using System.Collections.Generic;
using System.IO;
using fis.Vid.Visuals;

namespace fis.Vid
{
    
    /// <summary>
    /// Used for update the image data.
    /// </summary>
    internal interface IImageDataContainer
    {
        byte[] ImageData { get; set; }
    }

    /// <summary>
    /// This class is used for updating the image data.
    /// </summary>
    public class VinnoImageUpdater
    {
        private readonly IImageDataContainer _imageDataContainer;

        public VinnoImageUpdater(VinnoImage image)
        {
            _imageDataContainer = image;
        }

        /// <summary>
        /// Update VinnoImage's image data
        /// </summary>
        /// <param name="imageData">The image data to be updated.</param>
        public void Update(byte[] imageData)
        {
            _imageDataContainer.ImageData = imageData;
        }
    }

    public class VinnoImage : IImageDataContainer
    {

        /// <summary>
        /// Gets the index of this image.
        /// </summary>
        public int Index { get; }


        /// <summary>
        /// Gets the width of this image data.
        /// </summary>
        public int Width { get; }

        /// <summary>
        /// Gets the height of this image data.
        /// </summary>
        public int  Height { get; }


        /// <summary>
        /// Gets the image data of this image.
        /// </summary>
        public byte[] ImageData { get; private set; }


        /// <summary>
        /// Gets all visuals of this image.
        /// </summary>
        public IList<VinnoVisual> Visuals { get; }


        /// <summary>
        /// Implement the interface for update the image data.
        /// </summary>
        byte[] IImageDataContainer.ImageData
        {
            get => ImageData;
            set => ImageData = value;
        }

        public VinnoImage(int index, int width, int height, byte[] imageData)
        {
            Visuals = new List<VinnoVisual>();
            Index = index;
            Width = width;
            Height = height;
            ImageData = imageData;
        }


        /// <summary>
        /// Convert image to bytes.
        /// </summary>
        /// <returns>The converted bytes.</returns>
        public byte[] ToBytes()
        {
            byte[] result = new byte[0];
            using (var stream = new MemoryStream())
            {
                var writer = new VinnoStreamWriter(stream);
                if (writer != null)
                {
                    writer.WriteInt(Index);
                    writer.WriteByte((byte)Visuals.Count);
                    foreach (var visual in Visuals)
                    {
                        var buffer = visual?.ToBytes();
                        if (buffer != null)
                        {
                            writer.WriteBytes(buffer);
                        }
                    }
                    writer.WriteShort((short)Width);
                    writer.WriteShort((short)Height);
                    writer.WriteBytes(ImageData);
                    result = stream.ToArray();
                }
            }
            return result;
        }


        /// <summary>
        /// Convert bytes to a <see cref="VinnoImage"/>
        /// </summary>
        /// <param name="bytes">The bytes to be converted.</param>
        /// <returns>The converted <see cref="VinnoImage"/></returns>
        public static VinnoImage FromBytes(byte[] bytes)
        {
            VinnoImage result;
            using (var stream = new MemoryStream(bytes))
            {
                stream.Position = 0;
                var reader = new VinnoStreamReader(stream);
                var index = reader.ReadInt();
                var visualCount = reader.ReadByte();
                var visuals = new List<VinnoVisual>();
                for (int i = 0; i < visualCount; i++)
                {
                    var visual = VinnoVisual.FromBytes(reader.ReadBytes());
                    visuals.Add(visual);
                }
                var widht = reader.ReadShort();
                var height = reader.ReadShort();
                var imageData = reader.ReadBytes();
                result = new VinnoImage(index, widht, height, imageData);
                foreach (var visual in visuals)
                {
                    result.Visuals.Add(visual);
                }
            }
            return result;
        }
    }
}