Yana P.

task-1/com.hyfacademy/Main.java

@@ -1,7 +1,10 @@
 package com.hyfacademy;
 
+import com.hyfacademy.service.PlatformService;
+
 public class Main {
-    static void main(String[] args) {
-        System.out.println("Hello World!");
+   public static void main(String[] args) {
+       PlatformService platformService = new PlatformService();
+       platformService.run();
     }
 }

task-1/com.hyfacademy/exception/AlreadyEnrolledException.java

@@ -1,4 +1,15 @@
 package com.hyfacademy.exception;
 
-public class AlreadyEnrolledException {
+public class AlreadyEnrolledException extends EnrolmentException {
+    private final String studentName;
+    private final String courseName;
+
+    public AlreadyEnrolledException(String studentName, String courseName){
+        super(String.format("%s is already enrolled in '%s'", studentName, courseName));
+        this.studentName = studentName;
+        this.courseName = courseName;
+    }
+
+    public String getStudentName(){return studentName;}
+    public String getCourseName(){return courseName;}
 }

task-1/com.hyfacademy/exception/CourseFullException.java

@@ -1,4 +1,15 @@
 package com.hyfacademy.exception;
 
-public class CourseFullException {
+public class CourseFullException extends EnrolmentException{
+    private final String courseName;
+    private final int maxCapacity;
+
+    public CourseFullException(String courseName, int maxCapacity){
+        super(String.format("Course '%s' is full (max: %d students)", courseName, maxCapacity));
+        this.courseName = courseName;
+        this.maxCapacity = maxCapacity;
+    }
+
+    public String getCourseName(){return courseName;}
+    public int getMaxCapacity(){return maxCapacity;}
 }

task-1/com.hyfacademy/exception/EnrolmentException.java

@@ -1,4 +1,7 @@
 package com.hyfacademy.exception;
 
-public class EnrolmentException {
+public class EnrolmentException extends RuntimeException {
+    public EnrolmentException(String message){
+        super(message);
+    }
 }

task-1/com.hyfacademy/exception/InvalidProgressException.java

@@ -1,4 +1,14 @@
 package com.hyfacademy.exception;
 
-public class InvalidProgressException {
-}
+public class InvalidProgressException extends EnrolmentException{
+    private final int attemptedValue;
+
+    public InvalidProgressException(int attemptedValue){
+        super(String.format("Progress must be between 0 and 100, but received: %d", attemptedValue));
+        this.attemptedValue = attemptedValue;
+    }
+
+    public int getAttemptedValue(){return attemptedValue;}
+
+
+}

task-1/com.hyfacademy/model/Course.java

@@ -1,4 +1,143 @@
 package com.hyfacademy.model;
 
