using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Outlook2013TodoAddIn
{
    /// <summary>
    /// Custom calendar control with more flexibility and better skinning control
    /// </summary>
    public partial class CustomCalendar : UserControl
    {
        #region "Variables"

        /// <summary>
        /// Used to keep track of the currently selected Date
        /// </summary>
        DateTime _selectedDate = DateTime.Today;

        #endregion "Variables"

        #region "Properties"

        /// <summary>
        /// Gets/sets the current date
        /// </summary>
        public DateTime SelectedDate
        {
            get
            {
                return _selectedDate;
            }
            set
            {
                if (_selectedDate != value)
                {
                    _selectedDate = value;
                    // this.UpdateCalendar();
                    this.OnSelectedDateChanged(EventArgs.Empty);
                }
            }
        }

        /// <summary>
        /// Gets/sets the first day of week
        /// </summary>
        public DayOfWeek FirstDayOfWeek { get; set; }

        /// <summary>
        /// Set of dates to display in BOLD
        /// </summary>
        public DateTime[] BoldedDates { get; set; }

        /// <summary>
        /// Gets/sets font color of dates for current month
        /// </summary>
        public Color CurrentMonthForeColor { get; set; }

        /// <summary>
        /// Gets/sets font color of dates for other months (previous/next)
        /// </summary>
        public Color OtherMonthForeColor { get; set; }

        /// <summary>
        /// Gets/sets font color for today's date
        /// </summary>
        public Color TodayForeColor { get; set; }

        /// <summary>
        /// Gets/sets back color for today's date
        /// </summary>
        public Color TodayBackColor { get; set; }

        /// <summary>
        /// Gets/sets font color for selected's date
        /// </summary>
        public Color SelectedForeColor { get; set; }

        /// <summary>
        /// Gets/sets back color for selected's date
        /// </summary>
        public Color SelectedBackColor { get; set; }

        /// <summary>
        /// Gets/sets font color when mouse over a cell
        /// </summary>
        public Color HoverForeColor { get; set; }

        /// <summary>
        /// Gets/sets back color when mouse over a cell
        /// </summary>
        public Color HoverBackColor { get; set; }

        #endregion "Properties"

        #region "Methods"

        /// <summary>
        /// Default constructor
        /// </summary>
        public CustomCalendar()
        {
            InitializeComponent();
            this.FirstDayOfWeek = DayOfWeek.Sunday;
            //TODO: Thread.CurrentThread.CurrentCulture.DateTimeFormat.FirstDayOfWeek
            this.CurrentMonthForeColor = Color.Black;
            this.OtherMonthForeColor = Color.LightGray;
            this.TodayForeColor = Color.White;
            this.TodayBackColor = Color.Blue;

            this.SelectedForeColor = Color.Blue;
            this.SelectedBackColor = Color.LightBlue;

            this.HoverForeColor = Color.Black;
            this.HoverBackColor = Color.LightCyan;
            this.CreateTableControls();
        }

        /// <summary>
        /// Paint the month upon initial load
        /// </summary>
        /// <param name="sender">Sender</param>
        /// <param name="e">EventArgs</param>
        private void CustomCalendar_Load(object sender, EventArgs e)
        {
            // TODO: check initial double firing
            // TODO: Mark dates with colors from outlook
            // this.UpdateCalendar();
        }

        /// <summary>
        /// Creates all inner labels once to be updated when the calendar changes
        /// </summary>
        private void CreateTableControls()
        {
            this.tableLayoutPanel1.CellBorderStyle = TableLayoutPanelCellBorderStyle.None;
            for (int row = 0; row < this.tableLayoutPanel1.RowCount; row++)
            {
                for (int col = 0; col < this.tableLayoutPanel1.ColumnCount; col++)
                {
                    Label lblCtrl = new Label() { Text = "xx" };
                    lblCtrl.Name = String.Format("lbl_{0}_{1}", col.ToString(), row.ToString());
                    lblCtrl.Dock = DockStyle.Fill;
                    lblCtrl.TextAlign = ContentAlignment.MiddleCenter;
                    lblCtrl.Margin = Padding.Empty;
                    lblCtrl.Padding = Padding.Empty;
                    lblCtrl.FlatStyle = FlatStyle.Flat;
                    if (row != 0)
                    {
                        lblCtrl.MouseEnter += lblCtrl_MouseEnter;
                        lblCtrl.MouseLeave += lblCtrl_MouseLeave;
                        lblCtrl.Click += lblCtrl_Click; // TODO: If we disable this, then we can't select a date...
                        lblCtrl.DoubleClick += lblCtrl_DoubleClick;
                    }
                    this.tableLayoutPanel1.Controls.Add(lblCtrl);
                    this.tableLayoutPanel1.SetCellPosition(lblCtrl, new TableLayoutPanelCellPosition(col, row));
                }
            }

            this.btnPrevious.FlatAppearance.MouseOverBackColor = this.HoverBackColor;
            this.btnNext.FlatAppearance.MouseOverBackColor = this.HoverBackColor;
        }

