//	Spludlow Software
//	Copyright © Samuel P. Ludlow 2020 All Rights Reserved
//	Distributed under the terms of the GNU General Public License version 3
//	Distributed WITHOUT ANY WARRANTY; without implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE
//	https://www.spludlow.co.uk/LICENCE.TXT
//	The Spludlow logo is a registered trademark of Samuel P. Ludlow and may not be used without permission
//	v1.14

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using System.IO;

namespace Spludlow.Printing
{
	public class GhostScript
	{
		static string[] ProgramVaribles;

		static string ProgramPath;
		
		static GhostScript()
		{
			ProgramVaribles = new string[]
			{
				"",
			};
			ProgramVaribles = null;


			string rootDir = @"C:\Program Files\gs";

			if (Directory.Exists(rootDir) == false)
				throw new ApplicationException("Ghost Script Top Directory missing:\t" + rootDir);

			List<string> gsDirs = new List<string>();
			foreach (string dir in Directory.GetDirectories(rootDir))
				if (Path.GetFileName(dir).ToLower().StartsWith("gs") == true)
					gsDirs.Add(dir);

			if (gsDirs.Count == 0)
				throw new ApplicationException("Ghost Script Program Directory not found:\t" + rootDir);

			ProgramPath = gsDirs[gsDirs.Count - 1] + @"\bin\gswin64c.exe";

			if (File.Exists(ProgramPath) == false)
				throw new ApplicationException("Ghost Script Program EXE not found:\t" + ProgramPath);

			Spludlow.Log.Info("Ghost Script Program using:\t" + ProgramPath);
		}

		public static void PrintPdf(string pdfFilename, string pageSize, bool landscape, string printerType, string printerInfo)
		{

			PrintDoc printDoc = new PrintDoc(pageSize, landscape);

			using (Spludlow.TempDirectory tempDir = new TempDirectory())
			{
				string[] bitmapFilenames = RenderPdf(pdfFilename, tempDir.Path);

				for (int index = 0; index < bitmapFilenames.Length; ++index)
				{
					if (index > 0)
						printDoc.NewPage();

					printDoc.Place(bitmapFilenames[index], 0, 0, 1, 1);
				}
			}

			string address = Environment.MachineName + ":Run";

			string printData = printDoc.Save();

			Spludlow.Printing.Printer.PrintAt(address, printData, printerType, printerInfo);
		}

		public static string[] RenderPdf(string pdfFilename, string outputFilename)
		{
			return RenderPdf(pdfFilename, outputFilename, 600, false, false, false);
		}
		public static string[] RenderPdf(string pdfFilename, string outputFilename, int dpi)
		{
			return RenderPdf(pdfFilename, outputFilename, dpi, false, false, false);
		}
		public static string[] RenderPdf(string pdfFilename, string outputFilename, int dpi, bool loadFonts)
		{
			return RenderPdf(pdfFilename, outputFilename, dpi, loadFonts, false, false);
		}
		public static string[] RenderPdf(string pdfFilename, string outputFilename, int dpi, bool loadFonts, bool grey, bool dontAntialias)
		{
			string extention = Path.GetExtension(outputFilename).ToLower();

			string device;

			switch (extention)
			{
				case ".png":
					if (grey == false)
						device = "png16m";
					else
						device = "pnggray";
					break;

				case ".jpg":                //	the jpeg and jpeggray devices	-dJPEGQ=N (integer from 0 to 100, default 75) 
				case ".jpeg":
					if (grey == false)
						device = "jpeg";
					else
						device = "jpeggray";
					break;

				case ".tif":
				case ".tiff":
					if (grey == false)
						device = "tiff32nc";    //	tiff32nc	Produces 32-bit CMYK output(8 bits per component)
					else
						device = "tiffgray";
					break;

				default:
					throw new ApplicationException("GhostScript RenderPdf; Unsupported traget extention: " + extention);
			}
			
			using (Spludlow.TempDirectory tempDir = new TempDirectory())
			{
				StringBuilder arguments = new StringBuilder();

				if (loadFonts == true)
					arguments.Append(@"-sFONTPATH=C:\Windows\Fonts -dEmbedAllFonts=true ");

				if (dontAntialias == false)
					arguments.Append("-dTextAlphaBits=4 -dGraphicsAlphaBits=4 ");
				
				arguments.Append("-dSAFER -dBATCH -dNOPAUSE -sDEVICE=@DEVICE -r@DPIx@DPI -o \"@OUTPUT\" \"@INPUT\"");

				arguments.Replace("@DEVICE", device);
				arguments.Replace("@DPI", dpi.ToString());
				arguments.Replace("@OUTPUT", tempDir.Path + @"\bitmap%8d" + extention);
				arguments.Replace("@INPUT", pdfFilename);

				Spludlow.SpawnProcess.ProcessExitInfo info = Spludlow.SpawnProcess.Run(ProgramPath, arguments.ToString(), tempDir.Path, ProgramVaribles, 15 * 60, false);

				if (info.ExitCode != 0 || info.StandardError.Length > 0)
				{
					Spludlow.Log.Error("Ghost Script Exit Code: " + info.ExitCode, new object[] { info.ExitCode, info.StandardOutput, info.StandardError });
					throw new ApplicationException("Ghost Script Exit Code: " + info.ExitCode);
				}

				List<string> tempFilenames = new List<string>();
				foreach (string tempFilename in Directory.GetFiles(tempDir.Path))
				{
					string name = Path.GetFileName(tempFilename);

					if (name.StartsWith("bitmap") == false || name.EndsWith(extention) == false)
					{
						Spludlow.Log.Warning("Ghost Script Unexpected output file:\t" + tempFilename);
						continue;
					}

					tempFilenames.Add(tempFilename);
				}

				if (tempFilenames.Count == 0)
					throw new ApplicationException("Ghost Script no output files from:\t" + pdfFilename);

				string outputDirecory = null;
				string outputName = null;
				string digits = null;
				
				if (tempFilenames.Count > 1)
				{
					outputDirecory = Path.GetDirectoryName(outputFilename);
					outputName = Path.GetFileNameWithoutExtension(outputFilename);
					digits = new string('0', tempFilenames.Count.ToString().Length);
				}

				List<string> resultFilenames = new List<string>();

				foreach (string tempFilename in tempFilenames)
				{
					if (tempFilenames.Count > 1)
					{
						int page = Int32.Parse(Path.GetFileName(tempFilename).Substring(6, 8));
						outputFilename = outputDirecory + @"\" + outputName + "-" + page.ToString(digits) + extention;
					}

					File.Copy(tempFilename, outputFilename);

					resultFilenames.Add(outputFilename);
				}

				return resultFilenames.ToArray();
			}
		}


	}
}