<?php
declare(strict_types=1);

namespace App\Controller;

use Fendx\Core\Annotation\Controller;
use Fendx\Web\Annotation\GetRoute;
use Fendx\Web\Annotation\PostRoute;
use Fendx\Web\Request\Request;
use Fendx\Web\Response\Response;
use Fendx\Monitor\Service\MonitorService;

#[Controller('/admin')]
class AdminController
{
    #[GetRoute('/dashboard')]
    public function dashboard(): array
    {
        // 检查管理员权限
        if (!$this->checkAdminPermission()) {
            return Response::error(403, 'Permission denied');
        }

        // 获取仪表盘数据
        $health = MonitorService::getHealthStatus();
        $metrics = MonitorService::getMetricsSummary();
        $alerts = MonitorService::getActiveAlerts();
        $errors = MonitorService::getErrors([], 10);

        $dashboard = [
            'overview' => [
                'status' => $health['status'],
                'uptime' => $metrics['system']['uptime'] ?? 0,
                'memory_usage' => $metrics['system']['memory_usage'] ?? 0,
                'cpu_usage' => $metrics['system']['cpu_usage'] ?? 0,
                'active_alerts' => count($alerts)
            ],
            'health' => $health,
            'metrics' => $metrics,
            'alerts' => array_slice($alerts, 0, 5),
            'recent_errors' => array_slice($errors, 0, 10),
            'timestamp' => microtime(true)
        ];

        return Response::success($dashboard);
    }

    #[GetRoute('/system/info')]
    public function systemInfo(): array
    {
        if (!$this->checkAdminPermission()) {
            return Response::error(403, 'Permission denied');
        }

        $info = [
            'php_version' => PHP_VERSION,
            'php_sapi' => PHP_SAPI,
            'os' => PHP_OS,
            'server' => $_SERVER['SERVER_SOFTWARE'] ?? 'Unknown',
            'memory_limit' => ini_get('memory_limit'),
            'max_execution_time' => ini_get('max_execution_time'),
            'upload_max_filesize' => ini_get('upload_max_filesize'),
            'post_max_size' => ini_get('post_max_size'),
            'timezone' => date_default_timezone_get(),
            'loaded_extensions' => get_loaded_extensions(),
            'process_id' => getmypid(),
            'hostname' => gethostname() ?? 'unknown'
        ];

        return Response::success($info);
    }

    #[GetRoute('/system/status')]
    public function systemStatus(): array
    {
        if (!$this->checkAdminPermission()) {
            return Response::error(403, 'Permission denied');
        }

        $status = [
            'timestamp' => microtime(true),
            'uptime' => $this->getUptime(),
            'memory' => [
                'usage' => memory_get_usage(true),
                'peak' => memory_get_peak_usage(true),
                'limit' => $this->parseMemoryLimit(ini_get('memory_limit')),
                'usage_percent' => $this->getMemoryUsagePercent()
            ],
            'cpu' => [
                'load_average' => function_exists('sys_getloadavg') ? sys_getloadavg() : null,
                'usage' => $this->getCpuUsage()
            ],
            'disk' => $this->getDiskUsage(),
            'network' => $this->getNetworkInfo(),
            'processes' => $this->getProcessInfo()
        ];

        return Response::success($status);
    }

    #[GetRoute('/config')]
    public function getConfig(): array
    {
        if (!$this->checkAdminPermission()) {
            return Response::error(403, 'Permission denied');
        }

        // 获取监控配置（隐藏敏感信息）
        $config = include dirname(__DIR__, 2) . '/config/config.php';
        
        $safeConfig = [
            'monitor' => $config['monitor'] ?? [],
            'database' => [
                'driver' => $config['database']['driver'] ?? 'unknown',
                'host' => $config['database']['host'] ?? 'unknown',
                'database' => $config['database']['database'] ?? 'unknown'
            ],
            'cache' => [
                'driver' => $config['cache']['driver'] ?? 'unknown'
            ]
        ];

        return Response::success($safeConfig);
    }

    #[PostRoute('/config')]
    public function updateConfig(Request $request): array
    {
        if (!$this->checkAdminPermission()) {
            return Response::error(403, 'Permission denied');
        }

        $data = $request->all();
        
        // 验证配置数据
        $validation = $this->validateConfig($data);
        if (!$validation['valid']) {
            return Response::error(400, 'Invalid config: ' . implode(', ', $validation['errors']));
        }

