Merge branch 'main' into feat/add-exam-application-window-layout

LangLang/Core/Controller/EnrollmentRequestController.cs

@@ -1,9 +1,7 @@
-
-using LangLang.Core.Model.DAO;
+using LangLang.Core.Model.DAO;
 using System.Collections.Generic;
 using LangLang.Core.Model;
 using LangLang.Core.Observer;
-using System.Linq;
 
 namespace LangLang.Core.Controller
 {
@@ -16,7 +14,7 @@ public EnrollmentRequestController()
             _enrollmentRequests = new EnrollmentRequestDAO();
         }
 
-        public Dictionary<int, EnrollmentRequest> GetAll()
+        public List<EnrollmentRequest> GetAll()
         {
             return _enrollmentRequests.GetAllEnrollmentRequests();
         }
@@ -45,5 +43,23 @@ public List<EnrollmentRequest> GetStudentRequests(int studentId)
         {
             return _enrollmentRequests.GetStudentRequests(studentId);
         }
+
+        public bool CancelRequest(EnrollmentRequest enrollmentRequest, CourseController courseController)
+        {
+            Course course = courseController.GetById(enrollmentRequest.CourseId);
+            return _enrollmentRequests.CancelRequest(enrollmentRequest, course);
+        }
+
+        // this method is invoked when the tutor approves the request for the student
+        public void PauseRequests(int studentId, EnrollmentRequest enrollmentRequest)
+        {
+            _enrollmentRequests.PauseRequests(studentId, enrollmentRequest.Id);
+        }
+
+        // this method is invoked when the student complete/withdrawal_from course
+        public void ResumePausedRequests(int studentId)
+        {
+            _enrollmentRequests.ResumePausedRequests(studentId);
+        }
     }
 }

LangLang/Core/Controller/StudentController.cs

@@ -41,7 +41,6 @@ public void Subscribe(IObserver observer)
             _students.Subscribe(observer);
         }
 
-
         public List<Course> GetAvailableCourses(CourseController courseController) 
         {
             return _students.GetAvailableCourses(courseController);
@@ -52,9 +51,14 @@ public List<ExamSlot> GetAvailableExamSlots(Student student, CourseController co
             return _students.GetAvailableExamSlots(student, courseController, examSlotController, enrollmentRequestController);
         }
 
-        public bool CanModifyInfo(int studentId, EnrollmentRequestController erc)
+        public bool CanModifyInfo(int studentId, EnrollmentRequestController erController, CourseController courseController)
         {
-            return _students.CanModifyInfo(studentId, erc);
+            return _students.CanModifyInfo(studentId, erController, courseController);
+        }
+
+        public bool CanRequestEnroll(int id, EnrollmentRequestController erController, CourseController courseController)
+        {
+            return _students.CanRequestEnroll(id, erController, courseController);
         }
 
         public List<ExamSlot> SearchExamSlotsByStudent(ExamSlotController examSlotController, CourseController courseController, EnrollmentRequestController enrollmentRequestController, int studentId, DateTime examDate, string courseLanguage, LanguageLevel? languageLevel)
@@ -69,5 +73,6 @@ public List<Course> SearchCoursesByStudent(CourseController courseController, st
             List<Course> filteredCourses = courseController.SearchCourses(availableCourses, language, level, startDate, duration, online);
             return filteredCourses;
         }
+
     }
 }

LangLang/Core/Model/DAO/EnrollmentRequestDAO.cs

@@ -1,5 +1,7 @@
-using LangLang.Core.Observer;
+using LangLang.Core.Model.Enums;
+using LangLang.Core.Observer;
 using LangLang.Core.Repository;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 
@@ -18,17 +20,17 @@ public EnrollmentRequestDAO()
         private int GenerateId()
         {
             if (_enrollmentRequests.Count == 0) return 0;
-            return _enrollmentRequests.Count + 1;
+            return _enrollmentRequests.Keys.Max() + 1;
         }
 
         public EnrollmentRequest? GetEnrollmentRequestById(int id)
         {
             return _enrollmentRequests[id];
         }
 
