# File: Factoids.pm
# Author: pragma_
#
# Purpose: Provides functionality for factoids and a type of external module execution.

# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

package PBot::Factoids;

use warnings;
use strict;

use feature 'switch';
no if $] >= 5.018, warnings => "experimental::smartmatch";

use HTML::Entities;
use Time::HiRes qw(gettimeofday);
use Time::Duration qw(duration);
use Carp ();
use POSIX qw(strftime);
use Text::ParseWords;
use JSON;

use PPI;
use Safe;

use PBot::PBot qw($VERSION);
use PBot::FactoidCommands;
use PBot::FactoidModuleLauncher;
use PBot::DualIndexHashObject;

use PBot::Utils::Indefinite;
use PBot::Utils::ValidateString;

sub new {
  if(ref($_[1]) eq 'HASH') {
    Carp::croak("Options to Factoids should be key/value pairs, not hash reference");
  }

  my ($class, %conf) = @_;

  my $self = bless {}, $class;
  $self->initialize(%conf);
  return $self;
}

sub initialize {
  my ($self, %conf) = @_;

  my $filename    = delete $conf{filename};
  my $export_path = delete $conf{export_path};
  my $export_site = delete $conf{export_site};

  my $pbot = delete $conf{pbot} // Carp::croak("Missing pbot reference to Factoids");

  $self->{factoids}    = PBot::DualIndexHashObject->new(name => 'Factoids', filename => $filename);
  $self->{export_path} = $export_path;
  $self->{export_site} = $export_site;

  $self->{pbot}                  = $pbot;
  $self->{commands}              = PBot::FactoidCommands->new(pbot => $pbot);
  $self->{factoidmodulelauncher} = PBot::FactoidModuleLauncher->new(pbot => $pbot);

  $self->{pbot}->{registry}->add_default('text', 'factoids', 'default_rate_limit', '15');

  $self->{pbot}->{atexit}->register(sub { $self->save_factoids; return; });

  $self->{compartments} = {};
  $self->load_factoids;
}

sub load_factoids {
  my $self = shift;

  $self->{pbot}->{logger}->log("Loading factoids from " . $self->{factoids}->filename . " ...\n");

  $self->{factoids}->load;

  my ($text, $regex, $modules);

  foreach my $channel (keys %{ $self->{factoids}->hash }) {
    foreach my $trigger (keys %{ $self->{factoids}->hash->{$channel} }) {
      $text++   if $self->{factoids}->hash->{$channel}->{$trigger}->{type} eq 'text';
      $regex++  if $self->{factoids}->hash->{$channel}->{$trigger}->{type} eq 'regex';
      $modules++ if $self->{factoids}->hash->{$channel}->{$trigger}->{type} eq 'module';
    }
  }

  $self->{pbot}->{logger}->log("  " . ($text + $regex + $modules) . " factoids loaded ($text text, $regex regexs, $modules modules).\n");
  $self->{pbot}->{logger}->log("Done.\n");

  $self->add_default_factoids();
}

sub add_default_factoids {
  my $self = shift;
  $self->add_factoid('text', '.*', $self->{pbot}->{registry}->get_value('irc', 'botnick'), 'version', "/say $VERSION", 1);
}

sub save_factoids {
  my $self = shift;

  $self->{factoids}->save;
  $self->export_factoids;
}

sub add_factoid {
  my $self = shift;
  my ($type, $channel, $owner, $trigger, $action, $dont_save) = @_;

  $type = lc $type;
  $channel = '.*' if $channel !~ /^#/;
  $channel = lc $channel;

