using System;
using System.Collections.Generic;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;

namespace Tango.SharedUI.Rendering
{
    /// <summary>
    /// Represents an on window chart renderer.
    /// </summary>
    public partial class RenderWindow : Window
    {
        private Action<String> _fileCallback;
        private Action<RenderTargetBitmap> _bitmapCallback;
        private Size _renderSize;
        private ImageFormat _format;
        private int _quality;
        private String _filePath;
        private FrameworkElement _element;
        private bool renderToFile;

        /// <summary>
        /// Initializes a new instance of the <see cref="RenderWindow"/> class.
        /// </summary>
        /// <param name="element">The element.</param>
        public RenderWindow(FrameworkElement element)
        {
            InitializeComponent();
            element.HorizontalAlignment = System.Windows.HorizontalAlignment.Left;
            element.VerticalAlignment = System.Windows.VerticalAlignment.Top;
            _element = element;
            grid.Children.Add(_element);
        }

        /// <summary>
        /// Occurs when the window is completely loaded.
        /// </summary>
        /// <param name="sender">The sender.</param>
        /// <param name="e">The <see cref="EventArgs"/> instance containing the event data.</param>
        private void RenderWindow_ContentRendered(object sender, EventArgs e)
        {
            RenderTargetBitmap bmp = CreateBitmap(grid, new Size(_renderSize.Width, _renderSize.Height));

            if (renderToFile)
            {
                using (FileStream fs = new FileStream(_filePath, FileMode.Create))
                {
                    BitmapEncoder encoder = GetEncoderByImageFormat(_format, _quality);

                    encoder.Frames.Add(BitmapFrame.Create(bmp));
                    encoder.Save(fs);
                }

                if (_fileCallback != null)
                {
                    _fileCallback(_filePath);
                }
            }
            else
            {
                if (_bitmapCallback != null)
                {
                    _bitmapCallback(bmp);
                }
            }

            this.Close();
        }

        /// <summary>
        /// Renders to file.
        /// </summary>
        /// <param name="designSize">Size of the design.</param>
        /// <param name="renderSize">Size of the render.</param>
        /// <param name="filePath">The file path.</param>
        /// <param name="format">The format.</param>
        /// <param name="readyCallback">The ready callback.</param>
        public void RenderToFile(Size designSize, Size renderSize, String filePath, ImageFormat format, Action<String> readyCallback = null)
        {
            renderToFile = true;
            _renderSize = renderSize;
            _filePath = filePath;
            _format = format;
            _fileCallback = readyCallback;

            double scaleX = renderSize.Width / designSize.Width;
            double scaleY = scaleX;

            this.WindowStyle = WindowStyle.None;
            this.AllowsTransparency = true;
            this.Opacity = 0.001;
            this.ShowInTaskbar = false;
            this.ShowActivated = false;
            this.Width = 1;
            this.Height = 1;
            _element.Width = designSize.Width;
            _element.Height = designSize.Height;


            grid.LayoutTransform = new ScaleTransform(scaleX, scaleY, 0, 0);

            this.ContentRendered += RenderWindow_ContentRendered;

            this.Show();
        }

        /// <summary>
        /// Renders to file.
        /// </summary>
        /// <param name="designSize">Size of the design.</param>
        /// <param name="renderSize">Size of the render.</param>
        /// <param name="filePath">The file path.</param>
        /// <param name="format">The format.</param>
        /// <param name="readyCallback">The ready callback.</param>
        public void RenderToFileSynced(Size designSize, Size renderSize, String filePath, ImageFormat format, int quality, Action<String> readyCallback = null)
        {
            renderToFile = true;
            _renderSize = renderSize;
            _filePath = filePath;
            _format = format;
            _quality = quality;
            _fileCallback = readyCallback;

            double scaleX = renderSize.Width / designSize.Width;
            double scaleY = scaleX;

            this.WindowStyle = WindowStyle.None;
            this.AllowsTransparency = true;
            this.Opacity = 0.001;
            this.ShowInTaskbar = false;
            this.ShowActivated = false;
            this.Width = 1;
            this.Height = 1;
            _element.Width = designSize.Width;
            _element.Height = designSize.Height;


            grid.LayoutTransform = new ScaleTransform(scaleX, scaleY, 0, 0);

            this.ContentRendered += RenderWindow_ContentRendered;

            this.ShowDialog();
        }

        /// <summary>
        /// Renders to bitmap.
        /// </summary>
        /// <param name="designSize">Size of the design.</param>
        /// <param name="renderSize">Size of the render.</param>
        /// <param name="readyCallback">The ready callback.</param>
        public void RenderToBitmap(Size designSize, Size renderSize, Action<RenderTargetBitmap> readyCallback = null)
        {
            _renderSize = renderSize;
            _bitmapCallback = readyCallback;

            double scaleX = renderSize.Width / designSize.Width;
            double scaleY = scaleX;

            this.WindowStyle = WindowStyle.None;
            this.AllowsTransparency = true;
            this.Opacity = 0.001;
            this.ShowInTaskbar = false;
            this.ShowActivated = false;
            this.Width = 1;
            this.Height = 1;
            _element.Width = designSize.Width;
            _element.Height = designSize.Height;


            grid.LayoutTransform = new ScaleTransform(scaleX, scaleY, 0, 0);

            this.ContentRendered += RenderWindow_ContentRendered;

            this.Show();
        }

        /// <summary>
        /// Creates the bitmap.
        /// </summary>
        /// <param name="oVisual">The o visual.</param>
        /// <param name="oSize">Size of the o.</param>
        /// <returns></returns>
        private RenderTargetBitmap CreateBitmap(Visual oVisual, Size oSize)
        {
            int nWidth = (int)Math.Ceiling(oSize.Width);
            int nHeight = (int)Math.Ceiling(oSize.Height);

            RenderTargetBitmap oTargetBitmap = new RenderTargetBitmap(
                nWidth,
                nHeight,
                96,
                96,
                PixelFormats.Pbgra32
            );

            DrawingVisual oDrawingVisual = new DrawingVisual();

            using (DrawingContext oDrawingContext = oDrawingVisual.RenderOpen())
            {
                VisualBrush oVisualBrush = new VisualBrush(oVisual) { Stretch = Stretch.Fill };

                oDrawingContext.DrawRectangle(
                    oVisualBrush,
                    null,
                    new Rect(
                        new Point(),
                        new Size(nWidth, nHeight)
                    )
                );

                oDrawingContext.Close();
                oTargetBitmap.Render(oDrawingVisual);
            }

            return oTargetBitmap;
        }

        /// <summary>
        /// Gets the encoder by image format.
        /// </summary>
        /// <param name="format">The format.</param>
        /// <returns></returns>
        private static BitmapEncoder GetEncoderByImageFormat(ImageFormat format, int quality)
        {
            BitmapEncoder encoder = null;

            if (format == ImageFormat.Png)
            {
                encoder = new PngBitmapEncoder();
            }
            else if (format == ImageFormat.Jpeg)
            {
                encoder = new JpegBitmapEncoder();
                (encoder as JpegBitmapEncoder).QualityLevel = quality;
            }
            else
            {
                encoder = new BmpBitmapEncoder();
            }

            return encoder;
        }
    }
}