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

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

  try {
    const { id: noteId, attachmentId } = await params

    const download = request.nextUrl.searchParams.get('download')

    const attachment = await prisma.noteAttachment.findFirst({
      where: { id: attachmentId, noteId, note: { userId: session.user.id } },
      include: download ? undefined : {
        chunks: {
          select: { id: true, chunkIndex: true, pageNumber: true },
          orderBy: { chunkIndex: 'asc' },
        },
      },
    })

    if (!attachment) {
      return NextResponse.json({ error: 'Not found' }, { status: 404 })
    }

    if (download) {
      if (!fs.existsSync(attachment.filePath)) {
        return NextResponse.json({ error: 'File not found' }, { status: 404 })
      }
      const fileBuffer = fs.readFileSync(attachment.filePath)
      return new NextResponse(fileBuffer, {
        headers: {
          'Content-Type': attachment.mimeType || 'application/pdf',
          'Content-Disposition': `inline; filename="${attachment.fileName}"`,
        },
      })
    }

    return NextResponse.json({ success: true, data: attachment })
  } catch (error) {
    console.error('Error fetching attachment:', error)
    return NextResponse.json({ error: 'Failed to fetch attachment' }, { status: 500 })
  }
}

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

  try {
    const { id: noteId, attachmentId } = await params

    const attachment = await prisma.noteAttachment.findFirst({
      where: { id: attachmentId, noteId, note: { userId: session.user.id } },
    })

    if (!attachment) {
      return NextResponse.json({ error: 'Not found' }, { status: 404 })
    }

    try {
      if (fs.existsSync(attachment.filePath)) {
        fs.unlinkSync(attachment.filePath)
      }
    } catch {}

    await prisma.noteAttachment.delete({ where: { id: attachmentId } })

    return NextResponse.json({ success: true })
  } catch (error) {
    console.error('Error deleting attachment:', error)
    return NextResponse.json({ error: 'Failed to delete attachment' }, { status: 500 })
  }
}