using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Tango.Core.Commands;
using Tango.Logging;
using Tango.SharedUI;
using Tango.SharedUI.Components;
using Microsoft.WindowsAPICodePack.Dialogs;
using System.ComponentModel;
using System.Windows.Data;
using System.Diagnostics;
using System.IO;
using Tango.LogViewer.UI.LogViewerFileParser;
using System.Globalization;
using System.Windows.Input;
using System.Windows;

namespace Tango.LogViewer.UI.ViewModels
{
    public class MainViewVM : ViewModel
    {

        private LogViewerManager _logViewerManager;
        #region Properties
        public SelectedObjectCollection<LogCategory> SelectedLogCategories { get; set; }

        private TimeSpan? _endSelectedTime;
        /// <summary>
        /// Gets or sets the end selected time of time picker.
        /// </summary>
        public TimeSpan? EndSelectedTime
        {
            get { return _endSelectedTime; }
            set
            {
                _endSelectedTime = value;
                RaisePropertyChangedAuto();
                ApplyLogsFilter();
            }
        }

        private TimeSpan? _startSelectedTime;
        /// <summary>
        /// Gets or sets the start selected time of time picker.
        /// </summary>
        public TimeSpan? StartSelectedTime
        {
            get { return _startSelectedTime; }
            set
            {
                _startSelectedTime = value;
                RaisePropertyChangedAuto();
                ApplyLogsFilter();
            }
        }

        private String _filter;
        /// <summary>
        /// Gets or sets the filter for log message.
        /// </summary>
        public String Filter
        {
            get { return _filter; }
            set
            {
                _filter = value;
                RaisePropertyChangedAuto();
                ApplyLogsFilter();
            }
        }

        private ObservableCollection<LogItemBase> _logs;
        /// <summary>
        /// Gets or sets the collection of LogItemBase after parsing log files.
        /// </summary>
        public ObservableCollection<LogItemBase> Logs
        {
            get { return _logs; }
            set { _logs = value; RaisePropertyChangedAuto(); }
        }

        private ICollectionView _logsViewSource;

        /// <summary>
        /// Wrapper around the Logs collection that provides filtering
        /// </summary>
        public ICollectionView LogsViewSource
        {
            get { return _logsViewSource; }
            set { _logsViewSource = value; RaisePropertyChangedAuto(); }
        }

        private LogItemBase _selectedLog;
        /// <summary>
        /// Gets or sets the selected log.
        /// </summary>
        public LogItemBase SelectedLog
        {
            get { return _selectedLog; }
            set { _selectedLog = value; RaisePropertyChangedAuto(); Message = _selectedLog != null ? _selectedLog.Message : ""; }
        }


        private string _fileName;
        /// <summary>
        /// Gets or sets the full path of the open file to display in Status bar.
        /// </summary>
        public string FileName
        {
            get { return _fileName; }
            set { _fileName = value; RaisePropertyChangedAuto(); }
        }

        private int _countOfSet;
        /// <summary>
        /// Gets or sets the count of file set to display in Status bar.
        /// </summary>
        public int CountOfSet
        {
            get { return _countOfSet; }
            set { _countOfSet = value; RaisePropertyChangedAuto(); }
        }

        private string _message;
        /// <summary>
        /// Gets the message of selected log item to display in right panel.
        /// </summary>
        public string Message
        {
            get { return _message; }
            set { _message = value; RaisePropertyChangedAuto(); }

        }
        private bool _isEmbeddedLog;

        public bool IsEmbeddedLog
        {
            get { return _isEmbeddedLog; }
            set { _isEmbeddedLog = value; RaisePropertyChangedAuto(); }
        }

        private bool _isSet;
        /// <summary>
        /// Gets or sets a value indicating whether set of files.
        /// </summary>
        public bool IsSet
        {
            get { return _isSet; }
            set { _isSet = value; RaisePropertyChangedAuto(); }
        }

        private bool _loading;

        public bool Loading
        {
            get { return _loading; }
            set { _loading = value; RaisePropertyChangedAuto(); }
        }

        public CultureInfo Culture { get; set; }

        #endregion

        public RelayCommand OpeFileLogCommand { get; set; }

        #region Constructors
        public MainViewVM()
        {
            Culture = new CultureInfo("he-IL");

