using System;
using System.Runtime.InteropServices;

namespace Quik.Media.Color
{
    public class QImageBuffer : QImage
    {
        private byte[] buffer;
        GCHandle handle;

        public override QImageFormat InternalFormat { get; }
        public override int Width { get; }
        public override int Height { get; }
        public override int Depth { get; }

        public QImageBuffer(QImageFormat format, int width, int height, int depth = 1)
        {
            InternalFormat = format;
            Width = width;
            Height = height;
            Depth = depth;

            buffer = new byte[width * height * depth];
        }
        ~QImageBuffer()
        {
            Dispose(false);
        }

        private QImageLock Lock()
        {
            handle.Free();
            handle = GCHandle.Alloc(buffer, GCHandleType.Pinned);
            IntPtr ptr = Marshal.UnsafeAddrOfPinnedArrayElement(buffer, 0);
            return new QImageLock(InternalFormat, Width, Height, Depth, ptr);
        }

        protected override void Dispose(bool disposing)
        {
            buffer = null;
            handle.Free();

            GC.SuppressFinalize(this);
        }

        public override void LockBits2d(out QImageLock imageLock, QImageLockOptions options)
        {
            imageLock = Lock();
        }

        public override void LockBits3d(out QImageLock imageLock, QImageLockOptions options)
        {
            imageLock = Lock();
        }

        public override void LockBits3d(out QImageLock imageLock, QImageLockOptions options, int depth)
        {
            imageLock = Lock();
        }

        public override void UnlockBits()
        {
            handle.Free();
        }
    }
}