using System;
using System.Runtime.InteropServices;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Windows.Forms;
using SlimDX;
using SlimDX.Direct3D9;
using Font = SlimDX.Direct3D9.Font;
using BizHawk.Core;

namespace BizHawk.MultiClient
{
    public class ImageTexture : IDisposable
    {
        public Device GraphicsDevice;
        public Texture Texture;

        private int imageWidth;
        public int ImageWidth { get { return imageWidth; } }

        private int imageHeight;
        public int ImageHeight { get { return imageHeight; } }

        private int textureWidth;
        public int TextureWidth { get { return textureWidth; } }

        private int textureHeight;
        public int TextureHeight { get { return textureHeight; } }

        public ImageTexture(Device graphicsDevice)
        {
            GraphicsDevice = graphicsDevice;
        }

        public void SetImage(int[] data, int width, int height)
        {
            bool needsRecreating = false;
            if (Texture == null)
            {
                needsRecreating = true;
            }
            else
            {
                var currentTextureSize = Texture.GetLevelDescription(0);
                if (imageWidth != width || imageHeight != height)
                {
                    needsRecreating = true;
                }
            }
            // If we need to recreate the texture, do so.
            if (needsRecreating)
            {
                if (Texture != null)
                {
                    Texture.Dispose();
                    Texture = null;
                }
                // Copy the width/height to member fields.
                imageWidth = width;
                imageHeight = height;
                // Round up the width/height to the nearest power of two.
                textureWidth = 32; textureHeight = 32;
                while (textureWidth < imageWidth) textureWidth <<= 1;
                while (textureHeight < imageHeight) textureHeight <<= 1;
                // Create a new texture instance.
                Texture = new Texture(GraphicsDevice, textureWidth, textureHeight, 1, Usage.Dynamic, Format.X8R8G8B8, Pool.Default);
            }
            // Copy the image data to the texture.
            using (var Data = Texture.LockRectangle(0, new Rectangle(0, 0, imageWidth, imageHeight), LockFlags.None).Data)
            {
                if (imageWidth == textureWidth)
                {
                    // Widths are the same, just dump the data across (easy!)
                    Data.WriteRange(data, 0, imageWidth * imageHeight);
                }
                else
                {
                    // Widths are different, need a bit of additional magic here to make them fit:
                    long RowSeekOffset = 4 * (textureWidth - imageWidth);
                    for (int r = 0, s = 0; r < imageHeight; ++r, s += imageWidth)
                    {
                        Data.WriteRange(data, s, imageWidth);
                        Data.Seek(RowSeekOffset, SeekOrigin.Current);
                    }
                }
                Texture.UnlockRectangle(0);
            }
        }

        private bool disposed;

        public void Dispose()
        {
            if (!disposed)
            {
                disposed = true;
                if (Texture != null)
                    Texture.Dispose();
                Texture = null;
                GC.SuppressFinalize(this);
            }
        }
    }

	public interface IRenderer : IDisposable
	{
		void Render(IVideoProvider video);
		bool Resized { get; set; }
		void AddMessage(string msg);
	}

	public class SysdrawingRenderPanel : IRenderer
	{
		public bool Resized { get; set; }
		public void Dispose() { }
		public void Render(IVideoProvider video)
		{
            Color BackgroundColor = Color.FromArgb(video.BackgroundColor);

            int[] data = video.GetVideoBuffer();

			Bitmap bmp = new Bitmap(video.BufferWidth, video.BufferHeight, PixelFormat.Format32bppArgb);
			BitmapData bmpdata = bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height), ImageLockMode.WriteOnly, PixelFormat.Format32bppArgb);