  $self->{factoids}->hash->{$channel}->{$trigger}->{enabled}    = 1;
  $self->{factoids}->hash->{$channel}->{$trigger}->{type}       = $type;
  $self->{factoids}->hash->{$channel}->{$trigger}->{action}     = $action;
  $self->{factoids}->hash->{$channel}->{$trigger}->{owner}      = $owner;
  $self->{factoids}->hash->{$channel}->{$trigger}->{created_on} = gettimeofday;
  $self->{factoids}->hash->{$channel}->{$trigger}->{ref_count}  = 0;
  $self->{factoids}->hash->{$channel}->{$trigger}->{ref_user}   = "nobody";
  $self->{factoids}->hash->{$channel}->{$trigger}->{rate_limit} = $self->{pbot}->{registry}->get_value('factoids', 'default_rate_limit');

  $self->save_factoids unless $dont_save;

  unless ($dont_save) {
    $self->{commands}->log_factoid($channel, $trigger, $owner, "created: $action");
  }
}

sub remove_factoid {
  my $self = shift;
  my ($channel, $trigger) = @_;

  $channel = '.*' if $channel !~ /^#/;
  $channel = lc $channel;

  delete $self->{factoids}->hash->{$channel}->{$trigger};

  if(not scalar keys %{ $self->{factoids}->hash->{$channel} }) {
    delete $self->{factoids}->hash->{$channel};
  }

  $self->save_factoids;
}

sub export_factoids {
  my $self = shift;
  my $filename;

  if(@_) { $filename = shift; } else { $filename = $self->export_path; }
  return if not defined $filename;

  open FILE, "> $filename" or return "Could not open export path.";

  my $time = localtime;
  print FILE "<html><head>\n<link href='css/blue.css' rel='stylesheet' type='text/css'>\n";
  print FILE '<script type="text/javascript" src="js/jquery-latest.js"></script>' . "\n";
  print FILE '<script type="text/javascript" src="js/jquery.tablesorter.js"></script>' . "\n";
  print FILE '<script type="text/javascript" src="js/picnet.table.filter.min.js"></script>' . "\n";
  print FILE "</head>\n<body><i>Last updated at $time</i>\n";
  print FILE "<hr><h2>Candide's factoids</h2>\n";
  
  my $i = 0;
  my $table_id = 1;

  foreach my $channel (sort keys %{ $self->{factoids}->hash }) {
    next if not scalar keys %{ $self->{factoids}->hash->{$channel} };
    my $chan = $channel eq '.*' ? 'global' : $channel;

    print FILE "<a href='#" . encode_entities($chan) . "'>" . encode_entities($chan) . "</a><br>\n";
  }

  foreach my $channel (sort keys %{ $self->{factoids}->hash }) {
    next if not scalar keys %{ $self->{factoids}->hash->{$channel} };
    my $chan = $channel eq '.*' ? 'global' : $channel;
    print FILE "<a name='" . encode_entities($chan) . "'></a>\n";
    print FILE "<hr>\n<h3>" . encode_entities($chan) . "</h3>\n<hr>\n";
    print FILE "<table border=\"0\" id=\"table$table_id\" class=\"tablesorter\">\n";
    print FILE "<thead>\n<tr>\n";
    print FILE "<th>owner</th>\n";
    print FILE "<th>created on</th>\n";
    print FILE "<th>times referenced</th>\n";
    print FILE "<th>factoid</th>\n";
    print FILE "<th>last edited by</th>\n";
    print FILE "<th>edited date</th>\n";
    print FILE "<th>last referenced by</th>\n";
    print FILE "<th>last referenced date</th>\n";
    print FILE "</tr>\n</thead>\n<tbody>\n";
    $table_id++;

    foreach my $trigger (sort keys %{ $self->{factoids}->hash->{$channel} }) {
      if($self->{factoids}->hash->{$channel}->{$trigger}->{type} eq 'text') {
        $i++;
        if($i % 2) {
          print FILE "<tr bgcolor=\"#dddddd\">\n";
        } else {
          print FILE "<tr>\n";
        }
        
        print FILE "<td>" . encode_entities($self->{factoids}->hash->{$channel}->{$trigger}->{owner}) . "</td>\n";
        print FILE "<td>" . encode_entities(strftime "%Y/%m/%d %H:%M:%S", localtime $self->{factoids}->hash->{$channel}->{$trigger}->{created_on}) . "</td>\n";