-public class Course {
+import com.hyfacademy.exception.AlreadyEnrolledException;
+import com.hyfacademy.exception.CourseFullException;
+import com.hyfacademy.exception.EnrolmentException;
+import com.hyfacademy.exception.InvalidProgressException;
+import com.hyfacademy.service.Enrollable;
+
+public abstract class Course implements Enrollable {
+    private final String courseName;
+    private final String courseId;
+    private final int maxStudents;
+    private final int[] studentProgress;
+    private final Student[] enrolledStudent;
+
+    private int enrolledCount = 0;
+    private static int courseCounter = 0;
+
+    private static final int BAR_BLOCKS = 10;
+    public static final int MIN_PROGRESS = 0;
+   public static final int MAX_PROGRESS = 100;
+
+
+
+    public Course(String courseName, int maxStudents){
+        this.courseName = courseName;
+        this.maxStudents = maxStudents;
+        this.courseId = generateCourseId();
+
+        this.studentProgress = new int[maxStudents];
+        this.enrolledStudent = new Student[maxStudents];
+    }
+
+    public String getCourseName(){return courseName;}
+    public int getMaxStudents(){return maxStudents;}
+    public String getCourseId(){return courseId;}
+    public int getEnrolledCount(){return enrolledCount;}
+    public Student[] getEnrolledStudent(){return enrolledStudent;}
+
+    public abstract String getCourseType();
+    public abstract String getScheduleInfo();
+
+    @Override
+    public String toString(){
+        return String.format("[%s] %s (%s) | Enrolled: %d/%d",
+                courseId, courseName, getCourseType(), enrolledCount, maxStudents );
+    }
+
+    public void enrol(Student student){
+        if(isFull()){
+            throw new CourseFullException(courseName, maxStudents);
+        }
+
+        for(Course c : student.getCourses()){
+            if(c !=null && c.equals(this)){
+                throw new AlreadyEnrolledException(student.getName(), courseName);
+            }
+        }
+
+            student.enrol(this);
+
+        enrolledStudent[enrolledCount] = student;
+        studentProgress[enrolledCount] = 0;
+
+        enrolledCount ++;
+    }
+
+    public void updateProgress(Student student, int progress){
+        if(progress < MIN_PROGRESS || progress > MAX_PROGRESS){
+            throw new InvalidProgressException(progress);
+        }
+
+        for ( int i = 0; i < enrolledCount; i++){
+            if(enrolledStudent[i].getUserId().equals(student.getUserId())){
+                studentProgress[i] = progress;
+                return;
+            }
+        }
+        throw new EnrolmentException(String.format(
+                "%s doesn't enroll in course %s", student.getName(), courseName));
+    }
+
+    public int getStudentProgress(Student student) {
+        for (int i = 0; i < enrolledCount; i++) {
+            if (enrolledStudent[i].getUserId().equals(student.getUserId())) {
+                return studentProgress[i];
+            }
+        }
+        throw new EnrolmentException(String.format(
+                "%s doesn't enroll in course %s", student.getName(), courseName));
+    }
+
+    public boolean isFull(){
+        return enrolledCount == maxStudents;
+    }
+
+    public String getProgressBar(Student student){
+        int filledBlocks = (int) Math.round((float) getStudentProgress(student) / BAR_BLOCKS);
+
+        StringBuilder bar = new StringBuilder();
+
+        for(int i=0; i < BAR_BLOCKS; i++){
+            if(i < filledBlocks){
+                bar.append("█");
+            } else {
+                bar.append("░");
+            }
+        }
+        return bar.toString();
+    }
+
+    public String studentReportListProgress(){
+        StringBuilder sb = new StringBuilder();
+
+        for (int i=0; i < getEnrolledCount(); i++){
+            Student s = getEnrolledStudent()[i];
+            int progress = getStudentProgress(s);
+
+            sb.append(String.format("  %-6s %-13s %3d%% %s%n",
+                    s.getUserId(), s.getName(), progress, getProgressBar(s)));
+        }
+
+        return sb.toString();
+    }
+
+    public double getAverageCourseProgress(){
+        int totalStudentsProgress = 0;
+
+        if (getEnrolledCount() == 0) return 0;
+
+        Student[] students = getEnrolledStudent();
+        for(int i=0; i < getEnrolledCount(); i++){
+            totalStudentsProgress += getStudentProgress(students[i]);
+        }
+
+        return (double) totalStudentsProgress / getEnrolledCount();
+    }
+
+    public static String generateCourseId(){
+        courseCounter ++;
+        return String.format("CRS-%03d", courseCounter);
+    };
 }

task-1/com.hyfacademy/model/LiveCohortCourse.java

@@ -1,4 +1,59 @@
 package com.hyfacademy.model;
 
-public class LiveCohortCourse {
+import com.hyfacademy.service.Reportable;
+
+public class LiveCohortCourse extends Course implements Reportable {
+    private final String startDate;
+    private final String endDate;
+    private Mentor mentor;
+
+    public LiveCohortCourse(String courseName, int maxStudents, String startDate, String endDate){
+        super(courseName, maxStudents);
+        this.startDate = startDate;
+        this.endDate = endDate;
+    }
+
+    public String getStartDate(){return startDate;}
+    public String getEndDate(){return endDate;}
+    public Mentor getMentor(){return mentor;}
+
+    @Override
+    public String getCourseType() {
+        return "Live Cohort";
+    }
+
+    @Override
+    public String getScheduleInfo(){
+        return String.format("%s to %s | Mentor: %s",
+                startDate, endDate, mentor != null? mentor.getName() : "TBA");
+    }
+
+    public void assignMentor(Mentor mentor){
+        this.mentor = mentor;
+        mentor.assignToCourse(this);
+    }
+
+    @Override
+    public String generateReport() {
+        StringBuilder sb = new StringBuilder();
+
+        sb.append("══════════════════════════════════════════\n");
+        sb.append("  COURSE REPORT — Live Cohort\n");
+        sb.append("══════════════════════════════════════════\n");
+        sb.append(String.format("  %-12s : %s%n", "ID", getCourseId()));
+        sb.append(String.format("  %-12s : %s%n", "Name", getCourseName()));
+        sb.append(String.format("  %-12s : %s to %s%n", "Schedule", startDate, endDate));
+        sb.append(String.format("  %-12s : %s%n", "Mentor", mentor != null? mentor.getName() : "TBA" ));
+        sb.append(String.format("  %-12s : %s%n", "Capacity", capacityStatus()));
+        sb.append("──────────────────────────────────────────\n");
+        sb.append("  STUDENT PROGRESS\n");
+        sb.append("──────────────────────────────────────────\n");
+        sb.append(studentReportListProgress());
+        sb.append("──────────────────────────────────────────\n");
+        sb.append(String.format("  %-10s : %.0f%%%n", "Avg Progress", getAverageCourseProgress()));
+        sb.append("══════════════════════════════════════════\n");
+
+        return sb.toString();
+    }
+
 }

