#!/usr/bin/env perl

# This program is copyright 2007-2009 Baron Schwartz.
# Feedback and improvements are welcome.
#
# THIS PROGRAM IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
# WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
# MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
#
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free Software
# Foundation, version 2; OR the Perl Artistic License.  On UNIX and similar
# systems, you can issue `man perlgpl' or `man perlartistic' to read these
# licenses.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, write to the Free Software Foundation, Inc., 59 Temple
# Place, Suite 330, Boston, MA  02111-1307  USA.

use strict;
use warnings FATAL => 'all';

our $VERSION = '1.0.4';
our $DISTRIB = '3722';
our $SVN_REV = sprintf("%d", (q$Revision: 3701 $ =~ m/(\d+)/g, 0));

# ###########################################################################
# OptionParser package 3695
# ###########################################################################
package OptionParser;

use strict;
use warnings FATAL => 'all';

use Getopt::Long;
use List::Util qw(max);
use English qw(-no_match_vars);

use constant MKDEBUG => $ENV{MKDEBUG};

my $POD_link_re = '[LC]<"?([^">]+)"?>';

sub new {
   my ( $class, %args ) = @_;
   foreach my $arg ( qw(description) ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($program_name) = $PROGRAM_NAME =~ m/([.A-Za-z-]+)$/;
   $program_name ||= $PROGRAM_NAME;

   my $self = {
      description    => $args{description},
      prompt         => $args{prompt} || '<options>',
      strict         => (exists $args{strict} ? $args{strict} : 1),
      dp             => $args{dp}     || undef,
      program_name   => $program_name,
      opts           => {},
      got_opts       => 0,
      short_opts     => {},
      defaults       => {},
      groups         => {},
      allowed_groups => {},
      errors         => [],
      rules          => [],  # desc of rules for --help
      mutex          => [],  # rule: opts are mutually exclusive
      atleast1       => [],  # rule: at least one opt is required
      disables       => {},  # rule: opt disables other opts 
      defaults_to    => {},  # rule: opt defaults to value of other opt
      default_files  => [
         "/etc/maatkit/maatkit.conf",
         "/etc/maatkit/$program_name.conf",
         "$ENV{HOME}/.maatkit.conf",
         "$ENV{HOME}/.$program_name.conf",
      ],
   };
   return bless $self, $class;
}

sub get_specs {
   my ( $self, $file ) = @_;
   my @specs = $self->_pod_to_specs($file);
   $self->_parse_specs(@specs);
   return;
}

sub get_defaults_files {
   my ( $self ) = @_;
   return @{$self->{default_files}};
}

sub _pod_to_specs {
   my ( $self, $file ) = @_;
   $file ||= __FILE__;
   open my $fh, '<', $file or die "Cannot open $file: $OS_ERROR";

   my %types = (
      string => 's', # standard Getopt type
      'int'  => 'i', # standard Getopt type
      float  => 'f', # standard Getopt type
      Hash   => 'H', # hash, formed from a comma-separated list
      hash   => 'h', # hash as above, but only if a value is given
      Array  => 'A', # array, similar to Hash
      array  => 'a', # array, similar to hash
      DSN    => 'd', # DSN, as provided by a DSNParser which is in $self->{dp}
      size   => 'z', # size with kMG suffix (powers of 2^10)
      'time' => 'm', # time, with an optional suffix of s/h/m/d
   );
   my @specs = ();
   my @rules = ();
   my $para;

   local $INPUT_RECORD_SEPARATOR = '';
   while ( $para = <$fh> ) {
      next unless $para =~ m/^=head1 OPTIONS/;
      last;
   }

   while ( $para = <$fh> ) {
      last if $para =~ m/^=over/;
      chomp $para;
      $para =~ s/\s+/ /g;
      $para =~ s/$POD_link_re/$1/go;
      MKDEBUG && _d('Option rule:', $para);
      push @rules, $para;
   }

   die 'POD has no OPTIONS section' unless $para;

   do {
      if ( my ($option) = $para =~ m/^=item --(.*)/ ) {
         chomp $para;
         MKDEBUG && _d($para);
         my %attribs;

         $para = <$fh>; # read next paragraph, possibly attributes

         if ( $para =~ m/: / ) { # attributes
            $para =~ s/\s+\Z//g;
            %attribs = map { split(/: /, $_) } split(/; /, $para);
            if ( $attribs{'short form'} ) {
               $attribs{'short form'} =~ s/-//;
            }
            $para = <$fh>; # read next paragraph, probably short help desc
         }
         else {
            MKDEBUG && _d('Option has no attributes');
         }