        /// <summary>
        /// Changes labels according to the currently displayed month
        /// </summary>
        public void UpdateCalendar()
        {
            // All controls are previously created, just need to update labels, etc...
            this.lnkCurrentRange.Text = this.SelectedDate.ToString("MMM yyyy");
            this.lnkToday.Text = "Today: " + DateTime.Today.ToShortDateString();

            string[] daysOfWeek = Enum.GetNames(typeof(DayOfWeek));
            string sFirstDayOfWeek = Enum.GetName(typeof(DayOfWeek), this.FirstDayOfWeek);
            List<string> sortedDays = new List<string>();
            sortedDays.AddRange(daysOfWeek.SkipWhile(ow => ow != sFirstDayOfWeek));
            sortedDays.AddRange(daysOfWeek.TakeWhile(ow => ow != sFirstDayOfWeek));

            int dayCurrent = 0;
            int firstIndex = 0;
            DateTime firstOfCurrentMonth = new DateTime(this.SelectedDate.Year, this.SelectedDate.Month, 1);
            DateTime previousMonth = firstOfCurrentMonth.AddMonths(-1);
            DateTime nextMonth = firstOfCurrentMonth.AddMonths(1);
            int daysInPreviousMonth = DateTime.DaysInMonth(previousMonth.Year, previousMonth.Month);
            int daysInCurrentMonth = DateTime.DaysInMonth(this.SelectedDate.Year, this.SelectedDate.Month);

            for (int col = 0; col < this.tableLayoutPanel1.ColumnCount; col++)
            {
                if (sortedDays[col] == Enum.GetName(typeof(DayOfWeek), firstOfCurrentMonth.DayOfWeek))
                {
                    firstIndex = col; // Get the position of day 1 of the current month
                }
                Label lblDay = this.tableLayoutPanel1.GetControlFromPosition(col, 0) as Label;
                lblDay.Text = sortedDays[col].Substring(0, 2).ToUpper();
            }

            dayCurrent = daysInPreviousMonth - firstIndex + 1;
            if (dayCurrent > daysInPreviousMonth)
            {
                dayCurrent = daysInPreviousMonth - 6;
            }
            bool previousMonthVisible = (dayCurrent != 1);
            bool nextMonthVisible = false;

            // Row 0 is for days of week
            for (int row = 1; row < this.tableLayoutPanel1.RowCount; row++)
            {
                for (int col = 0; col < this.tableLayoutPanel1.ColumnCount; col++)
                {
                    Label lblCtrl = this.tableLayoutPanel1.GetControlFromPosition(col, row) as Label;
                    lblCtrl.Text = dayCurrent.ToString();

                    DateTime embeddedDate;
                    Font displayFont;
                    Color foreColor;
                    Color backColor = this.BackColor;
                    BorderStyle borderStyle = BorderStyle.None;

                    // Customize the days
                    if (previousMonthVisible)
                    {
                        embeddedDate = new DateTime(previousMonth.Year, previousMonth.Month, dayCurrent);
                        displayFont = this.Font;
                        foreColor = this.OtherMonthForeColor;
                    }
                    else if (nextMonthVisible)
                    {
                        embeddedDate = new DateTime(nextMonth.Year, nextMonth.Month, dayCurrent);
                        displayFont = this.Font;
                        foreColor = this.OtherMonthForeColor;
                    }
                    else // Current month
                    {
                        embeddedDate = new DateTime(this.SelectedDate.Year, this.SelectedDate.Month, dayCurrent);
                        displayFont = this.Font;
                        foreColor = this.CurrentMonthForeColor;
                    }

                    if (this.BoldedDates != null && this.BoldedDates.Contains(embeddedDate))
                    {
                        displayFont = new Font(this.Font, FontStyle.Bold);
                    }

                    if (embeddedDate == DateTime.Today)
                    {
                        foreColor = this.TodayForeColor;
                        backColor = this.TodayBackColor;
                    }
                    else if (embeddedDate == this.SelectedDate)
                    {
                        borderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
                        foreColor = this.SelectedForeColor;
                        backColor = this.SelectedBackColor;
                    }

                    lblCtrl.Tag = embeddedDate;
                    lblCtrl.Font = displayFont;
                    lblCtrl.ForeColor = foreColor;
                    lblCtrl.BackColor = backColor;
                    lblCtrl.BorderStyle = borderStyle;

                    dayCurrent++;

                    if (previousMonthVisible && dayCurrent > daysInPreviousMonth)
                    {
                        dayCurrent = 1; // Start current month
                        previousMonthVisible = false;
                    }
                    if (!previousMonthVisible && dayCurrent > daysInCurrentMonth)
                    {
                        dayCurrent = 1; // Start next month
                        nextMonthVisible = true;
                    }
                }
            }
        }

