///
/// Copyright (c) 2020 Sensus Slovensko a.s.
///
using System;
using System.Collections.Generic;
using System.Windows.Forms;
using log4net;
using NHibernate;
using Config.Entities;
using Config.CalendarEvent;
using Events.Entities;
using TBF.Resources;
using TBF.UiBridge;

namespace TBF.UI.Calendar
{
    public partial class CalendarTabPageCtrl : UserControl
    {
        static readonly ILog log = LogManager.GetLogger(typeof(CalendarTabPageCtrl));

        IList<ICalendarEvent> eventsFromComponents;
        IList<CustomEvent> customEvents;       /// Custom events loaded from the local config DB

        Timer timer;
        DateTime lastTimeCalendarEventsServed;

        public CalendarTabPageCtrl()
        {
            InitializeComponent();
            eventsFromComponents = new List<ICalendarEvent>();
            Localize();
		}

        void Localize()
        {
            newEventButton.Text = Strings.New_event;

            calendarEventsListViewEx.Columns.Add(Strings.Date_and_time, 100);
            calendarEventsListViewEx.Columns.Add(Strings.Frequency, 70);
            calendarEventsListViewEx.Columns.Add(Strings.Source, 50);
            calendarEventsListViewEx.Columns.Add(Strings.Title, 200);
            calendarEventsListViewEx.Columns.Add(Strings.Action);
            calendarEventsListViewEx.Columns.Add(Strings.Parameters);
            calendarEventsListViewEx.Columns.Add(Strings.On_exact_day);
            calendarEventsListViewEx.Columns.Add(Strings.Read_only);
        }

        void AddOne(ICalendarEvent evnt)
        {
            ListViewItem lvi = new ListViewItem(evnt.Date.ToString(evnt.AllDay ? Constants.DateFormat : Constants.DateTimeFormat));
            lvi.SubItems.Add(Config.CalendarEvent.Utils.Freq2String(evnt.Frequency));
            lvi.SubItems.Add(evnt.Source);
            lvi.SubItems.Add(evnt.Title);
            lvi.SubItems.Add(Config.CalendarEvent.Utils.Action2String(evnt.AutoAction));
            lvi.SubItems.Add(evnt.Parameters);
            lvi.SubItems.Add(evnt.TriggerOnExactDayOnly ? Strings.yes : Strings.no);
            lvi.SubItems.Add(evnt.ReadOnly ? Strings.yes : Strings.no);
            lvi.Tag = evnt;

            calendarEventsListViewEx.Items.Add(lvi);
        }

        public void StartCalendar(IList<ICalendarEvent> eventsFromComponents)
        {
            this.eventsFromComponents = eventsFromComponents;

            try
            {
                /// Read custom events from the database
                ISession session = Config.FluentCommon.CreateSession(Users.Entities.DBKind.Config);
                customEvents = session.QueryOver<CustomEvent>().List();

                TripplicateShiftCustomEvents(customEvents);

                /// Calendar
                foreach (var evnt in eventsFromComponents) calendarCtrl1.AddEvent(evnt);
                foreach (var evnt in customEvents) calendarCtrl1.AddEvent(evnt);

                /// List view in the right pane
                calendarEventsListViewEx.Items.Clear();
                foreach (var e in customEvents) AddOne(e);
                foreach (var e in eventsFromComponents) if (!e.Hidden) AddOne(e);

                /// Serve events (determine if any event was triggered)
                lastTimeCalendarEventsServed = DateTime.Now;
                ServeCalendarEventsNotifWarnErrorFatal(lastTimeCalendarEventsServed, session, customEvents);
            }
            catch (Exception)
            {
                customEvents = new List<CustomEvent>();
                log.ErrorFormat("Failed to load custom events from the LOCAL config database");
            }

            calendarCtrl1.CalendarView = CalendarViews.Month;

            timer = new System.Windows.Forms.Timer();
            timer.Interval = 300000;  /// 300000 ms = 300 s = 5 min
            timer.Tick += new EventHandler(timer_Tick);
            timer.Start();
        }

