import { NextRequest, NextResponse } from 'next/server'
import { auth } from '@/auth'
import { prisma } from '@/lib/prisma'
import { EmbeddingService } from '@/lib/ai/services/embedding.service'

export async function POST(req: NextRequest) {
  try {
    const session = await auth()
    if (!session?.user?.id) {
      return NextResponse.json({ success: false, error: 'Unauthorized' }, { status: 401 })
    }

    const userId = session.user.id

    // Fetch all notes for the user
    const notes = await prisma.note.findMany({
      where: { userId, trashedAt: null },
      select: { id: true, title: true, content: true }
    })

    const embeddingService = new EmbeddingService()
    let processedCount = 0

    // Process in small batches to avoid timeouts if possible
    // Note: In a real production app, this should be a background job
    for (const note of notes) {
      try {
        const textToEmbed = `${note.title || ''}\n${note.content}`
        if (textToEmbed.trim()) {
          const embedding = await embeddingService.generateEmbedding(textToEmbed)
          
          await prisma.noteEmbedding.upsert({
            where: { noteId: note.id },
            update: { embedding: JSON.stringify(embedding) },
            create: {
              noteId: note.id,
              embedding: JSON.stringify(embedding)
            }
          })
          processedCount++
        }
      } catch (err) {
        console.error(`Failed to reindex note ${note.id}:`, err)
      }
    }

    return NextResponse.json({
      success: true,
      count: processedCount,
      total: notes.length
    })
  } catch (error) {
    console.error('Reindex error:', error)
    return NextResponse.json(
      { success: false, error: 'Failed to reindex notes' },
      { status: 500 }
    )
  }
}