//#define COSMOSDEBUG
using System;
using System.Collections.Generic;
using System.Drawing;

using Cosmos.Debug.Kernel;
using Cosmos.HAL.Drivers.PCI.Video;

namespace Cosmos.System.Graphics
{
    /// <summary>
    /// SVGAIIScreen class. Used to draw ractengales to the screen. See also: <seealso cref="Canvas"/>.
    /// </summary>
    public class SVGAIICanvas : Canvas
    {
        /// <summary>
        /// Disables the SVGA driver, parent method returns to VGA text mode
        /// </summary>
        public override void Disable()
        {
            _xSVGADriver.Disable();
        }

        /// <summary>
        /// Debugger.
        /// </summary>
        internal Debugger mSVGAIIDebugger = new Debugger("System", "SVGAIIScreen");
        
        private static readonly Mode _DefaultMode = new Mode(1024, 768, ColorDepth.ColorDepth32);

        /// <summary>
        /// Graphics mode.
        /// </summary>
        private Mode _Mode;

        /// <summary>
        /// VMWare SVGA 2 driver.
        /// </summary>
        private readonly VMWareSVGAII _xSVGADriver;

        /// <summary>
        /// Create new instance of the <see cref="SVGAIICanvas"/> class.
        /// </summary>
        /// <exception cref="ArgumentOutOfRangeException">Thrown if default graphics mode is not suppoted.</exception>
        public SVGAIICanvas()
            : this(_DefaultMode)
        {
        }

        /// <summary>
        /// Create new instance of the <see cref="SVGAIICanvas"/> class.
        /// </summary>
        /// <param name="aMode">A graphics mode.</param>
        /// <exception cref="ArgumentOutOfRangeException">Thrown if mode is not suppoted.</exception>
        public SVGAIICanvas(Mode aMode)
        {
            mSVGAIIDebugger.SendInternal($"Called ctor with mode {aMode}");
            ThrowIfModeIsNotValid(aMode);

            _xSVGADriver = new VMWareSVGAII();
            Mode = aMode;
        }

        /// <summary>
        /// Get and set graphics mode.
        /// </summary>
        /// <exception cref="ArgumentOutOfRangeException">(set) Thrown if mode is not suppoted.</exception>
        public override Mode Mode
        {
            get => _Mode;
            set
            {
                _Mode = value;
                mSVGAIIDebugger.SendInternal($"Called Mode set property with mode {_Mode}");
                SetGraphicsMode(_Mode);
            }
        }

        /// <summary>
        /// Override canvas dufault graphics mode.
        /// </summary>
        public override Mode DefaultGraphicMode => _DefaultMode;

        /// <summary>
        /// Draw point.
        /// </summary>
        /// <param name="pen">Pen to draw with.</param>
        /// <param name="x">X coordinate.</param>
        /// <param name="y">Y coordinate.</param>
        /// <exception cref="Exception">Thrown on memory access violation.</exception>
        public override void DrawPoint(Pen aPen, int aX, int aY)
        {
            Color xColor = aPen.Color;

            if (xColor.A == 0)
            {
                return;
            }
            else if (xColor.A < 255)
            {
                xColor = AlphaBlend(xColor, GetPointColor(aX, aY), xColor.A);
            }

            mSVGAIIDebugger.SendInternal($"Drawing point to x:{aX}, y:{aY} with {xColor.Name} Color");
            _xSVGADriver.SetPixel((uint)aX, (uint)aY, (uint)xColor.ToArgb());
            mSVGAIIDebugger.SendInternal($"Done drawing point");
            /* No need to refresh all the screen to make the point appear on Screen! */
            //xSVGAIIDriver.Update((uint)x, (uint)y, (uint)mode.Columns, (uint)mode.Rows);
            _xSVGADriver.Update((uint)aX, (uint)aY, 1, 1);
        }

        /// <summary>
        /// Draw array of colors.
        /// Not implemented.
        /// </summary>
        /// <param name="colors">Array of colors.</param>
        /// <param name="x">X coordinate.</param>
        /// <param name="y">Y coordinate.</param>
        /// <param name="width">Width.</param>
        /// <param name="height">Height.</param>
        /// <exception cref="NotImplementedException">Thrown always.</exception>
        public override void DrawArray(Color[] aColors, int aX, int aY, int aWidth, int aHeight)
        {
            throw new NotImplementedException();
            //xSVGAIIDriver.
        }

