#!/usr/bin/perl
# ---------------------------------------------------------------------------
# Example function for reading the parameters to a CDS callout script from
# STDIN, and parsing them into a Perl object's hashes.
#
# NOTE: this code taken from my own production script code ;) --TJ
# ---------------------------------------------------------------------------

use strict;

# assuming this script _is_ the callout script, parse STDIN and write the
# callout parameters to a file (printing to STDOUT doesn't work too well
# as callouts don't really have an attached terminal)

my %params = ();
my $output_file = "/tmp/cds-callout-parameters-list.txt";

get_params(parameters => \%params);

open(OUTPUT, "> $output_file") or die "unable to open $output_file: $!\n";

foreach my $key (keys %params) {
  print OUTPUT "Parameter: $key\tValue: $params{$key}\n";
}

close(OUTPUT) or die "unable to close $output_file: $!\n");

# done!
exit 0;

# ---------------------------------------------------------------------------
sub get_params {
  my %args = @_;

  my $param = $args{'parameters'};

  my $line;

  my $element_index = 0;
  my $do_read_element = 0;

  # reading input from STDIN
  while ($line = <>) {

    # remove the newline characters...
    chomp $line;

    if ($line =~ /^Scalar/) {

      my ($datatype, $variable, @value) = split (/\s+/, $line);
      my $value = join(" ", @value);

      if ($do_read_element) {

        # read the parameter and value, a little deeper in the hash
        $param->{'parameters'}{'destinations'}[$element_index]{$variable} =
          $value;

      } else {

        # record the parameter and value in an internal hash
        $param->{'parameters'}{$variable} = $value;
      }

      next;

    } elsif ($line =~ /^BeginElement/) {

      # signal that we're reading element values...
      $do_read_element = 1;

      next;

    } elsif ($line =~ /^EndElement/) {

      # done reading that element...
      $do_read_element = 0;

      # don't forget to increment the element index
      $element_index++;

      next;

    } elsif ($line =~ /^EndParams/) {
      last;

    } else {

      # NOTE: what to do with unrecognized input??
    }
  }

  return 1;
}

# ---------------------------------------------------------------------------