using UnityEngine;
using System.Collections;

/// <summary>
/// Extension methods class
/// </summary>
public static class UniGifExtension
{
    /// <summary>
    /// Convert BitArray to int (Specifies the start index and bit length)
    /// </summary>
    /// <param name="startIndex">Start index</param>
    /// <param name="bitLength">Bit length</param>
    /// <returns>Converted int</returns>
    public static int GetNumeral(this BitArray array, int startIndex, int bitLength)
    {
        var newArray = new BitArray(bitLength);

        for (int i = 0; i < bitLength; i++)
        {
            if (array.Length <= startIndex + i)
            {
                newArray[i] = false;
            }
            else
            {
                bool bit = array.Get(startIndex + i);
                newArray[i] = bit;
            }
        }

        return newArray.ToNumeral();
    }

    /// <summary>
    /// Convert BitArray to int
    /// </summary>
    /// <returns>Converted int</returns>
    public static int ToNumeral(this BitArray array)
    {
        if (array == null)
        {
            Debug.LogError("array is nothing.");
            return 0;
        }
        if (array.Length > 32)
        {
            Debug.LogError("must be at most 32 bits long.");
            return 0;
        }

        var result = new int[1];
        array.CopyTo(result, 0);
        return result[0];
    }
}