        /// <summary>
        /// Draw point.
        /// Not implemented.
        /// </summary>
        /// <param name="pen">Pen to draw with.</param>
        /// <param name="x">X coordinate.</param>
        /// <param name="y">Y coordinate.</param>
        /// <exception cref="NotImplementedException">Thrown always (only int coordinates supported).</exception>
        public override void DrawPoint(Pen aPen, float aX, float aY)
        {
            //xSVGAIIDriver.
            throw new NotImplementedException();
        }

        /// <summary>
        /// Draw filled rectangle.
        /// </summary>
        /// <param name="aPen">Pen to draw with.</param>
        /// <param name="aX_start">starting X coordinate.</param>
        /// <param name="aY_start">starting Y coordinate.</param>
        /// <param name="aWidth">Width.</param>
        /// <param name="aHeight">Height.</param>
        /// <exception cref="Exception">Thrown on memory access violation.</exception>
        /// <exception cref="NotImplementedException">Thrown if VMWare SVGA 2 has no rectange copy capability</exception>
        public override void DrawFilledRectangle(Pen aPen, int aX_start, int aY_start, int aWidth, int aHeight)
        {
            _xSVGADriver.Fill((uint)aX_start, (uint)aY_start, (uint)aWidth, (uint)aHeight, (uint)aPen.Color.ToArgb());
        }

        //public override IReadOnlyList<Mode> AvailableModes { get; } = new List<Mode>
        /// <summary>
        /// Available SVGA 2 supported video modes.
        /// <para>
        /// SD:
        /// <list type="bullet">
        /// <item>320x200x32.</item>
        /// <item>320x240x32.</item>
        /// <item>640x480x32.</item>
        /// <item>720x480x32.</item>
        /// <item>800x600x32.</item>
        /// <item>1024x768x32.</item>
        /// <item>1152x768x32.</item>
        /// </list>
        /// </para>
        /// <para>
        /// HD:
        /// <list type="bullet">
        /// <item>1280x720x32.</item>
        /// <item>1280x768x32.</item>
        /// <item>1280x800x32.</item>
        /// <item>1280x1024x32.</item>
        /// </list>
        /// </para>
        /// <para>
        /// HDR:
        /// <list type="bullet">
        /// <item>1360x768x32.</item>
        /// <item>1366x768x32.</item>
        /// <item>1440x900x32.</item>
        /// <item>1400x1050x32.</item>
        /// <item>1600x1200x32.</item>
        /// <item>1680x1050x32.</item>
        /// </list>
        /// </para>
        /// <para>
        /// HDTV:
        /// <list type="bullet">
        /// <item>1920x1080x32.</item>
        /// <item>1920x1200x32.</item>
        /// </list>
        /// </para>
        /// <para>
        /// 2K:
        /// <list type="bullet">
        /// <item>2048x1536x32.</item>
        /// <item>2560x1080x32.</item>
        /// <item>2560x1600x32.</item>
        /// <item>2560x2048x32.</item>
        /// <item>3200x2048x32.</item>
        /// <item>3200x2400x32.</item>
        /// <item>3840x2400x32.</item>
        /// </list>
        /// </para>
        /// </summary>
        public override List<Mode> AvailableModes { get; } = new List<Mode>
        {
            /*  VmWare maybe supports 16 bit resolutions but CGS not yet (we should need to do RGB32->RGB16 conversion) */
#if false
            /* 16-bit Depth Resolutions*/

            /* SD Resolutions */
            new Mode(320, 200, ColorDepth.ColorDepth16),
            new Mode(320, 240, ColorDepth.ColorDepth16),
            new Mode(640, 480, ColorDepth.ColorDepth16),
            new Mode(720, 480, ColorDepth.ColorDepth16),
            new Mode(800, 600, ColorDepth.ColorDepth16),
            new Mode(1024, 768, ColorDepth.ColorDepth16),
            new Mode(1152, 768, ColorDepth.ColorDepth16),