         $para =~ s/\s+\Z//g;
         $para =~ s/\s+/ /g;
         $para =~ s/$POD_link_re/$1/go;

         $para =~ s/\.(?:\n.*| [A-Z].*|\Z)//s;
         MKDEBUG && _d('Short help:', $para);

         die "No description after option spec $option" if $para =~ m/^=item/;

         if ( my ($base_option) =  $option =~ m/^\[no\](.*)/ ) {
            $option = $base_option;
            $attribs{'negatable'} = 1;
         }

         push @specs, {
            spec  => $option
               . ($attribs{'short form'} ? '|' . $attribs{'short form'} : '' )
               . ($attribs{'negatable'}  ? '!'                          : '' )
               . ($attribs{'cumulative'} ? '+'                          : '' )
               . ($attribs{'type'}       ? '=' . $types{$attribs{type}} : '' ),
            desc  => $para
               . ($attribs{default} ? " (default $attribs{default})" : ''),
            group => ($attribs{'group'} ? $attribs{'group'} : 'default'),
         };
      }
      while ( $para = <$fh> ) {
         last unless $para;


         if ( $para =~ m/^=head1/ ) {
            $para = undef; # Can't 'last' out of a do {} block.
            last;
         }
         last if $para =~ m/^=item --/;
      }
   } while ( $para );

   die 'No valid specs in POD OPTIONS' unless @specs;

   close $fh;
   return @specs, @rules;
}

sub _parse_specs {
   my ( $self, @specs ) = @_;
   my %disables; # special rule that requires deferred checking

   foreach my $opt ( @specs ) {
      if ( ref $opt ) { # It's an option spec, not a rule.
         MKDEBUG && _d('Parsing opt spec:',
            map { ($_, '=>', $opt->{$_}) } keys %$opt);

         my ( $long, $short ) = $opt->{spec} =~ m/^([\w-]+)(?:\|([^!+=]*))?/;
         if ( !$long ) {
            die "Cannot parse long option from spec $opt->{spec}";
         }
         $opt->{long} = $long;

         die "Duplicate long option --$long" if exists $self->{opts}->{$long};
         $self->{opts}->{$long} = $opt;

         if ( length $long == 1 ) {
            MKDEBUG && _d('Long opt', $long, 'looks like short opt');
            $self->{short_opts}->{$long} = $long;
         }

         if ( $short ) {
            die "Duplicate short option -$short"
               if exists $self->{short_opts}->{$short};
            $self->{short_opts}->{$short} = $long;
            $opt->{short} = $short;
         }
         else {
            $opt->{short} = undef;
         }

         $opt->{is_negatable}  = $opt->{spec} =~ m/!/        ? 1 : 0;
         $opt->{is_cumulative} = $opt->{spec} =~ m/\+/       ? 1 : 0;
         $opt->{is_required}   = $opt->{desc} =~ m/required/ ? 1 : 0;

         $opt->{group} ||= 'default';
         $self->{groups}->{ $opt->{group} }->{$long} = 1;

         $opt->{value} = undef;
         $opt->{got}   = 0;

         my ( $type ) = $opt->{spec} =~ m/=(.)/;
         $opt->{type} = $type;
         MKDEBUG && _d($long, 'type:', $type);

         if ( $type && $type eq 'd' && !$self->{dp} ) {
            die "$opt->{long} is type DSN (d) but no dp argument "
               . "was given when this OptionParser object was created";
         }

         $opt->{spec} =~ s/=./=s/ if ( $type && $type =~ m/[HhAadzm]/ );

         if ( (my ($def) = $opt->{desc} =~ m/default\b(?: ([^)]+))?/) ) {
            if ( $opt->{is_negatable} ) {
               $def = $def eq 'yes' ? 1
                    : $def eq 'no'  ? 0
                    : $def;
            }
            $self->{defaults}->{$long} = defined $def ? $def : 1;
            MKDEBUG && _d($long, 'default:', $def);
         }

         if ( $long eq 'config' ) {
            $self->{defaults}->{$long} = join(',', $self->get_defaults_files());
         }

         if ( (my ($dis) = $opt->{desc} =~ m/(disables .*)/) ) {
            $disables{$long} = $dis;
            MKDEBUG && _d('Deferring check of disables rule for', $opt, $dis);
         }

