using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Data.Entity;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using Tango.BL;
using Tango.BL.Builders;
using Tango.BL.Entities;
using Tango.BL.Enumerations;
using Tango.BL.ValueObjects;
using Tango.Core.Commands;
using Tango.Core.ExtensionMethods;
using Tango.MachineStudio.Common;
using Tango.MachineStudio.Common.Notifications;
using Tango.SharedUI.Components;

namespace Tango.MachineStudio.ActionLogs.ViewModels
{
    public class MainViewVM : StudioViewModel
    {
        private INotificationProvider _notification;
        private List<User> _allUsers;

        #region Properties

        private DateTime _startSelectedDate;
        public DateTime StartSelectedDate
        {
            get { return _startSelectedDate; }
            set { _startSelectedDate = value; RaisePropertyChangedAuto(); }
        }

        private DateTime _endSelectedDate;
        public DateTime EndSelectedDate
        {
            get { return _endSelectedDate; }
            set { _endSelectedDate = value; RaisePropertyChangedAuto(); }
        }

        private string _searchFilter;
        public string SearchFilter
        {
            get { return _searchFilter; }
            set { _searchFilter = value; RaisePropertyChangedAuto(); }
        }

        private ObservableCollection<ActionLog> _actionLogs;
        public ObservableCollection<ActionLog> ActionLogs
        {
            get { return _actionLogs; }
            set { _actionLogs = value; RaisePropertyChanged(nameof(ActionLogs)); }
        }

        private SelectedObjectCollection<ActionLogType> _selectedActionLogTypes;
        public SelectedObjectCollection<ActionLogType> SelectedActionLogTypes
        {
            get { return _selectedActionLogTypes; }
            set
            {
                _selectedActionLogTypes = value;
                RaisePropertyChanged(nameof(SelectedActionLogTypes));
            }
        }

        private ActionLog _selectedActionLog = null;
        public ActionLog SelectedActionLog
        {
            get { return _selectedActionLog; }
            set
            {
                _selectedActionLog = value;
                SelectedItemChanged();
                RaisePropertyChangedAuto();
                InvalidateRelayCommands();
            }
        }

        private ActionLogDifference _differenceObject;
        public ActionLogDifference DifferenceObject
        {
            get { return _differenceObject; }
            set { _differenceObject = value; RaisePropertyChangedAuto(); }
        }

        private bool _isLoading;

        public bool IsLoading
        {
            get { return _isLoading; }
            set { _isLoading = value; RaisePropertyChangedAuto(); }
        }

        private bool _isLoadingDifferences;

        public bool IsLoadingDifferences
        {
            get { return _isLoadingDifferences; }
            set { _isLoadingDifferences = value; RaisePropertyChangedAuto(); }
        }




        #endregion

        public RelayCommand SearchCommand { get; set; }
        public RelayCommand CopyToClipBoardCommand { get; set; }
        public RelayCommand CopyRelateObjectIDCommand { get; set; }

        public MainViewVM(INotificationProvider notification)
        {
            _notification = notification;

            IsLoading = false;
            IsLoadingDifferences = false;
            ActionLogs = new ObservableCollection<ActionLog>();
            SearchCommand = new RelayCommand(async () => await GetActionLogs(), () => IsFree);
            CopyRelateObjectIDCommand = new RelayCommand(CopyRelateObjectID);
            CopyToClipBoardCommand = new RelayCommand(CopyToClipBoard, () => SelectedActionLog != null && SelectedActionLog.DifferenceObject != null);
            DateTime now = DateTime.Now;
            StartSelectedDate = now.AddMonths(-1);
            EndSelectedDate = now;
            var source = Enum.GetValues(typeof(ActionLogType)).Cast<ActionLogType>().ToObservableCollection();
            var syncedSource = Enum.GetValues(typeof(ActionLogType)).Cast<ActionLogType>().ToObservableCollection();

            SelectedActionLogTypes = new SelectedObjectCollection<ActionLogType>(source, syncedSource);
        }

        public override void OnApplicationReady()
        {
            InitUsers();
        }
        public async void InitUsers()
        {
            try
            {
                IsFree = false;

                using (var db = ObservablesContext.CreateDefault())
                {

                    _allUsers = await db.Users.Include(x => x.Contact).ToListAsync();
                }
            }
            catch (Exception ex)
            {
                LogManager.Log(ex, "Error loading users.");
            }
            finally
            {
                IsFree = true;
            }
        }

        private void CopyToClipBoard()
        {
            DataObject data = new DataObject(SelectedActionLog.DifferenceObject.ToJsonString());
            System.Windows.Clipboard.SetDataObject(data);