            /* Old HD-Ready Resolutions */
            new Mode(1280, 720, ColorDepth.ColorDepth16),
            new Mode(1280, 768, ColorDepth.ColorDepth16),
            new Mode(1280, 800, ColorDepth.ColorDepth16),  // WXGA
            new Mode(1280, 1024, ColorDepth.ColorDepth16), // SXGA

            /* Better HD-Ready Resolutions */
            new Mode(1360, 768, ColorDepth.ColorDepth16),
            new Mode(1366, 768, ColorDepth.ColorDepth16),  // Original Laptop Resolution
            new Mode(1440, 900, ColorDepth.ColorDepth16),  // WXGA+
            new Mode(1400, 1050, ColorDepth.ColorDepth16), // SXGA+
            new Mode(1600, 1200, ColorDepth.ColorDepth16), // UXGA
            new Mode(1680, 1050, ColorDepth.ColorDepth16), // WXGA++

            /* HDTV Resolutions */
            new Mode(1920, 1080, ColorDepth.ColorDepth16),
            new Mode(1920, 1200, ColorDepth.ColorDepth16), // WUXGA

            /* 2K Resolutions */
            new Mode(2048, 1536, ColorDepth.ColorDepth16), // QXGA
            new Mode(2560, 1080, ColorDepth.ColorDepth16), // UW-UXGA
            new Mode(2560, 1600, ColorDepth.ColorDepth16), // WQXGA
            new Mode(2560, 2048, ColorDepth.ColorDepth16), // QXGA+
            new Mode(3200, 2048, ColorDepth.ColorDepth16), // WQXGA+
            new Mode(3200, 2400, ColorDepth.ColorDepth16), // QUXGA
            new Mode(3840, 2400, ColorDepth.ColorDepth16), // WQUXGA
#endif
            /* 32-bit Depth Resolutions*/
            /* SD Resolutions */
                new Mode(320, 200, ColorDepth.ColorDepth32),
                new Mode(320, 240, ColorDepth.ColorDepth32),
                new Mode(640, 480, ColorDepth.ColorDepth32),
                new Mode(720, 480, ColorDepth.ColorDepth32),
                new Mode(800, 600, ColorDepth.ColorDepth32),
                new Mode(1024, 768, ColorDepth.ColorDepth32),
                new Mode(1152, 768, ColorDepth.ColorDepth32),

                /* Old HD-Ready Resolutions */
                new Mode(1280, 720, ColorDepth.ColorDepth32),
                new Mode(1280, 768, ColorDepth.ColorDepth32),
                new Mode(1280, 800, ColorDepth.ColorDepth32),  // WXGA
                new Mode(1280, 1024, ColorDepth.ColorDepth32), // SXGA

                /* Better HD-Ready Resolutions */
                new Mode(1360, 768, ColorDepth.ColorDepth32),
                //new Mode(1366, 768, ColorDepth.ColorDepth32),  // Original Laptop Resolution - this one is for some reason broken in vmware
                new Mode(1440, 900, ColorDepth.ColorDepth32),  // WXGA+
                new Mode(1400, 1050, ColorDepth.ColorDepth32), // SXGA+
                new Mode(1600, 1200, ColorDepth.ColorDepth32), // UXGA
                new Mode(1680, 1050, ColorDepth.ColorDepth32), // WXGA++

                /* HDTV Resolutions */
                new Mode(1920, 1080, ColorDepth.ColorDepth32),
                new Mode(1920, 1200, ColorDepth.ColorDepth32), // WUXGA

                /* 2K Resolutions */
                new Mode(2048, 1536, ColorDepth.ColorDepth32), // QXGA
                new Mode(2560, 1080, ColorDepth.ColorDepth32), // UW-UXGA
                new Mode(2560, 1600, ColorDepth.ColorDepth32), // WQXGA
                new Mode(2560, 2048, ColorDepth.ColorDepth32), // QXGA+
                new Mode(3200, 2048, ColorDepth.ColorDepth32), // WQXGA+
                new Mode(3200, 2400, ColorDepth.ColorDepth32), // QUXGA
                new Mode(3840, 2400, ColorDepth.ColorDepth32), // WQUXGA
        };

