program CmdLineParser_Demo;

{$mode objfpc}{$H+}

uses
  {$IFDEF UNIX}{$IFDEF UseCThreads}
  cthreads,
  {$ENDIF}{$ENDIF}
  JPL.CmdLineParser;

const
  ENDL = sLineBreak;
  APP_VERSION_STR = '1.0';

var
  Cmd: TJPCmdLineParser;

procedure RegisterOptions;
var
  Category: string;
begin

  {$IFDEF MSWINDOWS} Cmd.CommandLineParsingMode := cpmCustom; {$ELSE} Cmd.CommandLineParsingMode := cpmDelphi; {$ENDIF}
  Cmd.UsageFormat := cufWget;

  Category := 'main';

  // Short and long option. Value required.
  Cmd.RegisterOption('i', 'in-file', cvtRequired, False, False, 'Input file (value required).', 'FILE', Category);

  // Short and long option. Value optional.
  Cmd.RegisterOption('o', 'out-file', cvtOptional, False, False, 'Output file (value optional).', 'FILE', Category);

  // Short and long option. No value.
  Cmd.RegisterOption('a', 'Option-A', cvtNone, False, False, 'This is an --Option-A description.', '', Category);

  // Short option.
  Cmd.RegisterShortOption('b', cvtNone, False, False, 'This is an option -b description.', '', Category);

  // Long option.
  Cmd.RegisterLongOption('Option-C', cvtNone, False, False, 'This is an --Option-C description.', '', Category);

  Category := 'info';
  Cmd.RegisterOption('h', 'help', cvtNone, False, False, 'Show help and exit.', '', Category);
  Cmd.RegisterOption('V', 'version', cvtNone, False, False, 'Show application version and exit.', '', Category);

  // Hidden option.
  Cmd.RegisterShortOption('?', cvtNone, False, True, '', '', Category);

end;

procedure DisplayUsage;
var
  s: string;
begin
  s :=
    'JPL.CmdLineParser demo application' + ENDL + ENDL +
    'Main options: ' + ENDL + Cmd.OptionsUsageStr('  ', 'main', 120, '  ', 30) + ENDL +
    'Information: ' + ENDL + Cmd.OptionsUsageStr('  ', 'info', 120, '  ', 30);
  Writeln(s);
end;

procedure ProcessOptions;
begin
  if (Cmd.IsOptionExists('h')) or (Cmd.IsOptionExists('?')) then
  begin
    DisplayUsage;
    Exit;
  end;

  if Cmd.IsOptionExists('V') then
  begin
    Writeln('Version: ', APP_VERSION_STR);
    Exit;
  end;

  if Cmd.IsOptionExists('i') then Writeln('Input file: ', Cmd.GetOptionValue('i'))
  else Writeln ('Input file: NOT SPECIFIED');

  if Cmd.IsOptionExists('o') then Writeln('Output file: ', Cmd.GetOptionValue('o'))
  else Writeln('Output file: NOT SPECIFIED');

  if Cmd.IsOptionExists('a') then Writeln('Option -a: is set') else Writeln('Option -a: NOT SET');
  if Cmd.IsShortOptionExists('b') then Writeln('Option -b: is set') else Writeln('Option -b: NOT SET');
  if Cmd.IsLongOptionExists('Option-C') then Writeln('Option --Option-C: is set') else Writeln('Option --Option-C: NOT SET');
end;

begin

  Cmd := TJPCmdLineParser.Create;
  try

    RegisterOptions;

    if ParamCount = 0 then
    begin
      DisplayUsage;
      Exit;
    end;

    Cmd.Parse;

    if Cmd.ErrorCount > 0 then
    begin
      Writeln('An error occured while parsing command-line options: ', Cmd.ErrorsStr);
      ExitCode := 1;
      Exit;
    end;

    ProcessOptions;

    // Do something ...

  finally
    Cmd.Free;
  end;

end.