Yusup R.

task-1/com.hyfacademy/Main.java

@@ -1,7 +1,9 @@
 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) {
+        new PlatformService().run();
     }
-}
+}

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

@@ -1,4 +1,16 @@
 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 enroled 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 +1,11 @@
 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 +1,76 @@
 package com.hyfacademy.model;
 
-public class Course {
+import com.hyfacademy.exception.*;
+import com.hyfacademy.service.Enrollable;
+
+public abstract class Course implements Enrollable {
+    private static int idCounter = 1;
+
+    private final String courseName;
+    private final String courseId;
+    private final int maxStudents;
+    protected int enrolledCount;
+    protected Student[] enrolledStudents;
+    protected int[] studentProgress;
+
+    public Course(String courseName, int maxStudents){
+        this.courseName = courseName;
+        this.maxStudents = maxStudents;
+        this.courseId = String.format("CRS-%03d", idCounter++);
+        this.enrolledStudents = new Student[maxStudents];
+        this.studentProgress = new int[maxStudents];
+    }
+
+    public String getCourseName() { return courseName; }
+    public String getCourseId() { return courseId; }
+    public int getMaxStudents() { return maxStudents;}
+    public int getEnrolledCount() { return enrolledCount;}
+    public boolean isFull() { return enrolledCount >= maxStudents;}
+
+    @Override
+    public void enrol(Student student){
+        if (isFull())
+            throw new CourseFullException(courseName, maxStudents);
+        if (findStudentIndex(student) >= 0)
+            throw new AlreadyEnrolledException(student.getName(), courseName);
+        enrolledStudents[enrolledCount] = student;
+        studentProgress[enrolledCount] = 0;
+        enrolledCount++;
+    }
+
+    public void updateProgress(Student student, int progress){
+        if (progress <0 || progress >100)
+            throw new InvalidProgressException(progress);
+        int idx = findStudentIndex(student);
+        if (idx <0)
+            throw new EnrolmentException(
+                String.format("Student %s is not enrolled in %s", student.getName(), courseName)
+            );
+        studentProgress[idx] = progress;
+    }
+
+    public int getStudentProgress(Student student){
+        int idx = findStudentIndex(student);
+        if (idx <0)
+            throw new EnrolmentException(
+                String.format("Student %s is not enroled in %s", student.getName(), courseName)
+            );
+        return studentProgress[idx];
+    }
+
+    private int findStudentIndex(Student student){
+        for (int i = 0; i < enrolledCount; i++){
+            if (enrolledStudents[i].getUserId().equals(student.getUserId())) return i;
+        }
+        return -1;
+    }
+
+    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);
+    }
 }

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

@@ -1,4 +1,77 @@
 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 name, int maxStudents, String startDate, String endDate){
+        super(name, maxStudents);
+        this.startDate = startDate;
+        this.endDate = endDate;
+    }
+
+    public String getStartDate(){ return startDate;}
+    public String getEndDate(){ return endDate;}
+    public Mentor getMentor() { return mentor;}
+
+    public void assignMentor(Mentor mentor){
+        this.mentor = mentor;
+        mentor.assignToCourse(this);
+    }
+
+    @Override
+    public String getCourseType(){ return "Live Cohort";}
+
+    @Override
+    public String getScheduleInfo(){
+        String name = mentor != null? mentor.getName() : "TBD";
+        return String.format("%s to %s | Mentor: %s", startDate, endDate, name);
+
+    }
+
+    @Override
+    public String generateReport(){
+        String eq = "══════════════════════════════════════════";
+        String bq = "──────────────────────────────────────────";
+        String dq = "══════════════════════════════════════════";
+        StringBuilder sb = new StringBuilder();
+        sb.append(eq).append("\n");
+        sb.append("COURSE REPORT - Live Cohort\n");
+        sb.append(eq).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", "Schedule", getScheduleInfo()));
+        sb.append(dq).append("\n");
+        sb.append(" STUDENT PROGRESS\n");
+        sb.append(dq).append("\n");
+        int total = 0;
+        for (int i = 0; i < enrolledCount; i++){
+            int pct = studentProgress[i];
+            total += pct;
+            sb.append(String.format(" %-9s %-20s %3d%% %s%n",
+                enrolledStudents[i].getUserId(),
+                enrolledStudents[i].getName(),
+                pct,
+                progressBar(pct)
+
+            ));
+        }
+        sb.append(dq).append("\n");
+        int avg = enrolledCount > 0 ? total / enrolledCount : 0;
+        sb.append(String.format(" Avg Progress : %d%%%n", avg));
+        sb.append(eq);
+        return sb.toString();
+    }
+
+    private static String progressBar(int percent){
+        int filled = Math.round(percent / 10.0f);
+        StringBuilder bar = new StringBuilder();
+        for (int i = 0; i < 10; i++) bar.append(i < filled ? '█' : '░');
+        return bar.toString();
+    }
+
 }

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

@@ -1,4 +1,30 @@
 package com.hyfacademy.model;
 
