import { NextRequest, NextResponse } from 'next/server'
import { getServerSession } from 'next-auth'
import { authOptions } from '@/lib/auth'
import { prisma } from '@/lib/prisma'
import { uploadToS3 } from '@/lib/s3'
import { processImage, getProcessedFileName } from '@/lib/image-processor'
import { writeFile, mkdir } from 'fs/promises'
import path from 'path'

// Configure route to handle large files
export const runtime = 'nodejs'
export const dynamic = 'force-dynamic'

// Increase timeout for large file uploads
export const maxDuration = 10800 // 3 hours timeout (10800 seconds)

export async function POST(req: NextRequest) {
  try {
    console.log('[Upload] Starting upload process...')
    
    const session = await getServerSession(authOptions)
    console.log('[Upload] Session checked:', !!session)

    if (!session) {
      return NextResponse.json(
        { error: '请先登录' },
        { status: 401 }
      )
    }

    console.log('[Upload] Parsing form data...')
    const formData = await req.formData()
    
    const previewImage = formData.get('previewImage') as File
    const zipFile = formData.get('zipFile') as File
    const productModel = formData.get('productModel') as string
    const categoryName = formData.get('categoryName') as string
    const sceneName = formData.get('sceneName') as string
    const renderer = (formData.get('renderer') as string) || 'CR'

    console.log('[Upload] Form data received:', {
      hasPreviewImage: !!previewImage,
      previewImageSize: previewImage?.size,
      hasZipFile: !!zipFile,
      zipFileSize: zipFile?.size,
      productModel,
      categoryName,
      sceneName
    })

    // Validation
    if (!previewImage || !zipFile || !productModel || !categoryName || !sceneName) {
      console.log('[Upload] Validation failed - missing fields')
      return NextResponse.json(
        { error: '所有字段都是必填的' },
        { status: 400 }
      )
    }

    // 获取用户信息作为作者花名
    console.log('[Upload] Fetching user info...')
    const user = await prisma.user.findUnique({
      where: { id: (session.user as any).id },
      select: { username: true },
    })

    if (!user) {
      console.log('[Upload] User not found')
      return NextResponse.json(
        { error: '用户不存在' },
        { status: 404 }
      )
    }

    const authorName = user.username
    console.log('[Upload] User found:', authorName)

    // 验证预览图大小（限制50MB）
    const maxPreviewSize = 50 * 1024 * 1024 // 50MB
    if (previewImage.size > maxPreviewSize) {
      console.log(`[Upload] Preview image too large: ${(previewImage.size / 1024 / 1024).toFixed(2)}MB`)
      return NextResponse.json(
        { error: `预览图过大，请使用小于50MB的图片（当前：${(previewImage.size / 1024 / 1024).toFixed(2)}MB）` },
        { status: 400 }
      )
    }

    // 验证预览图格式
    const allowedImageTypes = ['image/jpeg', 'image/jpg', 'image/png', 'image/webp', 'image/gif']
    if (!allowedImageTypes.includes(previewImage.type)) {
      console.log(`[Upload] Invalid image type: ${previewImage.type}`)
      return NextResponse.json(
        { error: `不支持的图片格式：${previewImage.type}，请使用 JPG、PNG、WebP 或 GIF 格式` },
        { status: 400 }
      )
    }

    // 处理预览图：压缩到300KB以内，转换为webP，缩放到600px
    console.log(`[Upload] Processing image... (${previewImage.type}, ${(previewImage.size / 1024).toFixed(2)}KB)`)
    let processedBuffer: Buffer
    try {
      const originalBuffer = Buffer.from(await previewImage.arrayBuffer())
      processedBuffer = await processImage(originalBuffer, {
        maxSizeKB: 300,
        maxWidth: 600,
        format: 'webp',
      })
      console.log('[Upload] Image processed successfully')
    } catch (imageError) {
      console.error('[Upload] Image processing error:', imageError)
      return NextResponse.json(
        { error: `图片处理失败，请确保图片文件未损坏且格式正确。错误：${imageError instanceof Error ? imageError.message : '未知错误'}` },
        { status: 500 }
      )
    }

    // Upload processed preview image to S3
    console.log('[Upload] Uploading image to S3...')
    const processedFileName = getProcessedFileName(previewImage.name)
    const previewFileName = `preview-${Date.now()}-${processedFileName}`
    const previewUrl = await uploadToS3(
      processedBuffer,
      previewFileName,
      'image/webp'
    )
    console.log('[Upload] Image uploaded to S3:', previewUrl)

    // Save zip file locally
    console.log('[Upload] Saving zip file locally...')
    const uploadDir = process.env.UPLOAD_DIR || './uploads'
    await mkdir(uploadDir, { recursive: true })

    const zipFileName = `zip-${Date.now()}-${zipFile.name}`
    const zipFilePath = path.join(uploadDir, zipFileName)
    const zipBuffer = Buffer.from(await zipFile.arrayBuffer())
    await writeFile(zipFilePath, zipBuffer)
    const zipFileSize = BigInt(zipBuffer.length) // 记录文件大小（字节）
    console.log('[Upload] Zip file saved:', zipFilePath, `(${(Number(zipFileSize) / 1024 / 1024).toFixed(2)} MB)`)

    // Create material record
    console.log('[Upload] Creating database record...')
    const material = await prisma.material.create({
      data: {
        previewUrl,
        productModel,
        categoryName,
        sceneName,
        renderer,
        authorName,
        zipFileName,
        zipFilePath,
        zipFileSize,
        userId: (session.user as any).id,
      },
      include: {
        user: {
          select: {
            username: true,
          },
        },
      },
    })
    console.log('[Upload] Database record created:', material.id)

    // 转换BigInt为字符串以支持JSON序列化
    const materialData = {
      ...material,
      zipFileSize: material.zipFileSize.toString()
    }

    console.log('[Upload] Upload completed successfully!')
    return NextResponse.json(
      { message: '上传成功', material: materialData },
      { status: 201 }
    )
  } catch (error) {
    console.error('Upload error:', error)
    
    // Log detailed error information
    if (error instanceof Error) {
      console.error('Error name:', error.name)
      console.error('Error message:', error.message)
      console.error('Error stack:', error.stack)
    }
    
    // Return more specific error message for debugging
    const errorMessage = error instanceof Error ? error.message : '上传失败，请稍后再试'
    
    return NextResponse.json(
      { 
        error: '上传失败，请稍后再试',
        details: process.env.NODE_ENV === 'development' ? errorMessage : undefined 
      },
      { status: 500 }
    )
  }
}