added functionality for multi-edit of transactions

src/app/api/transactions/bulk/route.ts

@@ -0,0 +1,68 @@
+import { NextResponse } from 'next/server'
+import { z } from 'zod'
+import { auth } from '@/lib/auth'
+import { prisma } from '@/lib/prisma'
+
+const bulkSchema = z.discriminatedUnion('action', [
+  z.object({
+    action: z.literal('delete'),
+    ids: z.array(z.string()).min(1),
+  }),
+  z.object({
+    action: z.literal('assignBudget'),
+    ids: z.array(z.string()).min(1),
+    budgetId: z.string().nullable(),
+  }),
+  z.object({
+    action: z.literal('addNotes'),
+    ids: z.array(z.string()).min(1),
+    notes: z.string().max(500),
+  }),
+])
+
+export async function POST(req: Request) {
+  const session = await auth()
+  if (!session?.user?.id) return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
+
+  const body = await req.json()
+  const result = bulkSchema.safeParse(body)
+  if (!result.success) return NextResponse.json({ error: result.error.flatten() }, { status: 400 })
+
+  const { action, ids } = result.data
+  const userId = session.user.id
+
+  // Verify all transaction IDs belong to this user
+  const owned = await prisma.transaction.findMany({
+    where: { id: { in: ids }, account: { userId } },
+    select: { id: true },
+  })
+  if (owned.length !== ids.length) {
+    return NextResponse.json({ error: 'One or more transactions not found' }, { status: 404 })
+  }
+
+  if (action === 'delete') {
+    await prisma.transaction.deleteMany({ where: { id: { in: ids } } })
+    return NextResponse.json({ deleted: ids.length })
+  }
+
+  if (action === 'assignBudget') {
+    const { budgetId } = result.data
+    if (budgetId !== null) {
+      const budget = await prisma.budget.findFirst({ where: { id: budgetId, userId } })
+      if (!budget) return NextResponse.json({ error: 'Budget not found' }, { status: 404 })
+    }
+    await prisma.transaction.updateMany({
+      where: { id: { in: ids } },
+      data: { budgetId },
+    })
+    return NextResponse.json({ updated: ids.length })
+  }
+
+  // addNotes
+  const { notes } = result.data
+  await prisma.transaction.updateMany({
+    where: { id: { in: ids } },
+    data: { notes: notes || null },
+  })
+  return NextResponse.json({ updated: ids.length })
+}