<?php
// geocode-cache.php

// ==== KONFIGURACJA ====
const DB_DSN  = 'mysql:host=serwer1852487.home.pl;port=3380;dbname=28477142_0000006;charset=utf8mb4';
const DB_USER = '28477142_0000006';
const DB_PASS = '2aodCAiQSKThx4la6';

// Klucz trzymaj w .env/konfiguracji, tu tylko przykład:
const GOOGLE_GEOCODE_KEY = 'AIzaSyD-1SOVhJXr6HREtfmMILvlmV-hml3nxUg';

// Domyślne opcje zapytań do Google – zawęź region/język wg potrzeb
const GOOGLE_REGION   = 'pl';
const GOOGLE_LANGUAGE = 'pl';

// TTL cache w dniach
const CACHE_TTL_DAYS_FORWARD = 365;
const CACHE_TTL_DAYS_REVERSE = 365;

$ALLOWED_ORIGINS = [
  'https://twoja-domena.pl',
  'https://www.twoja-domena.pl',
  'http://localhost:3000',
  'https://shoppro.project-dc.pl',
  'https://moodo.pl'
];

// ==== NAGŁÓWKI/CORS ====
$origin = $_SERVER['HTTP_ORIGIN'] ?? '';
if ($origin && in_array($origin, $ALLOWED_ORIGINS, true)) {
  header('Access-Control-Allow-Origin: ' . $origin);
  header('Vary: Origin');
}
header('Access-Control-Allow-Methods: GET, OPTIONS');
header('Access-Control-Allow-Headers: Content-Type');
header('Content-Type: application/json; charset=utf-8');
if ($_SERVER['REQUEST_METHOD'] === 'OPTIONS') { http_response_code(204); exit; }

// ==== POMOCNICZE ====
function normalize_query(string $q): string {
  $q = trim($q);
  $q = preg_replace('/\s+/u', ' ', $q);
  return mb_strtolower($q, 'UTF-8');
}
function now_mysql(): string { return date('Y-m-d H:i:s'); }
function add_days(string $date, int $days): string { return date('Y-m-d H:i:s', strtotime("$date +$days days")); }

// Budowa stabilnego klucza cache
function build_cache_key(?string $q, ?float $lat, ?float $lng): array {
  if ($q !== null && $q !== '') {
    $raw = $q;
    $norm = normalize_query($q);
    $mode = 'forward';
  } else {
    // reverse: lat,lng
    $latR = round((float)$lat, 6);
    $lngR = round((float)$lng, 6);
    $raw  = sprintf('%F,%F', $lat, $lng);
    $norm = sprintf('latlng:%0.6f,%0.6f', $latR, $lngR);
    $mode = 'reverse';
  }
  return [
    'raw'  => $raw,
    'norm' => $norm,
    'hash' => hash('sha256', $norm),
    'mode' => $mode,
  ];
}

// DB
try {
  $pdo = new PDO(DB_DSN, DB_USER, DB_PASS, [
    PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
  ]);
} catch (Throwable $e) {
  http_response_code(500);
  echo json_encode(['error' => 'DB connection failed']);
  exit;
}

// Wejście
$q   = isset($_GET['q'])   ? trim((string)$_GET['q']) : '';
$lat = isset($_GET['lat']) ? (float)$_GET['lat'] : null;
$lng = isset($_GET['lng']) ? (float)$_GET['lng'] : null;

if ($q === '' && ($lat === null || $lng === null)) {
  http_response_code(400);
  echo json_encode(['error' => 'Provide q=address or lat & lng']);
  exit;
}

$key = build_cache_key($q, $lat, $lng);
$now = now_mysql();

// ===== 1) CACHE LOOKUP (forward i reverse) =====
$stmt = $pdo->prepare("SELECT * FROM geocode_cache WHERE query_hash = :h AND (expires_at IS NULL OR expires_at > NOW()) LIMIT 1");
$stmt->execute([':h' => $key['hash']]);
if ($row = $stmt->fetch()) {
  $pdo->prepare("UPDATE geocode_cache SET hits = hits + 1, updated_at = NOW() WHERE id = :id")->execute([':id' => $row['id']]);
  echo json_encode([
    'from_cache' => true,
    'source' => 'cache',
    'stale' => false,
    'lat' => (float)$row['lat'],
    'lng' => (float)$row['lng'],
    'formatted_address' => $row['formatted_address'],
    'place_id' => $row['place_id'],
    'provider' => $row['provider'],
  ], JSON_UNESCAPED_UNICODE);
  exit;
}

