersion = video.versions[0];
+        if (!activeVersion) {
+            return apiErrors.notFound('Video version');
+        }
+
+        // Get watch progress for this user and version
+        const progress = await db.watchProgress.findUnique({
+            where: {
+                userId_versionId: {
+                    userId: session.user.id,
+                    versionId: activeVersion.id,
+                },
+            },
+        });
+
+        return successResponse({
+            progress: progress ? progress.progress : 0,
+            duration: progress?.duration || activeVersion.duration || 0,
+            percentage: progress?.percentage || 0,
+            updatedAt: progress?.updatedAt || null,
+        });
+    } catch (error) {
+        console.error('Error fetching watch progress:', error);
+        return apiErrors.internalError('Failed to fetch watch progress');
+    }
+}
+
+// POST /api/watch/[videoId]/progress - Save watch progress for the current user
+export async function POST(request: NextRequest, { params }: RouteParams) {
+    try {
+        const session = await auth();
+        
+        if (!session?.user?.id) {
+            return apiErrors.unauthorized('Authentication required');
+        }
+
+        const { videoId } = await params;
+        const body = await request.json();
+        const { progress, duration, versionId } = body;
+
+        if (typeof progress !== 'number' || progress < 0) {
+            return apiErrors.badRequest('Invalid progress value');
+        }
+
+        // Get the video version
+        let targetVersionId = versionId;
+        
+        if (!targetVersionId) {
+            const video = await db.video.findUnique({
+                where: { id: videoId },
+                include: {
+                    versions: {
+                        where: { isActive: true },
+                        take: 1,
+                    },
+                },
+            });
+
+            if (!video) {
+                return apiErrors.notFound('Video');
+            }
+
+            const activeVersion = video.versions[0];
+            if (!activeVersion) {
+                return apiErrors.notFound('Video version');
+            }
+            targetVersionId = activeVersion.id;
+        }
+
+        // Calculate percentage
+        const safeDuration = duration || 0;
+        const percentage = safeDuration > 0 ? Math.min(100, (progress / safeDuration) * 100) : 0;
+
+        // Upsert watch progress
+        const watchProgress = await db.watchProgress.upsert({
+            where: {
+                userId_versionId: {
+                    userId: session.user.id,
+                    versionId: targetVersionId,
+                },
+            },
+            update: {
+                progress,
+                duration: safeDuration,
+                percentage,
+            },
+            create: {
+                userId: session.user.id,
+                versionId: targetVersionId,
+                progress,
+                duration: safeDuration,
+                percentage,
+            },
+        });
+
+        return successResponse({
+            success: true,
+            progress: watchProgress.progress,
+            percentage: watchProgress.percentage,
+        });
+    } catch (error) {
+        console.error('Error saving watch progress:', error);
+        return apiErrors.internalError('Failed to save watch progress');
+    }
+}

app/api/watch/[videoId]/route.ts

@@ -11,30 +11,39 @@ export async function GET(request: NextRequest, { params }: RouteParams) {
         const session = await auth();
         const { videoId } = await params;
 
+        // Parse query params
+        const searchParams = request.nextUrl.searchParams;
+        const includeComments = searchParams.get('includeComments') === 'true';
+
         const video = await db.video.findUnique({
             where: { id: videoId },
             include: {
                 project: true,
                 versions: {
+                    where: { isActive: true },
                     orderBy: { versionNumber: 'desc' },
-                    include: {
-                        comments: {
-                            orderBy: { timestamp: 'asc' },
-                            where: { parentId: null },
-                            include: {
-                                author: { select: { id: true, name: true, image: true } },
-                                tag: { select: { id: true, name: true, color: true } },
-                                replies: {
-                                    orderBy: { createdAt: 'asc' },
-                                    include: {
-                                        author: { select: { id: true, name: true, image: true } },
-                                        tag: { select: { id: true, name: true, color: true } },
-                                    },
+                    take: 1,
+                    ...(includeComments ? {
+                        include: {
+                            comments: {
+                                orderBy: { timestamp: 'asc' },
+                                where: { parentId: null },
+                                include: {
+                                    author: { select: { id: true, name: true, image: true } },
+                                    tag: { select: { id: true, name: true, color: true } },
                                 },
                             },
+                            _count: { select: { comments: true } },
                         },
-                        _count: { select: { comments: true } },
-                    },
+                    } : {
+                        select: {
+                            id: true,
+                            thumbnailUrl: true,
+                            duration: true,
+                            versionNumber: true,
+                            _count: { select: { comments: true } },
+                        },
+                    }),
                 },
             },
         });

app/api/workspaces/route.ts

@@ -63,13 +63,19 @@ export async function POST(request: NextRequest) {
             .replace(/\s+/g, '-')
             .replace(/-+/g, '-');
 
