using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;

namespace SmartCoalApplication.Core
{
    [Serializable]
    [StructLayout(LayoutKind.Explicit)]
    public struct ColorBgra
    {
        [FieldOffset(0)]
        public byte B;

        [FieldOffset(1)]
        public byte G;

        [FieldOffset(2)]
        public byte R;

        [FieldOffset(3)]
        public byte A;

        [NonSerialized]
        [FieldOffset(0)]
        public uint Bgra;

        public const int SizeOf = 4;

        /// <summary>
        /// Compares two ColorBgra instance to determine if they are equal.
        /// </summary>
        public override bool Equals(object obj)
        {
            if (obj != null && obj is ColorBgra && ((ColorBgra)obj).Bgra == this.Bgra)
            {
                return true;
            }
            else
            {
                return false;
            }
        }

        /// <summary>
        /// Returns a hash code for this color value.
        /// </summary>
        /// <returns></returns>
        public override int GetHashCode()
        {
            unchecked
            {
                return (int)Bgra;
            }
        }

        /// <summary>
        /// Creates a new ColorBgra instance with the given color and alpha values.
        /// </summary>
        public static ColorBgra FromBgra(byte b, byte g, byte r, byte a)
        {
            ColorBgra color = new ColorBgra();
            color.Bgra = BgraToUInt32(b, g, r, a);
            return color;
        }

        /// <summary>
        /// Packs color and alpha values into a 32-bit integer.
        /// </summary>
        public static UInt32 BgraToUInt32(byte b, byte g, byte r, byte a)
        {
            return (uint)b + ((uint)g << 8) + ((uint)r << 16) + ((uint)a << 24);
        }

        /// <summary>
        /// Constructs a new ColorBgra instance with the given 32-bit value.
        /// </summary>
        public static ColorBgra FromUInt32(UInt32 bgra)
        {
            ColorBgra color = new ColorBgra();
            color.Bgra = bgra;
            return color;
        }

        public override string ToString()
        {
            return "B: " + B + ", G: " + G + ", R: " + R + ", A: " + A;
        }

        /// <summary>
        /// Casts a ColorBgra to a UInt32.
        /// </summary>
        public static explicit operator UInt32(ColorBgra color)
        {
            return color.Bgra;
        }

        /// <summary>
        /// Compares two ColorBgra instance to determine if they are equal.
        /// </summary>
        public static bool operator ==(ColorBgra lhs, ColorBgra rhs)
        {
            return lhs.Bgra == rhs.Bgra;
        }

        /// <summary>
        /// Compares two ColorBgra instance to determine if they are not equal.
        /// </summary>
        public static bool operator !=(ColorBgra lhs, ColorBgra rhs)
        {
            return lhs.Bgra != rhs.Bgra;
        }

        /// <summary>
        /// Casts a UInt32 to a ColorBgra.
        /// </summary>
        public static explicit operator ColorBgra(UInt32 uint32)
        {
            return ColorBgra.FromUInt32(uint32);
        }

        /// <summary>
        /// Converts this ColorBgra instance to a Color instance.
        /// </summary>
        public Color ToColor()
        {
            return Color.FromArgb(A, R, G, B);
        }

        public static ColorBgra White
        {
            get
            {
                return ColorBgra.FromBgra(255, 255, 255, 255);
            }
        }

        public static ColorBgra Black
        {
            get
            {
                return ColorBgra.FromBgra(0, 0, 0, 255);
            }
        }

        /// <summary>
        /// Constructs a new ColorBgra instance from the values in the given Color instance.
        /// </summary>
        public static ColorBgra FromColor(Color c)
        {
            return FromBgra(c.B, c.G, c.R, c.A);
        }


        public static ColorBgra ParseHexString(string hexString)
        {
            uint value = Convert.ToUInt32(hexString, 16);
            return ColorBgra.FromUInt32(value);
        }

        public string ToHexString()
        {
            int rgbNumber = (this.R << 16) | (this.G << 8) | this.B;
            string colorString = Convert.ToString(rgbNumber, 16);

            while (colorString.Length < 6)
            {
                colorString = "0" + colorString;
            }

            string alphaString = System.Convert.ToString(this.A, 16);

            while (alphaString.Length < 2)
            {
                alphaString = "0" + alphaString;
            }

            colorString = alphaString + colorString;

            return colorString.ToUpper();
        }
    }
}