using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Text;

namespace StgSharp.Math
{

    [StructLayout(LayoutKind.Explicit)]
    public struct Array2x4 : IEquatable<Array2x4>
    {
        [FieldOffset(0)]
        public Vec4D row1;
        [FieldOffset(16)]
        public Vec4D row2;

        public Array2x4(Vec4D r1,Vec4D r2)
        {
            row1 = r1;
            row2 = r2;
        }

        

        public bool Equals(Array2x4 other)
        {
            if (this.GetHashCode() != other.GetHashCode())
            {
                return false;
            }
            else
            {
                return this.row1 == other.row1
                    && this.row2 == other.row2;
            }
        }

        public override bool Equals(object obj)
        {
            if (obj == null)
            {
                return false;
            }
            else if (obj.GetType() != typeof(Array2x4))
            {
                return false;
            }
            else
            {
                return this.Equals((Array2x4)obj);
            }
        }

        public override int GetHashCode()
        {
            return HashCode.Combine(this.row1, this.row2);
        }

        public override string ToString()
        {
            return $"{this.row1}\n{this.row2}";
        }

        public static Array2x4 operator +(Array2x4 array1,Array2x4 array2)
        {
            return new Array2x4(
                array1.row1 + array2.row1,
                array1.row2 + array2.row2
                ) ;
        }

        public static Array2x4 operator -(Array2x4 array1, Array2x4 array2)
        {
            return new Array2x4(
                array1.row1 - array2.row1,
                array1.row2 - array2.row2
                );
        }

        public static Array2x4 operator *(Array2x4 array, float x)
        {
            return new Array2x4(
                array.row1 * x,
                array.row2 * x
                );
        }

        public static Array2x4 operator /(Array2x4 array, float x)
        {
            return new Array2x4(
                array.row1 / x,
                array.row2 / x
                );
        }

        public static unsafe Array2x2 operator *(Array2x4 array1, Array4x2 array2)
        {
            float* p1 = &array1.row1.X;
            float* p2 = &array2.row2.X;

            return new Array2x2(
                *(p1 + 0) * *(p2 + 0)+ *(p1 + 1) * *(p2 + 2)+ *(p1 + 2) * *(p2 + 4)+ *(p1 + 3) * *(p2 + 6),
                *(p1 + 0) * *(p2 + 1)+ *(p1 + 1) * *(p2 + 3)+ *(p1 + 2) * *(p2 + 5)+ *(p1 + 3) * *(p2 + 7),
                *(p1 + 4) * *(p2 + 0)+ *(p1 + 5) * *(p2 + 2)+ *(p1 + 6) * *(p2 + 4)+ *(p1 + 7) * *(p2 + 6),
                *(p1 + 4) * *(p2 + 1)+ *(p1 + 5) * *(p2 + 3)+ *(p1 + 6) * *(p2 + 5)+ *(p1 + 7) * *(p2 + 7)
                );
        }
    }
}