from flask import current_app from src.models import DatabaseContextManager from src.models.models import ( CourseLevel, CourseWeek, CourseModule, Course, Tutor, Supervisor, UserType ) from sqlalchemy import or_, func, case, and_ from src.utils import ApiABC, custom_response import uuid from datetime import datetime, timedelta, date class CourseLevelManager(ApiABC): def __init__(self): super().__init__(CourseLevel) def create(self, payload): """Create a new course level""" with DatabaseContextManager() as ctx: try: # Validate required fields required_fields = ['course_id', 'level_name', 'requester_id'] for field in required_fields: if field not in payload or not payload[field]: return custom_response( success=False, data=f"Missing required field: {field}", status_code=400 ) # Verify course exists course = ctx.session.query(Course).filter(Course.id == payload['course_id']).first() if not course: return custom_response( success=False, data="Course not found", status_code=404 ) # Verify requester has permission requester = ctx.session.query(Supervisor).filter(Supervisor.id == payload['requester_id']).first() if not requester: return custom_response( success=False, data="Unauthorized - Only supervisors can create course levels", status_code=403 ) # Check if level name already exists for this course existing_level = ctx.session.query(CourseLevel).filter( CourseLevel.course_id == payload['course_id'], CourseLevel.level_name == payload['level_name'] ).first() if existing_level: return custom_response( success=False, data="A level with this name already exists for this course", status_code=400 ) # Get next level order max_order = ctx.session.query(func.max(CourseLevel.level_order)).filter( CourseLevel.course_id == payload['course_id'] ).scalar() or 0 # Create new course level new_level = CourseLevel( id=str(uuid.uuid4()), course_id=payload['course_id'], level_name=payload['level_name'], level_order=max_order + 1, description=payload.get('description', ''), learning_objectives=payload.get('learning_objectives', ''), estimated_duration_weeks=payload.get('estimated_duration_weeks', 1), is_active=True ) ctx.session.add(new_level) ctx.session.commit() return custom_response( success=True, data={ "message": "Course level created successfully", "level": { "id": new_level.id, "level_name": new_level.level_name, "level_order": new_level.level_order, "description": new_level.description, "learning_objectives": new_level.learning_objectives, "estimated_duration_weeks": new_level.estimated_duration_weeks, "is_active": new_level.is_active, "created_at": new_level.created_at.isoformat() } }, status_code=201 ) except Exception as e: ctx.session.rollback() current_app.logger.error(f"Error creating course level: {str(e)}", exc_info=True) return custom_response( success=False, data="Failed to create course level due to server error", status_code=500 ) def get(self, level_id): """Get course level details with weeks and modules""" with DatabaseContextManager() as ctx: try: level = ctx.session.query(CourseLevel).filter(CourseLevel.id == level_id).first() if not level: return custom_response( success=False, data="Course level not found", status_code=404 ) # Get weeks with modules weeks_data = [] for week in level.weeks: modules_data = [] for module in week.modules: modules_data.append({ "id": module.id, "title": module.title, "description": module.description, "module_type": module.module_type, "estimated_duration_minutes": module.estimated_duration_minutes, "learning_objectives": module.learning_objectives, "is_required": module.is_required, "is_published": module.is_published, "is_active": module.is_active, "sequence": module.sequence, "created_at": module.created_at.isoformat(), "updated_at": module.updated_at.isoformat() }) weeks_data.append({ "id": week.id, "week_number": week.week_number, "week_title": week.week_title, "description": week.description, "learning_outcomes": week.learning_outcomes, "estimated_hours": week.estimated_hours, "start_date": week.start_date.isoformat() if week.start_date else None, "end_date": week.end_date.isoformat() if week.end_date else None, "is_active": week.is_active, "created_at": week.created_at.isoformat(), "updated_at": week.updated_at.isoformat(), "modules": modules_data }) level_data = { "id": level.id, "course_id": level.course_id, "level_name": level.level_name, "level_order": level.level_order, "description": level.description, "learning_objectives": level.learning_objectives, "estimated_duration_weeks": level.estimated_duration_weeks, "is_active": level.is_active, "created_at": level.created_at.isoformat(), "weeks": weeks_data } return custom_response( success=True, data=level_data, status_code=200 ) except Exception as e: current_app.logger.error(f"Error fetching course level: {str(e)}", exc_info=True) return custom_response( success=False, data="Failed to fetch course level due to server error", status_code=500 ) def update(self, level_id, payload): """Update course level details""" with DatabaseContextManager() as ctx: try: level = ctx.session.query(CourseLevel).filter(CourseLevel.id == level_id).first() if not level: return custom_response( success=False, data="Course level not found", status_code=404 ) # Update fields if 'level_name' in payload: # Check if new name conflicts with existing levels existing_level = ctx.session.query(CourseLevel).filter( CourseLevel.course_id == level.course_id, CourseLevel.level_name == payload['level_name'], CourseLevel.id != level_id ).first() if existing_level: return custom_response( success=False, data="A level with this name already exists for this course", status_code=400 ) level.level_name = payload['level_name'] if 'description' in payload: level.description = payload['description'] if 'learning_objectives' in payload: level.learning_objectives = payload['learning_objectives'] if 'estimated_duration_weeks' in payload: level.estimated_duration_weeks = payload['estimated_duration_weeks'] if 'is_active' in payload: level.is_active = payload['is_active'] ctx.session.commit() return custom_response( success=True, data="Course level updated successfully", status_code=200 ) except Exception as e: ctx.session.rollback() current_app.logger.error(f"Error