import { NextRequest, NextResponse } from 'next/server'
import { requireAuth } from '@/lib/auth'
import { createUploadSession, generatePresignedUrl, validateFileType, validateFileSize } from '@/lib/upload'

export async function POST(request: NextRequest) {
  try {
    const user = await requireAuth()
    const body = await request.json()
    const { fileName, fileSize, mimeType, chunkSize, metadata } = body

    // Validate required fields
    if (!fileName || !fileSize || !mimeType) {
      return NextResponse.json(
        { error: 'Missing required fields: fileName, fileSize, mimeType' },
        { status: 400 }
      )
    }

    // Validate file size (max 500MB)
    const maxSize = 500 * 1024 * 1024 // 500MB
    if (!validateFileSize(fileSize, maxSize)) {
      return NextResponse.json(
        { error: `File size exceeds maximum allowed size of ${maxSize / 1024 / 1024}MB` },
        { status: 400 }
      )
    }

    // Validate allowed file types
    const allowedTypes = [
      'audio/*',
      'image/*',
    ]
    if (!validateFileType(mimeType, allowedTypes)) {
      return NextResponse.json(
        { error: 'File type not allowed' },
        { status: 400 }
      )
    }

    // Create upload session
    const uploadSession = await createUploadSession(
      user.id,
      fileName,
      fileSize,
      mimeType,
      chunkSize,
      metadata
    )

    // Generate first chunk presigned URL
    const { url, key } = await generatePresignedUrl(
      `chunk-0-${fileName}`,
      mimeType
    )

    return NextResponse.json(
      {
        uploadSession,
        presignedUrl: url,
        uploadKey: key,
        chunkSize: uploadSession.chunkSize,
        totalChunks: uploadSession.totalChunks,
      },
      { status: 201 }
    )
  } catch (error) {
    console.error('Upload init error:', error)
    if (error instanceof Error && error.message === 'Unauthorized') {
      return NextResponse.json(
        { error: 'Unauthorized' },
        { status: 401 }
      )
    }
    return NextResponse.json(
      { error: 'Failed to initialize upload' },
      { status: 500 }
    )
  }
}