         $self->{opts}->{$long} = $opt;
      }
      else { # It's an option rule, not a spec.
         MKDEBUG && _d('Parsing rule:', $opt); 
         push @{$self->{rules}}, $opt;
         my @participants = $self->_get_participants($opt);
         my $rule_ok = 0;

         if ( $opt =~ m/mutually exclusive|one and only one/ ) {
            $rule_ok = 1;
            push @{$self->{mutex}}, \@participants;
            MKDEBUG && _d(@participants, 'are mutually exclusive');
         }
         if ( $opt =~ m/at least one|one and only one/ ) {
            $rule_ok = 1;
            push @{$self->{atleast1}}, \@participants;
            MKDEBUG && _d(@participants, 'require at least one');
         }
         if ( $opt =~ m/default to/ ) {
            $rule_ok = 1;
            $self->{defaults_to}->{$participants[0]} = $participants[1];
            MKDEBUG && _d($participants[0], 'defaults to', $participants[1]);
         }
         if ( $opt =~ m/restricted to option groups/ ) {
            $rule_ok = 1;
            my ($groups) = $opt =~ m/groups ([\w\s\,]+)/;
            my @groups = split(',', $groups);
            %{$self->{allowed_groups}->{$participants[0]}} = map {
               s/\s+//;
               $_ => 1;
            } @groups;
         }

         die "Unrecognized option rule: $opt" unless $rule_ok;
      }
   }

   foreach my $long ( keys %disables ) {
      my @participants = $self->_get_participants($disables{$long});
      $self->{disables}->{$long} = \@participants;
      MKDEBUG && _d('Option', $long, 'disables', @participants);
   }

   return; 
}

sub _get_participants {
   my ( $self, $str ) = @_;
   my @participants;
   foreach my $long ( $str =~ m/--(?:\[no\])?([\w-]+)/g ) {
      die "Option --$long does not exist while processing rule $str"
         unless exists $self->{opts}->{$long};
      push @participants, $long;
   }
   MKDEBUG && _d('Participants for', $str, ':', @participants);
   return @participants;
}

sub opts {
   my ( $self ) = @_;
   my %opts = %{$self->{opts}};
   return %opts;
}

sub opt_values {
   my ( $self ) = @_;
   my %opts = map {
      my $opt = $self->{opts}->{$_}->{short} ? $self->{opts}->{$_}->{short}
              : $_;
      $opt => $self->{opts}->{$_}->{value}
   } keys %{$self->{opts}};
   return %opts;
}

sub short_opts {
   my ( $self ) = @_;
   my %short_opts = %{$self->{short_opts}};
   return %short_opts;
}

sub set_defaults {
   my ( $self, %defaults ) = @_;
   $self->{defaults} = {};
   foreach my $long ( keys %defaults ) {
      die "Cannot set default for nonexistent option $long"
         unless exists $self->{opts}->{$long};
      $self->{defaults}->{$long} = $defaults{$long};
      MKDEBUG && _d('Default val for', $long, ':', $defaults{$long});
   }
   return;
}

sub get_defaults {
   my ( $self ) = @_;
   return $self->{defaults};
}

sub get_groups {
   my ( $self ) = @_;
   return $self->{groups};
}

sub _set_option {
   my ( $self, $opt, $val ) = @_;
   my $long = exists $self->{opts}->{$opt}       ? $opt
            : exists $self->{short_opts}->{$opt} ? $self->{short_opts}->{$opt}
            : die "Getopt::Long gave a nonexistent option: $opt";

   $opt = $self->{opts}->{$long};
   if ( $opt->{is_cumulative} ) {
      $opt->{value}++;
   }
   else {
      $opt->{value} = $val;
   }
   $opt->{got} = 1;
   MKDEBUG && _d('Got option', $long, '=', $val);
}

sub get_opts {
   my ( $self ) = @_; 

   foreach my $long ( keys %{$self->{opts}} ) {
      $self->{opts}->{$long}->{got} = 0;
      $self->{opts}->{$long}->{value}
         = exists $self->{defaults}->{$long}       ? $self->{defaults}->{$long}
         : $self->{opts}->{$long}->{is_cumulative} ? 0
         : undef;
   }
   $self->{got_opts} = 0;

   $self->{errors} = [];

   if ( @ARGV && $ARGV[0] eq "--config" ) {
      shift @ARGV;
      $self->_set_option('config', shift @ARGV);
   }
   if ( $self->has('config') ) {
      my @extra_args;
      foreach my $filename ( split(',', $self->get('config')) ) {
         eval {
            push @ARGV, $self->_read_config_file($filename);
         };
         if ( $EVAL_ERROR ) {
            if ( $self->got('config') ) {
               die $EVAL_ERROR;
            }
            elsif ( MKDEBUG ) {
               _d($EVAL_ERROR);
            }
         }
      }
      unshift @ARGV, @extra_args;
   }

