using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace NumSharp.Extensions

{

public static partial class NDArrayExtensions

{

/// <summary>

/// Stack arrays in sequence horizontally

/// </summary>

/// <param name="nps"></param>

/// <returns></returns>

public static NDArray<T> HStack<T>(params NDArray<T>[] nps)

{

if (nps == null || nps.Length == 0)

throw new Exception("Input arrays can not be empty");

List<T> list = new List<T>();

NDArray<T> np = new NDArray<T>();

foreach (NDArray<T> ele in nps)

{

if (nps[0].Shape != ele.Shape)

throw new Exception("Arrays mush have same shapes");

}

int total = nps[0].Shape.Length == 1 ? 1 : nps[0].Shape.Shapes[0];

int pageSize = nps[0].Shape.Length == 1 ? nps[0].Shape.Shapes[0] : nps[0].Shape.DimOffset[0];

//int i = 0;

//Enumerable.Range(0, total)

// .Select(x =>

// {

// foreach (NDArray<T> ele in nps)

// {

// for (int j = i * pageSize; j < (i + 1) * pageSize; j++)

// list.Add(ele.Data[j]);

// }

// return i++;

// })

// .ToArray();

for (int i = 0; i < total; i++)

{

for (int k = 0; k < nps.Length; k++)

{

for (int j = i * pageSize; j < (i + 1) * pageSize; j++)

list.Add(nps[k].Data[j]);

}

}

np.Data = list.ToArray();

int[] shapes = nps[0].Shape.Shapes.ToArray();

if (shapes.Length == 1)

shapes[0] *= nps.Length;

else

shapes[1] *= nps.Length;

np.Shape = new Shape(shapes);

return np;

}

}

}