#!/usr/bin/perl -w

use strict;
use Getopt::Long;

my %languages = (
    'c' => [
        '^\s*#\s*ifdef\s+pod\b',           0,
        '^\s*#\s*endif\s*/\*\s*pod\s*\*/', 0,
        '^\s*', '^\s*=v\s',
    ],
    'awk' => [
        '^\s*#\s*=pod\b', 0,
        '^\s*#\s*=cut\b', 0,
        '^\s*#\s*', '^\s*#\s*=v\s',
    ],
    'perl' => [
        '^\s*=pod$', 0, '^\s*=cut$', 0,
        '^\s*', '^\s*=v\s',
    ],
);
for my $l qw( C c++ C++ ) {
    $languages{$l} = $languages{c};
}

my $language = 'c';
my ( $start, $showstart, $stop, $showstop, $trim, $verbatim ) =
  @{ $languages{c} };

my $result = GetOptions(
    "language=s" => \$language,
    "start=s"    => \$start,
    "stop=s"     => \$stop,
    "trim=s"     => \$trim,
    "verbatim=s" => \$verbatim,
    "showstart"  => \$showstart,
    "showstop"   => \$showstop,
);
exit(1) unless ($result);

if ( $language ne 'c' ) {
    unless ( exists( $languages{$language} ) ) {
        die("Language '$language' not recognized\n");
    }
    ( $start, $showstart, $stop, $showstop, $trim, $verbatim ) =
      @{ $languages{$language} };
}

$start    = qr{$start};
$stop     = qr{$stop};
$trim     = qr{$trim};
$verbatim = qr{$verbatim};
my $show      = 0;
my $lastempty = 1;

while ( my $line = <DATA> ) {
    if ( $line =~ $start ) {
        unless ($lastempty) {
            $lastempty = 1;
            print "\n";
        }
        $show = 1;
        next unless ($showstart);
    }
    elsif ( $line =~ $stop ) {
        $show = 0;
        goto SHOWSTOPPER if ($showstop);
    }
    if ($show) {
SHOWSTOPPER:
        chomp($line);
        $line =~ s/$trim//;
        $line =~ s/$verbatim/ /;
        $lastempty = ( $line eq '' );
        print $line, "\n";
    }
}

__DATA__
    This could be anything
    #ifdef pod
    =head2 title

    blah, blah, blah,
        blah, blah

    =v indent 1
    #endif /* pod */
    This could be anything, too
    #ifdef  pod
    =head2 another title

    yo ho ho
    #endif /* pod */

    more anything