        print FILE "<td>" . $self->{factoids}->hash->{$channel}->{$trigger}->{ref_count} . "</td>\n";

        my $action = $self->{factoids}->hash->{$channel}->{$trigger}->{action};

        if ($action =~ m/https?:\/\/[^ ]+/) {
          $action =~ s/(.*?)http(s?:\/\/[^ ]+)/encode_entities($1) . "<a href='http" . encode_entities($2) . "'>http" . encode_entities($2) . "<\/a>"/ge;
          $action =~ s/(.*)<\/a>(.*$)/"$1<\/a>" . encode_entities($2)/e;
        } else {
          $action = encode_entities($action);
        }

        if(exists $self->{factoids}->hash->{$channel}->{$trigger}->{action_with_args}) {
          my $with_args = $self->{factoids}->hash->{$channel}->{$trigger}->{action_with_args};
          $with_args =~ s/(.*?)http(s?:\/\/[^ ]+)/encode_entities($1) . "<a href='http" . encode_entities($2) . "'>http" . encode_entities($2) . "<\/a>"/ge;
          $with_args =~ s/(.*)<\/a>(.*$)/"$1<\/a>" . encode_entities($2)/e;
          print FILE "<td width=100%><b>" . encode_entities($trigger) . "</b> is $action<br><br><b>with_args:</b> " . encode_entities($with_args) . "</td>\n";
        } else {
          print FILE "<td width=100%><b>" . encode_entities($trigger) . "</b> is $action</td>\n";
        }

        if(exists $self->{factoids}->hash->{$channel}->{$trigger}->{edited_by}) { 
          print FILE "<td>" . $self->{factoids}->hash->{$channel}->{$trigger}->{edited_by} . "</td>\n";
          print FILE "<td>" . encode_entities(strftime "%Y/%m/%d %H:%M:%S", localtime $self->{factoids}->hash->{$channel}->{$trigger}->{edited_on}) . "</td>\n";
        } else {
          print FILE "<td></td>\n";
          print FILE "<td></td>\n";
        }

        print FILE "<td>" . encode_entities($self->{factoids}->hash->{$channel}->{$trigger}->{ref_user}) . "</td>\n";

        if(exists $self->{factoids}->hash->{$channel}->{$trigger}->{last_referenced_on}) {
          print FILE "<td>" . encode_entities(strftime "%Y/%m/%d %H:%M:%S", localtime $self->{factoids}->hash->{$channel}->{$trigger}->{last_referenced_on}) . "</td>\n";
        } else {
          print FILE "<td></td>\n";
        }
 
        print FILE "</tr>\n";
      }
    }
    print FILE "</tbody>\n</table>\n";
  }

  print FILE "<hr>$i factoids memorized.<br>";
  print FILE "<hr><i>Last updated at $time</i>\n";

  print FILE "<script type='text/javascript'>\n";
  $table_id--;
  print FILE '$(document).ready(function() {' . "\n";
  while($table_id > 0) {
    print FILE '$("#table' . $table_id . '").tablesorter();' . "\n";
    print FILE '$("#table' . $table_id . '").tableFilter();' . "\n";
    $table_id--;
  }
  print FILE "});\n";
  print FILE "</script>\n";
  print FILE "</body>\n</html>\n";
  
  close(FILE);
  
  #$self->{pbot}->{logger}->log("$i factoids exported to path: " . $self->export_path . ", site: " . $self->export_site . "\n");
  return "/say $i factoids exported to " . $self->export_site;
}

sub find_factoid {
  my ($self, $from, $keyword, $arguments, $exact_channel, $exact_trigger, $find_alias) = @_;

  my $debug = 0;

  $self->{pbot}->{logger}->log("find_factoid: from: [$from], kw: [$keyword], args: [" . (defined $arguments ? $arguments : "undef") . "], " . (defined $exact_channel ? $exact_channel : "undef") . ", " . (defined $exact_trigger ? $exact_trigger : "undef") . "\n") if $debug;

