<?php
/**
 * NIS2 Agile - AI Assistant Controller (ARIA)
 *
 * Endpoint dell'assistente conversazionale AI usato dal FAB "ARIA" (common.js).
 * Usa AIService::askWithRag() -> RAG su Knowledge Base (incl. fonti normative
 * certe ingerite, scope SYSTEM) + grounding con citazioni.
 */

require_once __DIR__ . '/BaseController.php';
require_once __DIR__ . '/../services/AIService.php';
require_once __DIR__ . '/../services/RateLimitService.php';

class AiController extends BaseController
{
    /**
     * POST /api/ai/ask
     * Body: { question: string, history?: array }
     * Risposta: { answer, sources, rag_used }
     */
    public function ask(): void
    {
        $this->requireAuth();

        $question = trim((string) $this->getParam('question', ''));
        if ($question === '') {
            $this->jsonError('Domanda mancante', 422, 'QUESTION_REQUIRED');
        }
        if (mb_strlen($question) > 2000) {
            $this->jsonError('Domanda troppo lunga (max 2000 caratteri)', 422, 'QUESTION_TOO_LONG');
        }

        // Rate limit per utente (riusa la soglia AI configurata)
        $userId = $this->getCurrentUserId();
        $rlKey = "ai_ask:{$userId}";
        if (defined('RATE_LIMIT_AI')) {
            RateLimitService::check($rlKey, RATE_LIMIT_AI);
            RateLimitService::increment($rlKey);
        }

        $user = $this->getCurrentUser() ?? [];
        // Pagina corrente (facoltativa) inviata dal frontend, per dare ad ARIA
        // contesto sulla schermata da cui l'utente sta scrivendo (ticket #424).
        $page = mb_substr(trim((string) $this->getParam('page', '')), 0, 120);
        // pageId canonico + testo dell'help "?" della pagina (allineamento ARIA↔Help).
        $pageId   = mb_substr(trim((string) $this->getParam('page_id', '')), 0, 40);
        $pageHelp = mb_substr(trim((string) $this->getParam('page_help', '')), 0, 2500);
        // Org attiva per lo snapshot dati di ARIA. ask() chiama requireAuth() ma NON
        // requireOrgAccess(), quindi getCurrentOrgId() resta null e org_data_ok sarebbe
        // sempre falso (ARIA cieca sui dati org). Risolviamo a mano: header
        // X-Organization-Id → param org_id → currentOrgId → org primaria dell'utente.
        // Lo spoofing è neutralizzato dal controllo membership qui sotto.
        $orgId = (int) ($_SERVER['HTTP_X_ORGANIZATION_ID'] ?? $this->getParam('org_id') ?? 0);
        if ($orgId <= 0) $orgId = (int) ($this->getCurrentOrgId() ?? 0);
        if ($orgId <= 0) {
            $primary = Database::fetchOne(
                'SELECT organization_id FROM user_organizations WHERE user_id = ? ORDER BY is_primary DESC, id ASC LIMIT 1',
                [$userId]
            );
            $orgId = (int) ($primary['organization_id'] ?? 0);
        }
        $userContext = [
            'user_id'            => $userId,
            'organization_id'    => $orgId ?: null,
            'consulting_firm_id' => $user['consulting_firm_id'] ?? null,
            'page'               => $page,
            'page_id'            => $pageId,
            'page_help'          => $pageHelp,
        ];

        // Membership verificata → ARIA può iniettare lo snapshot DATI dell'org
        // (anti-spoof X-Organization-Id; super_admin bypassa, come da modello ruoli).
        $orgId = (int) ($userContext['organization_id'] ?? 0);
        $userContext['org_data_ok'] = false;
        if ($orgId > 0) {
            if (($user['role'] ?? '') === 'super_admin') {
                $userContext['org_data_ok'] = true;
            } else {
                $member = Database::fetchOne(
                    'SELECT 1 FROM user_organizations WHERE user_id = ? AND organization_id = ?',
                    [$userId, $orgId]
                );
                $userContext['org_data_ok'] = (bool) $member;
            }
        }

        try {
            $aiService = new AIService();
            $result = $aiService->askWithRag($question, $userContext);

