///
/// Copyright (c) 2020 Sensus Slovensko a.s.
///
using System;
using System.Collections.Generic;
using System.Windows.Forms;
using NHibernate;
using Common.UIControls;
using Events;
using Events.Entities;
using EventViewer.Resources;
using System.Drawing;

namespace EventViewer
{
    public partial class EventViewerWnd : Form
    {
        public const int Dpi100pct = 96;
        int currentDpi;

        enum Column
        {
            DateTime,
            Bench,
            Source,
            Class,
            Severity,
            Message,
            Count
        }

        ISession session;
        IList<Subscriber> subscribers;
        IList<Event> events;
        SortOrder sortOrder = SortOrder.Ascending;
        int sortColumn = -1;                        /// 0-based index of column to be used for sorting

        EViewerOption eViewerOption;
        string loginUserName;
        string currentUser
        {
            get
            {
                if (!string.IsNullOrEmpty(loginUserName))
                {
                    return loginUserName;
                }
                else if (Program.LocalSettings != null && Program.LocalSettings.NonAnonymousAccess && !string.IsNullOrEmpty(Program.LocalSettings.UserName))
                {
                    return Program.LocalSettings.UserName;
                }
                else
                {
                    return null;
                }
            }
        }

        /// The following 3 private variables determine whether list of events is redrawn
        EViewerOption lastEViewerOption;
        string lastUser;
        int lastRecentTimePeriodInDays;


        public EventViewerWnd()
        {
            InitializeComponent();
            loginUserName = null;
            eViewerOption = string.IsNullOrEmpty(currentUser) ? EViewerOption.RecentEvents : EViewerOption.UnreadEvents;
            lastEViewerOption = EViewerOption.Undefined;
            lastRecentTimePeriodInDays = 0;
            Localize();
            currentDpi = (int)this.CreateGraphics().DpiX;
            LocalSettings ls = Program.LocalSettings;
            eventsListView.Columns.Add(Strings.Date_time, (ls.ColWid1 > 0) ? ls.ColWid1 :  80 * currentDpi / Dpi100pct);
            eventsListView.Columns.Add(Strings.Bench,     (ls.ColWid2 > 0) ? ls.ColWid2 :  50 * currentDpi / Dpi100pct);
            eventsListView.Columns.Add(Strings.Source,    (ls.ColWid3 > 0) ? ls.ColWid3 : 100 * currentDpi / Dpi100pct);
            eventsListView.Columns.Add(Strings.Class,     (ls.ColWid4 > 0) ? ls.ColWid4 :  60 * currentDpi / Dpi100pct);
            eventsListView.Columns.Add(Strings.Severity,  (ls.ColWid5 > 0) ? ls.ColWid5 :  70 * currentDpi / Dpi100pct);
            eventsListView.Columns.Add(Strings.Message,   (ls.ColWid6 > 0) ? ls.ColWid6 : 500 * currentDpi / Dpi100pct);
            LoadUISettings();
        }

        void Localize()
        {
            RedrawTitle();
            eventsSelectionGroupBox.Text = Strings.Event_selection;
            unreadEventsRadioButton.Text = Strings.Unread_events;
            recentEventsRadioButton.Text = Strings.Recent_events;
            allEventsRadioButton.Text = Strings.All_events;
            settingsButton.Text = Strings.Settings;
            userLoginButton.Text = Strings.User_login;
        }

        void RedrawTitle()
        {
            Text = string.Format("{0} {1} {2}", Strings.Event_viewer, Program.Version, !string.IsNullOrEmpty(currentUser) ? string.Format("({0})", currentUser) : string.Empty);
        }

        private void EventViewerWnd_Load(object sender, EventArgs e)
        {
            try
            {
                DB.DbType = DBType.MySql;
                DB.ConnectionString = Program.LocalSettings.ConnectionString;
                session = DB.CreateSession();
                subscribers = session.QueryOver<Subscriber>().List();
                unreadEventsRadioButton.Checked = true;
            }
            catch (Exception exc)
            {
                MessageBox.Show(string.Format("{0}{1}{2}", Strings.Cannot_connect_to_the_database, Environment.NewLine, exc.Message),
                                Strings.Error, MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
            }
        }

        private void unreadEventsRadioButton_CheckedChanged(object sender, EventArgs e)
        {
            if (unreadEventsRadioButton.Checked) eViewerOption = EViewerOption.UnreadEvents;
            Redraw();
        }

        private void recentEventsRadioButton_CheckedChanged(object sender, EventArgs e)
        {
            if (recentEventsRadioButton.Checked) eViewerOption = EViewerOption.RecentEvents;
            Redraw();
        }

        private void allEventsRadioButton_CheckedChanged(object sender, EventArgs e)
        {
            if (allEventsRadioButton.Checked) eViewerOption = EViewerOption.AllEvents;
            Redraw();
        }

