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

 * MercurialRev - Command line tool for Windows to build revision information text file from a mercurial project.

 * 

 * Copyright (C) 2012 Joerg Plenert

 * 

 * This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License 

 * as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. 

 * 

 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; 

 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. 

 * 

 * You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. 

 * 

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

using System;

using System.Diagnostics;

using System.IO;

using System.Reflection;



namespace MercurialRev

{

    public class Program

    {

        private string sourceFileName;

        private string destFileName;

        private string repositoryPath;



        private string hgRev;

        private string hgID;

        private string hgBranch;

        private string hgTag;

        private bool hgLocalMod;



        public Program(string[] args)

        {

            ParseArgs(args);

        }



        public enum ErrorType

        {

            None,

            Argument,

            Mercurial,

            SourceFile,

            DestFile,

            HandleFile

        }



        public static int Main(string[] args)

        {

            Program prg = new Program(args);

            return prg.Exec();

        }



        public int Exec()

        {

            StreamReader streamReader;

            StreamWriter streamWriter;

            ErrorType error;

            string line;



            error = ErrorType.None;

            streamReader = null;

            streamWriter = null;



            Console.WriteLine("MercurialRev V" + GetVersionString() + " (c) 2012 by Joerg Plenert");

            Console.WriteLine("");



            if (sourceFileName == null || destFileName == null || repositoryPath == null)

            {

                error = ErrorType.Argument;

            }



            if (error == ErrorType.None)

            {

                // Get infos from hg

                hgID = GetHGInfo(repositoryPath, "identify -i");

                hgRev = GetHGInfo(repositoryPath, "identify -n");

                hgBranch = GetHGInfo(repositoryPath, "identify -b");

                hgTag = GetHGInfo(repositoryPath, "identify -t");



                // Check for local modifications

                if (hgID != null && hgID.EndsWith("+"))

                {

                    hgLocalMod = true;

                    hgID = hgID.Substring(0, hgID.Length - 1);

                }



                if (hgRev != null && hgRev.EndsWith("+"))

                {

                    hgLocalMod = true;

                    hgRev = hgRev.Substring(0, hgRev.Length - 1);

                }



                if (hgID == null || hgRev == null || hgBranch == null || hgTag == null)

                {

                    error = ErrorType.Mercurial;

                }

            }



            if (error == ErrorType.None)

            {

                try

                {

                    streamReader = File.OpenText(sourceFileName);

                }

                catch

                {

                    error = ErrorType.SourceFile;

                }

            }



            if (error == ErrorType.None)

            {

                try

                {

                    streamWriter = File.CreateText(destFileName);

                }

                catch

                {

                    error = ErrorType.DestFile;

                }

            }



            if (error == ErrorType.None)

            {

                var now = DateTime.Now;

                string nowIsoFormat = now.ToString("s");

                string nowDateOnly = now.ToString("yyyy-mm-dd");

                string nowYearOnly = now.ToString("yyyy");

                while (true)

                {

                    try

                    {

                        line = streamReader.ReadLine();

                        if (line == null)

                        {

                            break;

                        }



                        line = line.Replace("<$HG:REV_NUM$>", hgRev);

                        line = line.Replace("<$HG:REV_LMOD_N$>", hgLocalMod ? "1" : "0");

                        line = line.Replace("<$HG:REV_LMOD_P$>", hgLocalMod ? "+" : "");

                        line = line.Replace("<$HG:REV_ID$>", hgID);

                        line = line.Replace("<$HG:BRANCH$>", hgBranch);

                        line = line.Replace("<$HG:TAG$>", hgTag);

                        line = line.Replace("<$HG:NOW_ISO$>", nowIsoFormat);

                        line = line.Replace("<$HG:NOW_DATE$>", nowDateOnly);

                        line = line.Replace("<$HG:NOW_YEAR$>", nowYearOnly);

                        streamWriter.WriteLine(line);

                    }

                    catch

                    {

                        error = ErrorType.HandleFile;

                    }

                }

            }



            if (streamReader != null)

            {

                streamReader.Close();

            }



            if (streamWriter != null)

            {

                streamWriter.Close();

            }



            if (error != ErrorType.None)

            {

                Console.WriteLine("Replaces revision information in a tagged text file.");

                Console.WriteLine("");

                Console.WriteLine("MercurialRev <SourceFile> <DestinationFile> <RepositoryPath>");

                Console.WriteLine("");

                Console.WriteLine("Tags:");

                Console.WriteLine("    <$HG:REV_NUM$>");

                Console.WriteLine("    <$HG:REV_LMOD_N$>");

                Console.WriteLine("    <$HG:REV_LMOD_P$>");

                Console.WriteLine("    <$HG:REV_ID$>");

                Console.WriteLine("    <$HG:BRANCH$>");

                Console.WriteLine("    <$HG:TAG$>");

                Console.WriteLine("");



                Console.WriteLine("Error: " + GetErrorDescription(error));

            }

            else

            {

                Console.WriteLine("Done!");

            }



            return (error == ErrorType.None) ? 0 : 1;

        }



        private void ParseArgs(string[] args)

        {

            if (args.Length == 3)

            {

                sourceFileName = args[0];

                destFileName = args[1];

                repositoryPath = args[2];



                // Repository path should not end in "\"

                if (repositoryPath.EndsWith("\\"))

                {

                    repositoryPath = repositoryPath.Substring(0, repositoryPath.Length - 1);

                }

            }

        }



        private string GetHGInfo(string repPath, string arg)

        {

            Process proc = new Process();

            proc.StartInfo.FileName = "hg.exe";

            proc.StartInfo.Arguments = string.Format("-R \"{0}\" {1}", repPath, arg);

            proc.StartInfo.UseShellExecute = false;

            proc.StartInfo.RedirectStandardOutput = true;



            proc.Start();



            return proc.StandardOutput.ReadLine();

        }



        private string GetErrorDescription(ErrorType error)

        {

            switch (error)

            {

                case ErrorType.Argument: return "Number of arguments";

                case ErrorType.Mercurial: return "Mercurial";

                case ErrorType.SourceFile: return "Source file";

                case ErrorType.DestFile: return "Destination file";

                case ErrorType.HandleFile: return "Handling files";

                default: return "Unexpected error";

            }

        }



        private string GetVersionString()

        {

            return Assembly.GetExecutingAssembly().GetName().Version.ToString();

        }

    }

}