03. Classroom(only class classroom) / C# Advanced Exam - 25 October 2020

using System;
using System.Collections.Generic;
using System.Dynamic;
using System.Linq;
using System.Reflection.Metadata.Ecma335;
using System.Security.Cryptography.X509Certificates;
using System.Text;

namespace ClassroomProject
{
    public class Classroom
    {
        public Classroom(int capacity)
        {
            this.Capacity = capacity;
            this.AllStudents = new List<Student>(capacity);
        }
        public int Capacity { get; set; }
        public List<Student> AllStudents { get; set; }
        public int Count => AllStudents.Count;

        //Method RegisterStudent(Student student) – adds an entity to the students if there is an empty seat for the student.
        //Returns "Added student {firstName} {lastName}" if the student is successfully added
        //Returns "No seats in the classroom" – if there are no more seats in the classroom

        public string RegisterStudent(Student student)
        {
            if (this.Capacity > this.Count)
            {
                AllStudents.Add(student);
                return $"Added student {student.FirstName} {student.LastName}";
            }
            return "No seats in the classroom";
        }
        // Method DismissStudent(string firstName, string lastName) – removes the student by the given names
        // Returns "Dismissed student {firstName} {lastName}" if the student is successfully dismissed
        // Returns "Student not found" if the student is not in the classroom
        public string DismissStudent(string firstName, string lastName)
        {
            if (AllStudents.Any(x => x.FirstName == firstName && x.LastName == lastName))
            {
                var removedStudent = AllStudents.FirstOrDefault(x => x.FirstName == firstName && x.LastName == lastName);
                AllStudents.Remove(removedStudent);
                return $"Dismissed student {removedStudent?.FirstName} {removedStudent?.LastName}";
            }
            return "Student not found";
        }
        //•   Method GetSubjectInfo(string subject) – returns all the students with the given subject in the following format:
        //"Subject: {subjectName}
        //Students:
        //{firstName {lastName}
        //{ firstName} { lastName}"
        public string GetSubjectInfo(string subject)
        {
            if (AllStudents.Any(s => s.Subject == subject))
            {
                StringBuilder result = new StringBuilder();

                result.AppendLine($"Subject: {subject}");
                result.AppendLine("Students:");

                foreach (var student in AllStudents.Where(student => student.Subject == subject))
                {
                    result.AppendLine($"{student.FirstName} {student.LastName}");
                }

                return result.ToString().TrimEnd();
            }
            return "No students enrolled for the subject";
        }
        //•   Method GetStudentsCount() – returns the count of the students in the classroom.
        public string GetStudentsCount()
        {
            return $"{AllStudents.Count}";
        }
        //•   Method GetStudent(string firstName, string lastName) – returns the student with the given names.
        public Student GetStudent(string firstName, string lastName)
        {
            var student = AllStudents.FirstOrDefault(x => x.FirstName == firstName && x.LastName == lastName);
            return student;
        }

    }
}