import { NextRequest, NextResponse } from 'next/server';

/**
 * API Proxy Route for Pastel API
 *
 * This proxy allows runtime configuration of the Pastel API URL
 * without rebuilding the Docker image. The API URL is read from
 * the server-side environment variable at runtime.
 *
 * Client requests go to: /api/pastel/*
 * Proxied to: PASTEL_API_URL/*
 */

const PASTEL_API_URL = process.env.PASTEL_API_URL || 'http://localhost:3001';

export async function GET(
  request: NextRequest,
  { params }: { params: Promise<{ path: string[] }> }
) {
  const { path } = await params;
  return proxyRequest(request, path, 'GET');
}

export async function POST(
  request: NextRequest,
  { params }: { params: Promise<{ path: string[] }> }
) {
  const { path } = await params;
  return proxyRequest(request, path, 'POST');
}

export async function PUT(
  request: NextRequest,
  { params }: { params: Promise<{ path: string[] }> }
) {
  const { path } = await params;
  return proxyRequest(request, path, 'PUT');
}

export async function DELETE(
  request: NextRequest,
  { params }: { params: Promise<{ path: string[] }> }
) {
  const { path } = await params;
  return proxyRequest(request, path, 'DELETE');
}

export async function PATCH(
  request: NextRequest,
  { params }: { params: Promise<{ path: string[] }> }
) {
  const { path } = await params;
  return proxyRequest(request, path, 'PATCH');
}

async function proxyRequest(
  request: NextRequest,
  pathSegments: string[],
  method: string
) {
  try {
    const path = pathSegments.join('/');
    const targetUrl = `${PASTEL_API_URL}/api/v1/${path}`;

    // Get request body if present
    const body = method !== 'GET' && method !== 'DELETE'
      ? await request.text()
      : undefined;

    // Forward the request to the Pastel API
    const response = await fetch(targetUrl, {
      method,
      headers: {
        'Content-Type': 'application/json',
        // Forward relevant headers
        ...(request.headers.get('accept') && {
          'Accept': request.headers.get('accept')!
        }),
      },
      body,
    });

    // Get response data
    const data = await response.text();

    // Return response with same status and headers
    return new NextResponse(data, {
      status: response.status,
      headers: {
        'Content-Type': response.headers.get('content-type') || 'application/json',
        // Add CORS headers if needed
        'Access-Control-Allow-Origin': '*',
        'Access-Control-Allow-Methods': 'GET, POST, PUT, DELETE, PATCH, OPTIONS',
        'Access-Control-Allow-Headers': 'Content-Type, Authorization',
      },
    });
  } catch (error) {
    console.error('Proxy error:', error);
    return NextResponse.json(
      {
        success: false,
        error: {
          code: 'PROXY_ERROR',
          message: error instanceof Error ? error.message : 'Failed to proxy request',
        },
      },
      { status: 500 }
    );
  }
}

// Handle OPTIONS requests for CORS
export async function OPTIONS() {
  return new NextResponse(null, {
    status: 204,
    headers: {
      'Access-Control-Allow-Origin': '*',
      'Access-Control-Allow-Methods': 'GET, POST, PUT, DELETE, PATCH, OPTIONS',
      'Access-Control-Allow-Headers': 'Content-Type, Authorization',
    },
  });
}