import { NextRequest, NextResponse } from 'next/server'
import prisma from '@/lib/prisma'
import { auth } from '@/auth'
import { generateBrainstormPptx } from '@/lib/brainstorm/export-pptx'

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

  try {
    const { sessionId } = await params

    const brainstormSession = await prisma.brainstormSession.findFirst({
      where: {
        id: sessionId,
        OR: [
          { userId: session.user.id },
          { participants: { some: { userId: session.user.id } } },
        ],
      },
      include: {
        ideas: {
          orderBy: [{ waveNumber: 'asc' }, { createdAt: 'asc' }],
        },
      },
    })

    if (!brainstormSession) {
      return NextResponse.json({ error: 'Session not found' }, { status: 404 })
    }

    const sessionData = {
      seedIdea: brainstormSession.seedIdea,
      createdAt: brainstormSession.createdAt,
      ideas: brainstormSession.ideas.map(idea => ({
        id: idea.id,
        title: idea.title,
        description: idea.description,
        waveNumber: idea.waveNumber,
        status: idea.status,
        isStarred: idea.isStarred,
        convertedToNoteId: idea.convertedToNoteId,
      })),
    }

    const { buffer, filename } = await generateBrainstormPptx(sessionData)

    return new NextResponse(new Uint8Array(buffer), {
      status: 200,
      headers: {
        'Content-Type': 'application/vnd.openxmlformats-officedocument.presentationml.presentation',
        'Content-Disposition': `attachment; filename="${filename}"`,
        'Content-Length': String(buffer.length),
      },
    })
  } catch (err) {
    console.error('[export-pptx]', err)
    return NextResponse.json({ error: 'Export failed' }, { status: 500 })
  }
}