Todo/app/api/lists/[id]/last-updated/route.ts

import { NextRequest, NextResponse } from 'next/server'
import { prisma } from '@/lib/db'
import { auth } from '@/auth'

export const dynamic = 'force-dynamic'
export const revalidate = 0

export async function GET(
  request: NextRequest,
  { params }: { params: { id: string } }
) {
  try {
    const session = await auth()
    if (!session?.user?.id) {
      return NextResponse.json(
        { error: 'Unauthorized' },
        { status: 401 }
      )
    }

    const userId = session.user.id
    const listId = params.id

    // Check if user has access to this list
    const list = await prisma.list.findFirst({
      where: {
        id: listId,
        OR: [
          { ownerId: userId },
          {
            collaborators: {
              some: {
                userId: userId,
              },
            },
          },
        ],
      },
      select: {
        updatedAt: true,
        items: {
          select: {
            updatedAt: true,
          },
          orderBy: {
            updatedAt: 'desc',
          },
          take: 1,
        },
      },
    })

    if (!list) {
      return NextResponse.json(
        { error: 'List not found or access denied' },
        { status: 404 }
      )
    }

    // Get the most recent update time (either list or its items)
    const listUpdated = list.updatedAt.getTime()
    const itemUpdated = list.items[0]?.updatedAt.getTime() || 0
    const lastUpdated = Math.max(listUpdated, itemUpdated)

    return NextResponse.json(
      { lastUpdated: new Date(lastUpdated).toISOString() },
      {
        headers: {
          'Cache-Control': 'no-store, no-cache, must-revalidate',
          'Pragma': 'no-cache',
          'Expires': '0',
        },
      }
    )
  } catch (error) {
    console.error('Error fetching last updated timestamp:', error)
    return NextResponse.json(
      { error: 'Internal server error' },
      { status: 500 }
    )
  }
}