ex-oop-01-pupil/Pupils/Pupil.cs

using System.Security.Principal;

namespace Pupils;

public class Pupil
{
    private static int _nextId;
    private readonly DateOnly _dateOfBirth;
    private int? _zipCode;
    private readonly string Name;

    /// <summary>
    /// Gets the age of the pupil.
    /// </summary>
    public int Age
    {
        get
        {
            var today = DateOnly.FromDateTime(DateTime.Today);
            var age = today.Year - _dateOfBirth.Year;
            if (today < _dateOfBirth.AddYears(age))
            {
                age--;
            }
            return age;
        }
    }

    /// <summary>
    /// Gets or sets the ZIP code of the pupil.
    /// </summary>
    /// <remarks>
    /// The ZIP code must be between 1000 and 9999 inclusive.
    /// </remarks>
    public int? ZipCode
    {
        get
        {
            return _zipCode;
        }

        set
        {
            if (value >= 1000 && value <= 9999)
            {
                _zipCode = value;
            }
        }
    }

    /// <summary>
    /// Gets the first name of the pupil.
    /// </summary>
    public string FirstName
    {
        get
        {
            string firstName = "";
            for (int i = 0; i < Name.Length; i++)
            {
                if (!String.IsNullOrWhiteSpace(char.ToString(Name[i])))
                {
                    firstName += Name[i];
                }
                else
                {
                    return firstName;
                }
            }
            return firstName;
        }
    }

    /// <summary>
    /// Gets the last name of the pupil.
    /// </summary>
    public string LastName
    {
        get
        {
            string lastName = "";
            for (int i = Name.Length - 1; i > 0; i--)
            {
                if (!String.IsNullOrWhiteSpace(char.ToString(Name[i])))
                {
                    lastName = Name[i] + lastName;
                }
                else
                {
                    return lastName;
                }
            }
            return lastName;
        }
    }

    /// <summary>
    /// Gets the unique ID of the pupil.
    /// </summary>
    public int Id { get; }

    /// <summary>
    /// Initializes a new instance of the <see cref="Pupil"/> class.
    /// </summary>
    /// <param name="firstName">The first name of the pupil.</param>
    /// <param name="lastName">The last name of the pupil.</param>
    /// <param name="dateOfBirth">The date of birth of the pupil.</param>
    public Pupil(string firstName, string lastName, DateOnly dateOfBirth)
    {
        Id = ++_nextId;
        Name = $"{firstName} {lastName}";
        _dateOfBirth = dateOfBirth;
    }

    /// <summary>
    /// Determines whether the pupil is of a specified age type.
    /// </summary>
    /// <param name="ageType">The age type to check.</param>
    /// <returns><c>true</c> if the pupil is of the specified age type; otherwise, <c>false</c>.</returns>
    public bool IsOfAge(AgeType ageType)
    {
        int requiredAge;

        switch (ageType)
        {
            case AgeType.VotingAge:
                requiredAge = 16;
                break;
            case AgeType.FullAge:
                requiredAge = 18;
                break;
            case AgeType.RetirementAge:
                requiredAge = 65;
                break;
            default:
                return false;
        }

        return Age >= requiredAge;
    }

    /// <summary>
    /// Determines whether the current pupil is older than another pupil.
    /// </summary>
    /// <param name="other">The other pupil to compare with.</param>
    /// <returns><c>true</c> if the current pupil is older than the other pupil; otherwise, <c>false</c>.</returns>
    public bool IsOlderThan(Pupil other)
    {
        return Age > other.Age;
    }

    /// <summary>
    /// Determines whether the current pupil lives nearby another pupil.
    /// </summary>
    /// <param name="other">The other pupil to compare with.</param>
    /// <returns><c>true</c> if the first two digits of the ZIP codes match; otherwise, <c>false</c>.</returns>
    public bool LivesNearby(Pupil other)
    {
        if (ZipCode == null || other.ZipCode == null)
        {
            return false;
        }

        string thisZipPrefix = ZipCode.Value.ToString().Substring(0, 2);
        string otherZipPrefix = other.ZipCode.Value.ToString().Substring(0, 2);

        return thisZipPrefix == otherZipPrefix;
    }
}