        /// <summary>
        /// Redraw events
        /// </summary>
        /// <param name="allEvents">true = Display all events (also confirmed read)</param>
        void Redraw(bool redrawAlways = false)
        {
            int days = Program.LocalSettings.RecentTimeDays;

            if (!redrawAlways &&
                lastEViewerOption == eViewerOption &&
                lastUser == currentUser &&
                lastRecentTimePeriodInDays == days)
            {
                return;     /// Do not redraw the list of events
            }

            try
            {
                if (eViewerOption == EViewerOption.AllEvents)
                {
                    /// Read all events
                    events = session.QueryOver<Event>().List();
                }
                else if (eViewerOption == EViewerOption.RecentEvents)
                {
                    /// Read events from tha last 'recentTimePeriodInDays' days
                    events = session.QueryOver<Event>()
                                    .Where(e => (e.TimeStamp >= DateTime.Now - new TimeSpan(days, 0, 0, 0)))
                                    .List();
                }
                else if (!string.IsNullOrEmpty(loginUserName))
                {
                    /// Read unread events of the specified user
                    events = session.QueryOver<Event>()
                                    .JoinQueryOver<Subscriber>(e => e.Subscribers)
                                    .Where(s => (s.Name == string.Format("User_{0}", loginUserName)))
                                    .List<Event>();
                }
                else
                {
                    /// Read unread events of all users
                    events = session.QueryOver<Event>()
                                    .JoinQueryOver<Subscriber>(e => e.Subscribers)
                                    .List<Event>();

                    for (int i = 0; i < events.Count; i++)
                    {
                        for (int j = events.Count - 1; j > i; j--)
                        {
                            if (events[i].Id == events[j].Id) events.RemoveAt(j);
                        }
                    }
                }

                eventsListView.Items.Clear();
                foreach (var e in events) AddOne(e);

                lastEViewerOption = eViewerOption;
                lastUser = currentUser;
                lastRecentTimePeriodInDays = days;
            }
            catch (Exception exc)
            {
                MessageBox.Show(string.Format("{0}{1}{2}", Strings.Cannot_connect_to_the_database, Environment.NewLine, exc.Message),
                                Strings.Error, MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
            }
        }

        void AddOne(Event evnt)
        {
            ListViewItem lvi = new ListViewItem(evnt.TimeStamp.ToString("dd.MM.yyyy HH:mm"));
            lvi.Tag = evnt;
            lvi.SubItems.Add(evnt.Bench);
            lvi.SubItems.Add(evnt.Source);
            lvi.SubItems.Add(evnt.EventClass.ToString());
            {
                lvi.UseItemStyleForSubItems = false;
                lvi.SubItems.Add(evnt.Severity.ToString());
                lvi.SubItems[lvi.SubItems.Count - 1].BackColor = Utils.GetSeverityColor(evnt.Severity);
                lvi.SubItems[lvi.SubItems.Count - 1].ForeColor = Utils.GetSeverityColor(evnt.Severity, true);
            }
            lvi.SubItems.Add(evnt.Message);
            eventsListView.Items.Add(lvi);
        }

        private void eventsListView_ColumnClick(object sender, ColumnClickEventArgs e)
        {
            if (e.Column == sortColumn)
            {
                sortOrder = (sortOrder == SortOrder.Ascending) ? SortOrder.Descending : SortOrder.Ascending;
            }
            else
            {
                /// Clicked on another column header => set sortOrder to SortOrder.Ascending
                sortColumn = e.Column;
                sortOrder = SortOrder.Ascending;
            }

            switch ((Column)sortColumn)
            {
                default:
                case Column.DateTime:
                    eventsListView.ListViewItemSorter = new LviDateTimeColumnComparer(sortColumn, sortOrder);
                    break;
                case Column.Bench:
                case Column.Source:
                case Column.Class:
                case Column.Severity:
                case Column.Message:
                    eventsListView.ListViewItemSorter = new LviTextColumnComparer(sortColumn, sortOrder);
                    break;
            }

            eventsListView.SetSortIcon(sortColumn, sortOrder);
            eventsListView.Sort();
        }

        private void eventsListView_MouseDoubleClick(object sender, MouseEventArgs e)
        {
            if (eventsListView.SelectedIndices.Count != 1) return;
            Event evnt = eventsListView.SelectedItems[0].Tag as Events.Entities.Event;
            if (evnt == null) return;
            bool enableConfirmReadButton = (session != null) && (eViewerOption == EViewerOption.UnreadEvents) && !string.IsNullOrEmpty(currentUser);

