<?php

declare(strict_types=1);

header('Content-Type: application/json; charset=utf-8');

if ($_SERVER['REQUEST_METHOD'] !== 'GET' && $_SERVER['REQUEST_METHOD'] !== 'POST') {
    http_response_code(405);
    echo json_encode([
        'status' => 'error',
        'message' => 'Method not allowed',
    ], JSON_UNESCAPED_UNICODE);
    exit;
}

$nipRaw = '';
if ($_SERVER['REQUEST_METHOD'] === 'GET') {
    $nipRaw = isset($_GET['nip']) ? (string) $_GET['nip'] : '';
} else {
    $rawBody = file_get_contents('php://input');
    $data = json_decode($rawBody ?: '', true);
    if (is_array($data) && isset($data['nip'])) {
        $nipRaw = (string) $data['nip'];
    } elseif (isset($_POST['nip'])) {
        $nipRaw = (string) $_POST['nip'];
    }
}

$nip = preg_replace('/[\s\-]/', '', $nipRaw) ?? '';

if ($nip === '' || !preg_match('/^\d{10}$/', $nip)) {
    http_response_code(422);
    echo json_encode([
        'status' => false,
        'message' => 'Podaj poprawny 10-cyfrowy NIP.',
    ], JSON_UNESCAPED_UNICODE);
    exit;
}

$config = require __DIR__ . '/../config/gus.php';
$apiKey = trim((string) ($config['api_key'] ?? ''));
$baseUrl = rtrim((string) ($config['base_url'] ?? ''), '/');
$timeout = (int) ($config['timeout_seconds'] ?? 12);

if ($apiKey === '' || $baseUrl === '') {
    http_response_code(500);
    echo json_encode([
        'status' => false,
        'message' => 'Brak konfiguracji GUS.',
    ], JSON_UNESCAPED_UNICODE);
    exit;
}

$url = $baseUrl . '/' . rawurlencode($nip) . '?api_key=' . rawurlencode($apiKey);

$responseBody = false;
$httpCode = 0;

if (function_exists('curl_init')) {
    $ch = curl_init($url);
    curl_setopt_array($ch, [
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_FOLLOWLOCATION => true,
        CURLOPT_TIMEOUT => max(3, $timeout),
        CURLOPT_HTTPHEADER => [
            'Accept: application/json',
        ],
    ]);

    $responseBody = curl_exec($ch);
    $curlErrno = curl_errno($ch);
    $httpCode = (int) curl_getinfo($ch, CURLINFO_HTTP_CODE);
    curl_close($ch);

    if ($curlErrno !== 0) {
        $responseBody = false;
    }
} else {
    $context = stream_context_create([
        'http' => [
            'method' => 'GET',
            'timeout' => max(3, $timeout),
            'header' => "Accept: application/json\r\n",
            'ignore_errors' => true,
        ],
    ]);
    $responseBody = @file_get_contents($url, false, $context);
    if (isset($http_response_header[0]) && preg_match('/\s(\d{3})\s/', $http_response_header[0], $m)) {
        $httpCode = (int) $m[1];
    }
}

if ($responseBody === false) {
    http_response_code(502);
    echo json_encode([
        'status' => false,
        'message' => 'Błąd połączenia z API GUS.',
    ], JSON_UNESCAPED_UNICODE);
    exit;
}

$decoded = json_decode($responseBody, true);
if (!is_array($decoded)) {
    http_response_code(502);
    echo json_encode([
        'status' => false,
        'message' => 'Niepoprawna odpowiedź API GUS.',
    ], JSON_UNESCAPED_UNICODE);
    exit;
}

if ($httpCode < 200 || $httpCode >= 300) {
    http_response_code($httpCode >= 400 ? $httpCode : 502);
}

echo json_encode($decoded, JSON_UNESCAPED_UNICODE);