<?php
/**
 * ╔══════════════════════════════════════════════════════════╗
 * ║  WEVIA OPUS — Agentic Tool Use Engine                  ║
 * ║  Function Calling + Tool Orchestration                 ║
 * ╚══════════════════════════════════════════════════════════╝
 */

class ToolUseEngine {
    private $tools = [];
    private $history = [];
    
    public function __construct() {
        $this->registerDefaultTools();
    }
    
    /**
     * Enregistre les outils disponibles
     */
    private function registerDefaultTools(): void {
        $this->tools = [
            'web_search' => [
                'name' => 'web_search',
                'description' => 'Recherche sur internet via SearXNG',
                'parameters' => ['query' => 'string', 'max_results' => 'int'],
                'handler' => [$this, 'toolWebSearch']
            ],
            'execute_code' => [
                'name' => 'execute_code',
                'description' => 'Exécute du code Python/Bash/PHP',
                'parameters' => ['language' => 'string', 'code' => 'string'],
                'handler' => [$this, 'toolExecuteCode']
            ],
            'database_query' => [
                'name' => 'database_query',
                'description' => 'Exécute une requête SQL SELECT',
                'parameters' => ['query' => 'string', 'database' => 'string'],
                'handler' => [$this, 'toolDatabaseQuery']
            ],
            'file_read' => [
                'name' => 'file_read',
                'description' => 'Lit le contenu d\'un fichier',
                'parameters' => ['path' => 'string'],
                'handler' => [$this, 'toolFileRead']
            ],
            'file_write' => [
                'name' => 'file_write',
                'description' => 'Écrit du contenu dans un fichier',
                'parameters' => ['path' => 'string', 'content' => 'string'],
                'handler' => [$this, 'toolFileWrite']
            ],
            'calculator' => [
                'name' => 'calculator',
                'description' => 'Calculs mathématiques',
                'parameters' => ['expression' => 'string'],
                'handler' => [$this, 'toolCalculator']
            ],
            'system_info' => [
                'name' => 'system_info',
                'description' => 'Information système (CPU, RAM, disk, services)',
                'parameters' => ['metric' => 'string'],
                'handler' => [$this, 'toolSystemInfo']
            ]
        ];
    }
    
    /**
     * Génère la description des outils pour le system prompt
     */
    public function getToolsPrompt(): string {
        $prompt = "Tu as accès aux outils suivants:\n\n";
        foreach ($this->tools as $tool) {
            $params = json_encode($tool['parameters']);
            $prompt .= "- **{$tool['name']}**: {$tool['description']}\n  Paramètres: $params\n\n";
        }
        $prompt .= "Pour utiliser un outil, réponds avec:\n";
        $prompt .= "<tool_call>{\"name\": \"tool_name\", \"params\": {...}}</tool_call>\n";
        return $prompt;
    }
    
    /**
     * Parse et exécute les tool calls dans une réponse LLM
     */
    public function processResponse(string $response): array {
        $calls = [];
        $results = [];
        
        preg_match_all('/<tool_call>(.*?)<\/tool_call>/s', $response, $matches);
        
        foreach ($matches[1] as $callJson) {
            $call = json_decode($callJson, true);
            if (!$call || !isset($call['name'])) continue;
            
            $calls[] = $call;
            
            if (isset($this->tools[$call['name']])) {
                $handler = $this->tools[$call['name']]['handler'];
                $params = $call['params'] ?? [];
                
                try {
                    $result = call_user_func($handler, $params);
                    $results[] = ['tool' => $call['name'], 'success' => true, 'result' => $result];
                } catch (\Exception $e) {
                    $results[] = ['tool' => $call['name'], 'success' => false, 'error' => $e->getMessage()];
                }
            }
        }
        
        $this->history = array_merge($this->history, $results);
        
        return ['calls' => $calls, 'results' => $results, 'had_tools' => !empty($calls)];
    }
    
    // Tool implementations
    public function toolWebSearch(array $params): string {
        $query = $params['query'] ?? '';
        $max = min($params['max_results'] ?? 5, 10);
        
        $ch = curl_init("http://127.0.0.1:8888/search?q=" . urlencode($query) . "&format=json&engines=google,duckduckgo&results=$max");
        curl_setopt_array($ch, [CURLOPT_RETURNTRANSFER => true, CURLOPT_TIMEOUT => 15]);
        $raw = curl_exec($ch);
        curl_close($ch);
        
