<?php

namespace App\Controllers;

use App\Core\Request;
use App\Core\Response;
use App\Services\CurriculumService;
use App\Services\CurriculumExtractorService;

class CurriculumController
{
    /**
     * Upload and Queue Real Ministry PDF Document for Deep Extraction
     */
    public function uploadPdf(Request $request, Response $response): void
    {
        if (empty($_FILES['pdf_file']) || $_FILES['pdf_file']['error'] !== UPLOAD_ERR_OK) {
            $response->status(400)->json([
                'status'  => 'error',
                'message' => 'يرجى اختيار ملف PDF صالح للمنهاج الوزاري.'
            ]);
            return;
        }

        $file = $_FILES['pdf_file'];
        $origName = $file['name'];
        $tmpPath = $file['tmp_name'];
        $taskId = uniqid('task_');

        // Setup processing directory
        $processingDir = __DIR__ . '/../../storage/curriculum/processing';
        if (!is_dir($processingDir)) {
            mkdir($processingDir, 0777, true);
        }

        $savedPdfPath = $processingDir . '/' . $taskId . '.pdf';
        move_uploaded_file($tmpPath, $savedPdfPath);

        // Initialize Task State
        $taskState = [
            'task_id'   => $taskId,
            'status'    => 'queued',
            'progress'  => 0,
            'message'   => 'تم استلام الملف وجاري تحويله للمعالجة المعمقة...',
            'orig_name' => $origName
        ];
        file_put_contents($processingDir . '/' . $taskId . '.json', json_encode($taskState, JSON_UNESCAPED_UNICODE));

        // Prepare task paths
        $scriptPath = realpath(__DIR__ . '/../../scripts/curriculum_worker.php');
        $logPath = $processingDir . '/' . $taskId . '.log';

        // Send processing response immediately
        $response->json([
            'status'  => 'processing',
            'task_id' => $taskId,
            'message' => 'تم استلام الكتاب، وجاري المعالجة المعمقة بواسطة الذكاء الاصطناعي. يرجى الانتظار...'
        ]);
        
        // Terminate request and flush buffers so the client receives the JSON immediately
        if (function_exists('fastcgi_finish_request')) {
            fastcgi_finish_request();
        } else {
            // Fallback for non-FPM
            ob_end_flush();
            flush();
        }

        // Run worker completely in the background via CLI
        try {
            $cmd = "php " . escapeshellarg($scriptPath) . " " . escapeshellarg($taskId) . " > /dev/null 2>&1 &";
            exec($cmd);
            
            // Log that we spawned it
            file_put_contents($logPath, "[System] Spawning background worker: $cmd\n", FILE_APPEND);
        } catch (\Exception $e) {
            $err = "[Exception] " . $e->getMessage();
            file_put_contents($logPath, $err . "\n", FILE_APPEND);
            
            // Update state file to error
            $stateFile = $processingDir . '/' . $taskId . '.json';
            if (file_exists($stateFile)) {
                $st = json_decode(file_get_contents($stateFile), true);
                $st['status'] = 'error';
                $st['message'] = 'تعطل النظام أثناء التحليل (Crash). يرجى مراجعة سجل الأخطاء.';
                file_put_contents($stateFile, json_encode($st, JSON_UNESCAPED_UNICODE));
            }
        }
        
        // Ensure script stops here so it doesn't return anything else
        exit;
    }

    /**
     * Poll Upload Status
     */
    public function getUploadStatus(Request $request, Response $response): void
    {
        $taskId = $request->getQueryParams()['task_id'] ?? '';
        if (empty($taskId)) {
            $response->status(400)->json(['status' => 'error', 'message' => 'رقم المهمة مفقود']);
            return;
        }

        $processingDir = __DIR__ . '/../../storage/curriculum/processing';
        $stateFile = $processingDir . '/' . $taskId . '.json';
        
        if (!file_exists($stateFile)) {
            $response->status(404)->json(['status' => 'error', 'message' => 'المهمة غير موجودة']);
            return;
        }

        $state = json_decode(file_get_contents($stateFile), true);
        $response->json($state);
    }