        /// <summary>
        /// Set graphics mode.
        /// </summary>
        /// <param name="aMode">A mode.</param>
        /// <exception cref="ArgumentOutOfRangeException">Thrown if mode is not suppoted.</exception>
        private void SetGraphicsMode(Mode aMode)
        {
            ThrowIfModeIsNotValid(aMode);

            var xWidth = (uint)aMode.Columns;
            var xHeight = (uint)aMode.Rows;
            var xColorDepth = (uint)aMode.ColorDepth;

            _xSVGADriver.SetMode(xWidth, xHeight, xColorDepth);
        }

        /// <summary>
        /// Clear screen to specified color.
        /// </summary>
        /// <param name="aColor">Color.</param>
        /// <exception cref="Exception">Thrown on memory access violation.</exception>
        /// <exception cref="NotImplementedException">Thrown if VMWare SVGA 2 has no rectange copy capability</exception>
        public override void Clear(Color aColor)
        {
            _xSVGADriver.Fill(0, 0, (uint)Mode.Columns, (uint)Mode.Rows, (uint)aColor.ToArgb());
        }

        /// <summary>
        /// Get pixel color.
        /// </summary>
        /// <param name="aX">A X coordinate.</param>
        /// <param name="aY">A Y coordinate.</param>
        /// <returns>Color value.</returns>
        /// <exception cref="Exception">Thrown on memory access violation.</exception>
        public Color GetPixel(int aX, int aY)
        {
            var xColorARGB = _xSVGADriver.GetPixel((uint)aX, (uint)aY);
            return Color.FromArgb((int)xColorARGB);
        }

        /// <summary>
        /// Set cursor.
        /// </summary>
        /// <param name="aVisible">Visible.</param>
        /// <param name="aX">A X coordinate.</param>
        /// <param name="aY">A Y coordinate.</param>
        public void SetCursor(bool aVisible, int aX, int aY)
        {
            _xSVGADriver.SetCursor(aVisible, (uint)aX, (uint)aY);
        }

        /// <summary>
        /// Create cursor.
        /// </summary>
        public void CreateCursor()
        {
            _xSVGADriver.DefineCursor();
        }

        /// <summary>
        /// Copy pixel
        /// </summary>
        /// <param name="aX">A source X coordinate.</param>
        /// <param name="aY">A source Y coordinate.</param>
        /// <param name="aNewX">A destination X coordinate.</param>
        /// <param name="aNewY">A destination Y coordinate.</param>
        /// <param name="aWidth">A width.</param>
        /// <param name="aHeight">A height.</param>
        /// <exception cref="NotImplementedException">Thrown if VMWare SVGA 2 has no rectangle copy capability</exception>
        public void CopyPixel(int aX, int aY, int aNewX, int aNewY, int aWidth = 1, int aHeight = 1)
        {
            _xSVGADriver.Copy((uint)aX, (uint)aY, (uint)aNewX, (uint)aNewY, (uint)aWidth, (uint)aHeight);
        }

        /// <summary>
        /// Move pixel
        /// </summary>
        /// <param name="aX">A X coordinate.</param>
        /// <param name="aY">A Y coordinate.</param>
        /// <param name="aNewX">A new X coordinate.</param>
        /// <param name="aNewY">A new Y coordinate.</param>
        /// <exception cref="NotImplementedException">Thrown if VMWare SVGA 2 has no rectange copy capability</exception>
        /// <exception cref="Exception">Thrown on memory access violation.</exception>
        public void MovePixel(int aX, int aY, int aNewX, int aNewY)
        {
            _xSVGADriver.Copy((uint)aX, (uint)aY, (uint)aNewX, (uint)aNewY, 1, 1);
            _xSVGADriver.SetPixel((uint)aX, (uint)aY, 0);
        }

        /// <summary>
        /// Get point color.
        /// </summary>
        /// <param name="aX">X coordinate.</param>
        /// <param name="aY">Y coordinate.</param>
        /// <returns>Color value.</returns>
        /// <exception cref="Exception">Thrown on memory access violation.</exception>
        public override Color GetPointColor(int aX, int aY)
        {
            return Color.FromArgb((int)_xSVGADriver.GetPixel((uint)aX, (uint)aY));
        }

        public override void Display()
        {
            
        }
    }
}