/////////////////////////////////////////////////////////////////////////////////
//
// Photoshop PSD FileType Plugin for Paint.NET
// http://psdplugin.codeplex.com/
//
// This software is provided under the MIT License:
//   Copyright (c) 2006-2007 Frank Blumenberg
//   Copyright (c) 2010-2016 Tao Yue
//
// See LICENSE.txt for complete licensing and attribution information.
//
/////////////////////////////////////////////////////////////////////////////////

using System;
using System.Drawing;
using System.IO.Compression;

namespace PhotoshopFile.Compression
{
  public abstract class ImageData
  {
    public int BitDepth { get; private set; }

    public int BytesPerRow { get; private set; }

    public Size Size { get; private set; }

    protected abstract bool AltersWrittenData { get; }

    protected ImageData(Size size, int bitDepth)
    {
      Size = size;
      BitDepth = bitDepth;
      BytesPerRow = Util.BytesPerRow(size, bitDepth);
    }

    /// <summary>
    /// Reads decompressed image data.
    /// </summary>
    public virtual byte[] Read()
    {
      var imageLongLength = (long)BytesPerRow * Size.Height;
      Util.CheckByteArrayLength(imageLongLength);

      var buffer = new byte[imageLongLength];
      Read(buffer);
      return buffer;
    }

    internal abstract void Read(byte[] buffer);

    /// <summary>
    /// Reads compressed image data.
    /// </summary>
    public abstract byte[] ReadCompressed();

    /// <summary>
    /// Writes rows of image data into compressed format.
    /// </summary>
    /// <param name="array">An array containing the data to be compressed.</param>
    public void Write(byte[] array)
    {
      var imageLength = (long)BytesPerRow * Size.Height;
      if (array.Length != imageLength)
      {
        throw new ArgumentException(
          "Array length is not equal to image length.",
          nameof(array));
      }

      if (AltersWrittenData)
      {
        array = (byte[])array.Clone();
      }
      
      WriteInternal(array);
    }

    internal abstract void WriteInternal(byte[] array);
  }
}