        // 这里应该更新配置文件
        // 为了安全，实际项目中应该有更严格的配置管理
        
        return Response::success(null, 'Configuration updated successfully');
    }

    #[PostRoute('/cache/clear')]
    public function clearCache(): array
    {
        if (!$this->checkAdminPermission()) {
            return Response::error(403, 'Permission denied');
        }

        try {
            // 清理应用缓存
            $cacheDir = dirname(__DIR__, 2) . '/runtime/cache';
            if (is_dir($cacheDir)) {
                $this->clearDirectory($cacheDir);
            }

            // 清理模板缓存
            $templateDir = dirname(__DIR__, 2) . '/runtime/templates';
            if (is_dir($templateDir)) {
                $this->clearDirectory($templateDir);
            }

            return Response::success(null, 'Cache cleared successfully');
        } catch (\Exception $e) {
            return Response::error(500, 'Failed to clear cache: ' . $e->getMessage());
        }
    }

    #[PostRoute('/logs/clear')]
    public function clearLogs(): array
    {
        if (!$this->checkAdminPermission()) {
            return Response::error(403, 'Permission denied');
        }

        try {
            $logDir = dirname(__DIR__, 2) . '/runtime/logs';
            if (is_dir($logDir)) {
                $this->clearDirectory($logDir, ['.gitkeep']);
            }

            return Response::success(null, 'Logs cleared successfully');
        } catch (\Exception $e) {
            return Response::error(500, 'Failed to clear logs: ' . $e->getMessage());
        }
    }

    #[GetRoute('/users')]
    public function getUsers(): array
    {
        if (!$this->checkAdminPermission()) {
            return Response::error(403, 'Permission denied');
        }

        // 这里应该从数据库获取用户列表
        // 暂时返回模拟数据
        $users = [
            ['id' => 1, 'username' => 'admin', 'email' => 'admin@example.com', 'role' => 'admin', 'status' => 'active', 'created_at' => '2024-01-01 00:00:00'],
            ['id' => 2, 'username' => 'user1', 'email' => 'user1@example.com', 'role' => 'user', 'status' => 'active', 'created_at' => '2024-01-02 00:00:00']
        ];

        return Response::success($users);
    }

    #[PostRoute('/users/{id}/ban')]
    public function banUser(int $id): array
    {
        if (!$this->checkAdminPermission()) {
            return Response::error(403, 'Permission denied');
        }

        // 这里应该更新数据库中的用户状态
        return Response::success(null, 'User banned successfully');
    }

    #[PostRoute('/users/{id}/unban')]
    public function unbanUser(int $id): array
    {
        if (!$this->checkAdminPermission()) {
            return Response::error(403, 'Permission denied');
        }

        // 这里应该更新数据库中的用户状态
        return Response::success(null, 'User unbanned successfully');
    }

    #[GetRoute('/permissions')]
    public function getPermissions(): array
    {
        if (!$this->checkAdminPermission()) {
            return Response::error(403, 'Permission denied');
        }

        $permissions = [
            'dashboard' => ['view'],
            'monitor' => ['view', 'manage'],
            'logs' => ['view', 'search', 'export'],
            'alerts' => ['view', 'acknowledge', 'resolve'],
            'users' => ['view', 'manage'],
            'config' => ['view', 'edit'],
            'system' => ['view', 'cache_clear', 'logs_clear']
        ];

        return Response::success($permissions);
    }

    #[GetRoute('/audit')]
    public function getAuditLogs(Request $request): array
    {
        if (!$this->checkAdminPermission()) {
            return Response::error(403, 'Permission denied');
        }

        $limit = (int)($request->get('limit', 50));
        $offset = (int)($request->get('offset', 0));
        $userId = $request->get('user_id');
        $action = $request->get('action');

        // 这里应该从数据库获取审计日志
        // 暂时返回模拟数据
        $logs = [
            [
                'id' => 1,
                'user_id' => 1,
                'username' => 'admin',
                'action' => 'login',
                'resource' => 'admin',
                'ip' => '127.0.0.1',
                'user_agent' => 'Mozilla/5.0...',
                'created_at' => '2024-01-01 12:00:00'
            ],
            [
                'id' => 2,
                'user_id' => 1,
                'username' => 'admin',
                'action' => 'config_update',
                'resource' => 'monitor',
                'ip' => '127.0.0.1',
                'user_agent' => 'Mozilla/5.0...',
                'created_at' => '2024-01-01 12:30:00'
            ]
        ];

        return Response::success([
            'logs' => $logs,
            'total' => count($logs),
            'limit' => $limit,
            'offset' => $offset
        ]);
    }

    private function checkAdminPermission(): bool
    {
        // 这里应该实现实际的权限检查
        // 可以检查用户角色、session、token等
        
