using System;
using System.Collections.Generic;
using System.Configuration;
using EdFi.ADSync.ConsoleApplication.Database;
using LinqToLdap;
using System.Linq;
using log4net;

namespace EdFi.ADSync.ConsoleApplication.ActiveDirectory
{
    public class LinqToLdapUserAccountManager : IUserAccountManager
    {
        private readonly IUserNameGenerator _userNameGenerator;
        private readonly IPasswordGenerator _passwordGenerator;
        private readonly IUserSearchProvider _userSearchProvider;
        private readonly Lazy<DirectoryContext> _directoryContext;

        private readonly ILog _logger = LogManager.GetLogger(typeof(LinqToLdapUserAccountManager));

        public LinqToLdapUserAccountManager(
            IUserNameGenerator userNameGenerator,
            IPasswordGenerator passwordGenerator,
            IUserSearchProvider userSearchProvider,
            Func<DirectoryContext> directoryContextFactory)
        {
            if (directoryContextFactory == null)
                throw new Exception("Directory configuration is required.");

            _directoryContext = new Lazy<DirectoryContext>(directoryContextFactory); ;

            _userNameGenerator = userNameGenerator;
            _passwordGenerator = passwordGenerator;
            _userSearchProvider = userSearchProvider;
        }

        /// <summary>
        /// Creates a new user account using the supplied staff identity.
        /// </summary>
        /// <param name="identity">The identity of the staff member for whom an account is to be created.</param>
        public User CreateUserAccount(StaffEducationOrganizationIdentity identity)
        {
            var userName = _userNameGenerator.GenerateUserName(identity, (username) =>
                !_userSearchProvider.GetUsersByUniqueIds(new[] { identity.StaffUniqueId }).Any()
            );
            var password = _passwordGenerator.GeneratePassword(8);

            var newUser = new User
                        {
                            CommonName = $"{identity.FirstName} {identity.LastSurname}",
                            DistinguishedName = string.Format("CN={0},CN={1},DC={2},DC={3}",
                            identity.FirstName + " " + identity.LastSurname,
                            "Users",
                            "test",
                            "com"),
                            ElectronicMailAddress = identity.ElectronicMailAddress,
                            FirstName = identity.FirstName,
                            LastName = identity.LastSurname,
                            StaffUniqueId = identity.StaffUniqueId,
                            UserName = userName
                            //UserPassword = password
                        };

            _directoryContext.Value.Add(newUser);

            _logger.Info($"User account '{newUser.UserName}' created for staff member '{newUser.CommonName}'.");

            return newUser;
        }

        /// <summary>
        /// Updates an existing user account (if necessary) using the supplied staff identity.
        /// </summary>
        /// <param name="user">The user account to be updated.</param>
        /// <param name="identity">The identity of the staff member associated with the account.</param>
        public void UpdateUserAccount(User user, StaffEducationOrganizationIdentity identity)
        {
            bool firstNameIsDirty = false;
            bool lastNameIsDirty = false;
            bool emailIsDirty = false;

            var userToReport = new User
            {
                FirstName = (user.FirstName = (firstNameIsDirty = !string.Equals(user.FirstName, identity.FirstName))
                                                ? identity.FirstName
                                                : user.FirstName) == identity.FirstName && firstNameIsDirty
                                ? identity.FirstName
                                : string.Empty,
                LastName = (user.LastName = (lastNameIsDirty = !string.Equals(user.LastName, identity.LastSurname))
                                                ? identity.LastSurname
                                                : user.LastName) == identity.LastSurname && lastNameIsDirty
                                ? identity.LastSurname
                                : string.Empty,
                ElectronicMailAddress = (user.ElectronicMailAddress = (emailIsDirty =
                                            !string.Equals(user.ElectronicMailAddress, identity.ElectronicMailAddress))
                                                ? identity.ElectronicMailAddress
                                                : user.ElectronicMailAddress) == identity.ElectronicMailAddress && emailIsDirty
                                ? identity.ElectronicMailAddress
                                : string.Empty
            };

            if (!firstNameIsDirty && !lastNameIsDirty && !emailIsDirty)
                return;

            _directoryContext.Value.Update(user);

            var modifiedProperties = new List<string>();

            if (firstNameIsDirty)
                modifiedProperties.Add("First Name");

            if (lastNameIsDirty)
                modifiedProperties.Add("Last Name");

            if (emailIsDirty)
                modifiedProperties.Add("Email");

            _logger.Info($"User account '{user.UserName}' updated with new values for {string.Join(",", modifiedProperties)}.");
        }
    }
}