import { NextRequest, NextResponse } from 'next/server'
import { auth } from '@/auth'
import prisma from '@/lib/prisma'
import { notebookWizardService, type WizardProfile } from '@/lib/ai/services/notebook-wizard.service'
import { checkEntitlementOrThrow, QuotaExceededError, incrementUsageAsync } from '@/lib/entitlements'

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

    const { profile, topic, level, count, language, notebookName, notebookIcon } = await request.json()

    if (!profile || !topic?.trim()) {
      return NextResponse.json({ error: 'Profile and topic are required' }, { status: 400 })
    }

    try {
      await checkEntitlementOrThrow(session.user.id, 'reformulate')
    } catch (err) {
      if (err instanceof QuotaExceededError) {
        const isTierLocked = err.currentQuota === 0
        return NextResponse.json(
          { error: isTierLocked ? 'feature_locked' : 'quota_exceeded', errorKey: isTierLocked ? 'ai.featureLocked' : 'ai.quotaExceeded', upgradeTier: err.upgradeTier },
          { status: 402 },
        )
      }
      throw err
    }

    const result = await notebookWizardService.generateCarnet(
      profile as WizardProfile,
      topic,
      { level, count, language: language || 'fr' }
    )

    // 1. Create notebook
    const notebook = await prisma.notebook.create({
      data: {
        name: notebookName || topic,
        icon: notebookIcon || '📚',
        userId: session.user.id,
        order: 0,
      },
    })

    // 2. Create schema
    const schema = await prisma.notebookSchema.create({
      data: { notebookId: notebook.id },
    })

    // 3. Create properties
    const defaultProperties = [
      { name: 'Statut', type: 'select', options: ['À réviser', 'En cours', 'Maîtrisé'] },
      { name: 'Difficulté', type: 'select', options: ['Facile', 'Moyen', 'Difficile'] },
    ]
    const propertiesToCreate = result.schemaProperties?.length ? result.schemaProperties : defaultProperties

    const propertyMap = new Map<string, string>()
    for (let i = 0; i < propertiesToCreate.length; i++) {
      const p = propertiesToCreate[i]
      const created = await prisma.notebookProperty.create({
        data: {
          schemaId: schema.id,
          name: p.name,
          type: p.type,
          options: p.options ? JSON.stringify(p.options) : null,
          position: i,
        },
      })
      propertyMap.set(p.name, created.id)
    }

    // 4. Create notes
    let noteIndex = 0
    for (const note of result.notes) {
      const created = await prisma.note.create({
        data: {
          title: note.title,
          content: note.content,
          userId: session.user.id,
          notebookId: notebook.id,
          type: 'richtext',
          order: noteIndex++,
        },
      })

      // 5. Set default property values
      if (note.difficulty && propertyMap.has('Difficulté')) {
        const difficultyMap: Record<string, string> = {
          facile: 'Facile', moyen: 'Moyen', difficile: 'Difficile',
          easy: 'Facile', medium: 'Moyen', hard: 'Difficile',
        }
        const val = difficultyMap[note.difficulty?.toLowerCase() || ''] || 'Moyen'
        await prisma.noteProperty.create({
          data: { noteId: created.id, propertyId: propertyMap.get('Difficulté')!, value: val },
        }).catch(() => {})
      }

      if (propertyMap.has('Statut')) {
        await prisma.noteProperty.create({
          data: { noteId: created.id, propertyId: propertyMap.get('Statut')!, value: 'À réviser' },
        }).catch(() => {})
      }

      // 6. Background embedding
      void (async () => {
        try {
          const { embeddingService } = await import('@/lib/ai/services/embedding.service')
          const { upsertNoteEmbedding } = await import('@/lib/embeddings')
          const { chunkIndexingService } = await import('@/lib/ai/services/chunk-indexing.service')
          const { embedding } = await embeddingService.generateNoteEmbedding(note.title, note.content)
          await upsertNoteEmbedding(created.id, embedding)
          await chunkIndexingService.indexNote(created.id, note.title, note.content)
        } catch (e) {
          console.error('[Wizard] Background embedding failed:', e)
        }
      })()
    }

    incrementUsageAsync(session.user.id, 'reformulate')

    return NextResponse.json({
      notebookId: notebook.id,
      notebookName: notebook.name,
      noteCount: result.notes.length,
      noteTitles: result.notes.map(n => n.title),
    })
  } catch (error: any) {
    console.error('[Notebook Wizard] Error:', error)
    return NextResponse.json({ error: error.message || 'Failed to generate notebook' }, { status: 500 })
  }
}