   Getopt::Long::Configure('no_ignore_case', 'bundling');
   GetOptions(
      map    { $_->{spec} => sub { $self->_set_option(@_); } }
      grep   { $_->{long} ne 'config' } # --config is handled specially above.
      values %{$self->{opts}}
   ) or $self->save_error('Error parsing options');

   if ( exists $self->{opts}->{version} && $self->{opts}->{version}->{got} ) {
      printf("%s  Ver %s Distrib %s Changeset %s\n",
         $self->{program_name}, $main::VERSION, $main::DISTRIB, $main::SVN_REV)
            or die "Cannot print: $OS_ERROR";
      exit 0;
   }

   if ( @ARGV && $self->{strict} ) {
      $self->save_error("Unrecognized command-line options @ARGV");
   }

   foreach my $mutex ( @{$self->{mutex}} ) {
      my @set = grep { $self->{opts}->{$_}->{got} } @$mutex;
      if ( @set > 1 ) {
         my $err = join(', ', map { "--$self->{opts}->{$_}->{long}" }
                      @{$mutex}[ 0 .. scalar(@$mutex) - 2] )
                 . ' and --'.$self->{opts}->{$mutex->[-1]}->{long}
                 . ' are mutually exclusive.';
         $self->save_error($err);
      }
   }

   foreach my $required ( @{$self->{atleast1}} ) {
      my @set = grep { $self->{opts}->{$_}->{got} } @$required;
      if ( @set == 0 ) {
         my $err = join(', ', map { "--$self->{opts}->{$_}->{long}" }
                      @{$required}[ 0 .. scalar(@$required) - 2] )
                 .' or --'.$self->{opts}->{$required->[-1]}->{long};
         $self->save_error("Specify at least one of $err");
      }
   }

   foreach my $long ( keys %{$self->{opts}} ) {
      my $opt = $self->{opts}->{$long};
      if ( $opt->{got} ) {
         if ( exists $self->{disables}->{$long} ) {
            my @disable_opts = @{$self->{disables}->{$long}};
            map { $self->{opts}->{$_}->{value} = undef; } @disable_opts;
            MKDEBUG && _d('Unset options', @disable_opts,
               'because', $long,'disables them');
         }

         if ( exists $self->{allowed_groups}->{$long} ) {

            my @restricted_groups = grep {
               !exists $self->{allowed_groups}->{$long}->{$_}
            } keys %{$self->{groups}};

            my @restricted_opts;
            foreach my $restricted_group ( @restricted_groups ) {
               RESTRICTED_OPT:
               foreach my $restricted_opt (
                  keys %{$self->{groups}->{$restricted_group}} )
               {
                  next RESTRICTED_OPT if $restricted_opt eq $long;
                  push @restricted_opts, $restricted_opt
                     if $self->{opts}->{$restricted_opt}->{got};
               }
            }

            if ( @restricted_opts ) {
               my $err;
               if ( @restricted_opts == 1 ) {
                  $err = "--$restricted_opts[0]";
               }
               else {
                  $err = join(', ',
                            map { "--$self->{opts}->{$_}->{long}" }
                            grep { $_ } 
                            @restricted_opts[0..scalar(@restricted_opts) - 2]
                         )
                       . ' or --'.$self->{opts}->{$restricted_opts[-1]}->{long};
               }
               $self->save_error("--$long is not allowed with $err");
            }
         }

      }
      elsif ( $opt->{is_required} ) { 
         $self->save_error("Required option --$long must be specified");
      }

      $self->_validate_type($opt);
   }

   $self->{got_opts} = 1;
   return;
}

sub _validate_type {
   my ( $self, $opt ) = @_;
   return unless $opt && $opt->{type};
   my $val = $opt->{value};

