import { NextRequest, NextResponse } from 'next/server'
import { getFileByObjectName } from '@/lib/fileStorage'
import { prisma } from '@/lib/prisma'
import { withCors } from '@/lib/middleware'

async function handleDownload(req: NextRequest) {
  try {
    const pathSegments = req.nextUrl.pathname.split('/')
    const fileIdIndex = pathSegments.indexOf('downloads') + 1
    const fileId = pathSegments[fileIdIndex]
    
    if (!fileId) {
      return NextResponse.json({ error: '缺少文件ID' }, { status: 400 })
    }

    // 从数据库查找 objectName
    let objectName: string | null = null
    
    // 尝试从 Version 表查找
    const version = await prisma.version.findFirst({
      where: { fileId },
      select: { objectName: true }
    })
    
    if (version) {
      objectName = version.objectName
    } else {
      // 尝试从 Nssm 表查找
      const nssm = await prisma.nssm.findFirst({
        where: { fileId },
        select: { objectName: true }
      })
      
      if (nssm) {
        objectName = nssm.objectName
      }
    }
    
    if (!objectName) {
      return NextResponse.json({ error: '文件不存在' }, { status: 404 })
    }

    const file = await getFileByObjectName(objectName)
    if (!file) {
      return NextResponse.json({ error: '文件不存在' }, { status: 404 })
    }

    return new NextResponse(file.buffer, {
      headers: {
        'Content-Type': file.contentType || 'application/octet-stream',
        'Content-Disposition': `attachment; filename=${file.filename || 'download'}`,
        'Cache-Control': 'public, max-age=31536000',
      }
    })

  } catch (error) {
    console.error('下载失败:', error)
    return NextResponse.json({ error: '下载失败' }, { status: 500 })
  }
}

export const GET = withCors(handleDownload)