using System;
using System.Collections.Generic;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Media.Imaging;
using Tango.RemoteDesktop.Frames;

namespace Tango.RemoteDesktop
{
    /// <summary>
    /// Represents a screen capture frame for holding the original bitmap and difference frame.
    /// </summary>
    /// <typeparam name="TFrame">The type of the frame.</typeparam>
    /// <seealso cref="Tango.RemoteDesktop.Frames.RasterFrame" />
    /// <seealso cref="System.IDisposable" />
    public class ScreenCaptureFrame<TFrame> : RasterFrame, IDisposable where TFrame : IFrame
    {
        private TFrame _diffFrame;

        /// <summary>
        /// Initializes a new instance of the <see cref="ScreenCaptureFrame{TFrame}"/> class.
        /// </summary>
        /// <param name="bitmap">The bitmap.</param>
        public ScreenCaptureFrame(Bitmap bitmap) : base(bitmap)
        {

        }

        /// <summary>
        /// Initializes a new instance of the <see cref="ScreenCaptureFrame{TFrame}"/> class.
        /// </summary>
        /// <param name="bitmap">The bitmap.</param>
        /// <param name="diffFrame">The difference frame.</param>
        public ScreenCaptureFrame(Bitmap bitmap, TFrame diffFrame) : this(bitmap)
        {
            _diffFrame = diffFrame;
        }

        /// <summary>
        /// Gets a value indicating whether a difference frame is available.
        /// </summary>
        public bool DifferenceAvailable
        {
            get { return _diffFrame != null; }
        }

        /// <summary>
        /// Gets or sets the number differences.
        /// </summary>
        public uint DifferenceCount { get; set; }

        /// <summary>
        /// Returns the difference frame.
        /// </summary>
        /// <returns></returns>
        /// <exception cref="InvalidOperationException">No difference is available at this point. Please use the 'DifferenceAvailable' property before attempting to get the difference.</exception>
        public TFrame ToDifference()
        {
            if (!DifferenceAvailable)
            {
                throw new InvalidOperationException("No difference is available at this point. Please use the 'DifferenceAvailable' property before attempting to get the difference.");
            }

            return _diffFrame;
        }

        /// <summary>
        /// Releases unmanaged and - optionally - managed resources.
        /// </summary>
        public override void Dispose()
        {
            base.Dispose();

            if (_diffFrame != null)
            {
                _diffFrame.Dispose();
            }
        }
    }
}