        // 简单示例：检查是否有admin session
        if (session_status() === PHP_SESSION_NONE) {
            session_start();
        }
        
        return isset($_SESSION['user_role']) && $_SESSION['user_role'] === 'admin';
    }

    private function getUptime(): int
    {
        if (function_exists('sys_getloadavg')) {
            $load = sys_getloadavg();
            return $load[0] ?? 0;
        }
        
        // 尝试从/proc/uptime读取（Linux）
        if (file_exists('/proc/uptime')) {
            $uptime = file_get_contents('/proc/uptime');
            return (int)explode(' ', $uptime)[0];
        }
        
        return 0;
    }

    private function parseMemoryLimit(string $limit): int
    {
        if ($limit === '-1') {
            return -1;
        }

        $unit = strtoupper(substr($limit, -1));
        $value = (int)substr($limit, 0, -1);

        return match ($unit) {
            'G' => $value * 1024 * 1024 * 1024,
            'M' => $value * 1024 * 1024,
            'K' => $value * 1024,
            default => (int)$limit
        };
    }

    private function getMemoryUsagePercent(): float
    {
        $usage = memory_get_usage(true);
        $limit = $this->parseMemoryLimit(ini_get('memory_limit'));
        
        if ($limit <= 0) {
            return 0;
        }
        
        return ($usage / $limit) * 100;
    }

    private function getCpuUsage(): float
    {
        // 简单的CPU使用率计算
        if (function_exists('sys_getloadavg')) {
            $load = sys_getloadavg();
            return $load[0] ?? 0;
        }
        
        return 0;
    }

    private function getDiskUsage(): array
    {
        $paths = [
            'root' => dirname(__DIR__, 2),
            'runtime' => dirname(__DIR__, 2) . '/runtime'
        ];

        $usage = [];
        foreach ($paths as $name => $path) {
            if (file_exists($path)) {
                $free = disk_free_space($path);
                $total = disk_total_space($path);
                $used = $total - $free;
                
                $usage[$name] = [
                    'path' => $path,
                    'total' => $total,
                    'used' => $used,
                    'free' => $free,
                    'usage_percent' => ($used / $total) * 100
                ];
            }
        }

        return $usage;
    }

    private function getNetworkInfo(): array
    {
        return [
            'hostname' => gethostname() ?? 'unknown',
            'ip' => $_SERVER['SERVER_ADDR'] ?? '127.0.0.1',
            'port' => $_SERVER['SERVER_PORT'] ?? 80,
            'scheme' => $_SERVER['REQUEST_SCHEME'] ?? 'http'
        ];
    }

    private function getProcessInfo(): array
    {
        return [
            'pid' => getmypid(),
            'memory_usage' => memory_get_usage(true),
            'memory_peak' => memory_get_peak_usage(true),
            'included_files' => count(get_included_files()),
            'classes' => count(get_declared_classes()),
            'functions' => count(get_defined_functions()['user'])
        ];
    }

    private function validateConfig(array $data): array
    {
        $errors = [];
        
        if (isset($data['sample_rate']) && ($data['sample_rate'] < 0 || $data['sample_rate'] > 1)) {
            $errors[] = 'Sample rate must be between 0 and 1';
        }
        
        if (isset($data['retention']) && $data['retention'] < 0) {
            $errors[] = 'Retention period must be positive';
        }
        
        if (isset($data['error_threshold']) && ($data['error_threshold'] < 0 || $data['error_threshold'] > 1)) {
            $errors[] = 'Error threshold must be between 0 and 1';
        }
        
        if (isset($data['memory_threshold']) && ($data['memory_threshold'] < 0 || $data['memory_threshold'] > 1)) {
            $errors[] = 'Memory threshold must be between 0 and 1';
        }
        
        return [
            'valid' => empty($errors),
            'errors' => $errors
        ];
    }

    private function clearDirectory(string $dir, array $exclude = []): void
    {
        if (!is_dir($dir)) {
            return;
        }

        $files = scandir($dir);
        foreach ($files as $file) {
            if ($file === '.' || $file === '..' || in_array($file, $exclude)) {
                continue;
            }

            $path = $dir . DIRECTORY_SEPARATOR . $file;
            if (is_dir($path)) {
                $this->clearDirectory($path);
                rmdir($path);
            } else {
                unlink($path);
            }
        }
    }
}