// ===== 2) PYTANIE DO GOOGLE =====
function google_request(array $params): array {
  $base = 'https://maps.googleapis.com/maps/api/geocode/json';
  $params['key'] = GOOGLE_GEOCODE_KEY;
  $params += ['language' => GOOGLE_LANGUAGE, 'region' => GOOGLE_REGION];
  $url = $base . '?' . http_build_query($params);

  $ch = curl_init($url);
  curl_setopt_array($ch, [CURLOPT_RETURNTRANSFER => true, CURLOPT_TIMEOUT => 5, CURLOPT_CONNECTTIMEOUT => 3]);
  $res = curl_exec($ch); $err = curl_error($ch); curl_close($ch);
  if ($res === false) throw new RuntimeException('cURL error: ' . $err);
  $data = json_decode($res, true);
  if (!is_array($data)) throw new RuntimeException('Invalid JSON from Google');
  if (($data['status'] ?? '') !== 'OK' || empty($data['results'][0])) {
    $status = $data['status'] ?? 'UNKNOWN';
    throw new RuntimeException('Geocoding failed: ' . $status);
  }
  return $data;
}

try {
  $data = ($key['mode'] === 'forward')
    ? google_request(['address' => $q])
    : google_request(['latlng' => $lat . ',' . $lng]);

  $top = $data['results'][0];
  $latV = (float)$top['geometry']['location']['lat'];
  $lngV = (float)$top['geometry']['location']['lng'];
  $fmt  = (string)($top['formatted_address'] ?? '');
  $pid  = (string)($top['place_id'] ?? '');

  // ===== 3) ZAPIS DO CACHE (forward i reverse) =====
  $ttlDays = ($key['mode'] === 'forward') ? CACHE_TTL_DAYS_FORWARD : CACHE_TTL_DAYS_REVERSE;
  $expires = add_days($now, $ttlDays);

  $stmt = $pdo->prepare("INSERT INTO geocode_cache
    (query_hash, query_raw, query_norm, lat, lng, formatted_address, place_id, provider, hits, created_at, updated_at, expires_at, raw_json)
    VALUES (:h, :raw, :norm, :lat, :lng, :fmt, :pid, 'google', 1, :now, :now, :exp, :json)
    ON DUPLICATE KEY UPDATE
      lat = VALUES(lat),
      lng = VALUES(lng),
      formatted_address = VALUES(formatted_address),
      place_id = VALUES(place_id),
      updated_at = VALUES(updated_at),
      expires_at = VALUES(expires_at),
      raw_json = VALUES(raw_json),
      hits = hits + 1");

  $stmt->execute([
    ':h'   => $key['hash'],
    ':raw' => $key['raw'],
    ':norm'=> $key['norm'],
    ':lat' => $latV,
    ':lng' => $lngV,
    ':fmt' => $fmt,
    ':pid' => $pid,
    ':now' => $now,
    ':exp' => $expires,
    ':json'=> json_encode($data, JSON_UNESCAPED_UNICODE),
  ]);

  echo json_encode([
    'from_cache' => false,
    'source' => 'google',
    'stale' => false,
    'lat' => $latV,
    'lng' => $lngV,
    'formatted_address' => $fmt,
    'place_id' => $pid,
    'provider' => 'google',
  ], JSON_UNESCAPED_UNICODE);
  exit;

} catch (Throwable $e) {
  try {
    $stmt = $pdo->prepare("SELECT * FROM geocode_cache WHERE query_hash = :h LIMIT 1");
    $stmt->execute([':h' => $key['hash']]);
    if ($row = $stmt->fetch()) {
      http_response_code(200);
      echo json_encode([
        'from_cache' => true,
        'source' => 'cache',
        'stale' => true,
        'lat' => (float)$row['lat'],
        'lng' => (float)$row['lng'],
        'formatted_address' => $row['formatted_address'],
        'place_id' => $row['place_id'],
        'provider' => $row['provider'],
      ], JSON_UNESCAPED_UNICODE);
      exit;
    }
  } catch (Throwable $ignored) {}

  // *** fallback „pusty” ***
  http_response_code(200);
  echo json_encode([
    'from_cache' => false,
    'source' => 'error',
    'stale' => false,
    'lat' => null,
    'lng' => null,
    'formatted_address' => '',
    'place_id' => '',
    'provider' => '',
    'error' => $e->getMessage(),
  ], JSON_UNESCAPED_UNICODE);
  exit;
}