        /// <summary>
        /// After StartCalendar() was called this function is invoked every 5 minutes
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="args"></param>
        void timer_Tick(object sender, EventArgs args)
        {
            DateTime currentTime = DateTime.Now;

            if ((currentTime.Hour != lastTimeCalendarEventsServed.Hour) ||
                (currentTime.Minute % 30) != (lastTimeCalendarEventsServed.Minute % 30))
            {
                /// Serve events at the beginning of each half hour
                ServeCalendarEventsNotifWarnErrorFatal(currentTime);
                lastTimeCalendarEventsServed = currentTime;
            }
        }


        /// <summary>
        /// Triggers events corresponding to triggered motification.warning/error calendar events.
        /// </summary>
        /// <param name="currentTime">Current time</param>
        void ServeCalendarEventsNotifWarnErrorFatal(DateTime currentTime, ISession parentSession = null, IList<CustomEvent> customEventsFromDB = null)
        {
            IList<Events.Entities.Event> eventsToTrigger = new List<Events.Entities.Event>();

            for (int i = eventsFromComponents.Count - 1; i >= 0; i--)
            {
                ICalendarEvent calEvent = eventsFromComponents[i];

                AutoAction a = calEvent.AutoAction;
                if (a == AutoAction.Notification || a == AutoAction.Warning || a == AutoAction.Error || a == AutoAction.FatalErr)
                {
                    if (Config.CalendarEvent.Utils.IsCalendarEventTrigerred(calEvent, currentTime))
                    {
                        eventsToTrigger.Add(new Events.Entities.Event(null,
                                                                      calEvent.Source,
                                                                      EventClass.Metrology,
                                                                      ToSeverity(calEvent.AutoAction),
                                                                      calEvent.Title,
                                                                      calEvent.Parameters,
                                                                      null,
                                                                      SubscriberGroup.Metrology | SubscriberGroup.Maintenance |
                                                                      SubscriberGroup.Production | SubscriberGroup.Management));

                        if (calEvent.Frequency == Frequency.Once)
                        {
                            eventsFromComponents.Remove(calEvent);
                        }
                        else
                        {
                            Config.CalendarEvent.Utils.UpdateRecurringDate(calEvent, currentTime);
                        }
                    }
                }
            }

            try
            {
                var session = (parentSession != null) ? parentSession : Config.FluentCommon.CreateSession(Users.Entities.DBKind.Config);
                var customEvents = (customEventsFromDB != null) ? customEventsFromDB : session.QueryOver<CustomEvent>() .List();

                for (int i = customEvents.Count - 1; i >= 0; i--)
                {
                    CustomEvent calEvent = customEvents[i];

                    AutoAction a = calEvent.AutoAction;
                    if (a == AutoAction.Notification || a == AutoAction.Warning || a == AutoAction.Error || a == AutoAction.FatalErr)
                    {
                        if (Config.CalendarEvent.Utils.IsCalendarEventTrigerred(calEvent, currentTime))
                        {
                            eventsToTrigger.Add(new Events.Entities.Event(null,
                                                                          calEvent.Source,
                                                                          EventClass.Undefined,
                                                                          ToSeverity(calEvent.AutoAction),
                                                                          calEvent.Title,
                                                                          calEvent.Parameters,
                                                                          null,
                                                                          SubscriberGroup.Metrology | SubscriberGroup.Maintenance |
                                                                          SubscriberGroup.Production | SubscriberGroup.Management));