    /**
     * Get Upload Log
     */
    public function getUploadLog(Request $request, Response $response): void
    {
        $taskId = $request->getQueryParams()['task_id'] ?? '';
        if (empty($taskId)) {
            $response->status(400)->json(['status' => 'error', 'message' => 'رقم المهمة مفقود']);
            return;
        }

        $processingDir = __DIR__ . '/../../storage/curriculum/processing';
        $logFile = $processingDir . '/' . $taskId . '.log';
        
        if (!file_exists($logFile)) {
            $response->status(404)->json(['status' => 'error', 'message' => 'سجل الأخطاء غير موجود']);
            return;
        }

        $logContent = file_get_contents($logFile);
        $response->json(['status' => 'success', 'log' => $logContent]);
    }

    /**
     * Get Complete Live Tree
     */

    public function getTree(Request $request, Response $response): void
    {
        $response->json([
            'status' => 'success',
            'data'   => CurriculumService::getCurriculumTree()
        ]);
    }

    /**
     * Get Single Lesson Markdown Content
     */
    public function getLessonContent(Request $request, Response $response): void
    {
        $file = $request->getQueryParams()['file'] ?? '';
        if (empty($file)) {
            $response->status(400)->json(['status' => 'error', 'message' => 'مسار الملف مطلوب']);
            return;
        }
        $content = CurriculumService::getLessonMarkdown($file);
        $assets = CurriculumService::getLessonAiAssets($file);
        $serverFullPath = realpath(__DIR__ . '/../../storage/curriculum') . '/' . ltrim($file, '/');

        $response->json([
            'status'           => 'success',
            'file'             => $file,
            'server_full_path' => $serverFullPath,
            'content'          => $content,
            'ai_assets'        => $assets
        ]);
    }

    public function saveLessonContent(Request $request, Response $response): void
    {
        $body = $request->getBody();
        $file = $body['file'] ?? '';
        $content = $body['content'] ?? '';
        $aiAssets = $body['ai_assets'] ?? null;

        if (empty($file) || empty($content)) {
            $response->status(400)->json(['status' => 'error', 'message' => 'بيانات الحفظ غير مكتملة']);
            return;
        }

        CurriculumService::saveLessonMarkdown($file, $content);
        if ($aiAssets !== null) {
            CurriculumService::saveLessonAiAssets($file, $aiAssets);
        }

        // Sync to MySQL Database Table `lessons` if connected
        try {
            $aiVideoUrl = $aiAssets['ai_video_url'] ?? null;
            $cheatSheet = $aiAssets['cheat_sheet'] ?? null;
            $socraticJson = isset($aiAssets['socratic_quiz']) ? json_encode($aiAssets['socratic_quiz'], JSON_UNESCAPED_UNICODE) : null;

            // Search lesson by matching filename or title
            $filename = basename($file, '.md');
            \App\Core\Database::query(
                "UPDATE lessons SET markdown_content = ?, ai_video_url = COALESCE(?, ai_video_url), cheat_sheet_markdown = COALESCE(?, cheat_sheet_markdown), socratic_quiz_json = COALESCE(?, socratic_quiz_json) 
                 WHERE title LIKE ? OR markdown_content LIKE ?",
                [$content, $aiVideoUrl, $cheatSheet, $socraticJson, "%{$filename}%", "%{$file}%"]
            );
        } catch (\Throwable $dbEx) {
            error_log("Curriculum DB save sync note: " . $dbEx->getMessage());
        }

        $serverFullPath = realpath(__DIR__ . '/../../storage/curriculum') . '/' . ltrim($file, '/');

        $response->json([
            'status'           => 'success',
            'message'          => 'تم حفظ واعتماد محتوى الدرس في المنهاج وقاعدة البيانات بنجاح!',
            'server_full_path' => $serverFullPath
        ]);
    }

    public function generateAiAssets(Request $request, Response $response): void
    {
        $body = $request->getBody();
        $file = $body['file'] ?? '';
        if (empty($file)) {
            $response->status(400)->json(['status' => 'error', 'message' => 'مسار الملف مطلوب']);
            return;
        }