-public class Mentor {
+import com.hyfacademy.exception.EnrolmentException;
+
+public class Mentor extends User{
+    private static int idCounter = 1;
+
+    private final String expertise;
+    private final Course[] assignedCourses = new Course[3];
+    private int courseCount;
+
+    public Mentor(String name, String email, String expertise){
+        super(name, email, String.format("COA-%03d", idCounter++));
+        this.expertise = expertise;
+    }
+
+    @Override
+    public String getRole(){ return "MENTOR";}
+
+    public void assignToCourse(Course course){
+        if (courseCount == assignedCourses.length)
+            throw new EnrolmentException(
+                getName() + " is already assigned to the maximum number of courses"
+            );
+        assignedCourses[courseCount++] = course;
+    }
+
+    public Course[] getAssignedCourses(){ return assignedCourses;}
+    public String getExpertise() { return expertise;}
 }

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

@@ -1,4 +1,64 @@
 package com.hyfacademy.model;
 
-public class SelfPacedCourse {
+import com.hyfacademy.service.Reportable;
+
+public class SelfPacedCourse extends Course implements Reportable {
+    private final int estimateHours;
+
+    public SelfPacedCourse(String name, int maxStudents, int estimateHours){
+        super(name, maxStudents);
+        this.estimateHours = estimateHours;
+    }
+
+    public int getEstimatedHours(){ return estimateHours;}
+
+    @Override
+    public String getCourseType(){ return "Self-Paced";}
+
+    @Override
+    public String getScheduleInfo(){
+        return String.format("Estimated: %d hours - complete at your own pace", estimateHours);
+    }
+
+    @Override
+    public String generateReport(){
+        String eq = "══════════════════════════════════════════";
+        String bq = "──────────────────────────────────────────";
+        String dq = "══════════════════════════════════════════";
+        StringBuilder sb = new StringBuilder();
+        sb.append(eq).append("\n");
+        sb.append("COURSE REPORT - Self-Paced\n");
+        sb.append(eq).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", getEstimatedHours()));
+        sb.append(dq).append("\n");
+        sb.append(" STUDENT PROGRESS\n");
+        sb.append(dq).append("\n");
+        int total = 0;
+        for (int i = 0; i < enrolledCount; i++){
+            int pct = studentProgress[i];
+            total += pct;
+            sb.append(String.format(" %-9s %-20s %3d%% %s%n",
+                enrolledStudents[i].getUserId(),
+                enrolledStudents[i].getName(),
+                pct,
+                progressBar(pct)
+
+            ));
+        }
+        sb.append(dq).append("\n");
+        int avg = enrolledCount > 0 ? total / enrolledCount : 0;
+        sb.append(String.format(" Avg Progress : %d%%%n", avg));
+        sb.append(eq);
+        return sb.toString();
+    }
+
+    private static String progressBar(int percent){
+        int filled = Math.round(percent / 10.0f);
+        StringBuilder bar = new StringBuilder();
+        for (int i = 0; i < 10; i++) bar.append(i < filled ? '█' : '░');
+        return bar.toString();
+    }
 }

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

@@ -1,4 +1,38 @@
 package com.hyfacademy.model;
 
-public class Student {
+import com.hyfacademy.exception.*;
+
+public class Student extends User {
+    private static int idCounter = 1;
+
+    private final Course[] enrolledCourses = new Course[5];
+    private int courseCount;
+
+    public Student(String name, String email){
+        super(name, email, String.format("STU-%03d", idCounter++));
+    }
+
+    @Override
+    public String getRole(){return "STUDENT";}
+
+    public void enrol(Course course){
+       if (courseCount == enrolledCourses.length)
+            throw new EnrolmentException(getName() + " cannot enrol in more than 5 courses");
+       for (int i =0; i < courseCount; i++){
+            if (enrolledCourses[i].getCourseId().equals(course.getCourseId()))
+                throw new AlreadyEnrolledException(getName(), course.getCourseName());
+       }
+       course.enrol(this);
+       enrolledCourses[courseCount++] = course; 
+    }
+
+    public int getProgress(String courseName){
+        for(int i = 0; i < courseCount; i++){
+            if (enrolledCourses[i].getCourseName().equals(courseName))
+                return enrolledCourses[i].getStudentProgress(this);
+        }
+        throw new EnrolmentException(String.format("%s is not enrolled in '%s'", getName(), courseName));
+    }
+    public Course[] getCourses() {return enrolledCourses;}
+    public int getCourseCount() {return courseCount;}
 }

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

@@ -1,4 +1,26 @@
 package com.hyfacademy.model;
 
-public class User {
+public abstract class User {
+    private final String name;
+    private final String email;
+    private final String userId;
+
+    public User(String name, String email, String userId){
+        this.name = name;
+        this.email = email;
+        this.userId = userId;
+    }
+
+    public String getName(){return name;}
+    public String getEmail(){return email;}
+    public String getUserId(){return userId;}
+
+    public abstract String getRole();
+
+    public String getSummary(){
+        return String.format("[%s] %s | %s", getRole(), name, email);
+    }
+
+    @Override
+    public String toString(){return getSummary();}
 }