                            if (calEvent.Frequency == Frequency.Once)
                            {
                                session.Delete(calEvent);
                            }
                            else if (calEvent.UpdateRecurringDate(currentTime))
                            {
                                session.SaveOrUpdate(calEvent);
                            }
                        }
                    }
                }
                session.Flush();
            }
            catch (Exception exc)
            {
                log.ErrorFormat("Failed to load or update CustomEvent-s in ServeTriggerEvtCalendarEvents(): {0}", exc.Message);
            }

            if (eventsToTrigger.Count > 0 && !string.IsNullOrEmpty(global::Events.DB.ConnectionString))
            {
                try
                {
                    ISession session = global::Events.DB.CreateSession();
                    global::Events.DB.LoadSubscribers(session);
                    foreach (var e in eventsToTrigger)
                    {
                        TBF.UiBridge.Bridge.TriggerEvent(session, e);
                    }
                    session.Flush();
                }
                catch (Exception exc)
                {
                    log.ErrorFormat("Failed to trigger events in ServeTriggerEvtCalendarEvents(): {0}", exc.Message);
                }
            }
        }


        /// <summary>
        /// Returns an array of parameters of selected actions.
        /// This function is not invoked from UI thread.
        /// </summary>
        /// <param name="selectedAction">Selected AutoAction</param>
        /// <param name="maxCount">Max. number of calendar events served</param>
        /// <returns>List of strings of triggered actions</returns>
        public static IList<string> ServeCalendarEventsInvokeXY(AutoAction selectedAction, int maxCount = 1)
        {
            DateTime currentTime = DateTime.Now;
            IList<string> parametersList = new List<string>();

            if (maxCount <= 0) return parametersList;

            try
            {
                ISession session = Config.FluentCommon.CreateSession(Users.Entities.DBKind.Config);
                var customEventsFromDB = session.QueryOver<CustomEvent>().List();

                for (int i = customEventsFromDB.Count - 1; i >= 0; i--)
                {
                    CustomEvent calEvent = customEventsFromDB[i];
                    if (calEvent.AutoAction == selectedAction && Config.CalendarEvent.Utils.IsCalendarEventTrigerred(calEvent, currentTime))
                    {
                        parametersList.Add(calEvent.Parameters);

                        if (calEvent.Frequency == Frequency.Once)
                        {
                            session.Delete(calEvent);
                        }
                        else if (calEvent.UpdateRecurringDate(currentTime))
                        {
                            session.SaveOrUpdate(calEvent);
                        }

                        if (parametersList.Count >= maxCount) break;
                    }
                }
                session.Flush();
            }
            catch (Exception exc)
            {
                log.ErrorFormat("Failed to load or update CustomEvent-s in ServeSelectedCalendarEvents(): {0}", exc.Message);
            }

            if (parametersList.Count > 0)
            {
                /// TODO: Invoke calendar redraw in UI thread
            }

            return parametersList;
        }


        /// <summary>
        /// Convert calendar event AutoAction to event Severity
        /// </summary>
        /// <param name="action">AutoAction enum value</param>
        /// <returns>Severity enum value</returns>
        Events.Entities.Severity ToSeverity(AutoAction action)
        {
            switch (action)
            {
                default:
                case AutoAction.Notification:   return global::Events.Entities.Severity.Notification;
                case AutoAction.Warning:        return global::Events.Entities.Severity.Warning;
                case AutoAction.Error:          return global::Events.Entities.Severity.Error;
                case AutoAction.FatalErr:     return global::Events.Entities.Severity.FatalError;
            }
        }


        void TripplicateShiftCustomEvents(IList<CustomEvent> customEvents)
        {
            /// Tripplicate each custom event with frequency 'EveryShift'
            for (int i = customEvents.Count - 1; i >= 0; i--)
            {
                if (customEvents[i].Frequency == Frequency.EveryShift)
                {
                    DateTime dt = customEvents[i].Date;

                    var ev2 = (CustomEvent)customEvents[i].Clone();
                    ev2.Date = new DateTime(dt.Year, dt.Month, dt.Day, (dt.Hour + 8) % 24, dt.Minute, 0);
                    ev2.ReadOnly = true;
                    customEvents.Insert(i + 1, ev2);

                    var ev3 = (CustomEvent)customEvents[i].Clone();
                    ev3.Date = new DateTime(dt.Year, dt.Month, dt.Day, (dt.Hour + 16) % 24, dt.Minute, 0);
                    ev3.ReadOnly = true;
                    customEvents.Insert(i + 2, ev3);
                }
            }
        }


        private void newEventButton_Click(object sender, EventArgs ea)
        {
            EventDetailsForm dlg = new EventDetailsForm();
            if (dlg.ShowDialog() == DialogResult.OK && dlg.NewEvent is CustomEvent)
            {
                try
                {
                    ISession session = Config.FluentCommon.CreateSession(Users.Entities.DBKind.Config);
                    session.SaveOrUpdate(dlg.NewEvent as CustomEvent);
                    session.Flush();

                    customEvents = session.QueryOver<CustomEvent>().List();
                    TripplicateShiftCustomEvents(customEvents);