        $content = CurriculumService::getLessonMarkdown($file);
        if (empty($content)) {
            $response->status(400)->json(['status' => 'error', 'message' => 'محتوى الدرس فارغ']);
            return;
        }

        // Generate Assets
        require_once __DIR__ . '/../Services/AiLessonEnhancerService.php';
        
        $assets = \App\Services\AiLessonEnhancerService::generateFromText('الدرس', $content);
        
        if ($assets) {
            CurriculumService::saveLessonAiAssets($file, $assets);
            $response->json(['status' => 'success', 'ai_assets' => $assets]);
        } else {
            $response->status(500)->json(['status' => 'error', 'message' => 'فشل توليد المخرجات الذكية']);
        }
    }

    /**
     * Direct Video Upload to Platform Storage with Semantic Lesson Binding
     */
    public function uploadLessonVideo(Request $request, Response $response): void
    {
        $file = $_POST['file'] ?? '';
        if (empty($file)) {
            $response->status(400)->json(['status' => 'error', 'message' => 'مسار الدرس مطلوب']);
            return;
        }

        if (empty($_FILES['video_file']) || $_FILES['video_file']['error'] !== UPLOAD_ERR_OK) {
            $response->status(400)->json(['status' => 'error', 'message' => 'يرجى اختيار ملف فيديو صالح (MP4, WebM, MOV)']);
            return;
        }

        try {
            // Resolve a valid FK-safe course_id for the master ministry curriculum.
            // IMPORTANT: course_id = 0 causes SQLSTATE[23000] FK violation because
            // the `lessons` table enforces courses(id) ON DELETE CASCADE.
            $courseId = CurriculumService::getOrCreateSystemCourse();
            $title = basename($file, '.md');

            // 1. Upload & Transcode to HLS & Push to R2 (handled by VideoService)
            $uploadResult = \App\Services\VideoService::handleDirectUpload($_FILES['video_file'], $courseId, $title);
            
            $videoUrl = $uploadResult['r2_url'] ?? $uploadResult['hls_url'];

            // 2. Insert into lessons table as AI-generated ministry version
            $lessonId = \App\Core\Database::insert(
                "INSERT INTO lessons (course_id, title, sequence_order, storage_type, video_uuid, bunny_video_id, local_path, hls_url, thumbnail_url, duration_seconds, is_free_preview, encoding_status, ai_video_url) 
                 VALUES (?, ?, 1, 'api_upload', ?, '', ?, ?, ?, ?, 0, 'ready', ?)",
                [
                    $courseId,
                    $title,
                    $uploadResult['video_uuid'],
                    $uploadResult['local_path'],
                    $uploadResult['hls_url'],
                    $uploadResult['thumbnail_url'],
                    $uploadResult['duration'] ?? 0,
                    $videoUrl
                ]
            );

            // 3. Trigger Autonomous Zero-Touch AI Analysis & Socratic Checkpoint Generation
            \App\Services\AiVideoAnalyzerService::processLessonAutonomously($lessonId);

            // 4. Update Lesson AI assets in manifest.json & filesystem
            $currentAssets = CurriculumService::getLessonAiAssets($file);
            $currentAssets['ai_video_url'] = $videoUrl;
            CurriculumService::saveLessonAiAssets($file, $currentAssets);

            // 5. Update any existing curriculum lesson rows with this video
            try {
                \App\Core\Database::query(
                    "UPDATE lessons SET ai_video_url = ? WHERE title LIKE ? OR markdown_content LIKE ?",
                    [$videoUrl, "%{$title}%", "%{$file}%"]
                );
            } catch (\Throwable $dbEx) {
                error_log("Video DB sync note: " . $dbEx->getMessage());
            }

            $response->status(201)->json([
                'status'    => 'success',
                'message'   => 'تم رفع وتثبيت فيديو الشرح ومعالجته HLS وربطه بالذكاء الاصطناعي بنجاح!',
                'video_url' => $videoUrl,
                'course_id' => $courseId,
                'lesson_id' => $lessonId,
                'data'      => $uploadResult
            ]);
        } catch (\Throwable $e) {
            $response->status(500)->json([
                'status'  => 'error',
                'message' => $e->getMessage()
            ]);
        }
    }
}