        }
        private void CopyRelateObjectID()
        {
            DataObject data = new DataObject(SelectedActionLog.RelatedObjectGuid);
            System.Windows.Clipboard.SetDataObject(data);
        }
        
        /// <summary>
        /// New Database Query with search parameters. Initialization ActionLogs property.
        /// </summary>
        private async Task GetActionLogs()
        {
            IsLoading = true;
            string filter = SearchFilter?.ToLower();

            if (String.IsNullOrWhiteSpace(filter)) filter = null;

            try
            {
                IsFree = false;

                using (ObservablesContext db = ObservablesContext.CreateDefault())
                {
                    DateTime startUtc = new DateTime(StartSelectedDate.Year, StartSelectedDate.Month, StartSelectedDate.Day, 0, 0, 0).ToUniversalTime();
                    TimeSpan offsetTime = (EndSelectedDate.Date == DateTime.Now.Date) ? DateTime.Now.TimeOfDay : new TimeSpan(23, 59, 59);
                    DateTime endUtc = EndSelectedDate.ToUniversalTime() + offsetTime;

                    Debug.Write($"TEST TIME {startUtc} to {endUtc}  "+ System.Environment.NewLine);

                    var db_ActionLogs = db.ActionLogs.Where(x => x.LastUpdated <= endUtc && x.LastUpdated >= startUtc)
                           .Select(x => new
                           {
                               x.ID,
                               x.Guid,
                               x.UserGuid,
                               x.LastUpdated,
                               x.Type,
                               x.RelatedObjectName,
                               x.RelatedObjectGuid,
                               x.Message
                           });

                    int[] actionTypes = SelectedActionLogTypes.SynchedSource.ToArray().Select(x => (int)x).ToArray();
                    if (actionTypes.Length > 0)
                    {
                        db_ActionLogs = db_ActionLogs.Where(x => actionTypes.Contains(x.Type));
                    }

                    var runs_db = await db_ActionLogs.ToListAsync();
                    var runs = runs_db.Select(x => new ActionLog()
                             {
                                 ID = x.ID,
                                 Guid = x.Guid,
                                 UserGuid = x.UserGuid,
                                 LastUpdated = x.LastUpdated,
                                 Type = x.Type,
                                 RelatedObjectName = x.RelatedObjectName,
                                 RelatedObjectGuid = x.RelatedObjectGuid,
                                 Message = x.Message,
                                 User = _allUsers.SingleOrDefault(y => y.Guid == x.UserGuid)
                             });

                    if (!String.IsNullOrEmpty(filter))
                    {
                        runs = runs.Where(x => x.ID.ToString().ToLower().StartsWith(filter) || (x.RelatedObjectName != null && x.RelatedObjectName.ToLower().StartsWith(filter))
                        || (x.RelatedObjectGuid != null && x.RelatedObjectGuid.ToLower().StartsWith(filter))
                        || (x.User != null && x.User.Contact != null && x.User.Contact.FullName.ToLower().StartsWith(filter)));
                    }
                    ActionLogs = runs.ToObservableCollection();
                }
            }
            catch (Exception ex)
            {
                IsFree = true;
                LogManager.Log(ex, "Error getting action logs.");
                _notification.ShowError($"Error occurred while trying to retrieve the action logs.\n{ex.Message}");
            }
            finally
            {
                IsFree = true;
                IsLoading = false;
            }
        }

        /// <summary>
        /// Update DifferenceObject on Selected item changed
        /// </summary>
        private async void SelectedItemChanged()
        {
            if (SelectedActionLog == null)
                return;
            if (SelectedActionLog.Difference == null)
            {
                await InitSelectedActionLogDifference();
            }
            DifferenceObject = SelectedActionLog.DifferenceObject;
        }

        /// <summary>
        /// Initializes the selected action log difference.
        /// </summary>
        public async Task InitSelectedActionLogDifference()
        {
            IsLoadingDifferences = true;
            try
            {
                using (var db = ObservablesContext.CreateDefault())
                {
                    var difference = await db.ActionLogs.SingleOrDefaultAsync(x => x.Guid.Equals(SelectedActionLog.Guid));
                    if (difference != null)
                    {
                        SelectedActionLog.DifferenceObject = difference.DifferenceObject;
                    }
                }
            }
            catch (Exception ex)
            {
                LogManager.Log(ex, "Error loading difference of the selected action log.");
            }
            finally
            {
                IsLoadingDifferences = false;
            }
        }
    }
}