using System;
using System.Collections.Generic;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Tango.RemoteDesktop.Utils;

namespace Tango.RemoteDesktop.Frames
{
    /// <summary>
    /// Represents a vector frame encapsulating a set of <see cref="VectorFramePixel"/>.
    /// </summary>
    /// <seealso cref="Tango.RemoteDesktop.Frame" />
    public class VectorFrame : Frame
    {
        private int _width;
        /// <summary>
        /// Gets the frame width.
        /// </summary>
        public override int Width
        {
            get { return _width; }
        }

        private int _height;
        /// <summary>
        /// Gets the frame height.
        /// </summary>
        public override int Height
        {
            get { return _height; }
        }

        /// <summary>
        /// Gets or sets the colors dictionary.
        /// </summary>
        public Dictionary<int, VectorFrameColor> Colors { get; set; }

        /// <summary>
        /// Gets the pixels.
        /// </summary>
        /// <value>
        /// The pixels.
        /// </value>
        public List<VectorFramePixel> Pixels { get; private set; }

        /// <summary>
        /// Initializes a new instance of the <see cref="VectorFrame"/> class.
        /// </summary>
        /// <param name="width">The frame width.</param>
        /// <param name="height">The frame height.</param>
        public VectorFrame(int width, int height)
        {
            _width = width;
            _height = height;
            Pixels = new List<VectorFramePixel>();
            Colors = new Dictionary<int, VectorFrameColor>();
        }

        /// <summary>
        /// Returns a GDI bitmap representing the frame.
        /// </summary>
        /// <returns></returns>
        public override Bitmap ToBitmap()
        {
            DirectBitmap directBitmap = new DirectBitmap(Width, Height);
            foreach (var pixel in Pixels)
            {
                directBitmap.SetPixel((int)pixel.X, (int)pixel.Y, pixel.Color.ToColor());
            }

            directBitmap.Dispose();
            return directBitmap.Bitmap;
        }

        /// <summary>
        /// Applies this frame onto an existing bitmap.
        /// </summary>
        /// <param name="bitmap">The bitmap.</param>
        public override void Apply(Bitmap bitmap)
        {
            using (FastBitmap fast = bitmap.FastLock())
            {
                foreach (var pixel in Pixels)
                {
                    fast.SetPixel((int)pixel.X, (int)pixel.Y, pixel.Color.ToColor());
                }
            }
        }

        /// <summary>
        /// Returns a byte array containing the binary serialized version of this frame.
        /// </summary>
        /// <returns></returns>
        public byte[] Serialize()
        {
            using (MemoryStream ms = new MemoryStream())
            {
                using (BinaryWriter writer = new BinaryWriter(ms))
                {
                    writer.Write((UInt16)Width);
                    writer.Write((UInt16)Height);
                    writer.Write((UInt16)Colors.Count);

                    if (Colors.Count > UInt16.MaxValue)
                    {
                        throw new InvalidOperationException("Number of color exceeded the maximum colors allowed.");
                    }

                    foreach (var color in Colors)
                    {
                        writer.Write(color.Value.R);
                        writer.Write(color.Value.G);
                        writer.Write(color.Value.B);
                    }

                    foreach (var pixel in Pixels)
                    {
                        writer.Write((UInt16)pixel.X);
                        writer.Write((UInt16)pixel.ColorIndex);
                    }

                    ms.Position = 0;
                    return ms.ToArray();
                }
            }
        }

        /// <summary>
        /// Calculates the size of <see cref="Serialize"/> byte output.
        /// </summary>
        /// <returns></returns>
        public int CalculateSize()
        {
            int size = 0;

            size += sizeof(int) * 3; //Width, Height, Count
            size += sizeof(ushort) * 2 * Pixels.Count; //X, Y
            size += sizeof(byte) * 3 * Pixels.Count; //RGB

            return size;
        }

        /// <summary>
        /// Creates a new instance of <see cref="VectorFrame"/> from the specified serialized byte array.
        /// </summary>
        /// <param name="data">The byte array.</param>
        /// <returns></returns>
        public static VectorFrame Deserialize(byte[] data)
        {
            using (MemoryStream ms = new MemoryStream(data))
            {
                using (BinaryReader reader = new BinaryReader(ms))
                {
                    ms.Position = 0;
                    var vector = new VectorFrame(reader.ReadUInt16(), reader.ReadUInt16());

                    int colorCount = reader.ReadUInt16(); //Number of colors in color table.

                    for (int i = 0; i < colorCount; i++)
                    {
                        VectorFrameColor color = new VectorFrameColor()
                        {
                            R = reader.ReadByte(),
                            G = reader.ReadByte(),
                            B = reader.ReadByte(),
                            Index = i,
                        };

                        vector.Colors.Add(color.ToInt32(), color);
                    }

                    for (int i = 0; i < vector.Height; i++)
                    {
                        VectorFramePixel pixel = new VectorFramePixel();
                        pixel.X = reader.ReadUInt16();
                        pixel.Y = i;
                        pixel.ColorIndex = reader.ReadUInt16();
                        pixel.Color = vector.Colors.ElementAt(pixel.ColorIndex).Value;
                        vector.Pixels.Add(pixel);
                    }

                    return vector;
                }
            }
        }

        /// <summary>
        /// Releases unmanaged and - optionally - managed resources.
        /// </summary>
        public override void Dispose()
        {
            Pixels.Clear();
            Pixels = null;
        }

        #region Color Helpers

        /// <summary>
        /// Converts the specified color to integer.
        /// </summary>
        /// <param name="color">The color.</param>
        /// <returns></returns>
        public static int ColorToInteger(byte r, byte g, byte b)
        {
            return (int)((255 << 24) | (r << 16) | (g << 8) | (b << 0));
        }

        /// <summary>
        /// Converts the specified integer to color.
        /// </summary>
        /// <param name="integer">The integer.</param>
        /// <returns></returns>
        public static Color IntegerToColor(int integer)
        {
            byte a = (byte)(integer >> 24);
            byte r = (byte)(integer >> 16);
            byte g = (byte)(integer >> 8);
            byte b = (byte)(integer >> 0);
            return Color.FromArgb(a, r, g, b);
        }

        #endregion
    }
}