#!/usr/bin/env perl

use strict;
use warnings FATAL => 'all';
use English qw(-no_match_vars);
use constant PTDEBUG => $ENV{PTDEBUG} || 0;

my $file = shift @ARGV;
die "I need a file" unless $file;
die "$file is not a file" unless -f $file;
open my $fh, '<', $file or die "Cannot open $file: $OS_ERROR";

my $tool = shift @ARGV;
die "I need a tool" unless $tool;

print ".. program:: $tool\n\n",
      ('=' x (length($tool) + 11)), "\n",
      ":program:`$tool`\n",
      ('=' x (length($tool) + 11)), "\n\n";

$INPUT_RECORD_SEPARATOR = '';

my $in_code_block = 0;
my $section       = '';

while (my $para = <$fh>) {
   next if $para =~ m/^\.\. highlight:: perl/;

   $in_code_block = $para =~ m/^\s{2,}/ ? 1 : 0;

   if ($para =~ m/^\*{2,}\n([\w\s,-]+)\n\*{2,}$/m) {
      print "$1\n",
            ('=' x length $1),
            "\n\n";
      $section = $1;
   }
   elsif ($para =~ m/^Usage: /) {
      $para =~ s/^Usage: //;
      print "Usage\n",
            "-----\n\n",
            "::\n\n",
            "  $para";
   }
   elsif ($para =~ m/^Examples:/) {
      print "Examples\n",
            "--------\n\n";
   }
   else {
      $para =~ s/\.\. code-block:: perl/.. code-block:: bash/mg;
      $para =~ s/`+$tool`+/$tool/g;
      $para =~ s/([^\/])$tool/$1:program:`$tool`/g unless $in_code_block;
      $para =~ s/^$tool/:program:`$tool`/gm;
      $para =~ s/^--(\S+)$/.. option:: --$1/mg;
      $para =~ s/"--(\S+)"/:option:`--$1`/g;
      $para =~ s/\\\*/*/g;
      $para =~ s/\\ //g;
      $para =~ s/^[ ]+$//mg;
      $para =~ s/^\n\n/\n/mg;
      $para =~ s/code-block:: bash(\s+)CREATE/code-block:: sql$1CREATE/sg;
      if ( ($section || '') eq 'OUTPUT' ) {
         $para =~ s/^([A-Z_]+)\n\n/$1\n/;
      }
      print $para;
   }
}

close $fh;
exit;