<?php
/**
 * 🚪 API GATEWAY LIGHT - Version simplifiée sans base de données
 * Version: 1.0 - Février 2026
 */

header('Content-Type: application/json');
header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: GET, POST, OPTIONS');
header('Access-Control-Allow-Headers: Content-Type, Authorization');

class ApiGatewayLight {
    private $modules = [
        'mind' => 'Weval Mind Core',
        'hamid' => 'HAMID IA Engine', 
        'brain' => 'Brain Engine',
        'status' => 'System Status',
        'health' => 'Health Check'
    ];
    
    /**
     * Get client IP
     */
    private function getClientIp() {
        $ip = $_SERVER['HTTP_X_FORWARDED_FOR'] ?? 
              $_SERVER['HTTP_CLIENT_IP'] ?? 
              $_SERVER['REMOTE_ADDR'] ?? 
              '0.0.0.0';
        return $ip;
    }
    
    /**
     * Log message
     */
    private function logMessage($level, $module, $message, $data = null) {
        $timestamp = date('Y-m-d H:i:s');
        $logEntry = "[$timestamp] [$level] [$module] $message";
        
        if ($data) {
            $logEntry .= " | Data: " . json_encode($data);
        }
        
        // Log to file
        $logFile = '/var/log/wevads/api-gateway-' . date('Y-m-d') . '.log';
        @file_put_contents($logFile, $logEntry . PHP_EOL, FILE_APPEND);
        
        return true;
    }
    
    /**
     * Route request
     */
    private function routeRequest($module, $action, $data) {
        switch ($module) {
            case 'status':
                return $this->getSystemStatus();
            case 'health':
                return $this->healthCheck();
            case 'mind':
                return $this->routeToMind($action, $data);
            case 'hamid':
                return $this->routeToHamid($action, $data);
            default:
                return [
                    'error' => 'Module not found',
                    'available_modules' => array_keys($this->modules)
                ];
        }
    }
    
    /**
     * Get system status
     */
    private function getSystemStatus() {
        // Check services
        $services = [
            'apache' => $this->checkService('apache2'),
            'postgresql' => $this->checkService('postgresql')
        ];
        
        // Get system metrics
        $load = @sys_getloadavg();
        $memory = @shell_exec("free -m | awk 'NR==2 {printf \"%.1f\", $3/$2*100}' 2>/dev/null");
        $disk = @shell_exec("df / | awk 'NR==2 {print $5}' | sed 's/%//' 2>/dev/null");
        
        return [
            'status' => 'operational',
            'timestamp' => date('Y-m-d H:i:s'),
            'services' => $services,
            'metrics' => [
                'cpu_load' => [
                    '1min' => $load[0] ?? 0,
                    '5min' => $load[1] ?? 0,
                    '15min' => $load[2] ?? 0
                ],
                'memory_usage' => floatval($memory) ?: 0,
                'disk_usage' => floatval($disk) ?: 0
            ],
            'modules' => $this->modules,
            'gateway' => 'light_version'
        ];
    }
    
    /**
     * Health check
     */
    private function healthCheck() {
        $checks = [];
        
        // Check services
        $services = ['apache2', 'postgresql'];
        foreach ($services as $service) {
            $checks['service_' . $service] = [
                'status' => $this->checkService($service) ? 'running' : 'stopped'
            ];
        }
        
        // Check disk space
        $disk = @shell_exec("df / | awk 'NR==2 {print $5}' | sed 's/%//' 2>/dev/null");
        $checks['disk_space'] = [
            'usage_percent' => floatval($disk) ?: 0,
            'status' => (floatval($disk) > 85) ? 'warning' : 'healthy'
        ];
        
        // Determine overall status
        $overall = 'healthy';
        foreach ($checks as $check) {
            if (isset($check['status']) && $check['status'] === 'stopped') {
                $overall = 'unhealthy';
                break;
            }
        }
        
        return [
            'status' => $overall,
            'checks' => $checks,
            'timestamp' => date('Y-m-d H:i:s'),
            'uptime' => @shell_exec("uptime -p 2>/dev/null") ?: 'unknown'
        ];
    }
    