+        // Find all existing slugs with the same prefix in a single query
+        const existingWorkspaces = await db.workspace.findMany({
+            where: { slug: { startsWith: baseSlug } },
+            select: { slug: true },
+        });
+
+        // Generate unique slug from the results
+        const usedSlugs = new Set(existingWorkspaces.map(w => w.slug));
         let slug = baseSlug;
-        let attempts = 0;
-        while (attempts < 10) {
-            const existing = await db.workspace.findUnique({ where: { slug } });
-            if (!existing) break;
-            slug = `${baseSlug}-${Math.random().toString(36).substring(2, 6)}`;
-            attempts++;
+        let counter = 1;
+        while (usedSlugs.has(slug)) {
+            slug = `${baseSlug}-${counter}`;
+            counter++;
         }
 
         const workspace = await db.workspace.create({

components/video-page-content.tsx

@@ -2,6 +2,7 @@
 
 import { useState, useRef, useCallback, useEffect } from 'react';
 import Link from 'next/link';
+import { usePathname } from 'next/navigation';
 import { toast } from 'sonner';
 import {
   ArrowLeft,
@@ -155,6 +156,7 @@ export function VideoPageContent({ mode, videoId, projectId: propProjectId }: Vi
   const playerRef = useRef<YT.Player | null>(null);
   const timelineRef = useRef<HTMLDivElement>(null);
   const videoContainerRef = useRef<HTMLDivElement>(null);
+  const pathname = usePathname();
   const [video, setVideo] = useState<VideoData | null>(null);
   const [loading, setLoading] = useState(true);
   const [error, setError] = useState('');
@@ -168,6 +170,7 @@ export function VideoPageContent({ mode, videoId, projectId: propProjectId }: Vi
   const [playbackSpeed, setPlaybackSpeed] = useState(1);
   const [cursorIdle, setCursorIdle] = useState(false);
   const cursorIdleTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
+  const lastPathnameRef = useRef<string>(pathname);
 
   const [commentText, setCommentText] = useState('');
   const [isSubmittingComment, setIsSubmittingComment] = useState(false);
@@ -188,6 +191,13 @@ export function VideoPageContent({ mode, videoId, projectId: propProjectId }: Vi
   const [selectedTimestamp, setSelectedTimestamp] = useState<number | null>(null);
   const [showResolved, setShowResolved] = useState(false);
 
+  // Watch progress state
+  const [savedProgress, setSavedProgress] = useState<number | null>(null);
+  const [showResumePrompt, setShowResumePrompt] = useState(false);
+  const progressSaveTimerRef = useRef<ReturnType<typeof setInterval> | null>(null);
+  const lastSavedProgressRef = useRef<number>(0);
+  const [progressFetchKey, setProgressFetchKey] = useState(0);
+
   const [replyingTo, setReplyingTo] = useState<string | null>(null);
   const [replyText, setReplyText] = useState('');
   const [isSubmittingReply, setIsSubmittingReply] = useState(false);
@@ -392,6 +402,116 @@ export function VideoPageContent({ mode, videoId, projectId: propProjectId }: Vi
     });
   }, [videoDuration, activeVersion?.id, activeVersion?.duration, propProjectId, videoId]);
 
