using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;

using System.Text.RegularExpressions;
using System.Threading.Tasks;
using NLog;
using Raytheon.Common;

namespace ProgramPostBuild
{
   /// <summary>
   /// Perform any needed function after Program project is built
   /// </summary>
   internal class Program
   {
      private static ILogger _logger;
      private static object syncObj = new object();
      private static Dictionary<string, string> dllNameDict = new Dictionary<string, string>();

      static void Main(string[] args)
      {
         _logger = LogManager.GetCurrentClassLogger();

         ModifyDllPathsInTestStandSequences();
      }

      /// <summary>
      /// Modify paths to DLLs in TestStand sequence files
      /// </summary>
      static void ModifyDllPathsInTestStandSequences()
      {
         string assemblyFolder = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
         IConfigurationFile config = new ConfigurationFile(Path.Combine(assemblyFolder, "config.ini"));

         string dllPath = config.ReadValue("TESTSTAND", "DLL_PATH");
         dllPath = Path.GetFullPath(Path.Combine(assemblyFolder, dllPath));
         string testStandSequencePath = config.ReadValue("TESTSTAND", "TESTSTAND_SEQUENCE_PATH");
         testStandSequencePath = Path.GetFullPath(Path.Combine(assemblyFolder, testStandSequencePath));

         if (Directory.Exists(dllPath) && Directory.Exists(testStandSequencePath))
         {
            // get all DLL files
            string[] dllFileArray = Directory.GetFiles(dllPath, "*.dll");

            // get all teststand sequence files
            List<string> seqFileList = Directory.GetFiles(testStandSequencePath, "*.seq", SearchOption.AllDirectories).ToList();

            int maxTaskNum = Environment.ProcessorCount;
            List<Task> taskList = new List<Task>();

            while (seqFileList.Count > 0)
            {
               if (taskList.Count < maxTaskNum)
               {
                  string seqFilePath = seqFileList[0];
                  taskList.Add(Task.Factory.StartNew(() => ModifyDllPathsInTestStandSequence(seqFilePath, dllFileArray)));
                  seqFileList.RemoveAt(0);
               }
               else
               {
                  int index = Task.WaitAny(taskList.ToArray());
                  taskList.RemoveAt(index);
               }
            }

            Task.WaitAll(taskList.ToArray());
         }
      }

      /// <summary>
      /// Modify paths to DLLs in a TestStand sequence
      /// </summary>
      static void ModifyDllPathsInTestStandSequence(string seqFilePath, string[] dllFileArray)
      {
         string seqNewContent = "";
         FileStream fs = new FileStream(seqFilePath, FileMode.Open, FileAccess.Read);
         StreamReader reader = new StreamReader(fs, Encoding.Default);

         string line;
         Console.WriteLine($"Processing {seqFilePath}");
         while ((line = reader.ReadLine()) != null)
         {
            Match regexMatch;

            regexMatch = Regex.Match(line, @"<value>.+\\([^\.]+\.dll)</value>", RegexOptions.IgnoreCase);

            if (regexMatch.Success)
            {
               string dllFile = regexMatch.Groups[1].Value;

               bool dllExists = false;
               string[] dllStringArray = null;
               int index = 0;
               string[] seqStringArray = seqFilePath.Split('\\');

               lock (syncObj)
               {
                  if (dllNameDict.ContainsKey(dllFile))
                  {
                     dllStringArray = dllNameDict[dllFile].Split('\\');
                     dllExists = true;
                  }
               }

               if (!dllExists)
               {
                  foreach (string dllFilePath in dllFileArray)
                  {
                     if (Regex.IsMatch(dllFilePath, Regex.Escape(dllFile) + @"$", RegexOptions.IgnoreCase))
                     {
                        lock (syncObj)
                        {
                           dllStringArray = dllFilePath.Split('\\');

                           if (!dllNameDict.ContainsKey(dllFile))
                           {
                              dllNameDict[dllFile] = dllFilePath;
                           }
                        }

                        break;
                     }
                  }
               }

               while (String.Equals(dllStringArray[index], seqStringArray[index], StringComparison.OrdinalIgnoreCase))
               {
                  index++;
               }

               int numGoBacks = seqStringArray.Length - (index + 1);

               string goBackString = String.Empty;
               for (int i = 1; i <= numGoBacks; i++)
               {
                  if (!String.IsNullOrEmpty(goBackString))
                     goBackString += @"\";
                  goBackString += "..";
               }

               string goForwardString = String.Empty;

               for (int i = index; i < dllStringArray.Length; i++)
               {
                  if (!String.IsNullOrEmpty(goForwardString))
                     goForwardString += @"\";
                  goForwardString += dllStringArray[i];
               }

               string newRelPath = Path.Combine(goBackString, goForwardString);

               line = Regex.Replace(line, @"<value>(.+\\[^\.]+\.dll)</value>", "<value>" + newRelPath + "</value>", RegexOptions.IgnoreCase);

            }

            seqNewContent += line + "\r\n";
         }

         reader.Close();
         fs.Close();

         FileStream fs2 = null;
         StreamWriter writer = null;
         try
         {
            fs2 = new FileStream(seqFilePath, FileMode.Create, FileAccess.ReadWrite);
            writer = new StreamWriter(fs2, Encoding.Default);
            writer.Write(seqNewContent);
         }
         catch (System.Exception ex)
         {
            throw ex;
         }
         finally
         {
            if (writer != null)
            {
               writer.Close();
               fs2.Close();
            }
         }

         Console.WriteLine($"Completed {seqFilePath}");
      }
   }
}