        /// <summary>
        /// Returns to the previous month
        /// </summary>
        /// <param name="sender">Sender</param>
        /// <param name="e">EventArgs</param>
        private void btnPrevious_Click(object sender, EventArgs e)
        {
            this.SelectedDate = this.SelectedDate.AddMonths(-1);
            //this.UpdateCalendar();
        }

        /// <summary>
        /// Advances to the next month
        /// </summary>
        /// <param name="sender">Sender</param>
        /// <param name="e">EventArgs</param>
        private void btnNext_Click(object sender, EventArgs e)
        {
            this.SelectedDate = this.SelectedDate.AddMonths(1);
            //this.UpdateCalendar();
        }

        /// <summary>
        /// Change background color of the label
        /// </summary>
        /// <param name="sender">Sender</param>
        /// <param name="e">EventArgs</param>
        private void lblCtrl_MouseEnter(object sender, EventArgs e)
        {
            Label lblCtrl = sender as Label;
            DateTime curDate = (DateTime)lblCtrl.Tag;
            if (curDate.Month == this.SelectedDate.Month && curDate.Year == this.SelectedDate.Year)
            {
                lblCtrl.ForeColor = this.HoverForeColor;
            }
            else
            {
                lblCtrl.ForeColor = this.OtherMonthForeColor;
            }
            //lblCtrl.ForeColor = this.HoverForeColor;
            lblCtrl.BackColor = this.HoverBackColor;
        }

        /// <summary>
        /// Change background color of the label
        /// </summary>
        /// <param name="sender">Sender</param>
        /// <param name="e">EventArgs</param>
        private void lblCtrl_MouseLeave(object sender, EventArgs e)
        {
            Label lblCtrl = sender as Label;
            DateTime curDate = (DateTime)lblCtrl.Tag;
            if (curDate == DateTime.Today)
            {
                lblCtrl.ForeColor = this.TodayForeColor;
                lblCtrl.BackColor = this.TodayBackColor;
            }
            else if (curDate == this.SelectedDate)
            {
                lblCtrl.ForeColor = this.SelectedForeColor;
                lblCtrl.BackColor = this.SelectedBackColor;
            }
            else
            {
                if (curDate.Month == this.SelectedDate.Month && curDate.Year == this.SelectedDate.Year)
                {
                    lblCtrl.ForeColor = this.CurrentMonthForeColor;
                }
                else
                {
                    lblCtrl.ForeColor = this.OtherMonthForeColor;
                }
                lblCtrl.BackColor = this.BackColor;
            }
        }

        /// <summary>
        /// Sets the currently selected day
        /// </summary>
        /// <param name="sender">Sender</param>
        /// <param name="e">EventArgs</param>
        private void lblCtrl_Click(object sender, EventArgs e)
        {
            this.SelectedDate = (DateTime)(sender as Label).Tag;
            //this.UpdateCalendar();
        }

        /// <summary>
        /// Event handler to subscribe to
        /// </summary>
        public event EventHandler CellDoubleClick;

        /// <summary>
        /// Fires the attached event handler
        /// </summary>
        /// <param name="e">EventArgs</param>
        protected virtual void OnCellDoubleClick(EventArgs e)
        {
            EventHandler handler = CellDoubleClick;
            if (handler != null)
            {
                handler(this, e);
            }
        }

        /// <summary>
        /// Fires the double-click event on any given day label
        /// </summary>
        /// <param name="sender">Sender</param>
        /// <param name="e">EventArgs</param>
        private void lblCtrl_DoubleClick(object sender, EventArgs e)
        {
            this.SelectedDate = (DateTime)(sender as Label).Tag;
            OnCellDoubleClick(EventArgs.Empty);
        }

        /// <summary>
        /// Event handler to subscribe to
        /// </summary>
        public event EventHandler SelectedDateChanged;

        /// <summary>
        /// Fires the attached event handler
        /// </summary>
        /// <param name="e">EventArgs</param>
        protected virtual void OnSelectedDateChanged(EventArgs e)
        {
            EventHandler handler = SelectedDateChanged;
            if (handler != null)
            {
                handler(this, e);
            }
        }

        /// <summary>
        /// Select today's date in the calendar
        /// </summary>
        /// <param name="sender">Sender</param>
        /// <param name="e">LinkLabelLinkClickedEventArgs</param>
        private void lnkToday_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
        {
            this.SelectedDate = DateTime.Today;
            //this.UpdateCalendar();
        }

        #endregion "Methods"
    }
}