//
// Copyright (c) 2001-2012 by PDFTron Systems Inc. All Rights Reserved.
//

using System;
using pdftron;
using pdftron.Common;
using pdftron.Filters;
using pdftron.SDF;
using pdftron.PDF;

namespace ElementEditTestCS
{
	/// <summary>
	/// The sample code shows how to edit the page display list and how to modify graphics state 
	/// attributes on existing Elements. In particular the sample program strips all images from 
	/// the page and changes text color to blue. 
	/// </summary>
	class ElementEditTest
	{
		// Helper function
		static void ProcessElements(ElementReader reader, ElementWriter writer)
		{
			Element element;
			while ((element = reader.Next()) != null) 	// Read page contents
			{
				switch (element.GetType())
				{
					case Element.Type.e_path:						// Process path data...
						break;
					case Element.Type.e_image:
					case Element.Type.e_inline_image:
						// remove all images by skipping them
						continue;
					case Element.Type.e_text: 				// Process text strings...
						{
							// Set all text to blue color.
							GState gs = element.GetGState();
							gs.SetFillColorSpace(ColorSpace.CreateDeviceRGB());
							gs.SetFillColor(new ColorPt(0, 0, 1));
							break;
						}
					case Element.Type.e_form:				// Recursively process form XObjects
						{
							reader.FormBegin();
							ProcessElements(reader, writer);
							reader.End();
							break;
						}
				}

				writer.WriteElement(element);
			}
		}

		/// <summary>
		/// The main entry point for the application.
		/// </summary>
		[STAThread]
		static void Main(string[] args)
		{
			PDFNet.Initialize();

			// Relative path to the folder containing test files.
			string input_path = "../../../../TestFiles/";
			string output_path = "../../../../TestFiles/Output/";
			string input_filename = "newsletter.pdf";
			string output_filename = "newsletter_edited.pdf";

			try
			{
				Console.WriteLine("-------------------------------------------------");

				// Open the test file
				Console.WriteLine("Opening the input file...");
				PDFDoc doc = new PDFDoc(input_path + input_filename);
				doc.InitSecurityHandler();

				int num_pages = doc.GetPageCount();

				ElementWriter writer = new ElementWriter();
				ElementReader reader = new ElementReader();

				for (int i = 1; i <= num_pages; ++i)
				{
					Page page = doc.GetPage(i);
					reader.Begin(page);
					writer.Begin(page, ElementWriter.WriteMode.e_replacement, false);
					ProcessElements(reader, writer);
					writer.End();
					reader.End();
				}

				// Calling Dispose() on ElementReader/Writer/Builder can result in increased performance and lower memory consumption.
				writer.Dispose();
				reader.Dispose();

				doc.Save(output_path + output_filename, SDFDoc.SaveOptions.e_remove_unused);
				doc.Close();
				Console.WriteLine("Done. Result saved in {0}...", output_filename);
			}
			catch (PDFNetException e)
			{
				Console.WriteLine(e.Message);
			}

			PDFNet.Terminate();
		}
	}
}