   if ( $val && $opt->{type} eq 'm' ) {
      MKDEBUG && _d('Parsing option', $opt->{long}, 'as a time value');
      my ( $num, $suffix ) = $val =~ m/(\d+)([a-z])?$/;
      if ( !$suffix ) {
         my ( $s ) = $opt->{desc} =~ m/\(suffix (.)\)/;
         $suffix = $s || 's';
         MKDEBUG && _d('No suffix given; using', $suffix, 'for',
            $opt->{long}, '(value:', $val, ')');
      }
      if ( $suffix =~ m/[smhd]/ ) {
         $val = $suffix eq 's' ? $num            # Seconds
              : $suffix eq 'm' ? $num * 60       # Minutes
              : $suffix eq 'h' ? $num * 3600     # Hours
              :                  $num * 86400;   # Days
         $opt->{value} = $val;
         MKDEBUG && _d('Setting option', $opt->{long}, 'to', $val);
      }
      else {
         $self->save_error("Invalid time suffix for --$opt->{long}");
      }
   }
   elsif ( $val && $opt->{type} eq 'd' ) {
      MKDEBUG && _d('Parsing option', $opt->{long}, 'as a DSN');
      my $from_key = $self->{defaults_to}->{ $opt->{long} };
      my $default = {};
      if ( $from_key ) {
         MKDEBUG && _d($opt->{long}, 'DSN copies from', $from_key, 'DSN');
         $default = $self->{dp}->parse(
            $self->{dp}->as_string($self->{opts}->{$from_key}->{value}) );
      }
      $opt->{value} = $self->{dp}->parse($val, $default);
   }
   elsif ( $val && $opt->{type} eq 'z' ) {
      MKDEBUG && _d('Parsing option', $opt->{long}, 'as a size value');
      my %factor_for = (k => 1_024, M => 1_048_576, G => 1_073_741_824);
      my ($pre, $num, $factor) = $val =~ m/^([+-])?(\d+)([kMG])?$/;
      if ( defined $num ) {
         if ( $factor ) {
            $num *= $factor_for{$factor};
            MKDEBUG && _d('Setting option', $opt->{y},
               'to num', $num, '* factor', $factor);
         }
         $opt->{value} = ($pre || '') . $num;
      }
      else {
         $self->save_error("Invalid size for --$opt->{long}");
      }
   }
   elsif ( $opt->{type} eq 'H' || (defined $val && $opt->{type} eq 'h') ) {
      $opt->{value} = { map { $_ => 1 } split(',', ($val || '')) };
   }
   elsif ( $opt->{type} eq 'A' || (defined $val && $opt->{type} eq 'a') ) {
      $opt->{value} = [ split(/(?<!\\),/, ($val || '')) ];
   }
   else {
      MKDEBUG && _d('Nothing to validate for option',
         $opt->{long}, 'type', $opt->{type}, 'value', $val);
   }

   return;
}

sub get {
   my ( $self, $opt ) = @_;
   my $long = (length $opt == 1 ? $self->{short_opts}->{$opt} : $opt);
   die "Option $opt does not exist"
      unless $long && exists $self->{opts}->{$long};
   return $self->{opts}->{$long}->{value};
}

sub got {
   my ( $self, $opt ) = @_;
   my $long = (length $opt == 1 ? $self->{short_opts}->{$opt} : $opt);
   die "Option $opt does not exist"
      unless $long && exists $self->{opts}->{$long};
   return $self->{opts}->{$long}->{got};
}

sub has {
   my ( $self, $opt ) = @_;
   my $long = (length $opt == 1 ? $self->{short_opts}->{$opt} : $opt);
   return defined $long ? exists $self->{opts}->{$long} : 0;
}

sub set {
   my ( $self, $opt, $val ) = @_;
   my $long = (length $opt == 1 ? $self->{short_opts}->{$opt} : $opt);
   die "Option $opt does not exist"
      unless $long && exists $self->{opts}->{$long};
   $self->{opts}->{$long}->{value} = $val;
   return;
}

sub save_error {
   my ( $self, $error ) = @_;
   push @{$self->{errors}}, $error;
}

sub errors {
   my ( $self ) = @_;
   return $self->{errors};
}

sub prompt {
   my ( $self ) = @_;
   return "Usage: $PROGRAM_NAME $self->{prompt}\n";
}

sub descr {
   my ( $self ) = @_;
   my $descr  = $self->{program_name} . ' ' . ($self->{description} || '')
              . "  For more details, please use the --help option, "
              . "or try 'perldoc $PROGRAM_NAME' "
              . "for complete documentation.";
   $descr = join("\n", $descr =~ m/(.{0,80})(?:\s+|$)/g);
   $descr =~ s/ +$//mg;
   return $descr;
}

sub usage_or_errors {
   my ( $self ) = @_;
   if ( $self->{opts}->{help}->{got} ) {
      print $self->print_usage() or die "Cannot print usage: $OS_ERROR";
      exit 0;
   }
   elsif ( scalar @{$self->{errors}} ) {
      print $self->print_errors() or die "Cannot print errors: $OS_ERROR";
      exit 0;
   }
   return;
}

sub print_errors {
   my ( $self ) = @_;
   my $usage = $self->prompt() . "\n";
   if ( (my @errors = @{$self->{errors}}) ) {
      $usage .= join("\n  * ", 'Errors in command-line arguments:', @errors)
              . "\n";
   }
   return $usage . "\n" . $self->descr();
}