task-1/com.hyfacademy/model/Mentor.java

@@ -1,4 +1,46 @@
 package com.hyfacademy.model;
 
-public class Mentor {
+import com.hyfacademy.exception.EnrolmentException;
+
+public class Mentor extends User {
+    private static final int MAX_ASSIGNED_COURSES = 3;
+    private final String expertise;
+    private final Course[] assignedCourses = new Course[MAX_ASSIGNED_COURSES];
+
+    private int courseCounter = 0;
+    private static int mentorCounter = 0;
+
+    public Mentor(String name, String email, String expertise){
+        super(name, email, generateMentorId());
+        this.expertise = expertise;
+    }
+
+    public String getExpertise(){return expertise;}
+    public Course[] getAssignedCourses(){return assignedCourses;}
+
+    @Override
+    public String getRole(){return "MENTOR";}
+
+   public void assignToCourse(Course course){
+        if(courseCounter == MAX_ASSIGNED_COURSES){
+            throw new EnrolmentException(
+                    String.format("Mentor %s cannot be assigned to more than 3 courses", getName())
+            );
+        }
+
+        for(Course c : assignedCourses){
+            if(c!=null && c.equals(course)){
+                throw new EnrolmentException(
+                        String.format("Mentor %s has already been assigned to %s course", getName(), course.getCourseName()));
+            }
+        }
+
+        assignedCourses[courseCounter] = course;
+        courseCounter++;
+   }
+
+    public static String generateMentorId(){
+        mentorCounter ++;
+        return String.format("COA-%03d", mentorCounter);
+    }
 }

task-1/com.hyfacademy/model/SelfPacedCourse.java

@@ -1,4 +1,47 @@
 package com.hyfacademy.model;
 
-public class SelfPacedCourse {
+import com.hyfacademy.service.Reportable;
+
+public class SelfPacedCourse extends Course implements Reportable {
+    private final int estimatedHours;
+
+    public SelfPacedCourse(String courseName, int maxStudents, int estimateHours){
+        super(courseName, maxStudents);
+        this.estimatedHours = estimateHours;
+    }
+
+    public int getEstimateHours(){return estimatedHours;}
+
+    @Override
+    public String getCourseType(){
+        return "Self-Paced";
+    };
+
+   @Override
+    public String getScheduleInfo(){
+        return String.format("Estimated: %d hours — complete at your own pace", estimatedHours);
+    };
+
+   @Override
+    public String generateReport() {
+       StringBuilder sb = new StringBuilder();
+
+        sb.append("══════════════════════════════════════════\n");
+        sb.append("  COURSE REPORT — Self-Paced\n");
+        sb.append("══════════════════════════════════════════\n");
+        sb.append(String.format("  %-12s : %s%n", "ID", getCourseId()));
+        sb.append(String.format("  %-12s : %s%n", "Name", getCourseName()));
+        sb.append(String.format("  %-12s : %s%n", "Capacity", capacityStatus()));
+        sb.append(String.format("  %-12s : %s%n", "Est. Hours", estimatedHours));
+        sb.append("──────────────────────────────────────────\n");
+        sb.append("  STUDENT PROGRESS\n");
+        sb.append("──────────────────────────────────────────\n");
+        sb.append(studentReportListProgress());
+        sb.append("──────────────────────────────────────────\n");
+
+        sb.append(String.format("  %-10s : %.2f%%%n", "Avg Progress", getAverageCourseProgress()));
+        sb.append("══════════════════════════════════════════\n");
+
+        return sb.toString();
+    }
 }