+  // Load watch progress when video is loaded (authenticated users only)
+  const loadWatchProgress = useCallback(async (showPrompt = true) => {
+    if (!video?.isAuthenticated || !activeVersionId) return;
+
+    // Reset state
+    setSavedProgress(null);
+    setShowResumePrompt(false);
+
+    try {
+      // Use cache: 'no-store' to always fetch fresh data
+      const res = await fetch(`/api/watch/${videoId}/progress`, { cache: 'no-store' });
+      if (res.ok) {
+        const response = await res.json();
+        const progress = response.data?.progress || 0;
+        const percentage = response.data?.percentage || 0;
+        
+        // Only show resume prompt if progress is between 5% and 95%
+        if (showPrompt && percentage > 5 && percentage < 95) {
+          setSavedProgress(progress);
+          setShowResumePrompt(true);
+        }
+      }
+    } catch (err) {
+      console.error('Error loading watch progress:', err);
+    }
+  }, [video?.isAuthenticated, activeVersionId, videoId]);
+
+  // Load progress on mount and when dependencies change
+  useEffect(() => {
+    loadWatchProgress();
+  }, [loadWatchProgress, progressFetchKey]);
+
+  // Refetch progress when pathname changes (user navigates back to this page)
+  useEffect(() => {
+    if (lastPathnameRef.current !== pathname) {
+      const previousPath = lastPathnameRef.current;
+      lastPathnameRef.current = pathname;
+      
+      // If we navigated away and came back to this video page, refetch progress
+      if (previousPath !== pathname) {
+        setProgressFetchKey(k => k + 1);
+      }
+    }
+  }, [pathname]);
+
+  // Save watch progress periodically while playing (authenticated users only)
+  useEffect(() => {
+    if (!video?.isAuthenticated || !isReady || !activeVersionId) return;
+
+    // Save progress every 5 seconds while playing
+    progressSaveTimerRef.current = setInterval(() => {
+      if (currentTime > 0 && Math.abs(currentTime - lastSavedProgressRef.current) >= 2) {
+        // Save to API
+        fetch(`/api/watch/${videoId}/progress`, {
+          method: 'POST',
+          headers: { 'Content-Type': 'application/json' },
+          body: JSON.stringify({
+            progress: currentTime,
+            duration: videoDuration,
+            versionId: activeVersionId,
+          }),
+        }).catch((err) => console.error('Error saving watch progress:', err));
+        
+        lastSavedProgressRef.current = currentTime;
+      }
+    }, 5000);
+
+    return () => {
+      if (progressSaveTimerRef.current) {
+        clearInterval(progressSaveTimerRef.current);
+      }
+    };
+  }, [video?.isAuthenticated, isReady, currentTime, videoDuration, activeVersionId, videoId]);
+
+  // Save progress when user leaves the page
+  useEffect(() => {
+    if (!video?.isAuthenticated) return;
+
+    const saveProgressOnLeave = () => {
+      if (currentTime > 0 && navigator.sendBeacon) {
+        // Use sendBeacon for reliable save on page unload
+        const data = new Blob([JSON.stringify({
+          progress: currentTime,
+          duration: videoDuration,
+          versionId: activeVersionId,
+        })], { type: 'application/json' });
+        navigator.sendBeacon(`/api/watch/${videoId}/progress`, data);
+      }
+    };
+
+    window.addEventListener('beforeunload', saveProgressOnLeave);
+    return () => window.removeEventListener('beforeunload', saveProgressOnLeave);
+  }, [video?.isAuthenticated, currentTime, videoDuration, activeVersionId, videoId]);
+
+  // Resume playback from saved position
+  const handleResumeFromSaved = useCallback(() => {
+    if (savedProgress !== null && playerRef.current?.seekTo) {
+      playerRef.current.seekTo(savedProgress, true);
+      setCurrentTime(savedProgress);
+      setShowResumePrompt(false);
+      setSavedProgress(null);
+    }
+  }, [savedProgress]);
+
+  // Dismiss resume prompt
+  const handleDismissResume = useCallback(() => {
+    setShowResumePrompt(false);
+    setSavedProgress(null);
+  }, []);
+
   useEffect(() => {
     if (!isReady || !playerRef.current) return;
 
@@ -1720,6 +1840,44 @@ export function VideoPageContent({ mode, videoId, projectId: propProjectId }: Vi
                   )}
                 </div>
               </div>
+
+              {/* Resume playback prompt */}
+              {showResumePrompt && savedProgress !== null && (
+                <div className="absolute inset-0 flex items-center justify-center bg-black/40 z-10">
+                  <div className="bg-background/95 backdrop-blur-sm rounded-lg p-4 shadow-lg max-w-sm mx-4">
+                    <div className="flex items-center gap-3 mb-3">
+                      <div className="w-10 h-10 rounded-full bg-primary/10 flex items-center justify-center">
+                        <Clock className="h-5 w-5 text-primary" />
+                      </div>
+                      <div>
+                        <p className="font-medium text-sm">Continue watching?</p>
+                        <p className="text-xs text-muted-foreground">
+                          Resume from {formatTime(savedProgress)}
+                        </p>
+                      </div>
+                    </div>
+                    <div className="flex gap-2">
+                      <Button
+                        size="sm"
+                        variant="default"
+                        onClick={handleResumeFromSaved}
+                        className="flex-1"
+                      >
+                        <Play className="h-4 w-4 mr-1" />
+                        Resume
+                      </Button>
+                      <Button
+                        size="sm"
+                        variant="ghost"
+                        onClick={handleDismissResume}
+                        className="flex-1"
+                      >
+                        Start over
+                      </Button>
+                    </div>
+                  </div>
+                </div>
+              )}
             </div>
           </div>
 

lib/db.ts

@@ -1,11 +1,52 @@
 import { PrismaClient } from '@prisma/client';
 import { PrismaPg } from '@prisma/adapter-pg';
-import { Pool } from 'pg';
+import { Pool, PoolConfig } from 'pg';
 
 const globalForPrisma = globalThis as unknown as {
   prisma: PrismaClient | undefined;
 };
 
