<?php

declare(strict_types=1);

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

require_once __DIR__ . '/../../../../src/Core/Db.php';
require_once __DIR__ . '/../../../../src/Modules/Watchdog/MonitorRepo.php';
require_once __DIR__ . '/../../../../src/Modules/Watchdog/EventLog.php';
require_once __DIR__ . '/../../../../src/Modules/Watchdog/TokenManager.php';

use Deploymentcenter\Core\Db;
use Deploymentcenter\Modules\Watchdog\MonitorRepo;
use Deploymentcenter\Modules\Watchdog\EventLog;
use Deploymentcenter\Modules\Watchdog\TokenManager;

function sendResponse(array $data, int $statusCode = 200): void {
    http_response_code($statusCode);
    echo json_encode($data, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE | JSON_PRETTY_PRINT);
    exit;
}

try {
    $config = require __DIR__ . '/../../../../config/config.php';
    $pdo = Db::init($config);

    $uri = parse_url($_SERVER['REQUEST_URI'] ?? '/', PHP_URL_PATH);
    $method = strtoupper($_SERVER['REQUEST_METHOD'] ?? 'GET');

    $authHeader = $_SERVER['HTTP_X_WATCHDOG_KEY'] ?? $_SERVER['HTTP_AUTHORIZATION'] ?? $_SERVER['HTTP_X_AGENT_TOKEN'] ?? null;
    if ($authHeader && str_starts_with($authHeader, 'Bearer ')) {
        $authHeader = substr($authHeader, 7);
    }

    $sharedKey = $config['security']['shared_key'] ?? '';
    $isAdminAuth = ($authHeader && hash_equals($sharedKey, $authHeader));

    $tokenManager = new TokenManager($pdo);
    $monitorRepo  = new MonitorRepo($pdo);
    $eventLog     = new EventLog($pdo);

    $verifyToken = function(string $source) use ($isAdminAuth, $authHeader, $tokenManager) {
        if ($isAdminAuth) return true;
        if (empty($authHeader)) {
            sendResponse(['error' => 'Unauthorized', 'message' => 'Missing authorization token.'], 401);
        }
        if (!$tokenManager->validateToken($authHeader, $source)) {
            sendResponse(['error' => 'Forbidden', 'message' => "Token unauthorized for source '{$source}'."], 403);
        }
        return true;
    };

    $rawInput = file_get_contents('php://input');
    $inputData = !empty($rawInput) ? (json_decode($rawInput, true) ?? []) : $_POST;

    // Heartbeat / Ping
    if ((str_ends_with($uri, '/ping') || str_ends_with($uri, '/heartbeat')) && $method === 'POST') {
        $source   = trim($inputData['source'] ?? '');
        $instance = trim($inputData['instance'] ?? 'default');
        $type     = trim($inputData['type'] ?? 'heartbeat');
        $interval = (int)($inputData['interval'] ?? $inputData['expected_interval_sec'] ?? 60);
        $metrics  = $inputData['metrics'] ?? null;
        $status   = strtolower(trim($inputData['status'] ?? 'ok'));
        $message  = $inputData['message'] ?? $inputData['reason'] ?? null;
        $groupKey = $inputData['group'] ?? $inputData['group_key'] ?? null;
        $os       = $inputData['os'] ?? null;

        if (empty($source)) {
            sendResponse(['error' => 'Bad Request', 'message' => 'Field "source" is required.'], 400);
        }

        $verifyToken($source);

        $monitor = $monitorRepo->upsertHeartbeat($source, $instance, $type, $interval, $metrics, $status, $message, $groupKey, $os);
        sendResponse([
            'status' => 'success',
            'message' => 'Heartbeat received',
            'monitor' => [
                'source' => $monitor['source'],
                'instance' => $monitor['instance'],
                'state' => $monitor['state'],
                'last_status' => $monitor['last_status'],
                'last_seen_utc' => $monitor['last_seen_utc'],
            ]
        ]);
    }

    // Log Event
    if (str_ends_with($uri, '/event') && $method === 'POST') {
        $source   = trim($inputData['source'] ?? '');
        $instance = trim($inputData['instance'] ?? 'default');
        $kind     = trim($inputData['kind'] ?? 'started');
        $severity = trim($inputData['severity'] ?? 'info');
        $message  = $inputData['message'] ?? null;
        $meta     = $inputData['meta'] ?? null;

        if (empty($source)) sendResponse(['error' => 'Bad Request', 'message' => 'Field "source" is required.'], 400);

        $verifyToken($source);
        $eventId = $eventLog->logEvent($source, $instance, $kind, null, null, $severity, $message, $meta);

        sendResponse(['status' => 'success', 'event_id' => $eventId]);
    }

    // Status / Monitore auflisten
    if (str_ends_with($uri, '/status') && $method === 'GET') {
        $monitors = $monitorRepo->getAllMonitors();
        sendResponse(['count' => count($monitors), 'monitors' => $monitors]);
    }

    // Events auflisten
    if (str_ends_with($uri, '/events') && $method === 'GET') {
        $limit  = (int)($_GET['limit'] ?? 50);
        $events = $eventLog->getRecentEvents($limit);
        sendResponse(['count' => count($events), 'events' => $events]);
    }

    sendResponse(['error' => 'Not Found', 'message' => 'Endpoint not found'], 404);

} catch (Throwable $t) {
    sendResponse(['error' => 'Server Error', 'message' => $t->getMessage()], 500);
}