<?php

declare(strict_types=1);

/**
 * Router for PHP built-in server (Option 2 proxy demo).
 *
 *   export DATA_CHECKS_API_KEY='your_32_char_server_side_key'
 *   php -S 127.0.0.1:8787 router.php
 *
 * POST http://127.0.0.1:8787/api/validate-email  {"email":"test@example.com"}
 * POST http://127.0.0.1:8787/api/validate-phone {"phone":"+441234567890"}
 */
$key = getenv('DATA_CHECKS_API_KEY') ?: '';
$base = rtrim(getenv('DATA_CHECKS_API_BASE') ?: 'https://api.data-checks.com', '/');
if ($key === '') {
    http_response_code(500);
    header('Content-Type: application/json; charset=utf-8');
    echo json_encode(['error' => 'server_misconfigured', 'message' => 'Set DATA_CHECKS_API_KEY']);

    return true;
}

$uri = parse_url($_SERVER['REQUEST_URI'] ?? '/', PHP_URL_PATH) ?: '/';
$method = $_SERVER['REQUEST_METHOD'] ?? 'GET';
if ($method !== 'POST') {
    http_response_code(405);

    return true;
}

$raw = file_get_contents('php://input') ?: '';
$input = json_decode($raw, true);
if (! is_array($input)) {
    $input = [];
}

if ($uri === '/api/validate-email') {
    $email = isset($input['email']) && is_string($input['email']) ? trim($input['email']) : '';
    if ($email === '') {
        http_response_code(400);
        header('Content-Type: application/json; charset=utf-8');
        echo json_encode(['error' => 'bad_request', 'message' => 'email required']);

        return true;
    }
    datachecks_proxy_forward($base, $key, '/v1/email', ['email' => $email]);

    return true;
}

if ($uri === '/api/validate-phone') {
    $phone = isset($input['phone']) && is_string($input['phone']) ? trim($input['phone']) : '';
    if ($phone === '') {
        http_response_code(400);
        header('Content-Type: application/json; charset=utf-8');
        echo json_encode(['error' => 'bad_request', 'message' => 'phone required']);

        return true;
    }
    datachecks_proxy_forward($base, $key, '/v1/phone', ['phone' => $phone]);

    return true;
}

return false;

/**
 * @param  array<string, string>  $payload
 */
function datachecks_proxy_forward(string $base, string $key, string $path, array $payload): void
{
    $url = $base.$path;
    $json = json_encode($payload, JSON_THROW_ON_ERROR);
    $ch = curl_init($url);
    if ($ch === false) {
        http_response_code(500);

        return;
    }
    curl_setopt_array($ch, [
        CURLOPT_POST => true,
        CURLOPT_POSTFIELDS => $json,
        CURLOPT_HTTPHEADER => [
            'Authorization: Bearer '.$key,
            'Content-Type: application/json',
            'Accept: application/json',
        ],
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_TIMEOUT => 30,
    ]);
    $response = curl_exec($ch);
    $status = (int) curl_getinfo($ch, CURLINFO_HTTP_CODE);
    curl_close($ch);
    http_response_code($status > 0 ? $status : 502);
    if (! is_string($response)) {
        return;
    }
    if ($status === 200) {
        $decoded = json_decode($response, true);
        if (is_array($decoded)) {
            unset($decoded['remaining_credits']);
            header('Content-Type: application/json; charset=utf-8');
            echo json_encode($decoded, JSON_UNESCAPED_UNICODE);

            return;
        }
    }
    $ct = 'application/json';
    if ($status === 503 && $response === '') {
        $ct = 'text/plain';
    }
    header('Content-Type: '.$ct.'; charset=utf-8');
    echo $response;
}