+const globalForPool = globalThis as unknown as {
+  pgPool: Pool | undefined;
+};
+
+function createPool(connectionString: string): Pool {
+  // Prevent multiple pools from being created during development (Next.js hot reload)
+  if (globalForPool.pgPool) {
+    return globalForPool.pgPool;
+  }
+
+  const poolConfig: PoolConfig = {
+    connectionString,
+    max: 20, // Maximum number of connections
+    idleTimeoutMillis: 30000, // Close idle connections after 30 seconds
+    connectionTimeoutMillis: 5000, // Return error after 5 seconds if can't connect
+  };
+
+  const pool = new Pool(poolConfig);
+
+  // Add error handling for pool errors
+  pool.on('error', (err, client) => {
+    console.error('Unexpected database pool error:', err.message);
+    // Don't crash the app on unexpected pool errors
+  });
+
+  pool.on('connect', () => {
+    console.debug('New database connection established');
+  });
+
+  pool.on('acquire', () => {
+    console.debug('Connection acquired from pool');
+  });
+
+  // Store pool globally to prevent multiple instances during development
+  if (process.env.NODE_ENV !== 'production') {
+    globalForPool.pgPool = pool;
+  }
+
+  return pool;
+}
+
 function createPrismaClient() {
   // In development without a database, we'll create a mock-friendly client
   // For production or when DATABASE_URL is set, use the real adapter
@@ -14,13 +55,14 @@ function createPrismaClient() {
   if (!connectionString) {
     console.warn('DATABASE_URL not set - database features will not work');
     // Return a client that will throw clear errors when used
+    const pool = createPool('postgresql://localhost:5432/dummy');
     return new PrismaClient({
       // This will fail on actual DB operations but allows imports to work
-      adapter: new PrismaPg(new Pool({ connectionString: 'postgresql://localhost:5432/dummy' })),
+      adapter: new PrismaPg(pool),
     });
   }
   
-  const pool = new Pool({ connectionString });
+  const pool = createPool(connectionString);
   const adapter = new PrismaPg(pool);
   
   return new PrismaClient({
@@ -35,4 +77,21 @@ if (process.env.NODE_ENV !== 'production') {
   globalForPrisma.prisma = db;
 }
 
+// Graceful shutdown handler
+async function shutdown() {
+  console.log('Shutting down database connections...');
+  
+  if (globalForPool.pgPool) {
+    await globalForPool.pgPool.end();
+    console.log('Database pool closed');
+  }
+  
+  await db.$disconnect();
+  console.log('Prisma client disconnected');
+}
+
+// Register shutdown handlers
+process.on('SIGINT', shutdown);
+process.on('SIGTERM', shutdown);
+
 export default db;

prisma/schema.prisma

@@ -31,6 +31,7 @@ model User {
   comments           Comment[]
   projectMemberships ProjectMember[]
   notificationSetting NotificationSetting?
+  watchProgress      WatchProgress[]
   
   @@map("users")
 }
@@ -158,6 +159,7 @@ model Project {
   @@index([ownerId])
   @@index([slug])
   @@index([workspaceId])
+  @@index([workspaceId, updatedAt(sort: Desc)])
   @@map("projects")
 }
 
@@ -239,9 +241,11 @@ model VideoVersion {
   
   // Relations
   comments        Comment[]
+  watchProgress   WatchProgress[]
   
   @@unique([videoParentId, versionNumber])
   @@index([videoParentId])
+  @@index([videoParentId, isActive])
   @@map("video_versions")
 }
 
@@ -293,6 +297,8 @@ model Comment {
   @@index([authorId])
   @@index([timestamp])
   @@index([tagId])
+  @@index([versionId, isResolved, timestamp])
+  @@index([versionId, parentId, createdAt])
   @@map("comments")
 }
 
@@ -345,6 +351,7 @@ model ShareLink {
   
   @@index([projectId])
   @@index([token])
+  @@index([token, expiresAt])
   @@map("share_links")
 }
 
@@ -386,6 +393,37 @@ model NotificationSetting {
   @@map("notification_settings")
 }
 
+// ============================================
+// WATCH PROGRESS
+// ============================================
+
+model WatchProgress {
+  id         String   @id @default(cuid())
+  
+  // User relation (optional for guest progress, though typically requires auth)
+  userId     String
+  user       User     @relation(fields: [userId], references: [id], onDelete: Cascade)
+  
+  // Video version relation
+  versionId  String
+  version    VideoVersion @relation(fields: [versionId], references: [id], onDelete: Cascade)
+  
+  // Progress data
+  progress   Float    // Current playback position in seconds
+  duration   Float    // Total video duration at time of save
+  percentage Float    // Progress as percentage (0-100)
+  
+  // Timestamps
+  updatedAt  DateTime @updatedAt
+  createdAt  DateTime @default(now())
+  
+  // One progress record per user per version
+  @@unique([userId, versionId])
+  @@index([userId])
+  @@index([versionId])
+  @@map("watch_progress")
+}
+
 // Rate limiting table (created as UNLOGGED via raw SQL migration)
 // Defined here so `prisma db push` doesn't drop it
 model RateLimit {