<?php
/**
 * Forward /citpl_website/api/* → Node (Express) without requiring Apache mod_proxy.
 * Start the API on the server:  cd /path/to/app && npm run server
 * Or:  pm2 start server/index.js --name citpl-api
 */
declare(strict_types=1);

$apiOrigin = getenv('CITPL_API_ORIGIN') ?: 'http://127.0.0.1:3001';

$requestUri = $_SERVER['REQUEST_URI'] ?? '/api';
$path = parse_url($requestUri, PHP_URL_PATH) ?: '/api';

// Keep everything from "/api" onward (works under /citpl_website/api/...)
if (preg_match('#(/api(?:/.*)?)$#', $path, $m)) {
  $forwardPath = $m[1];
} else {
  $forwardPath = '/api';
}

$query = $_SERVER['QUERY_STRING'] ?? '';
$url = rtrim($apiOrigin, '/') . $forwardPath . ($query !== '' ? '?' . $query : '');

$method = $_SERVER['REQUEST_METHOD'] ?? 'GET';
$body = file_get_contents('php://input');
if ($body === false) {
  $body = '';
}

$headers = [];
if (function_exists('getallheaders')) {
  foreach (getallheaders() as $name => $value) {
    $lower = strtolower((string) $name);
    if ($lower === 'host' || $lower === 'content-length') {
      continue;
    }
    $headers[] = $name . ': ' . $value;
  }
} else {
  foreach ($_SERVER as $key => $value) {
    if (strpos($key, 'HTTP_') !== 0) {
      continue;
    }
    $name = str_replace(' ', '-', ucwords(strtolower(str_replace('_', ' ', substr($key, 5)))));
    if (strtolower($name) === 'host') {
      continue;
    }
    $headers[] = $name . ': ' . $value;
  }
  if (!empty($_SERVER['CONTENT_TYPE'])) {
    $headers[] = 'Content-Type: ' . $_SERVER['CONTENT_TYPE'];
  }
}

if (!function_exists('curl_init')) {
  http_response_code(500);
  header('Content-Type: application/json');
  echo json_encode([
    'error' => 'PHP curl extension is required for the API proxy',
    'code' => 'PROXY_MISCONFIGURED',
  ]);
  exit;
}

$ch = curl_init($url);
curl_setopt_array($ch, [
  CURLOPT_CUSTOMREQUEST => $method,
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_HEADER => true,
  CURLOPT_FOLLOWLOCATION => false,
  CURLOPT_CONNECTTIMEOUT => 5,
  CURLOPT_TIMEOUT => 60,
  CURLOPT_HTTPHEADER => $headers,
]);

if ($method !== 'GET' && $method !== 'HEAD') {
  curl_setopt($ch, CURLOPT_POSTFIELDS, $body);
}

$response = curl_exec($ch);
if ($response === false) {
  $err = curl_error($ch);
  curl_close($ch);
  http_response_code(502);
  header('Content-Type: application/json');
  echo json_encode([
    'error' => 'API server unreachable. On the host run: npm run server (port 3001)',
    'detail' => $err,
    'code' => 'BAD_GATEWAY',
  ]);
  exit;
}

$status = (int) curl_getinfo($ch, CURLINFO_HTTP_CODE);
$headerSize = (int) curl_getinfo($ch, CURLINFO_HEADER_SIZE);
curl_close($ch);

$rawHeaders = substr($response, 0, $headerSize);
$responseBody = substr($response, $headerSize);

http_response_code($status > 0 ? $status : 502);

$skip = ['transfer-encoding', 'connection', 'keep-alive', 'content-length'];
foreach (explode("\r\n", $rawHeaders) as $line) {
  if ($line === '' || stripos($line, 'HTTP/') === 0) {
    continue;
  }
  $parts = explode(':', $line, 2);
  if (count($parts) < 2) {
    continue;
  }
  $name = trim($parts[0]);
  if (in_array(strtolower($name), $skip, true)) {
    continue;
  }
  header($name . ':' . $parts[1], false);
}

echo $responseBody;