            // Audit best-effort (non blocca la risposta)
            try {
                $aiService->logInteraction(
                    (int) ($userContext['organization_id'] ?? 0),
                    (int) ($userId ?? 0),
                    'qa',
                    mb_substr($question, 0, 200),
                    mb_substr((string) ($result['answer'] ?? ''), 0, 500),
                );
            } catch (Throwable $e) {
                error_log('[AiController::ask] logInteraction failed: ' . $e->getMessage());
            }

            $this->jsonSuccess([
                'answer'   => $result['answer']   ?? '',
                'sources'  => $result['sources']  ?? [],
                'rag_used' => $result['rag_used'] ?? false,
            ]);
        } catch (Throwable $e) {
            error_log('[AiController::ask] ' . $e->getMessage());
            $this->jsonError('Assistente AI non disponibile in questo momento', 503, 'AI_UNAVAILABLE');
        }
    }

    /**
     * POST /api/ai/tts — Voce naturale di ARIA.
     * Proxy same-origin verso nexus-voice-ms (ElevenLabs): il voice-ms non espone CORS
     * per l'origin NIS2 → il browser non può chiamarlo diretto. Cache MP3 per hash del
     * testo (stesse frasi → niente costo ripetuto). Stream audio/mpeg.
     */
    public function tts(): void
    {
        $this->requireAuth();

        $text = trim((string) $this->getParam('text', ''));
        if ($text === '') { $this->jsonError('Testo mancante', 422, 'TTS_EMPTY'); }
        if (mb_strlen($text) > 800) { $text = mb_substr($text, 0, 800); }

        $lang  = substr(strtolower(preg_replace('/[^a-z]/', '', (string) $this->getParam('lang', 'it')) ?: 'it'), 0, 5) ?: 'it';
        $voice = (string) $this->getParam('voice_id', defined('TTS_VOICE_ID') ? TTS_VOICE_ID : 'EXAVITQu4vr4xnSDxMaL');
        if (!preg_match('/^[A-Za-z0-9]{8,40}$/', $voice)) {
            $voice = defined('TTS_VOICE_ID') ? TTS_VOICE_ID : 'EXAVITQu4vr4xnSDxMaL';
        }

        $cacheDir  = sys_get_temp_dir() . '/nis2-tts-cache';
        $cacheFile = $cacheDir . '/' . hash('sha256', $voice . '|' . $lang . '|' . $text) . '.mp3';
        if (is_file($cacheFile) && filesize($cacheFile) > 256) {
            $this->streamMp3((string) file_get_contents($cacheFile), 'HIT');
            return;
        }

        $payload = json_encode([
            'text'             => $text,
            'lang'             => $lang,
            'voice_id'         => $voice,
            'model'            => 'eleven_turbo_v2_5',
            'stability'        => 0.5,
            'similarity_boost' => 0.75,
            'style'            => 0.0,
            'output_format'    => 'mp3_44100_128',
        ]);

        $url = defined('VOICE_MS_URL') ? VOICE_MS_URL : 'http://172.21.0.1:4215/tts/speak';
        $ch = curl_init($url);
        curl_setopt_array($ch, [
            CURLOPT_POST           => true,
            CURLOPT_POSTFIELDS     => $payload,
            CURLOPT_HTTPHEADER     => ['Content-Type: application/json'],
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_CONNECTTIMEOUT => 6,
            CURLOPT_TIMEOUT        => 30,
        ]);
        $audio = curl_exec($ch);
        $code  = (int) curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $ctype = (string) curl_getinfo($ch, CURLINFO_CONTENT_TYPE);
        curl_close($ch);

        if ($code !== 200 || !$audio || strlen($audio) < 256 || stripos($ctype, 'audio') === false) {
            $this->jsonError('Sintesi vocale non disponibile', 502, 'TTS_UPSTREAM');
        }

        if (!is_dir($cacheDir)) { @mkdir($cacheDir, 0775, true); }
        @file_put_contents($cacheFile . '.tmp', $audio);
        @rename($cacheFile . '.tmp', $cacheFile);

        $this->streamMp3($audio, 'MISS');
    }

    private function streamMp3(string $audio, string $cache): void
    {
        header('Content-Type: audio/mpeg');
        header('Content-Length: ' . strlen($audio));
        header('Cache-Control: private, max-age=86400');
        header('X-TTS-Cache: ' . $cache);
        echo $audio;
        exit;
    }
}