-        public Dictionary<int, EnrollmentRequest> GetAllEnrollmentRequests()
+        public List<EnrollmentRequest> GetAllEnrollmentRequests()
         {
-            return _enrollmentRequests;
+            return _enrollmentRequests.Values.ToList();
         }
 
         public EnrollmentRequest Add(EnrollmentRequest enrollmentRequest)
@@ -42,19 +44,20 @@ public EnrollmentRequest Add(EnrollmentRequest enrollmentRequest)
 
         public EnrollmentRequest? Update(EnrollmentRequest enrollmentRequest)
         {
-            EnrollmentRequest oldRequest = GetEnrollmentRequestById(enrollmentRequest.Id);
+            EnrollmentRequest? oldRequest = GetEnrollmentRequestById(enrollmentRequest.Id);
             if (oldRequest == null) return null;
 
-            oldRequest.Status = enrollmentRequest.Status;
-
+            oldRequest.UpdateStatus(enrollmentRequest.Status);
+            oldRequest.IsCanceled = enrollmentRequest.IsCanceled;
+            oldRequest.LastModifiedTimestamp = DateTime.Now;
             _repository.Save(_enrollmentRequests);
             NotifyObservers();
             return oldRequest;
         }
 
         public EnrollmentRequest? Remove(int id)
         {
-            EnrollmentRequest enrollmentRequest = GetEnrollmentRequestById(id);
+            EnrollmentRequest? enrollmentRequest = GetEnrollmentRequestById(id);
             if (enrollmentRequest == null) return null; 
 
             _enrollmentRequests.Remove(enrollmentRequest.Id);
@@ -65,13 +68,48 @@ public EnrollmentRequest Add(EnrollmentRequest enrollmentRequest)
 
         public List<EnrollmentRequest> GetStudentRequests(int studentId)
         {
-            Dictionary<int, EnrollmentRequest> studentRequests = new();
-            foreach (EnrollmentRequest enrollmentRequest in GetAllEnrollmentRequests().Values)
+            List<EnrollmentRequest> studentRequests = new();
+            foreach (EnrollmentRequest enrollmentRequest in GetAllEnrollmentRequests())
             {
-                if (enrollmentRequest.StudentId == studentId) studentRequests.Add(enrollmentRequest.Id, enrollmentRequest);
+                if (enrollmentRequest.StudentId == studentId) studentRequests.Add(enrollmentRequest);
+            }
+            return studentRequests;
+        }
+
+        // returns true if the cancellation was successful, otherwise false
+        public bool CancelRequest(EnrollmentRequest enrollmentRequest, Course course)
+        {
+            if (course.StartDateTime.Date - DateTime.Now.Date <= TimeSpan.FromDays(7))
+                return false; // course start date must be at least 7 days away
+
+            enrollmentRequest.IsCanceled = true;
+            return true;
+        }
 
+        public void PauseRequests(int studentId, int acceptedRequestId)
+        {
+            var studentRequests = GetStudentRequests(studentId);
+            foreach (EnrollmentRequest er in studentRequests)
+            {
+                if (er.Id == acceptedRequestId)
+                {
+                    er.UpdateStatus(Status.Accepted);
+                }
+                else if (er.Status == Status.Pending && !er.IsCanceled)
+                {
+                    er.UpdateStatus(Status.Paused);
+                }
             }
-            return studentRequests.Values.ToList();
         }
+
+        public void ResumePausedRequests(int studentId)
+        {
+            var studentRequests = GetStudentRequests(studentId);
+            foreach (EnrollmentRequest request in studentRequests)
+            {
+                if (request.Status == Status.Paused) request.UpdateStatus(Status.Pending);
+            }
+        }
+
     }
 }