sub print_usage {
   my ( $self ) = @_;
   die "Run get_opts() before print_usage()" unless $self->{got_opts};
   my @opts = values %{$self->{opts}};

   my $maxl = max(
      map { length($_->{long}) + ($_->{is_negatable} ? 4 : 0) }
      @opts);

   my $maxs = max(0,
      map { length($_) + ($self->{opts}->{$_}->{is_negatable} ? 4 : 0) }
      values %{$self->{short_opts}});

   my $lcol = max($maxl, ($maxs + 3));
   my $rcol = 80 - $lcol - 6;
   my $rpad = ' ' x ( 80 - $rcol );

   $maxs = max($lcol - 3, $maxs);

   my $usage = $self->descr() . "\n" . $self->prompt();

   my @groups = reverse sort grep { $_ ne 'default'; } keys %{$self->{groups}};
   push @groups, 'default';

   foreach my $group ( reverse @groups ) {
      $usage .= "\n".($group eq 'default' ? 'Options' : $group).":\n\n";
      foreach my $opt (
         sort { $a->{long} cmp $b->{long} }
         grep { $_->{group} eq $group }
         @opts )
      {
         my $long  = $opt->{is_negatable} ? "[no]$opt->{long}" : $opt->{long};
         my $short = $opt->{short};
         my $desc  = $opt->{desc};
         if ( $opt->{type} && $opt->{type} eq 'm' ) {
            my ($s) = $desc =~ m/\(suffix (.)\)/;
            $s    ||= 's';
            $desc =~ s/\s+\(suffix .\)//;
            $desc .= ".  Optional suffix s=seconds, m=minutes, h=hours, "
                   . "d=days; if no suffix, $s is used.";
         }
         $desc = join("\n$rpad", grep { $_ } $desc =~ m/(.{0,$rcol})(?:\s+|$)/g);
         $desc =~ s/ +$//mg;
         if ( $short ) {
            $usage .= sprintf("  --%-${maxs}s -%s  %s\n", $long, $short, $desc);
         }
         else {
            $usage .= sprintf("  --%-${lcol}s  %s\n", $long, $desc);
         }
      }
   }

   if ( (my @rules = @{$self->{rules}}) ) {
      $usage .= "\nRules:\n\n";
      $usage .= join("\n", map { "  $_" } @rules) . "\n";
   }
   if ( $self->{dp} ) {
      $usage .= "\n" . $self->{dp}->usage();
   }
   $usage .= "\nOptions and values after processing arguments:\n\n";
   foreach my $opt ( sort { $a->{long} cmp $b->{long} } @opts ) {
      my $val   = $opt->{value};
      my $type  = $opt->{type} || '';
      my $bool  = $opt->{spec} =~ m/^[\w-]+(?:\|[\w-])?!?$/;
      $val      = $bool                     ? ( $val ? 'TRUE' : 'FALSE' )
                : !defined $val             ? '(No value)'
                : $type eq 'd'              ? $self->{dp}->as_string($val)
                : $type =~ m/H|h/           ? join(',', sort keys %$val)
                : $type =~ m/A|a/           ? join(',', @$val)
                :                             $val;
      $usage .= sprintf("  --%-${lcol}s  %s\n", $opt->{long}, $val);
   }
   return $usage;
}

sub prompt_noecho {
   shift @_ if ref $_[0] eq __PACKAGE__;
   my ( $prompt ) = @_;
   local $OUTPUT_AUTOFLUSH = 1;
   print $prompt
      or die "Cannot print: $OS_ERROR";
   my $response;
   eval {
      require Term::ReadKey;
      Term::ReadKey::ReadMode('noecho');
      chomp($response = <STDIN>);
      Term::ReadKey::ReadMode('normal');
      print "\n"
         or die "Cannot print: $OS_ERROR";
   };
   if ( $EVAL_ERROR ) {
      die "Cannot read response; is Term::ReadKey installed? $EVAL_ERROR";
   }
   return $response;
}

if ( MKDEBUG ) {
   print '# ', $^X, ' ', $], "\n";
   my $uname = `uname -a`;
   if ( $uname ) {
      $uname =~ s/\s+/ /g;
      print "# $uname\n";
   }
   printf("# %s  Ver %s Distrib %s Changeset %s line %d\n",
      $PROGRAM_NAME, ($main::VERSION || ''), ($main::DISTRIB || ''),
      ($main::SVN_REV || ''), __LINE__);
   print('# Arguments: ',
      join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n");
}

sub _read_config_file {
   my ( $self, $filename ) = @_;
   open my $fh, "<", $filename or die "Cannot open $filename: $OS_ERROR\n";
   my @args;
   my $prefix = '--';
   my $parse  = 1;

