//此文件来自 SharpDevelop

using System;
using System.IO;
using System.Printing;
using System.Drawing.Printing;
using System.Windows;
using System.Windows.Media;
using System.Windows.Documents;

namespace LunarSF.SHomeWorkshop.LunarMarkdownEditor
{
    /// <summary>
    /// Represents the DocumentPaginatorWrapper adding headers and footers to the document.
    /// </summary>
    public class DocumentPaginatorWrapper : DocumentPaginator
    {
        string m_Title;
        Margins m_Margins;
        Size m_PageSize;
        DocumentPaginator m_Paginator;
        Typeface m_Typeface;

        #region Properties

        /// <summary>
        /// Sets the header title for each document page.
        /// </summary>
        public string Title
        {
            set { m_Title = value; }
        }

        public override bool IsPageCountValid
        {
            get { return m_Paginator.IsPageCountValid; }
        }

        public override int PageCount
        {
            get { return m_Paginator.PageCount; }
        }
        
        public override Size PageSize
        {
            get { return m_Paginator.PageSize; }
            set { m_Paginator.PageSize = value; }
        }

        public override IDocumentPaginatorSource Source
        {
            get { return m_Paginator.Source; }
        }

        #endregion
        
        public DocumentPaginatorWrapper(DocumentPaginator paginator, PageSettings pageSettings, PrintTicket printTicket, FontFamily headerFooterfontFamily)
        {
            m_Margins = ConvertMarginsToPx(pageSettings.Margins);

            if (pageSettings.Landscape)
                m_PageSize = new Size((int)printTicket.PageMediaSize.Height, (int)printTicket.PageMediaSize.Width);
            else
                m_PageSize = new Size((int)printTicket.PageMediaSize.Width, (int)printTicket.PageMediaSize.Height);

            m_Paginator = paginator;
            m_Paginator.PageSize = new Size(m_PageSize.Width - m_Margins.Left - m_Margins.Right, m_PageSize.Height - m_Margins.Top - m_Margins.Bottom);
            
            m_Typeface = new Typeface(headerFooterfontFamily, FontStyles.Normal, FontWeights.Normal, FontStretches.Normal);
        }

        Rect Move(Rect rect)
        {
            if (rect.IsEmpty)
            {
                return rect;
            }
            else
            {
                return new Rect(rect.Left + m_Margins.Left, rect.Top + m_Margins.Top, rect.Width, rect.Height);
            }
        }

        public override DocumentPage GetPage(int pageNumber)
        {
            DocumentPage page = m_Paginator.GetPage(pageNumber);

            ContainerVisual newpage = new ContainerVisual();
            //
            // Header
            //
            DrawingVisual header = new DrawingVisual();
            using (DrawingContext ctx = header.RenderOpen())
            {
                DrawPath(ctx, m_Margins.Top - 20, m_Title, TextAlignment.Left);
                DrawText(ctx, m_Margins.Top - 20, String.Format("{0}", DateTime.Now), TextAlignment.Right);
                DrawLine(ctx, m_Margins.Top - 5, 0.5);
            }
            //
            // Footer
            //
            DrawingVisual footer = new DrawingVisual();
            using (DrawingContext ctx = footer.RenderOpen())
            {
                DrawText(ctx, m_PageSize.Height - m_Margins.Bottom + 5, "-" + (pageNumber + 1) + "-", TextAlignment.Center);
                DrawLine(ctx, m_PageSize.Height - m_Margins.Bottom + 5, 0.5);
            }

            ContainerVisual pageVisual = new ContainerVisual();
            pageVisual.Children.Add(page.Visual);
            newpage.Children.Add(header);
            newpage.Children.Add(pageVisual);
            newpage.Children.Add(footer);

            return new DocumentPage(newpage, m_PageSize, Move(page.BleedBox), Move(page.ContentBox));
        }

        /// <summary>
        /// Draws a text at specified y-postion with specified text alignment.
        /// </summary>
        void DrawText(DrawingContext ctx, double yPos, string text, TextAlignment alignment)
        {
            if (string.IsNullOrEmpty(text))
                return;

            if (m_Typeface == null)
            {
                m_Typeface = new Typeface("Times New Roman");
            }

