App/sample.cpp

// #################################################################################################
//  ALib C++ Framework
//  Configuration Sample
//
//  Copyright 2025 A-Worx GmbH, Germany
//  Published under Boost Software License (a free software license, see LICENSE.txt)
// #################################################################################################
#include "ALib.Lang.H"
#if !DOXYGEN // otherwise this sample would be seen in the ALib dox
 
#include "sample.hpp"
 
// Include necessary ALib headers
#include "ALib.Strings.StdIOStream.H"    // Support to write ALib strings and boxes to cout
#include "ALib.Strings.Calendar.H"       // Module ALib Strings, calendar formatting
#include "ALib.Variables.Plugins.H"      // Module ALib Variables, environment and cli-plugins
#include "ALib.Bootstrap.H"              // Module ALib Strings, calendar formatting
 
#include <filesystem>                    // C++ filesystem
#include <chrono>                        // C++ chrono
 
 
// namespaces to use locally
using namespace alib;
 
void Sample::bsCLIDefine() {
    AppCli::bsCLIDefine();
 
    cli.DefineExitCodes <DateExitCodes >();
    cli.DefineParameters<DateParameters>();
    cli.DefineCommands  <DateCommands  >();
    cli.DefineOptions   <DateOptions   >();
}
 
void Sample::onBsPrepareConfig() {
    // call parent's implementation. This bulk-loads the resources into the camps.
    AppCli::onBsPrepareConfig();
 
    // now, we just add the resources that parent AppCli did not define for us.
 
    APPCLI_CAMP.GetResourcePool().BootstrapBulk( APPCLI_CAMP.ResourceCategory,
#define EOS ,
 
//-------------------- Things required by AppCli --------------------
"HlpCLIAppName",  A_CHAR("sample"),
"HlpUsage"     ,  A_CHAR("sample [format=\"FORMATSPEC\" [now]|[file FILENAME]"),
 
 
"HlpGeneral", A_CHAR(
  "\nABOUT sample\n"
  "@>>"
  "This is a sample application provided with C++ library 'ALib'\n"
  "to demonstrate the use of its module \"ALib App\"."
  "\n@<<\n" ) EOS
 
//-------------------- CLI Commands/Options/Parameters/ExitCodes --------------------
"DateC<",       A_CHAR("datesample::Commands::"),
"DateC", A_CHAR(
     //enum       ident          minread     Params
       "1,"       "now"           ",1"        ","               ","
       "2,"       "file"          ",1"        ",filename"               ) EOS
 
"THlpCmdSht_now",  A_CHAR("Reports the actual date/time"),
"THlpCmdLng_now",  A_CHAR("Reports the actual date/time. May be omitted, as this is the\n"
                          "default if no command is given.")                         EOS
 
"THlpCmdSht_file", A_CHAR("Returns the date/time of a file. "),
"THlpCmdLng_file", A_CHAR("Returns the last modification date/time of a file.")      EOS
 
 
"DateO<",       A_CHAR("datesample::Options::"),
"DateO", A_CHAR(
//enum  ident        minread    identChar   in-arg-separ.   args to consume    ShortcutTo
 "0,"  "format"      ",1,"        "f,"        "="             ",1"              ","       ) EOS
 
"TOptUsg_format",  A_CHAR("--format[=]\"placeholders\""),
"TOptHlp_format",  A_CHAR("Sets the output format. The format specification is given with\n"
                          "documentation of ALib method CalendarDateTime::Format, found here:\n"
                          "https://alib.dev/classalib_1_1strings_1_1util_1_1CalendarDateTime.html" ) ,
 
 
"DateP<", A_CHAR("datesample::Parameters::"),
"DateP",  A_CHAR(
//enum  name           minIdentLen   identifier          in-arg-sep   delim   args to consume  isOptional
//                                   (if empty -> mandatory!)
"0,"  "FILENAME"         ",1,"        ""                 ","          "="  ","  ",-1"          ",0"   ) EOS
 
"THlpParSht_FILENAME",   A_CHAR("Mandatory parameter of command 'file."),
"THlpParLng_FILENAME",   A_CHAR("Denotes the file that is used for retrieving the modification date.\n"
                                "This parameter is mandatory to command file and has to be appended\n"
                                "to this command, separated by '='")        EOS
 
"DateE<",  A_CHAR("datesample::"),
"DateE",  A_CHAR(
//enum  name                             assoc. cli exception
"101,"  "ErrMissingFilename"             ",-1,"
"102,"  "ErrFileNotFound"                ",-1,"
"103,"  "ErrPermissionDenied"            ",-1"            ) EOS
 
