using System;
using System.Collections.Generic;
using Globalization = System.Globalization;
using System.Linq;
using System.Text;
using Microsoft.Build.Framework;
using System.IO;
using Microsoft.Build.Utilities;
using System.Diagnostics;
using Cosmos.Debug.Common;

namespace Cosmos.Build.MSBuild {
  public class ExtractMapFromElfFile : BaseToolTask {
    [Required]
    public string InputFile {
      get;
      set;
    }

    [Required]
    public string DebugInfoFile {
      get;
      set;
    }

    [Required]
    public string WorkingDir {
      get;
      set;
    }

    [Required]
    public string CosmosBuildDir {
      get;
      set;
    }

    public override bool Execute() {
      // Important! A given address can have more than one label.
      // Do NOT filter by duplicate addresses as this causes serious lookup problems.

      string xSymbolString;
      //TODO: This reads the file (13MB currently) into RAM...
      // Thats not needed.. read it line by line instead. Wait till we move to direct
      // DB only use though as we can do this at one time.
      if (!RunObjDump(out xSymbolString)) {
        return false;
      }

      var xResult = new List<KeyValuePair<uint, string>>();
      var xLines = xSymbolString.Split(new string[] { "\r\n", "\n", "\r" }, StringSplitOptions.RemoveEmptyEntries);
      
      // Parse file
      bool xListStarted = false;
      foreach (string xLine in xLines) {
        if (String.IsNullOrEmpty(xLine)) {
          continue;
        } else if (!xListStarted) {
          // Find start of the data
          if (xLine == "SYMBOL TABLE:") {
            xListStarted = true;
          }
          continue;
        }

        uint xAddress;
        try {
          xAddress = UInt32.Parse(xLine.Substring(0, 8), Globalization.NumberStyles.HexNumber);
        } catch (Exception) {
          Log.LogError("Error processing line '" + xLine + "'");
          throw;
        }
        
        string xSection = xLine.Substring(17, 5);
        if (xSection != ".text" && xSection != ".data") {
          continue;
        }
        string xLabel = xLine.Substring(32);
        if (xLabel == xSection) {
          // Non label, skip
          continue;
        }
        xResult.Add(new KeyValuePair<uint, string>(xAddress, xLabel));
      }

      using (var xDebugInfo = new DebugInfo(DebugInfoFile)) {
        xDebugInfo.WriteLabels(xResult);
      }
      return true;
    }

    private bool RunObjDump(out string result) {
      result = "";
      var xTempBatFile = Path.Combine(WorkingDir, "ExtractMapFromElfFileTemp.bat");
      if (File.Exists(xTempBatFile)) {
        File.Delete(xTempBatFile);
        if (File.Exists(xTempBatFile)) {
          Log.LogError("ExtractMapFromElfFileTemp.bat already exists!");
          return false;
        }
      }

      var xTempOutFile = Path.Combine(WorkingDir, "ExtractMapFromElfFileTemp.out");
      if (File.Exists(xTempOutFile)) {
        File.Delete(xTempOutFile);
        if (File.Exists(xTempOutFile)) {
          Log.LogError("ExtractMapFromElfFileTemp.out already exists!");
          return false;
        }
      }

      File.WriteAllText(xTempBatFile, "@ECHO OFF\r\n\"" + Path.Combine(CosmosBuildDir, @"tools\cygwin\objdump.exe") + "\" --wide --syms \"" + InputFile + "\" > ExtractMapFromElfFileTemp.out");
      if (!ExecuteTool(WorkingDir, xTempBatFile, "", "objdump")) {
        return false;
      }
      result = File.ReadAllText(xTempOutFile);

      return true;
    }
  }
}