import DateTime as dt;
import Algorithms as algo;
import Text as text;

class Calendar {
  _monthNames_ = none;
  _dayNames_ = none;
  constructor() {
    t = dt.now();
    _monthNames_ = algo.materialize( algo.map( algo.range( 1, 13 ), @[t]( m ) { dt.format( "%B", t.set_date( 1, m, 1 ) ); } ), tuple );
    _dayNames_ = algo.materialize( algo.map( algo.range( 1, 8 ), @[t]( d ) { dt.format( "%a", t.set_date( 1, 1, d ) )[:2]; } ), tuple );
  }
  print_year( year_, cols_ ) {
    t = dt.now();
    print( "{:^66d}\n".format( year_ ) );
    for ( rm : algo.range( 12 / cols_ ) ) {
      m = rm * cols_;
      print( text.repeat( "{:^22s}", cols_ ).format( _monthNames_[m:m + cols_]... ) + "\n" );
      day = [];
      daysInMonth = [];
      for ( mc : algo.range( cols_ ) ) {
        print( " {} {} {} {} {} {} {} ".format( _dayNames_... ) );
        t.set_date( year_, m + mc + 1, 1 );
        day.push( - t.get_day_of_week() + 1 );
        daysInMonth.push( t.get_days_in_month() );
      }
      print( "\n" );
      haveDay = true;
      while ( haveDay ) {
        haveDay = false;
        for ( mc : algo.range( cols_ ) ) {
          for ( d : algo.range( 7 ) ) {
            if ( ( day[mc] > 0 ) && ( day[mc] <= daysInMonth[mc] ) ) {
              print( " {:2d}".format( day[mc] ) );
              haveDay = true;
            } else {
              print( "   " );
            }
            day[mc] += 1;
          }
          print( " " );
        }
        print( "\n" );
      }
    }
  }
}

main( argv_ ) {
  cal = Calendar();
  cols = size( argv_ ) > 2 ? integer( argv_[2] ) : 3;
  if ( 12 % cols != 0 ) {
    cols = 3;
  }
  cal.print_year(
    size( argv_ ) > 1
      ? integer( argv_[1] )
      : dt.now().get_year(),
    cols
  );
}