import { NextRequest, NextResponse } from 'next/server'
import { photoService } from '@/lib/photo-service'
import { imageClassifier } from '@/lib/image-classifier'
import { existsSync } from 'fs'

interface ClassifyRequest {
  photoId?: string
  photoIds?: string[]
  minConfidence?: number
  dryRun?: boolean // Just return classifications without saving
  customLabels?: string[]
  maxResults?: number
  categories?: {
    general?: string[]
    time?: string[]
    weather?: string[]
    subjects?: string[]
    locations?: string[]
    style?: string[]
    seasons?: string[]
  }
}

export async function POST(request: NextRequest) {
  try {
    const body: ClassifyRequest = await request.json()
    
    if (!body.photoId && !body.photoIds) {
      return NextResponse.json(
        { error: 'Either photoId or photoIds must be provided' },
        { status: 400 }
      )
    }

    // Initialize classifier if not already done
    console.log('[CLASSIFY API] Initializing image classifier...')
    await imageClassifier.initialize()

    const photoIds = body.photoId ? [body.photoId] : body.photoIds!
    const minConfidence = body.minConfidence || 0.3
    const dryRun = body.dryRun || false
    
    // Build classifier configuration
    const classifierConfig = {
      minConfidence,
      maxResults: body.maxResults,
      customLabels: body.customLabels,
      categories: body.categories
    }
    
    const results = []
    
    for (const photoId of photoIds) {
      try {
        console.log(`[CLASSIFY API] Processing photo: ${photoId}`)
        
        // Get photo from database
        const photo = photoService.getPhoto(photoId)
        if (!photo) {
          console.warn(`[CLASSIFY API] Photo not found: ${photoId}`)
          results.push({
            photoId,
            error: 'Photo not found',
            success: false
          })
          continue
        }

        // Try to get cached thumbnail first, fall back to file path
        let imageSource: string | Buffer = photo.filepath
        const thumbnailBlob = photoService.getCachedThumbnail(photoId, 200) // Use 200px thumbnail for classification
        
        if (thumbnailBlob) {
          console.log(`[CLASSIFY API] Using cached thumbnail for classification: ${photo.filename}`)
          imageSource = thumbnailBlob
        } else {
          // Check if file exists for fallback
          if (!existsSync(photo.filepath)) {
            console.warn(`[CLASSIFY API] Photo file not found and no thumbnail: ${photo.filepath}`)
            results.push({
              photoId,
              error: 'Photo file not found and no cached thumbnail',
              success: false,
              filepath: photo.filepath
            })
            continue
          }
          console.log(`[CLASSIFY API] Using original file for classification (no thumbnail): ${photo.filepath}`)
        }

        // Classify the image with configuration
        const sourceDesc = thumbnailBlob ? `thumbnail for ${photo.filename}` : photo.filepath
        console.log(`[CLASSIFY API] Classifying image: ${sourceDesc}`)
        const classifications = await imageClassifier.classifyImage(imageSource, body.customLabels, classifierConfig)
        
        // Filter by confidence (already done by classifyImage, but keep for backward compatibility)
        const filteredTags = classifications
          .map(result => ({ name: result.label, confidence: result.score }))
        
        if (dryRun) {
          // Just return the classifications without saving
          results.push({
            photoId,
            filename: photo.filename,
            classifications: filteredTags,
            success: true,
            dryRun: true
          })
        } else {
          // Save tags to database
          const addedCount = photoService.addPhotoTags(photoId, filteredTags)
          
          results.push({
            photoId,
            filename: photo.filename,
            classificationsFound: classifications.length,
            tagsAdded: addedCount,
            tags: filteredTags,
            success: true
          })
          
          console.log(`[CLASSIFY API] Added ${addedCount} tags to photo: ${photo.filename}`)
        }
        
      } catch (error) {
        console.error(`[CLASSIFY API] Error processing photo ${photoId}:`, error)
        results.push({
          photoId,
          error: error instanceof Error ? error.message : 'Unknown error',
          success: false
        })
      }
    }

    const successful = results.filter(r => r.success).length
    const failed = results.filter(r => !r.success).length
    
    console.log(`[CLASSIFY API] Completed: ${successful} successful, ${failed} failed`)

    return NextResponse.json({
      results,
      summary: {
        total: photoIds.length,
        successful,
        failed,
        config: classifierConfig,
        dryRun
      }
    })

  } catch (error) {
    console.error('[CLASSIFY API] Error:', error)
    return NextResponse.json(
      { error: 'Failed to classify images' },
      { status: 500 }
    )
  }
}

// Health check endpoint
export async function GET() {
  try {
    const isReady = imageClassifier.isReady()
    
    return NextResponse.json({
      status: 'ok',
      classifierReady: isReady,
      message: isReady ? 'Classifier ready' : 'Classifier not initialized'
    })
  } catch (error) {
    return NextResponse.json(
      { error: 'Service unavailable' },
      { status: 500 }
    )
  }
}