feat: introduce Joi validation schemas and integrate them across various controllers for categories, lessons, courses, chapters, announcements, and admin course approvals.

Backend/src/validators/CoursesStudent.validator.ts

@@ -0,0 +1,38 @@
+import Joi from 'joi';
+
+/**
+ * Validator for saving video progress
+ */
+export const SaveVideoProgressValidator = Joi.object({
+    video_progress_seconds: Joi.number().min(0).required().messages({
+        'any.required': 'Video progress seconds is required',
+        'number.min': 'Video progress must be at least 0'
+    }),
+    video_duration_seconds: Joi.number().min(0).optional().messages({
+        'number.min': 'Video duration must be at least 0'
+    })
+});
+
+/**
+ * Validator for quiz answer
+ */
+const QuizAnswerValidator = Joi.object({
+    question_id: Joi.number().integer().positive().required().messages({
+        'any.required': 'Question ID is required',
+        'number.positive': 'Question ID must be positive'
+    }),
+    choice_id: Joi.number().integer().positive().required().messages({
+        'any.required': 'Choice ID is required',
+        'number.positive': 'Choice ID must be positive'
+    })
+});
+
+/**
+ * Validator for submitting quiz answers
+ */
+export const SubmitQuizValidator = Joi.object({
+    answers: Joi.array().items(QuizAnswerValidator).min(1).required().messages({
+        'any.required': 'Answers are required',
+        'array.min': 'At least one answer is required'
+    })
+});