// Use LogFile.nui  // Class for handling a log file (No User Interface)
//
// by Sture ApS
//
//
// This package implements the cLogFile class. An object of this class may
// be used to generate output to a logfile.
//
// Typical application:
//
//   Writing detailed information to a file as a batch process progresses.
//   Could also be used to log information every time the application performs
//   a specific action.
//
// Code sample:
//
//   object oStructure_LogFile is a cLogFile
//     set psFileName to "dfmatrix.log" // Write to this file
//     set piCloseOnWrite to DFTRUE     // Close the log file on each write
//     set psPurpose to "Events during table restructuring" // A little friendliness won't hurt
//   end_object // oStructure_LogFile
//
Use Base.nui     // Item_Property command, Various macros (FOR_EX...), cArray, cSet and cStack classes (No User Interface)
Use Files.nui    // Utilities for handling file related stuff
Use Dates.nui    // Date manipulation for VDF
Use Strings.nui  // String manipulation for VDF (No User Interface)

class cLogFile is a cArray
  procedure construct_object integer liImg
    forward send construct_object liImg
    // Public
    property integer piCloseOnWrite  public DFFALSE
    property string  psPurpose       public ""
    property integer pbANSI_State    public 1
    // Private
    property string  prv.psFileName  public ""
    property integer prv.piChannel   public -1
  end_procedure

  function psFileName returns string
    function_return (prv.psFileName(self))
  end_function

  procedure set psFileName string lsFileName
    integer liExists
    if (SEQ_ExtractPathFromFileName(lsFileName)="") begin
      get SEQ_FileExists lsFileName to liExists
      if liExists eq SEQIT_DIRECTORY error 123 "Illegal file name in cLogFile object"
      else begin
        if liExists eq SEQIT_NONE get SEQ_TranslatePathToAbsolute lsFileName to lsFileName
        else get SEQ_ConvertToAbsoluteFileName lsFileName to lsFileName
      end
    end
    set prv.psFileName to lsFileName
  end_procedure

            procedure DirectOutputHelp integer liAppend string lsFileName
              integer liChannel liWasCreated
              string lsFile
              if NUM_ARGUMENTS eq 2 begin
                move lsFileName to lsFile
                set psFileName to lsFile
              end
              else get psFileName to lsFile
              if liAppend begin
                move (not(SEQ_FileExists(lsFile))) to liWasCreated
                get SEQ_AppendOutput lsFile to liChannel
              end
              else begin
                get SEQ_DirectOutput lsFile to liChannel
                move 1 to liWasCreated
              end
              set prv.piChannel to liChannel
              if (piCloseOnWrite(self)) Close_Output channel liChannel
              if liWasCreated send OnLogFileCreated
              send OnLogFileOpen
            end_procedure

  procedure OnLogFileOpen
  end_procedure
  procedure OnLogFileClose
  end_procedure
  procedure OnLogFileCreated
    string lsPurpose
    get psPurpose to lsPurpose
    if (lsPurpose<>"") begin
      send WriteLn lsPurpose
      send WriteLn (repeat("-",length(lsPurpose)))
      send DoWriteTimeEntry "File created"
    end
  end_procedure

  procedure DeleteFile string lsFileName
    string lsFile
    if NUM_ARGUMENTS eq 1 move lsFileName to lsFile
    else get psFileName to lsFile
    get SEQ_TranslatePathToAbsolute lsFile to lsFile
    erasefile lsFile
  end_procedure

  procedure DirectOutput string lsFileName
    if NUM_ARGUMENTS send DirectOutputHelp DFFALSE lsFileName
    else send DirectOutputHelp DFFALSE (psFileName(self))
  end_procedure

  procedure AppendOutput string lsFileName
    if NUM_ARGUMENTS send DirectOutputHelp DFTRUE lsFileName
    else send DirectOutputHelp DFTRUE (psFileName(self))
  end_procedure

  procedure CloseOutput
    send OnLogFileClose
    ifnot (piCloseOnWrite(self)) send SEQ_CloseOutput (prv.piChannel(self))
    else send Seq_Release_Channel (prv.piChannel(self))
    set prv.piChannel to -1
  end_procedure

  procedure WriteLn string lsLine
    integer liCloseOnWrite liChannel lbRelease liPos liOriginalCloseOnWrite
    if (pbANSI_State(self)) move (StringOemToAnsi(lsLine)) to lsLine
    get piCloseOnWrite to liCloseOnWrite
    get prv.piChannel to liChannel

    if (liChannel=-1) begin
      get Seq_New_Channel to liChannel
      move (TRUE) to lbRelease
      move liCloseOnWrite to liOriginalCloseOnWrite
      move 1 to liCloseOnWrite
    end

    if liCloseOnWrite Append_Output channel liChannel (psFileName(self))
    if lbRelease begin
      get_channel_position liChannel to liPos
      if (liPos<=0) begin
        set piCloseOnWrite to 0
        set prv.piChannel to liChannel
        send OnLogFileCreated
        set prv.piChannel to -1
        set piCloseOnWrite to liOriginalCloseOnWrite
      end
    end
    writeln channel liChannel lsLine
    if liCloseOnWrite Close_Output channel liChannel

    if lbRelease send Seq_Release_Channel liChannel
  end_procedure

  procedure DoWriteTimeEntry string lsValue
    if NUM_ARGUMENTS send WriteLn (TS_ConvertToString(TS_SysTime())+": "+lsValue)
    else send WriteLn (TS_ConvertToString(TS_SysTime()))
  end_procedure

  procedure Output_Image integer liImg
    integer liAuxChannel liChannel liCloseOnWrite liSeqEof lbRelease
    string lsLine

    get Seq_New_Channel to liAuxChannel
    get piCloseOnWrite to liCloseOnWrite
    get prv.piChannel to liChannel

    if (liChannel=-1) begin
      get Seq_New_Channel to liChannel
      move (TRUE) to lbRelease
      move 1 to liCloseOnWrite
    end

    if liCloseOnWrite Append_Output channel liChannel (psFileName(self))

    direct_input channel liAuxChannel ("image: "+string(liImg))
    ifnot (SeqEof) readln channel liAuxChannel lsLine
    repeat
      move (SeqEof) to liSeqEof
      ifnot liSeqEof begin
        writeln channel liChannel (rtrim(lsLine))
        readln channel liAuxChannel lsLine
      end
    until liSeqEof
    close_input channel liAuxChannel

    if liCloseOnWrite Close_Output channel liChannel
    if lbRelease send Seq_Release_Channel liChannel

    send Seq_Release_Channel liAuxChannel
  end_procedure
end_class // cLogFile