import { NextRequest, NextResponse } from 'next/server';
import { getPresignedUrl, getMultiplePresignedUrls } from '@/lib/s3';

/**
 * Generate pre-signed URL(s) for S3 objects
 * POST /api/s3/presigned-url
 *
 * Body:
 * - Single key: { "key": "path/to/file.mp3", "expiresIn": 3600 }
 * - Multiple keys: { "keys": ["path/file1.mp3", "path/file2.mp3"], "expiresIn": 3600 }
 */
export async function POST(request: NextRequest) {
  try {
    const body = await request.json();
    const { key, keys, expiresIn = 3600 } = body;

    // Validate expiration time (max 7 days)
    if (expiresIn > 604800) {
      return NextResponse.json(
        { error: 'expiresIn cannot exceed 7 days (604800 seconds)' },
        { status: 400 }
      );
    }

    // Handle single key
    if (key) {
      if (typeof key !== 'string' || !key.trim()) {
        return NextResponse.json(
          { error: 'Invalid key provided' },
          { status: 400 }
        );
      }

      const url = await getPresignedUrl(key, expiresIn);
      return NextResponse.json({ url, expiresIn }, { status: 200 });
    }

    // Handle multiple keys
    if (keys) {
      if (!Array.isArray(keys) || keys.length === 0) {
        return NextResponse.json(
          { error: 'keys must be a non-empty array' },
          { status: 400 }
        );
      }

      if (keys.length > 100) {
        return NextResponse.json(
          { error: 'Cannot generate more than 100 URLs at once' },
          { status: 400 }
        );
      }

      const urls = await getMultiplePresignedUrls(keys, expiresIn);
      return NextResponse.json({ urls, expiresIn }, { status: 200 });
    }

    return NextResponse.json(
      { error: 'Either "key" or "keys" must be provided' },
      { status: 400 }
    );
  } catch (error: any) {
    console.error('Presigned URL generation error:', error);
    return NextResponse.json(
      { error: error.message || 'Failed to generate presigned URL' },
      { status: 500 }
    );
  }
}