    /**
     * Route to Weval Mind
     */
    private function routeToMind($action, $data) {
        $validActions = ['autonomous_cycle', 'status', 'report'];
        
        if (!in_array($action, $validActions)) {
            return [
                'error' => 'Invalid action for mind module',
                'valid_actions' => $validActions
            ];
        }
        
        if ($action === 'autonomous_cycle') {
            // Call the simple API
            $url = "http://localhost:5890/api/weval-mind-core-simple.php?action=autonomous_cycle";
            $response = @file_get_contents($url);
            
            if ($response === false) {
                return ['error' => 'Failed to call mind API'];
            }
            
            $result = json_decode($response, true);
            return $result ?: ['error' => 'Invalid response from mind API'];
        }
        
        return [
            'module' => 'mind',
            'action' => $action,
            'status' => 'available',
            'message' => 'Mind module operational'
        ];
    }
    
    /**
     * Route to HAMID IA
     */
    private function routeToHamid($action, $data) {
        $validActions = ['chat', 'providers', 'stats'];
        
        if (!in_array($action, $validActions)) {
            return [
                'error' => 'Invalid action for hamid module',
                'valid_actions' => $validActions
            ];
        }
        
        if ($action === 'chat') {
            if (empty($data['message'])) {
                return ['error' => 'Message is required for chat action'];
            }
            
            return [
                'response' => "🤖 **HAMID IA Light**\n\nJe reçois votre message : \"" . 
                            htmlspecialchars(substr($data['message'], 0, 200)) . "\"\n\n" .
                            "**Capacités disponibles:**\n" .
                            "• Analyse technique de l'architecture\n" .
                            "• Diagnostic des problèmes système\n" .
                            "• Réponses basées sur la connaissance système\n\n" .
                            "**Version complète en développement**",
                'provider' => 'gateway_light',
                'timestamp' => date('Y-m-d H:i:s')
            ];
        }
        
        if ($action === 'providers') {
            return [
                'providers' => [
                    ['name' => 'Cerebras', 'status' => 'available', 'priority' => 1],
                    ['name' => 'Groq', 'status' => 'available', 'priority' => 2],
                    ['name' => 'DeepSeek', 'status' => 'available', 'priority' => 3],
                    ['name' => 'Gemini', 'status' => 'available', 'priority' => 4],
                    ['name' => 'Claude', 'status' => 'available', 'priority' => 5]
                ],
                'note' => 'Light version - Providers configuration en attente'
            ];
        }
        
        return [
            'module' => 'hamid',
            'action' => $action,
            'status' => 'available',
            'message' => 'HAMID module operational'
        ];
    }
    
    /**
     * Check if service is running
     */
    private function checkService($service) {
        $status = @shell_exec("systemctl is-active $service 2>/dev/null");
        return trim($status) === 'active';
    }
    
    /**
     * Process incoming request
     */
    public function processRequest() {
        try {
            // Get request data
            $method = $_SERVER['REQUEST_METHOD'];
            $clientIp = $this->getClientIp();
            
            // Handle preflight requests
            if ($method === 'OPTIONS') {
                http_response_code(200);
                exit;
            }
            
            // Get module and action
            $module = $_GET['module'] ?? $_POST['module'] ?? 'status';
            $action = $_GET['action'] ?? $_POST['action'] ?? 'status';
            
            // Get request data
            $input = file_get_contents('php://input');
            $data = json_decode($input, true);
            
            if (json_last_error() !== JSON_ERROR_NONE) {
                $data = $_POST ?: [];
            }
            
            // Log the request
            $this->logMessage('INFO', 'API Gateway Light', 'Request received', [
                'module' => $module,
                'action' => $action,
                'ip' => $clientIp,
                'method' => $method
            ]);
            
            // Route the request
            $result = $this->routeRequest($module, $action, $data);
            
            // Add metadata
            $result['gateway'] = [
                'version' => '1.0-light',
                'timestamp' => date('Y-m-d H:i:s'),
                'request_id' => 'REQ-' . uniqid()
            ];
            
            // Return response
            http_response_code(200);
            echo json_encode($result, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);
            
        } catch (Exception $e) {
            $this->logMessage('ERROR', 'API Gateway Light', 'Processing error: ' . $e->getMessage());
            
            http_response_code(500);
            echo json_encode([
                'error' => 'Internal server error',
                'message' => $e->getMessage(),
                'timestamp' => date('Y-m-d H:i:s'),
                'gateway' => 'light_version'
            ]);
        }
    }
}

// Handle request
$gateway = new ApiGatewayLight();
$gateway->processRequest();
?>