LangLang/Core/Model/DAO/StudentDAO.cs

@@ -4,20 +4,16 @@
 using LangLang.Core.Observer;
 using LangLang.Core.Controller;
 using LangLang.Core.Model.Enums;
+using System;
 
 namespace LangLang.Core.Model.DAO
 {
-    /**
-     * This class encapsulates a list of Student objects and provides methods
-     * for adding, updating, deleting, and retrieving Student objects.
-     * Additionally, this class uses Repository<Student> for loading and saving objects.
-    **/
     public class StudentDAO : Subject
     {
         private readonly Dictionary<int, Student> _students;
         private readonly Repository<Student> _repository;
-    
-    
+
+
         public StudentDAO()
         {
             _repository = new Repository<Student>("students.csv");
@@ -69,7 +65,7 @@ public Student AddStudent(Student student)
             NotifyObservers();
             return oldStudent;
         }
-     
+
         public Student? RemoveStudent(int id, EnrollmentRequestController enrollmentRequestController)
         {
             Student student = GetStudentById(id);
@@ -130,15 +126,28 @@ public List<ExamSlot> GetAvailableExamSlots(Student student, CourseController co
             return availableExamSlots;
         }
 
-        public bool CanModifyInfo(int studentId, EnrollmentRequestController erc)
+        public bool CanModifyInfo(int studentId, EnrollmentRequestController erController, CourseController courseController)
         {
-            List<EnrollmentRequest> studentRequests = erc.GetStudentRequests(studentId);
-            foreach (EnrollmentRequest request in studentRequests)
-            {
-                if (request.Status == Status.Accepted) return false; // TODO: Check if the course is incomplete upon implementing functionality in courseController.
+            // can modify - student is not currently enrolled in any course and has not applied for any exams
+            return (CanRequestEnroll(studentId, erController, courseController) && !HasRegisteredForExam());
+        }
 
+        public bool CanRequestEnroll(int id, EnrollmentRequestController erController, CourseController courseController)
+        {
+            foreach (EnrollmentRequest er in erController.GetStudentRequests(id))
+            {
+                if (er.Status == Status.Accepted && !er.IsCanceled)
+                {
+                    if (!courseController.IsCompleted(er.Id)) return false;
+                }
             }
             return true;
         }
+
+        public bool HasRegisteredForExam()
+        {
+            // TODO: Implement this method once the exam application class is implemented.
+            return false;
+        }
     }
 }

LangLang/Core/Model/EnrollmentRequest.cs

@@ -9,19 +9,28 @@ public class EnrollmentRequest : ISerializable
         public int Id { get; set; }
         public int StudentId { get; set; }
         public int CourseId { get; set; }
-        public Status Status { get; set; }
+        public Status Status { get; private set; }
         public DateTime RequestSentAt { get; set; }
         public DateTime LastModifiedTimestamp { get; set; }
+        public bool IsCanceled { get; set; }
 
         public EnrollmentRequest() { }
 
-        public EnrollmentRequest(int id, int studentId, int courseId, Status erStatus, DateTime requestSentAt)
+        public EnrollmentRequest(int id, int studentId, int courseId, Status status, DateTime requestSentAt)
         {
             Id = id;
             StudentId = studentId;
             CourseId = courseId;
-            Status = erStatus;
+            Status = status;
             RequestSentAt = requestSentAt;
+            LastModifiedTimestamp = requestSentAt; //Later this will refer to the date of acceptance/rejection/cancellation
+            IsCanceled = false; // this refers whether the student has canceled request before the course has started  
+        }
+
+        public void UpdateStatus(Status status)
+        {
+            Status = status;
+            LastModifiedTimestamp = DateTime.Now;
         }
 
         public void FromCSV(string[] values)
@@ -38,6 +47,7 @@ public void FromCSV(string[] values)
             StudentId = int.Parse(values[1]);
             CourseId = int.Parse(values[2]);
             Status = (Status)Enum.Parse(typeof(Status), values[3]);
+            IsCanceled = bool.Parse(values[6]);
         }
 
         public string[] ToCSV()
@@ -48,7 +58,8 @@ public string[] ToCSV()
                 CourseId.ToString(),
                 Status.ToString(),
                 RequestSentAt.ToString("yyyy-MM-dd"),
-                LastModifiedTimestamp.ToString("yyyy-MM-dd")
+                LastModifiedTimestamp.ToString("yyyy-MM-dd"),
+                IsCanceled.ToString()
             };
         }
     }

LangLang/Core/Model/Enums/Status.cs

@@ -5,6 +5,7 @@ public enum Status
     {
         Pending,
         Accepted,
-        Rejected
+        Rejected,
+        Paused
     }
 }