ln.identities/AssignedRoles.cs

using System;
using System.Collections;
using System.Collections.Generic;
namespace ln.identities
{
    public class AssignedRoles : IEnumerable<AssignedRole>
    {
        IIdentityProvider identityProvider;
        public IIdentityProvider IdentityProvider => identityProvider;

        Dictionary<Guid, AssignedRole> assignedRoles = new Dictionary<Guid, AssignedRole>();

        public AssignedRoles(IIdentityProvider identityProvider)
        {
            this.identityProvider = identityProvider;
        }

        public AssignedRole this[Identity identity]
        {
            get
            {
                if (!assignedRoles.ContainsKey(identity.UniqueID))
                {
                    assignedRoles.Add(identity.UniqueID, new AssignedRole(identityProvider, identity));
                }
                return assignedRoles[identity.UniqueID];
            }
        }
        public AssignedRole this[Guid identityUniqueID]
        {
            get
            {
                if (!assignedRoles.ContainsKey(identityUniqueID))
                {
                    if (identityUniqueID.Equals(Guid.Empty))
                        assignedRoles.Add(identityUniqueID, new AssignedRole(identityProvider, Identity.Anonymous(identityProvider)));
                    else
                        throw new KeyNotFoundException();
                }
                return assignedRoles[identityUniqueID];
            }
        }

        public bool HasRole(Role role) => HasRole(null, role);
        public bool HasRole(Identity identity, Role role) => HasRole(identity?.UniqueID ?? Guid.Empty, role);
        public bool HasRole(Guid identityUniqueID, Role role)=> (this[identityUniqueID].Role & role) == role;

        public IEnumerator<AssignedRole> GetEnumerator()
        {
            return assignedRoles.Values.GetEnumerator();
        }

        IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
    }
}