using Disco.Data.Repository;
using Disco.Models.Repository;
using Disco.Services.Interop.ActiveDirectory;
using Disco.Services.Plugins;
using Disco.Services.Plugins.Features.DetailsProvider;
using System;
using System.Collections.Generic;
using System.Linq;

namespace Disco.Plugins.ADCompare.Features
{
    [PluginFeature(Id = "ADCompareDetails", Name = "AD Compare Detail Provider", PrimaryFeature = true)]
    public class ADCompareDetailsProvider : DetailsProviderFeature
    {
        private const string DetailsScope = "Details";
        private const string ADCompareScope = "ADCompare";

        /// <summary>
        /// Updates all user details by comparing AD attributes against Disco records.
        /// Stores comparison metadata as UserDetails with ADCompare scope.
        /// </summary>
        public override void UpdateAllDetails(DiscoDataContext database)
        {
            var users = database.Users.ToList();

            foreach (var user in users)
            {
                try
                {
                    var adUser = ActiveDirectory.RetrieveADUserAccount(user.UserId);
                    if (adUser == null)
                    {
                        SetUserDetail(database, user, ADCompareScope, "ADStatus", "NotFound");
                        SetUserDetail(database, user, ADCompareScope, "LastChecked", DateTime.Now.ToString("o"));
                        continue;
                    }

                    // Store comparison results as UserDetails
                    SetUserDetail(database, user, ADCompareScope, "ADStatus", adUser.IsDisabled ? "Disabled" : "Active");
                    SetUserDetail(database, user, ADCompareScope, "LastChecked", DateTime.Now.ToString("o"));

                    // Store AD values for reference
                    SetUserDetail(database, user, ADCompareScope, "AD_DisplayName", adUser.DisplayName ?? string.Empty);
                    SetUserDetail(database, user, ADCompareScope, "AD_Surname", adUser.Surname ?? string.Empty);
                    SetUserDetail(database, user, ADCompareScope, "AD_GivenName", adUser.GivenName ?? string.Empty);
                    SetUserDetail(database, user, ADCompareScope, "AD_Email", adUser.Email ?? string.Empty);
                    SetUserDetail(database, user, ADCompareScope, "AD_Phone", adUser.Phone ?? string.Empty);
                    SetUserDetail(database, user, ADCompareScope, "AD_DistinguishedName", adUser.DistinguishedName ?? string.Empty);

                    // Check for mismatches
                    var mismatches = new List<string>();
                    if (!StringMatch(user.DisplayName, adUser.DisplayName)) mismatches.Add("DisplayName");
                    if (!StringMatch(user.Surname, adUser.Surname)) mismatches.Add("Surname");
                    if (!StringMatch(user.GivenName, adUser.GivenName)) mismatches.Add("GivenName");
                    if (!StringMatch(user.EmailAddress, adUser.Email)) mismatches.Add("Email");
                    if (!StringMatch(user.PhoneNumber, adUser.Phone)) mismatches.Add("Phone");

                    SetUserDetail(database, user, ADCompareScope, "MismatchedFields",
                        mismatches.Count > 0 ? string.Join(",", mismatches) : "None");
                }
                catch (Exception ex)
                {
                    SetUserDetail(database, user, ADCompareScope, "ADStatus", "Error");
                    SetUserDetail(database, user, ADCompareScope, "ADError", ex.Message);
                    SetUserDetail(database, user, ADCompareScope, "LastChecked", DateTime.Now.ToString("o"));
                }
            }

            database.SaveChanges();
        }

        /// <summary>
        /// Gets user photo from AD (thumbnailPhoto attribute).
        /// Returns null if no photo or cache is still valid.
        /// </summary>
        public override byte[] GetUserPhoto(DiscoDataContext database, User user, DateTime? cacheTimestamp)
        {
            // Only refresh photos older than 24 hours
            if (cacheTimestamp.HasValue && cacheTimestamp.Value > DateTime.Now.AddHours(-24))
                return null;

            try
            {
                var adUser = ActiveDirectory.RetrieveADUserAccount(user.UserId, new[] { "thumbnailPhoto" });
                if (adUser == null)
                    return null;

                var photoData = adUser.GetPropertyValue<byte[]>("thumbnailPhoto");
                return photoData;
            }
            catch
            {
                return null;
            }
        }

        #region Helpers

        private bool StringMatch(string discoValue, string adValue)
        {
            var a = string.IsNullOrWhiteSpace(discoValue) ? string.Empty : discoValue.Trim();
            var b = string.IsNullOrWhiteSpace(adValue) ? string.Empty : adValue.Trim();
            return string.Equals(a, b, StringComparison.OrdinalIgnoreCase);
        }

        private void SetUserDetail(DiscoDataContext database, User user, string scope, string key, string value)
        {
            var existing = database.UserDetails
                .FirstOrDefault(d => d.UserId == user.UserId && d.Scope == scope && d.Key == key);

            if (existing != null)
            {
                existing.Value = value;
            }
            else
            {
                database.UserDetails.Add(new UserDetail
                {
                    UserId = user.UserId,
                    Scope = scope,
                    Key = key,
                    Value = value
                });
            }
        }

        #endregion
    }
}