using System.ComponentModel;
using System.Drawing;
using System.Windows.Forms;

namespace CoreUnit.Common
{
    public class FlatTabControl : TabControl
    {
        #region Public Properties

        [Description("Color for a decorative line"), Category("Appearance")]
        public Color LineColor { get; set; } = SystemColors.Highlight;

        [Description("Color for all Borders"), Category("Appearance")]
        public Color BorderColor { get; set; } = SystemColors.ControlDark;

        [Description("Back color for selected Tab"), Category("Appearance")]
        public Color SelectTabColor { get; set; } = SystemColors.ControlLight;

        [Description("Fore Color for Selected Tab"), Category("Appearance")]
        public Color SelectedForeColor { get; set; } = SystemColors.HighlightText;

        [Description("Back Color for un-selected tabs"), Category("Appearance")]
        public Color TabColor { get; set; } = SystemColors.ControlLight;

        [Description("Background color for the whole control"), Category("Appearance"), Browsable(true)]
        public override Color BackColor { get; set; } = SystemColors.Control;

        [Description("Fore Color for all Texts"), Category("Appearance")]
        public override Color ForeColor { get; set; } = SystemColors.ControlText;

        #endregion

        public FlatTabControl()
        {
            try {
                Appearance = TabAppearance.Buttons;
                DrawMode = TabDrawMode.Normal;
                ItemSize = new Size(0, 0);
                SizeMode = TabSizeMode.Fixed;
            } catch { }
        }

        protected override void InitLayout()
        {
            SetStyle(ControlStyles.AllPaintingInWmPaint, true);
            SetStyle(ControlStyles.DoubleBuffer, true);
            SetStyle(ControlStyles.ResizeRedraw, true);
            SetStyle(ControlStyles.SupportsTransparentBackColor, true);
            SetStyle(ControlStyles.UserPaint, true);
            base.InitLayout();
        }

        protected override void OnPaint(PaintEventArgs e)
        {
            base.OnPaint(e);
            DrawControl(e.Graphics);
        }

        internal void DrawControl(Graphics g)
        {
            try {
                if (!Visible) {
                    return;
                }

                Rectangle clientRectangle = ClientRectangle;
                clientRectangle.Inflate(2, 2);

                // Whole Control Background:
                using (Brush bBackColor = new SolidBrush(BackColor)) {
                    g.FillRectangle(bBackColor, ClientRectangle);
                }

                Region region = g.Clip;

                for (int i = 0; i < TabCount; i++) {
                    DrawTab(g, TabPages[i], i);
                    TabPages[i].BackColor = TabColor;
                }

                g.Clip = region;

                using (Pen border = new Pen(BorderColor)) {
                    g.DrawRectangle(border, clientRectangle);

                    if (SelectedTab != null) {
                        clientRectangle.Offset(1, 1);
                        clientRectangle.Width -= 2;
                        clientRectangle.Height -= 2;
                        g.DrawRectangle(border, clientRectangle);
                        clientRectangle.Width -= 1;
                        clientRectangle.Height -= 1;
                        g.DrawRectangle(border, clientRectangle);
                    }
                }

                // a decorative line on top of pages:
                using (Brush bLineColor = new SolidBrush(LineColor)) {
                    Rectangle rectangle = ClientRectangle;
                    rectangle.Height = 1;
                    rectangle.Y = 25;
                    g.FillRectangle(bLineColor, rectangle);

                    rectangle = ClientRectangle;
                    rectangle.Height = 1;
                    rectangle.Y = 26;
                    g.FillRectangle(bLineColor, rectangle);
                }

            } catch { }
        }

        internal void DrawTab(Graphics g, TabPage customTabPage, int nIndex)
        {
            Rectangle tabRect = GetTabRect(nIndex);
            Rectangle tabTextRect = GetTabRect(nIndex);
            bool isSelected = (SelectedIndex == nIndex);
            Point[] points;

            if (Alignment == TabAlignment.Top) {
                points = new[]
                {
                    new Point(tabRect.Left, tabRect.Bottom),
                    new Point(tabRect.Left, tabRect.Top + 0),
                    new Point(tabRect.Left + 0, tabRect.Top),
                    new Point(tabRect.Right - 0, tabRect.Top),
                    new Point(tabRect.Right, tabRect.Top + 0),
                    new Point(tabRect.Right, tabRect.Bottom),
                    new Point(tabRect.Left, tabRect.Bottom)
                };
            } else {
                points = new[]
                {
                    new Point(tabRect.Left, tabRect.Top),
                    new Point(tabRect.Right, tabRect.Top),
                    new Point(tabRect.Right, tabRect.Bottom - 0),
                    new Point(tabRect.Right - 0, tabRect.Bottom),
                    new Point(tabRect.Left + 0, tabRect.Bottom),
                    new Point(tabRect.Left, tabRect.Bottom - 0),
                    new Point(tabRect.Left, tabRect.Top)
                };
            }

            // Draws the Tab Header:
            Color HeaderColor = isSelected ? SelectTabColor : BackColor;
            using (Brush brush = new SolidBrush(HeaderColor)) {
                g.FillPolygon(brush, points);
                brush.Dispose();
                g.DrawPolygon(new Pen(HeaderColor), points);
            }

            Rectangle rectangleF = tabTextRect;
            rectangleF.Y += 2;

            TextRenderer.DrawText(g, customTabPage.Text, Font, rectangleF,
                 isSelected ? SelectedForeColor : ForeColor);
        }
    }
}