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

require_once __DIR__ . '/../config/database.php';
require_once __DIR__ . '/get_table_name.php';

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

$rawBody = file_get_contents('php://input');
$data = json_decode($rawBody, true);
if (!is_array($data)) {
    http_response_code(400);
    echo json_encode([
        'status' => 'error',
        'message' => 'Invalid JSON payload'
    ], JSON_UNESCAPED_UNICODE);
    exit;
}

$payload = isset($data['payload']) && is_array($data['payload']) ? $data['payload'] : [];

if (
    (isset($data['skipAnalytics']) && $data['skipAnalytics'] === true)
    || (isset($payload['staffPreview']) && $payload['staffPreview'] === true)
) {
    echo json_encode(['status' => 'success', 'skipped' => true], JSON_UNESCAPED_UNICODE);
    exit;
}

$eventName = isset($data['eventName']) ? trim((string)$data['eventName']) : '';
$sessionId = isset($data['sessionId']) ? trim((string)$data['sessionId']) : '';
$tableId = isset($data['tableId']) ? trim((string)$data['tableId']) : null;
$zone = isset($data['zone']) ? trim((string)$data['zone']) : null;
$qrHash = isset($data['qrHash']) ? trim((string)$data['qrHash']) : null;
$deviceType = isset($data['deviceType']) ? trim((string)$data['deviceType']) : null;
$browser = isset($data['browser']) ? trim((string)$data['browser']) : null;

$allowedEvents = [
    'qr_scan',
    'session_start',
    'geo_check_started',
    'geo_check_passed',
    'geo_check_failed',
    'geo_bypass_host',
    'waiter_call_requested',
    'view_status',
    'view_menu',
    'menu_search',
    'bill_dialog_opened',
    'bill_request_sent',
    'menu_only_entered',
    'geo_gate_prompted',
    'geo_retry_from_menu',
];

if ($eventName === '' || !in_array($eventName, $allowedEvents, true)) {
    http_response_code(422);
    echo json_encode([
        'status' => 'error',
        'message' => 'Invalid eventName'
    ], JSON_UNESCAPED_UNICODE);
    exit;
}

if ($sessionId === '' || strlen($sessionId) > 64) {
    http_response_code(422);
    echo json_encode([
        'status' => 'error',
        'message' => 'Invalid sessionId'
    ], JSON_UNESCAPED_UNICODE);
    exit;
}

if ($qrHash && !$tableId && isset($conn)) {
    $resolved = getTableNameByHash($conn, $qrHash);
    if ($resolved !== '') {
        $tableId = $resolved;
    }
}

if ($tableId !== null && strlen($tableId) > 32) {
    $tableId = substr($tableId, 0, 32);
}
if ($zone !== null && strlen($zone) > 16) {
    $zone = substr($zone, 0, 16);
}
if ($qrHash !== null && strlen($qrHash) > 128) {
    $qrHash = substr($qrHash, 0, 128);
}
if ($deviceType !== null && strlen($deviceType) > 16) {
    $deviceType = substr($deviceType, 0, 16);
}
if ($browser !== null && strlen($browser) > 32) {
    $browser = substr($browser, 0, 32);
}

$ip = '';
if (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
    $parts = explode(',', (string)$_SERVER['HTTP_X_FORWARDED_FOR']);
    $ip = trim($parts[0]);
} elseif (!empty($_SERVER['REMOTE_ADDR'])) {
    $ip = trim((string)$_SERVER['REMOTE_ADDR']);
}
$ipHash = $ip !== '' ? hash('sha256', $ip . '|karczma_analytics_v1') : null;
$payload = is_array($payload) ? $payload : [];
if ($ip !== '' && !isset($payload['ipAddress'])) {
    $payload['ipAddress'] = $ip;
}
$payloadJson = $payload ? json_encode($payload, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES) : null;

try {
    $pdo = getAnalyticsPdo();
    $stmt = $pdo->prepare("
        INSERT INTO analytics_events (
            created_at,
            event_name,
            session_id,
            table_id,
            zone,
            qr_hash,
            device_type,
            browser,
            ip_hash,
            payload_json
        ) VALUES (
            NOW(3),
            :event_name,
            :session_id,
            :table_id,
            :zone,
            :qr_hash,
            :device_type,
            :browser,
            :ip_hash,
            :payload_json
        )
    ");

    $stmt->execute([
        ':event_name' => $eventName,
        ':session_id' => $sessionId,
        ':table_id' => $tableId,
        ':zone' => $zone,
        ':qr_hash' => $qrHash,
        ':device_type' => $deviceType,
        ':browser' => $browser,
        ':ip_hash' => $ipHash,
        ':payload_json' => $payloadJson,
    ]);

    echo json_encode([
        'status' => 'success'
    ], JSON_UNESCAPED_UNICODE);
} catch (Throwable $e) {
    // Best-effort analytics: return success=false, but do not crash frontend flow.
    http_response_code(200);
    echo json_encode([
        'status' => 'error',
        'message' => 'Analytics insert failed'
    ], JSON_UNESCAPED_UNICODE);
}