			//TODO - this is not very intelligent. no handling of pitch, for instance
			Marshal.Copy(data, 0, bmpdata.Scan0, bmp.Width * bmp.Height);

			bmp.UnlockBits(bmpdata);

			backingControl.SetBitmap(bmp);
		}
		public SysdrawingRenderPanel(RetainedViewportPanel control)
		{
			backingControl = control;
		}
		RetainedViewportPanel backingControl;
		public void AddMessage(string msg) { }
	}


	public class Direct3DRenderPanel : IRenderer
    {
        public Color BackgroundColor { get; set; }
        public bool Resized { get; set; }

        private Direct3D d3d;
        private Device Device;
        private Control backingControl;
        public ImageTexture Texture;
        private Sprite Sprite;
        private Font MessageFont;

		public Direct3DRenderPanel(Direct3D direct3D, Control control)
        {
            d3d = direct3D;
            backingControl = control;
		    control.DoubleClick += (o, e) => Global.MainForm.ToggleFullscreen();
        }

        private void DestroyDevice()
        {
            if (Texture != null)
            {
                Texture.Dispose();
                Texture = null;
            }
            if (Sprite != null)
            {
                Sprite.Dispose();
                Sprite = null;
            }
            if (MessageFont != null)
            {
                MessageFont.Dispose();
                MessageFont = null;
            }
        }

        public void CreateDevice()
        {
            DestroyDevice();
			var pp = new PresentParameters
                {
                    BackBufferWidth = Math.Max(1, backingControl.ClientSize.Width),
                    BackBufferHeight = Math.Max(1, backingControl.ClientSize.Height),
                    DeviceWindowHandle = backingControl.Handle,
                    PresentationInterval = Global.Config.DisplayVSync?PresentInterval.One:PresentInterval.Immediate
                };
            Device = new Device(d3d, 0, DeviceType.Hardware, backingControl.Handle, CreateFlags.HardwareVertexProcessing, pp);
            Sprite = new Sprite(Device);
            Texture = new ImageTexture(Device);
            MessageFont = new Font(Device, 16, 0, FontWeight.Bold, 1, false, CharacterSet.Default, Precision.Default, FontQuality.Default, PitchAndFamily.Default | PitchAndFamily.DontCare, "Arial");
        }

        public void Render()
        {
            if (Device == null || Resized)
                CreateDevice();

            Resized = false;
            Device.Clear(ClearFlags.Target, BackgroundColor, 1.0f, 0);
            Device.Present(Present.DoNotWait);
        }

        public void Render(IVideoProvider video)
        {
            if (video == null)
            {
                Render();
                return;
            }

            if (Device == null || Resized)
                CreateDevice();
            Resized = false;

            BackgroundColor = Color.FromArgb(video.BackgroundColor);

            int[] data = video.GetVideoBuffer();
            Texture.SetImage(data, video.BufferWidth, video.BufferHeight);

            Device.Clear(ClearFlags.Target, BackgroundColor, 1.0f, 0);

            // figure out scaling factor
            float widthScale = (float) backingControl.Size.Width /  video.BufferWidth;
            float heightScale = (float) backingControl.Size.Height / video.BufferHeight;
            float finalScale = Math.Min(widthScale, heightScale);

            Device.BeginScene();

            Sprite.Begin(SpriteFlags.None);
            Device.SetSamplerState(0, SamplerState.MagFilter, TextureFilter.Point);
            Device.SetSamplerState(1, SamplerState.MagFilter, TextureFilter.Point);
            Sprite.Transform = Matrix.Scaling(finalScale, finalScale, 0f);
            Sprite.Draw(Texture.Texture, new Rectangle(0, 0, video.BufferWidth, video.BufferHeight), new Vector3(video.BufferWidth / 2f, video.BufferHeight / 2f, 0), new Vector3(backingControl.Size.Width / 2f / finalScale, backingControl.Size.Height / 2f / finalScale, 0), Color.White);
            Sprite.End();

            DrawMessages();

            Device.EndScene();
            Device.Present(Present.DoNotWait);
        }

        /// <summary>
        /// Display all screen info objects like fps, frame counter, lag counter, and input display
        /// </summary>
        public void DrawScreenInfo()
        {
            //TODO: If movie loaded use that frame counter, and also display total movie frame count if read-only
            if (Global.Config.DisplayFrameCounter)
                MessageFont.DrawString(null, Global.Emulator.Frame.ToString(), 1, 1, new Color4(Color.White)); //TODO: Allow user to set screen coordinates?