updating course level: {str(e)}", exc_info=True) return custom_response( success=False, data="Failed to update course level due to server error", status_code=500 ) def delete(self, level_id, requester_id): """Delete a course level (soft delete)""" with DatabaseContextManager() as ctx: try: level = ctx.session.query(CourseLevel).filter(CourseLevel.id == level_id).first() if not level: return custom_response( success=False, data="Course level not found", status_code=404 ) # Verify requester has permission requester = ctx.session.query(Supervisor).filter(Supervisor.id == requester_id).first() if not requester: return custom_response( success=False, data="Unauthorized - Only supervisors can delete course levels", status_code=403 ) # Soft delete - deactivate the level level.is_active = False ctx.session.commit() return custom_response( success=True, data="Course level deleted successfully", status_code=200 ) except Exception as e: ctx.session.rollback() current_app.logger.error(f"Error deleting course level: {str(e)}", exc_info=True) return custom_response( success=False, data="Failed to delete course level due to server error", status_code=500 ) def fetch_all(self, course_id, page=1, per_page=10): """Get all course levels for a course with pagination""" with DatabaseContextManager() as ctx: try: # Verify course exists course = ctx.session.query(Course).filter(Course.id == course_id).first() if not course: return custom_response( success=False, data="Course not found", status_code=404 ) # Get levels with pagination query = ctx.session.query(CourseLevel).filter( CourseLevel.course_id == course_id, CourseLevel.is_active == True ).order_by(CourseLevel.level_order) total = query.count() levels = query.offset((page - 1) * per_page).limit(per_page).all() levels_data = [] for level in levels: levels_data.append({ "id": level.id, "level_name": level.level_name, "level_order": level.level_order, "description": level.description, "learning_objectives": level.learning_objectives, "estimated_duration_weeks": level.estimated_duration_weeks, "is_active": level.is_active, "weeks_count": len(level.weeks), "created_at": level.created_at.isoformat() }) return custom_response( success=True, data={ "levels": levels_data, "pagination": { "page": page, "per_page": per_page, "total": total, "pages": (total + per_page - 1) // per_page } }, status_code=200 ) except Exception as e: current_app.logger.error(f"Error fetching course levels: {str(e)}", exc_info=True) return custom_response( success=False, data="Failed to fetch course levels due to server error", status_code=500 ) def get_by_course(self, course_id, user_id, user_type): """Get all levels for a course with full structure (weeks and modules)""" with DatabaseContextManager() as ctx: try: # Verify course exists course = ctx.session.query(Course).filter(Course.id == course_id).first() if not course: return custom_response( success=False, data="Course not found", status_code=404 ) # Verify user has access to this course if not self._has_course_access(ctx, course_id, user_id, user_type): return custom_response( success=False, data="Unauthorized - You don't have access to this course", status_code=403 ) # Get levels with weeks and modules levels = ctx.session.query(CourseLevel).filter( CourseLevel.course_id == course_id, CourseLevel.is_active == True ).order_by(CourseLevel.level_order).all() levels_data = [] for level in levels: weeks_data = [] for week in level.weeks: modules_data = [] for module in week.modules: modules_data.append({ "id": module.id, "title": module.title, "description": module.description, "module_type": module.module_type, "estimated_duration_minutes": module.estimated_duration_minutes, "learning_objectives": module.learning_objectives, "is_required": module.is_required, "is_published": module.is_published, "is_active": module.is_active, "sequence": module.sequence, "created_at": module.created_at.isoformat(), "updated_at": module.updated_at.isoformat() }) weeks_data.append({ "id": week.id, "week_number": week.week_number, "week_title": week.week_title, "description": week.description, "learning_outcomes": week.learning_outcomes, "estimated_hours": week.estimated_hours, "start_date": week.start_date.isoformat() if week.start_date else None, "end_date": week.end_date.isoformat() if week.end_date else None, "is_active": week.is_active, "created_at": week.created_at.isoformat(), "updated_at": week.updated_at.isoformat(), "modules": modules_data }) levels_data.append({ "id": level.id, "level_name": level.level_name, "level_order": level.level_order, "description": level.description, "learning_objectives": level.learning_objectives, "estimated_duration_weeks": level.estimated_duration_weeks, "is_active": level.is_active, "created_at": level.created_at.isoformat(), "weeks": weeks_data }) return custom_response( success=True, data=levels_data, status_code=200 ) except Exception as e: current_app.logger.error(f"Error fetching course structure: {str(e)}", exc_info=True) return custom_response( success=False, data="Failed to fetch course structure due to server error", status_code=500 ) def fetchAll(self): """Required by ApiABC - not used in this context""" return custom_response( success=False, data="Use get_by_course method instead", status_code=400 ) def _has_course_access(self, ctx, course_id, user_id, user_type): """Check if user has access to the course""" try: if user_type == UserType.supervisor.value: # Supervisors have access to all courses return True elif user_type == UserType.tutor.value: # Check if tutor is assigned to this course tutor = ctx.session.query(Tutor).filter(Tutor.id == user_id).first() if tutor: return course_id in [course.id for course in tutor.courses] elif user_type == UserType.student.value: # Check if student is enrolled in this course from src.models.models import Enrollment, enrollment_courses enrollment = ctx.session.query(Enrollment).join(enrollment_courses).filter( enrollment_courses.c.course_id == course_id, Enrollment.student_id == user_id ).first() return enrollment is not None return False except Exception as e: current_app.logger.error(f"Error checking course access: {str(e)}", exc_info=True) return False