            SelectedLogCategories = new SelectedObjectCollection<LogCategory>(new ObservableCollection<LogCategory>()
            {
                LogCategory.Info,
                LogCategory.Warning,
                LogCategory.Error,
                LogCategory.Critical,
                LogCategory.Debug,
            }, new ObservableCollection<LogCategory>()
            {
                LogCategory.Info,
                LogCategory.Warning,
                LogCategory.Error,
                LogCategory.Critical,
                LogCategory.Debug,
            });
            _logViewerManager = new LogViewerManager();
            IsSet = false;
            IsEmbeddedLog = false;
            Loading = false;
            Clear();
            OpeFileLogCommand = new RelayCommand(OpenLogFile);
            SelectedLogCategories.SynchedSource.CollectionChanged += (_, __) =>
            {
                ApplyLogsFilter();
            };
        }
        #endregion

        #region Loading
        /// <summary>
        /// Clears the all filters. Set filter properties to init state.
        /// </summary>
        private void Clear()
        {
            FileName = "";
            StartSelectedTime = null;
            EndSelectedTime = null;
            Filter = "";
            SelectedLog = null;
            SelectedLogCategories.SynchedSource = SelectedLogCategories.Source;
            CountOfSet = 0;
            IsSet = false;
            if (Logs != null)
            {
                Logs.Clear();
                RaisePropertyChanged("Logs");
            }

        }

        /// <summary>
        /// Opens the log file from menu.
        /// </summary>
        private void OpenLogFile()
        {
            var dialog = new CommonOpenFileDialog()
            {
                Multiselect = false,
                EnsureFileExists = true,

            };
            dialog.Filters.Add(new CommonFileDialogFilter("Log files", "*.log"));
            CommonFileDialogResult result = dialog.ShowDialog();
            if (result == CommonFileDialogResult.Ok)
            {
                LoadLogFile(dialog.FileName);
            }
        }

        /// <summary>
        /// Loads the log file from menu or command line.
        /// </summary>
        public async void LoadLogFile(String fileName)
        {
            try
            {
                Clear();
                Loading = true;

                Mouse.OverrideCursor = Cursors.Wait;
                _logViewerManager.InitLogFile(fileName);
                List<LogItemBase> logs = new List<LogItemBase>();
                await Task.Factory.StartNew(() =>
                {
                    logs.AddRange(_logViewerManager.Parse());
                });

                CountOfSet = _logViewerManager.CountOfSet;
                IsSet = CountOfSet > 0 ? true : false;
                IsEmbeddedLog = _logViewerManager.IsEmbeddedLog;
                FileName = _logViewerManager.FileName;
                Logs = new ObservableCollection<LogItemBase>(logs);
                LogsViewSource = CollectionViewSource.GetDefaultView(Logs);
                StartSelectedTime = Logs.Min(x => x.TimeStamp).TimeOfDay;
                EndSelectedTime = Logs.Max(x => x.TimeStamp).TimeOfDay;
                ApplyLogsFilter();
            }
            catch (Exception ex)
            {
                Mouse.OverrideCursor = null;
                Loading = false;
                MessageBox.Show(ex.FlattenMessage());
            }
            finally
            {
                Mouse.OverrideCursor = null;
                Loading = false;
            }
        }


        #endregion

        #region Filtering
        /// <summary>
        /// Applies the all filters( time, categories,filter massage) to view.
        /// </summary>
        private void ApplyLogsFilter()
        {
            if (LogsViewSource != null)
            {
                LogsViewSource.Filter = (x) =>
                            {
                                LogItemBase log = x as LogItemBase;
                                return (SelectedLogCategories.SynchedSource.Contains(log.Category) && (String.IsNullOrWhiteSpace(Filter) || log.Message.ToLower().Contains(Filter.ToLower()))
                                && (StartSelectedTime == null || StartSelectedTime == TimeSpan.Zero || log.TimeStamp.TimeOfDay >= StartSelectedTime) && (EndSelectedTime == null || EndSelectedTime == TimeSpan.Zero || log.TimeStamp.TimeOfDay <= EndSelectedTime));
                            };
            }

        }
        #endregion

    }
}