Wrap song updates and deletes in database transactions for consistency

app/api/songs/route.ts

@@ -469,51 +469,55 @@ export async function PUT(request: Request) {
             };
         }
 
-        // Handle SpecialSong relations separately
-        if (effectiveSpecialIds !== undefined) {
-            // First, get current special assignments
-            const currentSpecials = await prisma.specialSong.findMany({
-                where: { songId: Number(id) }
-            });
-
-            const currentSpecialIds = currentSpecials.map(ss => ss.specialId);
-            const newSpecialIds = effectiveSpecialIds as number[];
-
-            // Delete removed specials
-            const toDelete = currentSpecialIds.filter(sid => !newSpecialIds.includes(sid));
-            if (toDelete.length > 0) {
-                await prisma.specialSong.deleteMany({
-                    where: {
-                        songId: Number(id),
-                        specialId: { in: toDelete }
-                    }
+        // Execute all database write operations in a transaction to ensure consistency
+        const updatedSong = await prisma.$transaction(async (tx) => {
+            // Handle SpecialSong relations separately
+            if (effectiveSpecialIds !== undefined) {
+                // First, get current special assignments (within transaction)
+                const currentSpecials = await tx.specialSong.findMany({
+                    where: { songId: Number(id) }
                 });
-            }
 
-            // Add new specials
-            const toAdd = newSpecialIds.filter(sid => !currentSpecialIds.includes(sid));
-            if (toAdd.length > 0) {
-                await prisma.specialSong.createMany({
-                    data: toAdd.map(specialId => ({
-                        songId: Number(id),
-                        specialId,
-                        startTime: 0
-                    }))
-                });
-            }
-        }
+                const currentSpecialIds = currentSpecials.map(ss => ss.specialId);
+                const newSpecialIds = effectiveSpecialIds as number[];
 
-        const updatedSong = await prisma.song.update({
-            where: { id: Number(id) },
-            data,
-            include: {
-                genres: true,
-                specials: {
-                    include: {
-                        special: true
-                    }
+                // Delete removed specials
+                const toDelete = currentSpecialIds.filter(sid => !newSpecialIds.includes(sid));
+                if (toDelete.length > 0) {
+                    await tx.specialSong.deleteMany({
+                        where: {
+                            songId: Number(id),
+                            specialId: { in: toDelete }
+                        }
+                    });
+                }
+
+                // Add new specials
+                const toAdd = newSpecialIds.filter(sid => !currentSpecialIds.includes(sid));
+                if (toAdd.length > 0) {
+                    await tx.specialSong.createMany({
+                        data: toAdd.map(specialId => ({
+                            songId: Number(id),
+                            specialId,
+                            startTime: 0
+                        }))
+                    });
                 }
             }
+
+            // Update song (this also handles genre relations via Prisma's set operation)
+            return await tx.song.update({
+                where: { id: Number(id) },
+                data,
+                include: {
+                    genres: true,
+                    specials: {
+                        include: {
+                            special: true
+                        }
+                    }
+                }
+            });
         });
 
         return NextResponse.json(updatedSong);
@@ -559,7 +563,7 @@ export async function DELETE(request: Request) {
             }
         }
 
-        // Delete file
+        // Delete files first (outside transaction, as file system operations can't be rolled back)
         const filePath = path.join(process.cwd(), 'public/uploads', song.filename);
         try {
             await unlink(filePath);
@@ -578,9 +582,11 @@ export async function DELETE(request: Request) {
             }
         }
 
-        // Delete from database (will cascade delete related puzzles)
-        await prisma.song.delete({
-            where: { id: Number(id) },
+        // Delete from database in transaction (will cascade delete related puzzles, SpecialSong, etc.)
+        await prisma.$transaction(async (tx) => {
+            await tx.song.delete({
+                where: { id: Number(id) },
+            });
         });
 
         return NextResponse.json({ success: true });