            if (Global.Config.DisplayInput)
            {
                string input = "";
                switch (Global.Emulator.SystemId)
                {
                    case "SMS":
                        input = MakeSMSInputDisplay();
                        break;
                    case "PCE":
                        input = MakePCEInputDisplay();
                        break;
                    default:
                        break;

                }

                MessageFont.DrawString(null, input, 1, 16, new Color4(Color.White));
            }
        }

        private List<UIMessage> messages = new List<UIMessage>(5);

        public void AddMessage(string message)
        {
            messages.Add(new UIMessage {Message = message, ExpireAt = DateTime.Now + TimeSpan.FromSeconds(2)});
        }

        private void DrawMessages()
        {
            messages.RemoveAll(m => DateTime.Now > m.ExpireAt);
            DrawScreenInfo();
            int line = 1;
            for (int i=messages.Count - 1; i>=0; i--, line++)
            {
                int x = 3;
                int y = backingControl.Size.Height - (line*18);
                MessageFont.DrawString(null, messages[i].Message, x+2, y+2, new Color4(Color.Black));
                MessageFont.DrawString(null, messages[i].Message, x, y, new Color4(Color.White));
            }
        }

        private bool disposed;

        public void Dispose()
        {
            if (disposed == false)
            {
                disposed = true;
                DestroyDevice();
            }
        }

        public string MakeSMSInputDisplay()
        {
            string input = "";
            if (Global.Emulator.Controller.IsPressed("P1 Up")) input += "U";
            else input += " ";
            if (Global.Emulator.Controller.IsPressed("P1 Down")) input += "D";
            else input += " ";
            if (Global.Emulator.Controller.IsPressed("P1 Left")) input += "L";
            else input += " ";
            if (Global.Emulator.Controller.IsPressed("P1 Right")) input += "R";
            else input += " ";
            if (Global.Emulator.Controller.IsPressed("P1 B1")) input += "1";
            else input += " ";
            if (Global.Emulator.Controller.IsPressed("P1 B2")) input += "2";
            else input += " ";
            if (Global.Emulator.Controller.IsPressed("P2 Up")) input += "U";
            else input += " ";
            if (Global.Emulator.Controller.IsPressed("P2 Down")) input += "D";
            else input += " ";
            if (Global.Emulator.Controller.IsPressed("P2 Left")) input += "L";
            else input += " ";
            if (Global.Emulator.Controller.IsPressed("P2 Right")) input += "R";
            else input += " ";
            if (Global.Emulator.Controller.IsPressed("P2 B1")) input += "1";
            else input += " ";
            if (Global.Emulator.Controller.IsPressed("P2 B2")) input += "2";
            else input += " ";
            if (Global.Emulator.Controller.IsPressed("Pause")) input += "S";
            else input += " ";
            if (Global.Emulator.Controller.IsPressed("Reset")) input += "R";
            else input += " ";
            return input;
        }

        public string MakePCEInputDisplay()
        {
            string input = "";
            if (Global.Emulator.Controller.IsPressed("Up")) input += "U";
            else input += " ";
            if (Global.Emulator.Controller.IsPressed("Down")) input += "D";
            else input += " ";
            if (Global.Emulator.Controller.IsPressed("Left")) input += "L";
            else input += " ";
            if (Global.Emulator.Controller.IsPressed("Right")) input += "R";
            else input += " ";
            if (Global.Emulator.Controller.IsPressed("I")) input += "1";
            else input += " ";
            if (Global.Emulator.Controller.IsPressed("II")) input += "2";
            else input += " ";
            if (Global.Emulator.Controller.IsPressed("Select")) input += "S";
            else input += " ";
            if (Global.Emulator.Controller.IsPressed("Run")) input += "R";
            else input += " ";
            return input;
        }
    }

    class UIMessage
    {
        public string Message;
        public DateTime ExpireAt;
    }
}