public static IEnumerable<User> GetUsers(
    PrincipalContext principalContext)
{
    var users = new List<User>();
    using (var up = new UserPrincipal(principalContext))
    {
        using (var ps = new PrincipalSearcher(up))
        {
            using (var psr = ps.FindAll())
            {
                users.AddRange(
                    from UserPrincipal u in psr select new User(u));
            }
        }
    }

    return users;
}

public class User : AuthenticablePrincipalWrapper, IUserPrincipal,
    IUserDirectoryEntry
{
    private static readonly PrincipalContext PrincipalContext =
        new PrincipalContext(ContextType.Domain);

    public User(UserPrincipal userPrincipal)
        : base(userPrincipal)
    {
        EmailAddress = userPrincipal.EmailAddress;
        EmployeeId = userPrincipal.EmployeeId;
        GivenName = userPrincipal.GivenName;
        MiddleName = userPrincipal.MiddleName;
        Surname = userPrincipal.Surname;
        VoiceTelephoneNumber = userPrincipal.VoiceTelephoneNumber;
        UserCannotChangePassword = userPrincipal.UserCannotChangePassword;
        Assistant = userPrincipal.GetAssistant();
        City = userPrincipal.GetCity();
        Comment = userPrincipal.GetComment();
        Company = userPrincipal.GetCompany();
        Country = userPrincipal.GetCountry();
        Department = userPrincipal.GetDepartment();
        DirectReports = GetDirectReports(userPrincipal);
        Division = userPrincipal.GetDivision();
        Fax = userPrincipal.GetFax();
        HomeAddress = userPrincipal.GetHomeAddress();
        HomePhone = userPrincipal.GetHomePhone();
        Initials = userPrincipal.GetInitials();
        IsActive = userPrincipal.IsActive();
        Manager = GetManager(userPrincipal);
        Mobile = userPrincipal.GetMobile();
        Notes = userPrincipal.GetNotes();
        Pager = userPrincipal.GetPager();
        Sip = userPrincipal.GetSip();
        State = userPrincipal.GetState();
        StreetAddress = userPrincipal.GetStreetAddress();
        Suffix = userPrincipal.GetSuffix();
        Title = userPrincipal.GetTitle();
        Voip = userPrincipal.GetVoip();
    }

    public string Assistant { get; set; }
    public string City { get; set; }
    public string Comment { get; set; }
    public string Company { get; set; }
    public string Country { get; set; }
    public string Department { get; set; }
    public IEnumerable<User> DirectReports { get; set; }
    public string Division { get; set; }
    public string EmailAddress { get; set; }
    public string EmployeeId { get; set; }
    public string Fax { get; set; }
    public string GivenName { get; set; }
    public string HomeAddress { get; set; }
    public string HomePhone { get; set; }
    public string Initials { get; set; }
    public bool IsActive { get; set; }
    public User Manager { get; set; }
    public string MiddleName { get; set; }
    public string Mobile { get; set; }
    public string Notes { get; set; }
    public string Pager { get; set; }
    public string Sip { get; set; }
    public string State { get; set; }
    public string StreetAddress { get; set; }
    public string Suffix { get; set; }
    public string Surname { get; set; }
    public string Title { get; set; }
    public bool UserCannotChangePassword { get; set; }
    public string VoiceTelephoneNumber { get; set; }
    public string Voip { get; set; }

    private static UserPrincipal FindUser(string distinguishedName)
    {
        return UserPrincipal.FindByIdentity(
            PrincipalContext, IdentityType.DistinguishedName,
            distinguishedName);
    }

    private static IEnumerable<User> GetDirectReports(
        UserPrincipal userPrincipal)
    {
        var directReports = new List<User>();
        foreach (var directReportDistinguishedName in
            userPrincipal.GetDirectReportDistinguishedNames())
        {
            using (var directReportUserPrincipal =
                FindUser(directReportDistinguishedName))
            {
                directReports.Add(new User(directReportUserPrincipal));
            }
        }
        return directReports;
    }

    private static User GetManager(UserPrincipal userPrincipal)
    {
        using (var managerUserPrincipal =
            FindUser(userPrincipal.GetManager()))
        {
            return new User(managerUserPrincipal);
        }
    }
}

public class AuthenticablePrincipalWrapper : PrincipalWrapper,
    IAuthenticablePrincipal
{
    protected AuthenticablePrincipalWrapper(
        AuthenticablePrincipal authenticablePrincipal)
        : base(authenticablePrincipal)
    {
        AccountExpirationDate =
            authenticablePrincipal.AccountExpirationDate;

        AccountLockoutTime = authenticablePrincipal.AccountLockoutTime;

        AllowReversiblePasswordEncryption =
            authenticablePrincipal.AllowReversiblePasswordEncryption;

        BadLogonCount = authenticablePrincipal.BadLogonCount;
        Certificates = authenticablePrincipal.Certificates;
        DelegationPermitted = authenticablePrincipal.DelegationPermitted;
        Enabled = authenticablePrincipal.Enabled;
    }

    public DateTime? AccountExpirationDate { get; set; }
    public DateTime? AccountLockoutTime { get; set; }
    public bool AllowReversiblePasswordEncryption { get; set; }
    public int BadLogonCount { get; set; }
    public X509Certificate2Collection Certificates { get; set; }
    public bool? DelegationPermitted { get; set; }
    public bool? Enabled { get; set; }
    public string HomeDirectory { get; set; }
    public string HomeDrive { get; set; }
    public DateTime? LastBadPasswordAttempt { get; set; }
    public DateTime? LastLogon { get; set; }
    public DateTime? LastPasswordSet { get; set; }
    public bool PasswordNeverExpires { get; set; }
    public bool PasswordNotRequired { get; set; }
    public byte[] PermittedLogonTimes { get; set; }

    public PrincipalValueCollection<string> PermittedWorkstations { get;
        set; }

    public string ScriptPath { get; set; }
    public bool SmartCardLogonRequired { get; set; }
}

public class PrincipalWrapper : IPrincipal
{
    protected PrincipalWrapper(Principal principal)
    {
        Context = principal.Context;
        ContextType = principal.ContextType;
        Description = principal.Description;
        DisplayName = principal.DisplayName;
        DistinguishedName = principal.DistinguishedName;
        Guid = principal.Guid;
        Name = principal.Name;
        SamAccountName = principal.SamAccountName;
        StructuralObjectClass = principal.StructuralObjectClass;
        UserPrincipalName = principal.UserPrincipalName;
    }

    public PrincipalContext Context { get; set; }
    public ContextType ContextType { get; set; }
    public string Description { get; set; }
    public string DisplayName { get; set; }
    public string DistinguishedName { get; set; }
    public Guid? Guid { get; set; }
    public string Name { get; set; }
    public string SamAccountName { get; set; }
    public string StructuralObjectClass { get; set; }
    public string UserPrincipalName { get; set; }

    public override string ToString()
    {
        return Name;
    }
}