   LINE:
   while ( my $line = <$fh> ) {
      chomp $line;
      next LINE if $line =~ m/^\s*(?:\#|\;|$)/;
      $line =~ s/\s+#.*$//g;
      $line =~ s/^\s+|\s+$//g;
      if ( $line eq '--' ) {
         $prefix = '';
         $parse  = 0;
         next LINE;
      }
      if ( $parse
         && (my($opt, $arg) = $line =~ m/^\s*([^=\s]+?)(?:\s*=\s*(.*?)\s*)?$/)
      ) {
         push @args, grep { defined $_ } ("$prefix$opt", $arg);
      }
      elsif ( $line =~ m/./ ) {
         push @args, $line;
      }
      else {
         die "Syntax error in file $filename at line $INPUT_LINE_NUMBER";
      }
   }
   close $fh;
   return @args;
}

sub read_para_after {
   my ( $self, $file, $regex ) = @_;
   open my $fh, "<", $file or die "Can't open $file: $OS_ERROR";
   local $INPUT_RECORD_SEPARATOR = '';
   my $para;
   while ( $para = <$fh> ) {
      next unless $para =~ m/^=pod$/m;
      last;
   }
   while ( $para = <$fh> ) {
      next unless $para =~ m/$regex/;
      last;
   }
   $para = <$fh>;
   chomp($para);
   close $fh or die "Can't close $file: $OS_ERROR";
   return $para;
}

sub clone {
   my ( $self ) = @_;

   my %clone = map {
      my $hashref  = $self->{$_};
      my $val_copy = {};
      foreach my $key ( keys %$hashref ) {
         my $ref = ref $hashref->{$key};
         $val_copy->{$key} = !$ref           ? $hashref->{$key}
                           : $ref eq 'HASH'  ? { %{$hashref->{$key}} }
                           : $ref eq 'ARRAY' ? [ @{$hashref->{$key}} ]
                           : $hashref->{$key};
      }
      $_ => $val_copy;
   } qw(opts short_opts defaults);

   foreach my $scalar ( qw(got_opts) ) {
      $clone{$scalar} = $self->{$scalar};
   }

   return bless \%clone;     
}

sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

1;

# ###########################################################################
# End OptionParser package
# ###########################################################################

package main;

use English qw(-no_match_vars);
use POSIX qw(mkfifo);
use IO::File;

use constant MKDEBUG => $ENV{MKDEBUG};

sub main {
      @ARGV = @_;  # set global ARGV for this package

   # ############################################################################
   # Get configuration information.
   # ############################################################################
   my $o = new OptionParser(
      strict      => 0,
      prompt      => '[options] [FILE ...]',
      description => q{splits FILE and pipes lines to a fifo.  With no FILE, }
                   . q{or when FILE is -, read standard input.},
   );
   $o->get_specs();
   $o->get_opts();

   if ( !$o->get('lines') || $o->get('lines') <= 0 ) {
      $o->save_error('--lines must be a positive integer');
   }
   $o->usage_or_errors();

   # TODO: binmode
   # TODO: add limit arguments so you can read a splice out of the middle.
   # TODO: print out $. on exit (including exit by CTRL-C).
   # TODO make progress messages the default
   # TODO: use tell to figure out percentage, and print %complete and ETA.  See
   # http://www.perlmonks.org/?node_id=698607 for inspiration.  This would probably
   # only work when a single file is named in @ARGV (would not work when <> is
   # reading STDIN, for example).

   my $file = $o->get('fifo');

   if ( $o->get('force') && -e $file ) {
      unlink($file) or die "Can't unlink $file: $OS_ERROR";
   }
   mkfifo($file, 0777) or die "Can't make fifo $file: $OS_ERROR";

   my $fh;

   $fh = IO::File->new($file, '>') or die "Can't open $file: $OS_ERROR";
   $fh->autoflush(1);

   if ( $o->get('statistics') ) {
      printf("%5s %9s %5s %8s %8s\n", qw(chunks lines time overall current));
   }

   # This is for runtime efficiency.
   my $OFFSET = $o->get('offset');
   my $LINES  = $o->get('lines');

   my $lines  = 0;
   my $chunks = 0;
   my $start  = time();
   my $cstart = time();
   while ( my $line = <> ) {
      $lines++;
      next if $OFFSET && $lines < $OFFSET;
      if ( $lines % $LINES == 0 ) {
         close $fh or die "Can't close: $OS_ERROR";

         unlink($file) or die "Can't unlink $file: $OS_ERROR";
         mkfifo($file, 0777) or die "Can't make fifo $file: $OS_ERROR";