  $from = '.*' if not defined $from or $from !~ /^#/;
  $from = lc $from;

  $self->{pbot}->{logger}->log("from: $from\n") if $debug;

  my @result = eval {
    my @results;
    for (my $depth = 0; $depth < 5; $depth++) {
      my $string = $keyword . (defined $arguments ? " $arguments" : "");
      $self->{pbot}->{logger}->log("string: $string\n") if $debug;
      return undef if $self->{pbot}->{commands}->exists($keyword);
      # check factoids
      foreach my $channel (sort keys %{ $self->{factoids}->hash }) {
        if($exact_channel) {
          if(defined $exact_trigger && $exact_trigger == 1) {
            next unless $from eq lc $channel;
          } else {
            next unless $from eq lc $channel or $channel eq '.*';
          }
        }

        foreach my $trigger (keys %{ $self->{factoids}->hash->{$channel} }) {
          if($keyword =~ m/^\Q$trigger\E$/i) {
            $self->{pbot}->{logger}->log("return $channel: $trigger\n") if $debug;

            if($find_alias && $self->{factoids}->hash->{$channel}->{$trigger}->{action} =~ /^\/call\s+(.*)$/) {
              my $command;
              if(length $arguments) {
                $command = "$1 $arguments";
              } else {
                $command = $1;
              }
              ($keyword, $arguments) = split /\s+/, $command, 2;
              goto NEXT_DEPTH;
            }

            if (defined $exact_channel && $exact_channel == 1) {
              return ($channel, $trigger);
            } else {
              push @results, [$channel, $trigger];
            }
          }
        }
      }

      # then check regex factoids
      if(not $exact_trigger) {
        foreach my $channel (sort keys %{ $self->{factoids}->hash }) {
          if($exact_channel) {
            next unless $from eq lc $channel or $channel eq '.*';
          }

          foreach my $trigger (sort keys %{ $self->{factoids}->hash->{$channel} }) {
            if($self->{factoids}->hash->{$channel}->{$trigger}->{type} eq 'regex') {
              $self->{pbot}->{logger}->log("checking regex $string =~ m/$trigger/i\n") if $debug >= 2;
              if($string =~ m/$trigger/i) {
                $self->{pbot}->{logger}->log("return regex $channel: $trigger\n") if $debug;

                if($find_alias) {
                  my $command = $self->{factoids}->hash->{$channel}->{$trigger}->{action};
                  ($keyword, $arguments) = split /\s+/, $command, 2;
                  $string = $keyword . (length $arguments ? " $arguments" : "");
                  goto NEXT_DEPTH;
                }

                if ($exact_channel == 1) {
                  return ($channel, $trigger);
                } else {
                  push @results, [$channel, $trigger];
                }
              }
            }
          }
        }
      }

      NEXT_DEPTH:
      last if not $find_alias;
    }

    if ($debug) {
      if (not @results) {
        $self->{pbot}->{logger}->log("find_factoid: no match\n");
      } else {
        $self->{pbot}->{logger}->log("find_factoid: got results: " . (join ', ', map { "$_->[0] -> $_->[1]" } @results) . "\n");
      }
    }
    return @results;
  };

  if($@) {
    $self->{pbot}->{logger}->log("find_factoid: bad regex: $@\n");
    return undef;
  }

  return @result;
}

sub escape_json {
  my ($self, $text) = @_;
  my $thing = {thing => $text};
  # not sure why we need this here, but it seems to stop strange
  # text encoding issues in the following encode_json call
  use Encode;
  $thing->{thing} = decode('utf8', $thing->{thing});
  my $json = encode_json $thing;
  $json =~ s/^{".*":"//;
  $json =~ s/"}$//;
  return $json;
}

sub expand_special_vars {
  my ($self, $from, $nick, $root_keyword, $action) = @_;

