using System;
using System.Collections.Generic;
using System.Linq;

namespace ln.identities
{
    public abstract class BaseIdentityProvider : IIdentityProvider
    {
        public BaseIdentityProvider()
        {
        }

        public virtual Identity Authenticate(AuthenticationProve authenticationProve)
        {
            Identity identity = GetIdentity(authenticationProve.IdentityName);
            if (identity == null)
                throw new KeyNotFoundException();

            SecureAttribute secureAttribute = identity.GetSecureAttribute(authenticationProve.SecureAttributeUniqueID);
            if (secureAttribute.Authenticate(authenticationProve.Challenge, authenticationProve.Prove))
            {
                return identity;
            }
            throw new ArgumentOutOfRangeException();
        }

        public abstract Identity CreateIdentity(string identityName);
        public abstract IEnumerable<KeyValuePair<Guid, string>> GetIdentities();
        public abstract Identity GetIdentity(Guid uniqueID);
        public abstract bool Save(Identity identity);

        public virtual Identity GetIdentity(string identityName) => GetIdentity(GetIdentities().FirstOrDefault((kvp) => identityName.Equals(kvp.Value)).Key);

        public abstract IEnumerable<RoleAssignment> GetRoleAssignments(Identity identity);

        public virtual AssignedRoles GetAssignedRoles(Identity identity)
        {
            AssignedRoles assignedRoles = new AssignedRoles(this);
            GetAssignedRoles(identity, assignedRoles);
            return assignedRoles;
        }

        public virtual void GetAssignedRoles(Identity identity,AssignedRoles assignedRoles)
        {
            assignedRoles[identity].Role |= Role.BE;

            foreach (RoleAssignment roleAssignment in identity.RoleAssignments)
            {
                foreach (AssignedRole foreignRole in roleAssignment.EffectiveIdentity.AssignedRoles)
                {
                    if (roleAssignment.Role.HasFlag(Role.IMPERSONATE) || foreignRole.Identity.Equals(roleAssignment.EffectiveIdentity))
                    {
                        AssignedRole currentRole = assignedRoles[foreignRole.Identity];
                        currentRole.Role |= (foreignRole.Role & roleAssignment.Role);
                    }
                }
            }
        }













    }
}