feat: fix quiz scoring to use Choice model correctness, add YouTube video support to lesson content, and include show_answers_after_completion in quiz data

Update quiz attempt detail scoring to determine correctness from Choice.is_correct instead of StudentAnswer.is_correct and calculate earned score based on correctness. Add YouTube video support to getLessonContent endpoint by checking LessonAttachment for YouTube videos (mime_type 'video/youtube') and building YouTube URLs from video IDs. Ad

Backend/src/services/CoursesInstructor.service.ts

@@ -905,14 +905,19 @@ export class CoursesInstructorService {
                 const selectedChoiceId = studentAnswer?.choice_id || null;
                 const selectedChoice = selectedChoiceId ? question.choices.find(c => c.id === selectedChoiceId) : null;
 
+                // Check if selected choice is correct from Choice model
+                const isCorrect = selectedChoice?.is_correct || false;
+                // Score is question.score if correct, otherwise 0
+                const earnedScore = isCorrect ? question.score : 0;
+
                 return {
                     question_id: question.id,
                     sort_order: question.sort_order,
                     question_text: question.question as { th: string; en: string },
                     selected_choice_id: selectedChoiceId,
                     selected_choice_text: selectedChoice ? selectedChoice.text as { th: string; en: string } : null,
-                    is_correct: studentAnswer?.is_correct || false,
+                    is_correct: isCorrect,
-                    score: studentAnswer?.score || 0,
+                    score: earnedScore,
                     question_score: question.score,
                 };
             });

Backend/src/services/CoursesStudent.service.ts

@@ -486,17 +486,35 @@ export class CoursesStudentService {
             // Import additional MinIO functions
             // Using MinIO functions imported above
 
-            // Get video URL from video folder (first file)
+            // Get video URL - check for YouTube or MinIO
             let video_url: string | null = null;
-            try {
+            const videoAttachment = await prisma.lessonAttachment.findFirst({
-                const videoPrefix = getVideoFolder(chapter_course_id, lesson_id);
+                where: { lesson_id, sort_order: 0 }
-                const videoFiles = await listObjects(videoPrefix);
+            });
-                if (videoFiles.length > 0) {
+
-                    // Get presigned URL for the first video file
+            if (videoAttachment) {
-                    video_url = await getPresignedUrl(videoFiles[0].name, 3600);
+                if (videoAttachment.mime_type === 'video/youtube') {
+                    // YouTube video - build URL from video ID stored in file_path
+                    video_url = `https://www.youtube.com/watch?v=${videoAttachment.file_path}`;
+                } else {
+                    // MinIO video - get presigned URL
+                    try {
+                        video_url = await getPresignedUrl(videoAttachment.file_path, 3600);
+                    } catch (err) {
+                        logger.error(`Failed to get video from MinIO: ${err}`);
+                    }
+                }
+            } else {
+                // Fallback: try to get video from MinIO folder (legacy support)
+                try {
+                    const videoPrefix = getVideoFolder(chapter_course_id, lesson_id);
+                    const videoFiles = await listObjects(videoPrefix);
+                    if (videoFiles.length > 0) {
+                        video_url = await getPresignedUrl(videoFiles[0].name, 3600);
+                    }
+                } catch (err) {
+                    logger.error(`Failed to get video from MinIO: ${err}`);
                 }
-            } catch (err) {
-                logger.error(`Failed to get video from MinIO: ${err}`);
             }
 
             // Get attachments from MinIO folder
@@ -578,6 +596,7 @@ export class CoursesStudentService {
                         shuffle_questions: lesson.quiz.shuffle_questions,
                         shuffle_choices: lesson.quiz.shuffle_choices,
                         is_skippable: lesson.quiz.is_skippable,
+                        show_answers_after_completion: lesson.quiz.show_answers_after_completion,
                         questions: lesson.quiz.questions.map(q => ({
                             id: q.id,
                             question: q.question as { th: string; en: string },

Backend/src/types/CoursesStudent.types.ts

@@ -158,6 +158,7 @@ export interface LessonContentData {
         shuffle_questions: boolean;
         shuffle_choices: boolean;
         is_skippable: boolean;
+        show_answers_after_completion: boolean;
         questions: {
             id: number;
             question: MultiLangText;