  $action =~ s/\$nick:json/$self->escape_json($nick)/ge;
  $action =~ s/\$channel:json/$self->escape_json($from)/ge;
  $action =~ s/\$randomnick:json/my $random = $self->{pbot}->{nicklist}->random_nick($from); $random ? $self->escape_json($random) : $self->escape_json($nick)/ge;
  $action =~ s/\$0:json/$self->escape_json($root_keyword)/ge;

  $action =~ s/\$nick/$nick/g;
  $action =~ s/\$channel/$from/g;
  $action =~ s/\$randomnick/my $random = $self->{pbot}->{nicklist}->random_nick($from); $random ? $random : $nick/ge;
  $action =~ s/\$0\b/$root_keyword/g;

  return validate_string($action);
}

sub expand_factoid_vars {
  my ($self, $from, $nick, $root_keyword, $action, @exclude) = @_;

  $root_keyword = lc $root_keyword;

  my $depth = 0;
  while (1) {
    last if ++$depth >= 100;
    my $matches = 0;
    $action =~ s/\$0/$root_keyword/g;
    my $const_action = $action;
    while ($const_action =~ /(\ba\s*|\ban\s*)?(?<!\\)\$([a-zA-Z0-9_:\-#\[\]]+)/gi) {
      last if ++$depth >= 100;
      my ($a, $v) = ($1, $2);
      $v =~ s/(.):$/$1/;
      next if $v =~ m/^[\W_]/; # special character prefix skipped for shell/code-factoids/etc
      next if $v =~ m/^(nick|channel|randomnick|arglen|args|arg\[.+\]|[_0])$/i; # don't override special variables
      next if @exclude && grep { $v =~ m/^\Q$_\E$/i } @exclude;

      $matches++;

      my $modifier = '';
      if ($v =~ s/(:.*)$//) {
        $modifier = $1;
      }

      if ($modifier =~ m/^:(#[^:]+|global)/i) {
        $from = $1;
        $from = '.*' if lc $from eq 'global';
      }

      my $recurse = 0;
      my $test_v = $v;
      ALIAS:
      my @factoids = $self->find_factoid($from, $test_v, undef, 2, 2);
      next if not @factoids or not $factoids[0];

      my ($var_chan, $var) = ($factoids[0]->[0], $factoids[0]->[1]);

      if ($self->{factoids}->hash->{$var_chan}->{$var}->{action} =~ m{^/call (.*)}) {
        $test_v = $1;
        next if ++$recurse > 10;
        goto ALIAS;
      }

      if ($self->{factoids}->hash->{$var_chan}->{$var}->{type} eq 'text') {
        my $change = $self->{factoids}->hash->{$var_chan}->{$var}->{action};
        my @list = split(/\s|(".*?")/, $change);
        my @mylist;
        for (my $i = 0; $i <= $#list; $i++) {
          push @mylist, $list[$i] if defined $list[$i] and length $list[$i];
        }
        my $line = int(rand($#mylist + 1));
        $mylist[$line] =~ s/"//g;

        foreach my $mod (split /:/, $modifier) {
          given ($mod) {
            when ('uc') {
              $mylist[$line] = uc $mylist[$line];
            }
            when ('lc') {
              $mylist[$line] = lc $mylist[$line];
            }
            when ('ucfirst') {
              $mylist[$line] = ucfirst $mylist[$line];
            }
            when ('title') {
              $mylist[$line] = ucfirst lc $mylist[$line];
            }
            when ('json') {
              $mylist[$line] = $self->escape_json($mylist[$line]);
            }
          }
        }

        if ($a) {
          my $fixed_a = select_indefinite_article $mylist[$line];
          $action =~ s/$a\$$v$modifier/$fixed_a $mylist[$line]/;
        } else {
          $action =~ s/\$$v$modifier/$mylist[$line]/;
        }
      }
    }
    last if $matches == 0;
  }