            if ((new Forms.EventDetailsDlg(evnt, enableConfirmReadButton)).ShowDialog() == DialogResult.OK)
            {
                /// Reading selected event was confirmed => delete subscriber from this event.Subscribers
                foreach (var s in subscribers)
                {
                    if (s.Name == string.Format("User_{0}", currentUser))
                    {
                        session.CreateSQLQuery(string.Format("DELETE FROM `eventsubscriber` WHERE Event_id = {0} AND Subscriber_id = {1};", evnt.Id, s.Id))
                               .ExecuteUpdate();
                        session.Flush();
                        Redraw(true);
                        break;
                    }
                }
            }
        }

        private void settingsButton_Click(object sender, EventArgs e)
        {
            //Users.Entities.GID[] groupsWithAccess = new Users.Entities.GID[] { Users.Entities.GID.Administrators };
            Users.Forms.LoginDlg dlg = new Users.Forms.LoginDlg(true);
            if (dlg.ShowDialog() == DialogResult.OK)
            {
                if ((new Forms.SettingsDlg()).ShowDialog() == DialogResult.OK)
                {
                    Close();
                }
            }
        }

        private void userLoginButton_Click(object sender, EventArgs e)
        {
            try
            {
                Users.GlobalData.RemoteUsersDB = new Users.DBSettings(Users.Entities.DBType.MySql, Program.LocalSettings.UsersDBConnString);
                Users.Forms.LoginDlg dlg = new Users.Forms.LoginDlg();
                if (dlg.ShowDialog() == DialogResult.OK)
                {
                    loginUserName = dlg.UserName;
                    RedrawTitle();
                    Redraw();
                }
            }
            catch (Exception)
            {
            }
        }

        private void EventViewerWnd_FormClosing(object sender, FormClosingEventArgs e)
        {
            SaveUISettings();
        }

        private void LoadUISettings()
        {
            LocalSettings ls = Program.LocalSettings;
            if (ls != null)
            {
                WindowState = (ls.WndMaximized ? FormWindowState.Maximized : FormWindowState.Normal);
                Width = (ls.WndWidth > 0) ? ls.WndWidth : 800;
                Height = (ls.WndHeight > 0) ? ls.WndHeight : 420;
                Left = (ls.WndLeft != 0) ? ls.WndLeft : 150;
                Top = (ls.WndTop != 0) ? ls.WndTop : 150;
            }
        }

        private void SaveUISettings()
        {
            /// Obtain ProcedureDlg dimensions, etc.
            bool isMaximized = (WindowState == FormWindowState.Maximized);
            int left = (WindowState == FormWindowState.Normal) ? Location.X : RestoreBounds.Left;
            int top = (WindowState == FormWindowState.Normal) ? Location.Y : RestoreBounds.Top;
            int width = (WindowState == FormWindowState.Normal) ? Size.Width : RestoreBounds.Width;
            int height = (WindowState == FormWindowState.Normal) ? Size.Height : RestoreBounds.Height;

            LocalSettings ls = Program.LocalSettings;

            if (ls != null && (ls.WndMaximized != isMaximized ||
                               ls.WndLeft != left ||
                               ls.WndTop != top ||
                               ls.WndWidth != width ||
                               ls.WndHeight != height ||
                               ls.ColWid1 != eventsListView.Columns[0].Width ||
                               ls.ColWid2 != eventsListView.Columns[1].Width ||
                               ls.ColWid3 != eventsListView.Columns[2].Width ||
                               ls.ColWid4 != eventsListView.Columns[3].Width ||
                               ls.ColWid5 != eventsListView.Columns[4].Width ||
                               ls.ColWid6 != eventsListView.Columns[5].Width))
            {
                /// At least one ProcedureDlg dimension differs => Update local settings and save them
                ls.WndMaximized = isMaximized;
                ls.WndLeft = left;
                ls.WndTop = top;
                ls.WndWidth = width;
                ls.WndHeight = height;
                ls.ColWid1 = eventsListView.Columns[0].Width;
                ls.ColWid2 = eventsListView.Columns[1].Width;
                ls.ColWid3 = eventsListView.Columns[2].Width;
                ls.ColWid4 = eventsListView.Columns[3].Width;
                ls.ColWid5 = eventsListView.Columns[4].Width;
                ls.ColWid6 = eventsListView.Columns[5].Width;
                ls.Save();
            }
        }
    }
}