         $fh = IO::File->new($file, '>') or die "Can't open $file: $OS_ERROR";
         $fh->autoflush(1);

         $chunks++;
         my $end = time();
         if ( $o->get('statistics') ) {
            my $overall = ($end - $start)  || 1;
            my $current = ($end - $cstart) || 1;
            printf("%5d %9d %5d %5.2f %5.2f\n", $chunks, $lines, ($end - $start),
               ($lines / $overall), ($LINES / $current));
         }
         $cstart = $end;
      }
      print $fh $line or die "Can't print: $OS_ERROR";
   }
   close $fh or die "Can't close: $OS_ERROR";

   unlink($file) or die "Can't unlink $file: $OS_ERROR";
}

# ############################################################################
# Run the program.
# ############################################################################
if ( !caller ) { exit main(@ARGV); }

# ############################################################################
# Documentation
# ############################################################################
=pod

=head1 NAME

mk-fifo-split - Split files and pipe lines to a fifo without really splitting.

=head1 SYNOPSIS

Read hugefile.txt in chunks of a million lines without physically splitting it:

 mk-fifo-split --lines 1000000 hugefile.txt
 while [ -e /tmp/mk-fifo-split ]; do cat /tmp/mk-fifo-split; done

=head1 DESCRIPTION

mk-fifo-split lets you read from a file as though it contains only some of the
lines in the file.  When you read from it again, it contains the next set of
lines; when you have gone all the way through it, the file disappears.  This
works only on Unix-like operating systems.

You can specify multiple files on the command line.  If you don't specify any,
or if you use the special filename C<->, lines are read from standard input.

=head1 DOWNLOADING

You can download Maatkit from Google Code at
L<http://code.google.com/p/maatkit/>, or you can get any of the tools
easily with a command like the following:

   wget http://www.maatkit.org/get/toolname
   or
   wget http://www.maatkit.org/trunk/toolname

Where C<toolname> can be replaced with the name (or fragment of a name) of any
of the Maatkit tools.  Once downloaded, they're ready to run; no installation is
needed.  The first URL gets the latest released version of the tool, and the
second gets the latest trunk code from Subversion.

=head1 OPTIONS

=over

=item --config

type: Array

Read this comma-separated list of config files; if specified, this must be the
first option on the command line.

=item --fifo

type: string; default: /tmp/mk-fifo-split

The name of the fifo from which the lines can be read.

=item --force

Remove the fifo if it exists already, then create it again.

=item --help

Show help and exit.

=item --lines

type: int; default: 1000

The number of lines to read in each chunk.

=item --offset

type: int; default: 0

Begin at the Nth line.  If the argument is 0, all lines are printed to the fifo.
If 1, then beginning at the first line, lines are printed (exactly the same as
0).  If 2, the first line is skipped, and the 2nd and subsequent lines are
printed to the fifo.

=item --statistics

Print out statistics between chunks.  The statistics are the number of chunks,
the number of lines, elapsed time, and lines per second overall and during the
last chunk.

=item --version

Show version and exit.

=back

=head1 ENVIRONMENT

The environment variable C<MKDEBUG> enables verbose debugging output in all of
the Maatkit tools:

   MKDEBUG=1 mk-....

=head1 SYSTEM REQUIREMENTS

You need Perl, DBI, DBD::mysql, and some core packages that ought to be
installed in any reasonably new version of Perl.

=head1 BUGS

Please use Google Code Issues and Groups to report bugs or request support:
L<http://code.google.com/p/maatkit/>.  You can also join #maatkit on Freenode to
discuss Maatkit.

Please include the complete command-line used to reproduce the problem you are
seeing, the version of all MySQL servers involved, the complete output of the
tool when run with L<"--version">, and if possible, debugging output produced by
running with the C<MKDEBUG=1> environment variable.

=head1 COPYRIGHT, LICENSE AND WARRANTY

This program is copyright 2007-2009 Baron Schwartz.
Feedback and improvements are welcome.

THIS PROGRAM IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation, version 2; OR the Perl Artistic License.  On UNIX and similar
systems, you can issue `man perlgpl' or `man perlartistic' to read these
licenses.

You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place, Suite 330, Boston, MA  02111-1307  USA.

=head1 AUTHOR

Baron Schwartz.

=head1 VERSION

This manual page documents Ver 1.0.4 Distrib 3722 $Revision: 3701 $.

=cut