            FormattedText formattedText = new FormattedText(text,
                    System.Globalization.CultureInfo.CurrentCulture, FlowDirection.LeftToRight,
                    m_Typeface, 12, Brushes.Black);

            if (alignment == TextAlignment.Left)
            {
                formattedText.TextAlignment = TextAlignment.Left;
                formattedText.MaxTextWidth = m_PageSize.Width * 2 / 3;
                formattedText.MaxTextHeight = 16;
                formattedText.Trimming = TextTrimming.WordEllipsis;
                ctx.DrawText(formattedText, new Point(m_Margins.Left, yPos));
            }
            else if (alignment == TextAlignment.Right)
            {
                formattedText.TextAlignment = TextAlignment.Right;
                ctx.DrawText(formattedText, new Point(m_PageSize.Width - m_Margins.Right, yPos));
            }
            else if (alignment == TextAlignment.Center)
            {
                formattedText.TextAlignment = TextAlignment.Center;
                ctx.DrawText(formattedText, new Point(m_PageSize.Width / 2, yPos));
            }
        }
        
        /// <summary>
        /// Draws a path as document title.
        /// </summary>
        void DrawPath(DrawingContext ctx, double yPos, string text, TextAlignment alignment)
        {
            if (string.IsNullOrEmpty(text))
                return;

            if (!File.Exists(text))
            {
                DrawText(ctx, yPos, text, alignment);
                return;
            }

            if (m_Typeface == null)
            {
                m_Typeface = new Typeface("Times New Roman");
            }

            double textWidth;
            FormattedText formattedText = new FormattedText(text,
                    System.Globalization.CultureInfo.CurrentCulture, FlowDirection.LeftToRight,
                    m_Typeface, 12, Brushes.Black);

            textWidth = formattedText.Width;

            double maxTextLength = m_PageSize.Width * 2 / 3;

            if (textWidth < maxTextLength)
            {
                ctx.DrawText(formattedText, new Point(m_Margins.Left, yPos));
                return;
            }
            //
            // if someone has a more clever solution
            // to do WordEllipsis trimming for paths, please shout
            //
            string path = Path.GetDirectoryName(text);
            string fileName = "\\" + Path.GetFileName(text);

            // get the length of the trimmed file name
            formattedText = new FormattedText(fileName,
                    System.Globalization.CultureInfo.CurrentCulture, FlowDirection.LeftToRight,
                    m_Typeface, 12, Brushes.Black);

            formattedText.MaxTextWidth = maxTextLength - 100;
            formattedText.MaxTextHeight = 16;
            formattedText.Trimming = TextTrimming.WordEllipsis;
            textWidth = formattedText.Width;
            // draw the path
            formattedText = new FormattedText(path,
                    System.Globalization.CultureInfo.CurrentCulture, FlowDirection.LeftToRight,
                    m_Typeface, 12, Brushes.Black);

            formattedText.MaxTextWidth = maxTextLength - textWidth;
            formattedText.MaxTextHeight = 16;
            formattedText.Trimming = TextTrimming.WordEllipsis;
            ctx.DrawText(formattedText, new Point(m_Margins.Left, yPos));
            textWidth = formattedText.Width;

            // draw the file name
            formattedText = new FormattedText(fileName,
                    System.Globalization.CultureInfo.CurrentCulture, FlowDirection.LeftToRight,
                    m_Typeface, 12, Brushes.Black);

            formattedText.MaxTextWidth = maxTextLength - textWidth;
            formattedText.MaxTextHeight = 16;

            formattedText.Trimming = TextTrimming.WordEllipsis;
            ctx.DrawText(formattedText, new Point(m_Margins.Left + textWidth, yPos));
        }

        /// <summary>
        /// Draws a line form left to right margin at specified y-postion.
        /// </summary>
        void DrawLine(DrawingContext ctx, double yPos, double thickness)
        {
            ctx.DrawLine(new Pen(new SolidColorBrush(Colors.Black), thickness),
                    new Point(m_Margins.Left, yPos),
                    new Point(m_PageSize.Width - m_Margins.Right, yPos));
        }

        /// <summary>
        /// Converts specified Margins (hundredths of an inch) to pixel margin (px).
        /// </summary>
        Margins ConvertMarginsToPx(Margins margins)
        {
            margins.Left = ConvertToPx(margins.Left);
            margins.Top = ConvertToPx(margins.Top);
            margins.Right = ConvertToPx(margins.Right);
            margins.Bottom = ConvertToPx(margins.Bottom);
            return margins;
        }

        /// <summary>
        /// Converts specified inch (hundredths of an inch) to pixels (px).
        /// </summary>
        int ConvertToPx(double inch)
        {
            return (int)(inch * 0.96);
        }
    }
}