"TExit101" ,  A_CHAR("Command 'file' given without a filename argument."         )   EOS
"TExit102" ,  A_CHAR("File not found."         )   EOS
"TExit103" ,  A_CHAR("Permission denied."         )   EOS
 
// custom resources
"FNOTFND"  ,  A_CHAR("The file {!Q} specified with command 'file' was not found.")   EOS
"FNOACC"   ,  A_CHAR("Access denied to file {!Q} specified with command 'file'." )   EOS
"MSNGFNAME",  A_CHAR("Error: no filename given with command 'file'"              )   EOS
 
 
    // end of BootstrapBulk()
    nullptr );
 
    enumrecords::bootstrap::Bootstrap<DateCommands  >();
    enumrecords::bootstrap::Bootstrap<DateParameters>();
    enumrecords::bootstrap::Bootstrap<DateOptions   >();
    enumrecords::bootstrap::Bootstrap<DateExitCodes >();
 
}
 
bool Sample::cliProcessCmd(alib::cli::Command* cmd ) {
    if ( AppCli::cliProcessCmd(cmd) )
        return true;
 
    if ( cmd == nullptr ) {
        String128 dateWritten;
        CalendarDateTime(DateTime()).Format( format, dateWritten );
        cOut->Add(dateWritten);
        return true;
    }
 
    // Note: Alternatively we could do:
    // auto actCmdCode= cmd->Declaration->Element();
    //
    // if ( actCmdCode == DateCommands::Now )  {
    //     ...
    // }
    //
    // else if ( actCmdCode == DateCommands::File )  {
    // {
    //     ...
    //
    // But the following version lets the compiler assure us that
    // all custom commands are handled:
 
    ALIB_ALLOW_SWITCH_WITHOUT_DEFAULT
    if ( cmd->Declaration->Element().IsEnumType<DateCommands>()) {
        switch (cmd->Declaration->Element().Get<DateCommands>()) {
            case DateCommands::Now: {
                String128 dateWritten;
                CalendarDateTime(DateTime()).Format( format, dateWritten);
                cOut->Add(dateWritten);
                return true;
            }
            case DateCommands::File: {
                // check if filename was given as parameter
                if(cmd->ParametersMandatory.size() < 1)
                {
                    cErr->Add(APPCLI_CAMP.GetResource("MSNGFNAME"));
                    ALIB_ASSERT_RESULT_EQUALS(
                        CLIUtil::GetHelp( cli, cmd->Declaration->Identifier(), *cOut )
                    ,true)
                    machine.SetExitCode(DateExitCodes::ErrMissingFilename);
                    return true;
                }
 
                // get file (or directory) modification date
                String4K name( cmd->ParametersMandatory.front()->Args.front() );
                std::filesystem::path stdpath( name.Terminate() );
                DateTime dt;
 
                // While class App catches exceptions and provides explicit virtual method
                // App::exceptionToExitCode() to be overridden, we use the non-throwing version
                // of std::filesystem::last_write_time. Here is why:
                // - We have the filename here at hand. No need to pass it over
                // - while exceptionToExitCode is nice in respect to having all exceptions in
                //   one place, it is also nice to handle an error where it occurs.
                // So, maybe a matter of taste. And finally we mix it: if we do not handle the
                // error code here, we then throw!
                std::error_code errorCode;
                auto timeValue= std::filesystem::last_write_time( stdpath, errorCode );
                if ( errorCode.value() != 0 ) {
                    // not found
                    if ( errorCode.value() == int(std::errc::no_such_file_or_directory) ) {
                        cErr->Add( APPCLI_CAMP.GetResource("FNOTFND"), name);
                        machine.SetExitCode( DateExitCodes::ErrFileNotFound );
                        return true;
                    }
 
                    // permission denied
                    if ( errorCode.value() == int(std::errc::permission_denied) ) {
                        cErr->Add( APPCLI_CAMP.GetResource("FNOACC"), name);
                        machine.SetExitCode( DateExitCodes::ErrPermissionDenied );
                        return true;
                    }
 
                    // other errors
                    throw exceptions::CreateExceptionFromSystemError(ALIB_CALLER_NULLED, errorCode);
                }
                dt.Import( std::chrono::clock_cast<std::chrono::system_clock>(timeValue) );
                String128 dateWritten;
                CalendarDateTime(dt).Format( format, dateWritten );
                cOut->Add(dateWritten);
 
                return true;
            }
        }
    }
 
    ALIB_POP_ALLOWANCE
 
    return false;
}
 
#endif // !DOXYGEN