<?php

// ================= GLOBAL ERROR HANDLER =================
error_reporting(E_ALL);
ini_set('display_errors', 0);
ini_set('log_errors', 1);
ini_set('error_log', __DIR__ . '/php_error.log');

// tangkap fatal error
register_shutdown_function(function () {
    $error = error_get_last();
    if ($error !== NULL) {
        file_put_contents(
            __DIR__ . '/fatal_error.log',
            date('Y-m-d H:i:s') . " | " . json_encode($error) . "\n",
            FILE_APPEND
        );
    }
});

// ================= LOGGER =================
function writeLog($title, $data = null)
{
    $logFile = __DIR__ . '/callback_debug.log';

    try {
        if (!file_exists($logFile)) {
            touch($logFile);
            chmod($logFile, 0777);
        }

        $log  = "=============================\n";
        $log .= "TIME : " . date('Y-m-d H:i:s') . "\n";
        $log .= "TITLE: " . $title . "\n";

        if ($data !== null) {
            if (is_array($data) || is_object($data)) {
                $log .= "DATA : " . json_encode($data, JSON_PRETTY_PRINT) . "\n";
            } else {
                $log .= "DATA : " . $data . "\n";
            }
        }

        $log .= "=============================\n\n";

        file_put_contents($logFile, $log, FILE_APPEND);

    } catch (Throwable $e) {
        file_put_contents(
            __DIR__ . '/callback_fallback.log',
            date('Y-m-d H:i:s') . " | LOG ERROR: " . $e->getMessage() . "\n",
            FILE_APPEND
        );
    }
}

// ================= LOAD CONFIG =================
$config = require __DIR__ . '/doku_config.php';
$secretKey = trim($config['secret_key']);

// ================= CONNECT DB =================
try {
    require __DIR__ . '/../../../config/connect.php';
} catch (Throwable $e) {
    writeLog("ERROR DB CONNECT", $e->getMessage());
}

// ================= AMBIL BODY =================
$rawBody = file_get_contents("php://input");
$data    = json_decode($rawBody, true);

// ================= AMBIL HEADER =================
if (function_exists('getallheaders')) {
    $headers = getallheaders();
} else {
    $headers = [];
    foreach ($_SERVER as $name => $value) {
        if (substr($name, 0, 5) == 'HTTP_') {
            $headers[str_replace('_', '-', substr($name, 5))] = $value;
        }
    }
}

// ================= NORMALISASI HEADER =================
$signature = $headers['Signature'] ?? $headers['signature'] ?? '';
$requestId = $headers['Request-Id'] ?? $headers['request-id'] ?? '';
$timestamp = $headers['Request-Timestamp'] ?? $headers['request-timestamp'] ?? '';
$clientId  = $headers['Client-Id'] ?? $headers['client-id'] ?? '';

$target = parse_url($_SERVER['REQUEST_URI'], PHP_URL_PATH);

// ================= VALIDASI SIGNATURE =================
$digest = base64_encode(hash('sha256', $rawBody, true));

$stringToSign =
    "Client-Id:" . $clientId . "\n" .
    "Request-Id:" . $requestId . "\n" .
    "Request-Timestamp:" . $timestamp . "\n" .
    "Request-Target:" . $target . "\n" .
    "Digest:" . $digest;

$generated = "HMACSHA256=" . base64_encode(
    hash_hmac('sha256', $stringToSign, $secretKey, true)
);


if ($generated !== $signature) {
    writeLog("ERROR SIGNATURE INVALID");
    http_response_code(401);
    echo "INVALID SIGNATURE";
    exit;
}

// ================= PARSE DATA =================
$invoice = $data['order']['invoice_number'] ?? null;
$amount  = $data['order']['amount'] ?? 0;
$status  = strtoupper($data['transaction']['status'] ?? 'PENDING');

// ================= VALIDASI =================
if (!$invoice) {
    writeLog("ERROR NO INVOICE");
    http_response_code(400);
    exit('INVALID DATA');
}

// ================= CEK DB =================
$stmt = $pdo->prepare("SELECT id,status,amount FROM payment_winpay WHERE trx_id = ?");
$stmt->execute([$invoice]);
$trx = $stmt->fetch(PDO::FETCH_ASSOC);


if (!$trx) {
    writeLog("ERROR NOT FOUND");
    http_response_code(404);
    exit('NOT FOUND');
}

// ================= VALIDASI AMOUNT =================
if ((int)$trx['amount'] !== (int)$amount) {
    writeLog("ERROR AMOUNT MISMATCH", [
        'db' => $trx['amount'],
        'callback' => $amount
    ]);
    http_response_code(400);
    exit('INVALID AMOUNT');
}

// ================= ANTI DOUBLE =================
if ($trx['status'] === 'PAID') {
    writeLog("ALREADY PAID");
    echo json_encode(['message' => 'ALREADY PAID']);
    exit;
}

// ================= MAP STATUS =================
switch ($status) {
    case 'SUCCESS':
        $dbStatus = 'PAID';
        break;
    case 'EXPIRED':
        $dbStatus = 'EXPIRED';
        break;
    default:
        $dbStatus = 'PENDING';
}

// ================= UPDATE DB =================
try {
    
    $stmt = $pdo->prepare("
        UPDATE payment_winpay
        SET 
            status = :status,
            paid_at = CASE WHEN :status = 'PAID' THEN NOW() ELSE paid_at END,
            response_callback = :callback,
            updated_at = NOW()
        WHERE trx_id = :trx_id
    ");
    $stmt->execute([
        ':status'   => $dbStatus,
        ':callback' => $rawBody,
        ':trx_id'   => $invoice
    ]);

} catch (Throwable $e) {
    writeLog("DB UPDATE ERROR", $e->getMessage());
    http_response_code(500);
    exit('DB ERROR');
}

echo json_encode([
    "responseCode" => "2000000",
    "responseMessage" => "SUCCESS"
]);