/*
 * QR code generator library (.NET)
 *
 * Copyright (c) Manuel Bleichenbacher (MIT License)
 * https://github.com/manuelbl/QrCodeGenerator
 * Copyright (c) Project Nayuki (MIT License)
 * https://www.nayuki.io/page/qr-code-generator-library
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

using System;
using System.Collections;

namespace zero.Rendering.QrCode;

/// <summary>
/// Extension methods for the <see cref="BitArray"/> class.
/// </summary>
public static class BitArrayExtensions
{
  /// <summary>
  /// Appends the specified number bits of the specified value to this bit array.
  /// <para>
  /// The least significant bits of the specified value are added. They are appended in reverse order,
  /// from the most significant to the least significant one, i.e. bits 0 to <i>len-1</i>
  /// are appended in the order <i>len-1</i>, <i>len-2</i> ... 1, 0.
  /// </para>
  /// <para>
  /// Requires 0 &#x2264; len &#x2264; 31, and 0 &#x2264; val &lt; 2<sup>len</sup>.
  /// </para>
  /// </summary>
  /// <param name="bitArray">The BitArray instance that this method extends.</param>
  /// <param name="val">The value to append.</param>
  /// <param name="len">The number of low-order bits in the value to append.</param>
  /// <exception cref="ArgumentOutOfRangeException">Value or number of bits is out of range.</exception>
  public static void AppendBits(this BitArray bitArray, uint val, int len)
  {
    if (len < 0 || len > 31)
    {
      throw new ArgumentOutOfRangeException(nameof(len), "'len' out of range");
    }

    if (val >> len != 0)
    {
      throw new ArgumentOutOfRangeException(nameof(val), "'val' out of range");
    }

    var bitLength = bitArray.Length;
    bitArray.Length = bitLength + len;
    var mask = 1U << (len - 1);
    for (var i = bitLength; i < bitLength + len; i++) // Append bit by bit
    {
      if ((val & mask) != 0)
      {
        bitArray.Set(i, true);
      }

      mask >>= 1;
    }
  }


  /// <summary>
  /// Appends the content of the specified bit array to the end of this array.
  /// </summary>
  /// <param name="bitArray">The BitArray instance that this method extends.</param>
  /// <param name="otherArray">The bit array to append</param>
  /// <exception cref="ArgumentNullException">If <c>bitArray</c> is <c>null</c>.</exception>
  public static void AppendData(this BitArray bitArray, BitArray otherArray)
  {
    Objects.RequireNonNull(otherArray);
    var bitLength = bitArray.Length;
    bitArray.Length = bitLength + otherArray.Length;
    for (var i = 0; i < otherArray.Length; i++, bitLength++) // Append bit by bit
    {
      if (otherArray[i])
      {
        bitArray.Set(bitLength, true);
      }
    }
  }
}