/***************************************************************************

Copyright (c) Microsoft Corporation 2011.

This code is licensed using the Microsoft Public License (Ms-PL).  The text of the license can be found here:

http://www.microsoft.com/resources/sharedsource/licensingbasics/publiclicense.mspx

***************************************************************************/

using System.Collections.Generic;
using System.Drawing;
using System.IO;
using System.Xml;
using System.Xml.Linq;
using System.Xml.XPath;
using DocumentFormat.OpenXml.Packaging;
using System;
using System.Drawing.Imaging;

namespace OpenXmlPowerTools
{
    /// <summary>
    /// Provides access to picture operations
    /// </summary>
    public class PictureAccessor
    {
        private static XNamespace mainns;
        private static XNamespace wordprocessingDrawingns;
        private static XNamespace drawingmlMainns;
        private static XNamespace picturens;
        private static XNamespace relationshipns;
        private const int pixelsPerEmu = 9525;

        static PictureAccessor() {
            mainns = "http://schemas.openxmlformats.org/wordprocessingml/2006/main";
            wordprocessingDrawingns = "http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawing";
            drawingmlMainns = "http://schemas.openxmlformats.org/drawingml/2006/main";
            picturens = "http://schemas.openxmlformats.org/drawingml/2006/picture";
            relationshipns = "http://schemas.openxmlformats.org/officeDocument/2006/relationships";
        }

        public static OpenXmlPowerToolsDocument Insert(WmlDocument doc, string xpathInsertionPoint, Image pictureToInsert, string name)
        {
            using (OpenXmlMemoryStreamDocument streamDoc = new OpenXmlMemoryStreamDocument(doc))
            {
                using (WordprocessingDocument document = streamDoc.GetWordprocessingDocument())
                {
                    XDocument xmlMainDocument = document.MainDocumentPart.GetXDocument();
                    ImagePart picturePart = null;
                    XmlNamespaceManager namespaceManager = new XmlNamespaceManager(new NameTable());
                    namespaceManager.AddNamespace("w", mainns.NamespaceName);
                    IEnumerable<XElement> insertionPoints = xmlMainDocument.XPathSelectElements(xpathInsertionPoint, namespaceManager);

                    //make the insertion for each insertion point specified in the xpath query
                    foreach (XElement insertionPoint in insertionPoints)
                    {
                        if (picturePart == null)
                        {
                            //  Create the picture part in the package
                            picturePart = document.MainDocumentPart.AddImagePart(GetImagePartType(pictureToInsert.RawFormat));
                        }

                        //  the pictures in the main document part goes in a very long xml, wich specifies the way the picture
                        //  has to be placed using drawingXml.
                        insertionPoint.AddAfterSelf(
                            new XElement(mainns + "p",
                                new XElement(mainns + "r",
                                    new XElement(mainns + "drawing",
                                        new XElement(wordprocessingDrawingns + "inline",
                                            new XElement(wordprocessingDrawingns + "extent",
                                                new XAttribute("cx", pictureToInsert.Width * pixelsPerEmu),
                                                new XAttribute("cy", pictureToInsert.Height * pixelsPerEmu)
                                            ),
                                            new XElement(wordprocessingDrawingns + "docPr",
                                                new XAttribute("name", name),
                                                new XAttribute("id", "1")
                                            ),
                                            new XElement(drawingmlMainns + "graphic",
                                                new XAttribute(XNamespace.Xmlns + "a", drawingmlMainns.NamespaceName),
                                                new XElement(drawingmlMainns + "graphicData",
                                                    new XAttribute("uri", picturens.NamespaceName),
                                                    new XElement(picturens + "pic",
                                                        new XAttribute(XNamespace.Xmlns + "pic", picturens.NamespaceName),
                                                        new XElement(picturens + "nvPicPr",
                                                            new XElement(picturens + "cNvPr",
                                                                new XAttribute("id", "0"),
                                                                new XAttribute("name", name)
                                                            ),
                                                            new XElement(picturens + "cNvPicPr")
                                                        ),
                                                        new XElement(picturens + "blipFill",
                                                            new XElement(drawingmlMainns + "blip",
                                                                new XAttribute(relationshipns + "embed", document.MainDocumentPart.GetIdOfPart(picturePart))
                                                            ),
                                                            new XElement(drawingmlMainns + "stretch",
                                                                new XElement(drawingmlMainns + "fillRect")
                                                            )
                                                        ),
                                                        new XElement(picturens + "spPr",
                                                            new XElement(drawingmlMainns + "xfrm",
                                                                new XElement(drawingmlMainns + "off",
                                                                    new XAttribute("x", "0"),
                                                                    new XAttribute("y", "0")
                                                                ),
                                                                new XElement(drawingmlMainns + "ext",
                                                                    new XAttribute("cx", pictureToInsert.Width * pixelsPerEmu),
                                                                    new XAttribute("cy", pictureToInsert.Height * pixelsPerEmu)
                                                                )
                                                            ),
                                                            new XElement(drawingmlMainns + "prstGeom",
                                                                new XAttribute("prst", "rect")
                                                            )
                                                        )
                                                    )
                                                )
                                            )
                                        )
                                    )
                                )
                            )
                        );
                    }
                    if (picturePart != null)
                    {
                        Stream partStream = picturePart.GetStream(FileMode.Create, FileAccess.ReadWrite);
                        pictureToInsert.Save(partStream, pictureToInsert.RawFormat);
                    }
                    else
                        throw new ArgumentException("The xpath query did not return a valid location.");
                    document.MainDocumentPart.PutXDocument();
                }
                return streamDoc.GetModifiedDocument();
            }
        }

       
        /// <summary>
        /// Gets the image type representation for a mimetype
        /// </summary>
        /// <param name="format">Content mimetype</param>
        /// <returns>Image type</returns>
        private static ImagePartType GetImagePartType(ImageFormat format)
        {
            if (format.Equals(ImageFormat.Jpeg))
                return ImagePartType.Jpeg;
            else if (format.Equals(ImageFormat.Emf))
                return ImagePartType.Emf;
            else if (format.Equals(ImageFormat.Gif))
                return ImagePartType.Gif;
            else if (format.Equals(ImageFormat.Icon))
                return ImagePartType.Icon;
            else if (format.Equals(ImageFormat.Png))
                return ImagePartType.Png;
            else if (format.Equals(ImageFormat.Tiff))
                return ImagePartType.Tiff;
            else if (format.Equals(ImageFormat.Wmf))
                return ImagePartType.Wmf;
            else
                return ImagePartType.Bmp;
        }
    }
}