package com.mail.lenka949;

import java.util.TreeSet;

public class Group {

	private TreeSet<Student> students = new TreeSet<Student>(new StudentComporator());
	private int num = 0;

	public Group() {
		super();
	}

	public void addStudent(Student student) {
		students.add(student);
	}

	public void removeStudent(Student student) {
		if (students.contains(student)) {
			students.remove(student);
		} else {
			System.out.println("The student is not found in this group");
			return;
		}
	}

	public Student getStudentByName(String lastName) {
		Student st = students.stream().filter(lastName::equals).findFirst().orElse(null);
		return st;
	}

	public String genListByChar(char c) {
		StringBuffer sb = new StringBuffer();
		sb.append("Group:").append(c).append(System.lineSeparator());
		students.stream().filter(n -> n.getLastName().charAt(0) == c)
				.forEachOrdered(n -> sb.append(getNextNum()).append(n).append(System.lineSeparator()));
		this.num = 0;
		return sb.toString();
	}

	public Group genGroupByChar(char c) {
		Group newGroup = new Group();
		students.stream().filter(n -> n.getLastName().charAt(0) == c)
		.forEachOrdered(n -> newGroup.addStudent(n));
		return newGroup;
	}

	private String getNextNum(){
		this.num = num + 1;
		return num + ") ";
	}

	@Override
	public String toString() {
		StringBuffer sb = new StringBuffer();
		sb.append("Group:").append(System.lineSeparator());
		students.stream().forEachOrdered(n -> sb.append(getNextNum()).append(n).append(System.lineSeparator()));
		this.num = 0;
		return sb.toString();
	}

}