                    /// Calendar
                    calendarCtrl1.ClearEvents();
                    foreach (var e in eventsFromComponents) calendarCtrl1.AddEvent(e);
                    foreach (var e in customEvents) calendarCtrl1.AddEvent(e);

                    /// List view in the right pane
                    calendarEventsListViewEx.Items.Clear();
                    foreach (var e in customEvents) AddOne(e);
                    foreach (var e in eventsFromComponents) if (!e.Hidden) AddOne(e);
                }
                catch (Exception)
                {
                    log.ErrorFormat("Failed to save new calendar event to the local config database");
                }
            }
        }


        private void calendarEventsListViewEx_MouseDoubleClick(object sender, MouseEventArgs mea)
        {
            if (calendarEventsListViewEx.SelectedIndices.Count != 1) return;
            CustomEvent evnt = calendarEventsListViewEx.SelectedItems[0].Tag as CustomEvent;
            if (evnt == null || evnt.ReadOnly) return;
            EventDetailsForm dlg = new EventDetailsForm { Event = evnt };
            if (dlg.ShowDialog() != DialogResult.OK) return;

            try
            {
                /// Re-read selected custom event from the database
                ISession session = Config.FluentCommon.CreateSession(Users.Entities.DBKind.Config);
                var cEvents = session.QueryOver<CustomEvent>()
                                     .Where(x => (x.Id == evnt.Id))
                                     .List();

                if (cEvents.Count == 1)
                {
                    cEvents[0].Date = dlg.NewEvent.Date;
                    cEvents[0].Frequency = dlg.NewEvent.Frequency;
                    cEvents[0].AllDay = dlg.NewEvent.AllDay;
                    cEvents[0].TriggerOnExactDayOnly = dlg.NewEvent.TriggerOnExactDayOnly;
                    cEvents[0].Source = dlg.NewEvent.Source;
                    cEvents[0].Title = dlg.NewEvent.Title;
                    cEvents[0].AutoAction = dlg.NewEvent.AutoAction;
                    cEvents[0].Parameters = dlg.NewEvent.Parameters;
                    cEvents[0].Rank = dlg.NewEvent.Rank;
                    cEvents[0].Hidden = dlg.NewEvent.Hidden;
                    cEvents[0].ReadOnly = dlg.NewEvent.ReadOnly;
                    cEvents[0].BackColor = dlg.NewEvent.BackColor;
                    cEvents[0].TextColor = dlg.NewEvent.TextColor;
                    cEvents[0].TooltipEnabled = dlg.NewEvent.TooltipEnabled;
                    cEvents[0].CustomRecurringFunction = null;
                    session.SaveOrUpdate(cEvents[0]);
                    session.Flush();

                    customEvents = session.QueryOver<CustomEvent>().List();
                    TripplicateShiftCustomEvents(customEvents);

                    /// Calendar
                    calendarCtrl1.ClearEvents();
                    foreach (var e in eventsFromComponents) calendarCtrl1.AddEvent(e);
                    foreach (var e in customEvents) calendarCtrl1.AddEvent(e);

                    /// List view in the right pane
                    calendarEventsListViewEx.Items.Clear();
                    foreach (var e in customEvents) AddOne(e);
                    foreach (var e in eventsFromComponents) if (!e.Hidden) AddOne(e);
                }
            }
            catch (Exception)
            {
                MessageBox.Show("Cannot save change to the database", Strings.Error, MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
            }
        }
    }
}