        $data = json_decode($raw, true);
        $results = [];
        foreach (($data['results'] ?? []) as $r) {
            $results[] = "**{$r['title']}**\n{$r['content']}\nURL: {$r['url']}";
        }
        
        return implode("\n---\n", $results) ?: "Aucun résultat trouvé.";
    }
    
    public function toolExecuteCode(array $params): string {
        $lang = $params['language'] ?? 'python';
        $code = $params['code'] ?? '';
        $tmp = '/tmp/wevia_exec_' . uniqid();
        
        switch ($lang) {
            case 'python':
                file_put_contents("$tmp.py", $code);
                $out = shell_exec("timeout 30 python3 $tmp.py 2>&1");
                @unlink("$tmp.py");
                break;
            case 'bash':
                file_put_contents("$tmp.sh", $code);
                $out = shell_exec("timeout 30 bash $tmp.sh 2>&1");
                @unlink("$tmp.sh");
                break;
            case 'php':
                file_put_contents("$tmp.php", "<?php\n$code");
                $out = shell_exec("timeout 30 php $tmp.php 2>&1");
                @unlink("$tmp.php");
                break;
            default:
                return "Langage non supporté: $lang";
        }
        
        return trim($out ?? '(no output)');
    }
    
    public function toolDatabaseQuery(array $params): string {
        $query = $params['query'] ?? '';
        $db = $params['database'] ?? 'wevia_db';
        
        // Security: SELECT only
        if (!preg_match('/^\s*SELECT/i', $query)) {
            return "ERROR: Seules les requêtes SELECT sont autorisées.";
        }
        
        try {
            $pdo = new PDO("pgsql:host=127.0.0.1;dbname=$db", "postgres", "");
            $stmt = $pdo->query($query);
            $rows = $stmt->fetchAll(PDO::FETCH_ASSOC);
            return json_encode($rows, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);
        } catch (\Exception $e) {
            return "SQL ERROR: " . $e->getMessage();
        }
    }
    
    public function toolFileRead(array $params): string {
        $path = $params['path'] ?? '';
        if (!file_exists($path)) return "Fichier non trouvé: $path";
        $content = file_get_contents($path);
        if (strlen($content) > 10000) {
            return substr($content, 0, 5000) . "\n...[TRUNCATED]...\n" . substr($content, -2000);
        }
        return $content;
    }
    
    public function toolFileWrite(array $params): string {
        $path = $params['path'] ?? '';
        $content = $params['content'] ?? '';
        $dir = dirname($path);
        if (!is_dir($dir)) @mkdir($dir, 0755, true);
        file_put_contents($path, $content);
        return "Fichier écrit: $path (" . strlen($content) . " bytes)";
    }
    
    public function toolCalculator(array $params): string {
        $expr = $params['expression'] ?? '';
        $safe = preg_replace('/[^0-9+\-*\/().%\s]/', '', $expr);
        try {
            $result = eval("return $safe;");
            return "$expr = $result";
        } catch (\Throwable $e) {
            return "Erreur calcul: " . $e->getMessage();
        }
    }
    
    public function toolSystemInfo(array $params): string {
        $metric = $params['metric'] ?? 'all';
        $info = [];
        
        if (in_array($metric, ['all', 'cpu'])) {
            $info[] = "CPU: " . trim(shell_exec("nproc")) . " cores, load: " . trim(shell_exec("uptime | awk -F'load average:' '{print \$2}'"));
        }
        if (in_array($metric, ['all', 'ram'])) {
            $info[] = "RAM: " . trim(shell_exec("free -h | grep Mem | awk '{print \$3\"/\"\$2}'"));
        }
        if (in_array($metric, ['all', 'disk'])) {
            $info[] = "Disk: " . trim(shell_exec("df -h / | tail -1 | awk '{print \$3\"/\"\$2\" (\"\$5\" used)\"}'"));
        }
        if (in_array($metric, ['all', 'gpu'])) {
            $info[] = "GPU: " . trim(shell_exec("nvidia-smi --query-gpu=name,memory.used,memory.total --format=csv,noheader 2>/dev/null") ?: "N/A");
        }
        
        return implode("\n", $info);
    }
}