package importopt;

use strict;

my %type = (i => "^[+-]?[0-9]+\$",
            s => ".",
            f => "^[+-]?[0-9.]+(e[+-][0-9]+)?\$",
            v => "^\$");

sub import (@) {
  no strict 'refs';
  shift (@_);
  my %arg = @_;
  if (!defined ($arg {options})) { return(); }
  my $ns = $arg {namespace} || "";
  my %opt = %{$arg {options}};
  my $args = \@{"$ns\::_args"};
  my $err = \${"$ns\::_err"};  
  foreach my $o (keys (%opt)) {
    if ($opt{$o} =~ /^([a-zA-Z])(\[\])?$|^=(.*)/) {
      my ($t, $a, $r) = ($1 || "", $2 || "", $3 || "");
      
      if ($r) { # option is an alias for another option
        unless ($opt{$r}) {
          print STDERR ("$o: reference to nonexistent option $r\n");
          $$err = 3;
        }
        $opt{$o} = $opt{$r};
        if (defined (@{"$ns\::$r"})) {
          *{"$ns\::$o"} = \@{"$ns\::$r"};
        } else {
          *{"$ns\::$o"} = \${"$ns\::$r"};
        }
      } else { # assigning twice to avoid "used only once" warning - perhaps not the cleanest solution
        if ($a) {
          @{"$ns\::$o"} = ();
          @{"$ns\::$o"} = ();
        } else {
          ${"$ns\::$o"} = "";
          ${"$ns\::$o"} = "";
        }
        $opt{$o} = $t;
      }
    }
  }
  
  @$args = ();
  $$err = 0;

  while (@ARGV) {
    if ($ARGV[0] =~ /^--?(.*?)(?:=(.*))?$/o) {
      my ($n, $v) = ($1, $2);
      if (defined ($opt{$n})) {
        if (($type{$opt{$n}}) && (($v || "") =~ /$type{$opt{$n}}/i)) {
          unless (defined ($v)) { $v = ""; }
          if (defined (${"$ns\::$n"})) {
            ${"$ns\::$n"} = $v;
          } else {
            push (@{"$ns\::$n"}, $v);
          }
        } else {
          print STDERR ("\"$v\": invalid value for $n ($opt{$n})\n");
          $$err = 1;
        }
      } else {
        print STDERR ("$n: unknown option\n");
        $$err = 2;
      }
    } else {
      push (@$args, $ARGV[0]);
    }
    shift (@ARGV);
  }
  @ARGV = @$args;
}

1;