  $action =~ s/\\\$/\$/g;

  unless (@exclude) {
    $action = $self->expand_special_vars($from, $nick, $root_keyword, $action);
  }

  return validate_string($action);
}

sub expand_action_arguments {
  my ($self, $action, $input, $nick) = @_;

  $action = validate_string($action);
  $input = validate_string($input);

  my %h;
  if (not defined $input or $input eq '') {
    %h = (args => $nick);
  } else {
    %h = (args => $input);
  }

  # not sure why we need this here, but it seems to stop strange
  # text encoding issues in the following encode_json call
  use Encode;
  $h{args} = decode('utf8', $h{args});

  my $jsonargs = encode_json \%h;
  $jsonargs =~ s/^{".*":"//;
  $jsonargs =~ s/"}$//;

  if (not defined $input or $input eq '') {
    $input = "";
    $action =~ s/\$args:json/$jsonargs/ge;
    $action =~ s/\$args(?![[\w])/$nick/g;
  } else {
    $action =~ s/\$args:json/$jsonargs/g;
    $action =~ s/\$args(?![[\w])/$input/g;
  }

  my $qinput = quotemeta $input;
  $qinput =~ s/\\ / /g;
  my @args = shellwords($qinput);

  $action =~ s/\$arglen\b/scalar @args/eg;

  my $depth = 0;
  my $const_action = $action;
  while ($const_action =~ m/\$arg\[([^]]+)]/g) {
    my $arg = $1;

    last if ++$depth >= 100;

    if ($arg eq '*') {
      if (not defined $input or $input eq '') {
        $action =~ s/\$arg\[\*\]/$nick/;
      } else {
        $action =~ s/\$arg\[\*\]/$input/;
      }
      next;
    }

    if ($arg =~ m/([^:]*):(.*)/) {
      my $arg1 = $1;
      my $arg2 = $2;

      my $arg1i = $arg1;
      my $arg2i = $arg2;

      $arg1i = 0 if $arg1i eq '';
      $arg2i = $#args if $arg2i eq '';
      $arg2i = $#args if $arg2i > $#args;

      my @values = eval {
        local $SIG{__WARN__} = sub {};
        return @args[$arg1i .. $arg2i];
      };

      if ($@) {
        next;
      } else {
        my $string = join(' ', @values);

        if ($string eq '') {
          $action =~ s/\s*\$arg\[$arg1:$arg2\]//;
        } else {
          $action =~ s/\$arg\[$arg1:$arg2\]/$string/;
        }
      }

      next;
    }

    my $value = eval {
      local $SIG{__WARN__} = sub {};
      return $args[$arg];
    };

    if ($@) {
      next;
    } else {

      if (not defined $value) {
        if ($arg == 0) {
          $action =~ s/\$arg\[$arg\]/$nick/;
        } else {
          $action =~ s/\s*\$arg\[$arg\]//;
        }
      } else {
        $action =~ s/\$arg\[$arg\]/$value/;
      }
    }
  }

  return $action;
}

sub execute_code_factoid_using_safe {
  my ($self, $nick, $user, $host, $from, $chan, $root_keyword, $keyword, $arguments, $lang, $code, $tonick) = @_;

  return "/say code-factoids are temporarily disabled.";

  my $ppi = PPI::Document->new(\$code, readonly => 1);
  return "/say $nick: I don't feel so good." if not $ppi;
  my $vars = $ppi->find(sub { $_[1]->isa('PPI::Token::Symbol') });

  my @names = map { $_->symbol =~ /^[\%\@\$]+(.*)/; $1 } @$vars if $vars;
  my %uniq = map { $_, 1 } @names;
  @names = keys %uniq;

  unless ($self->{factoids}->hash->{$chan}->{$keyword}->{interpolate} eq '0') {
    $code = $self->expand_factoid_vars($from, $nick, $root_keyword, $code, @names);
  }

  my %signals = %SIG;
  alarm 0;

  my $safe;
  my $new_compartment;

  if ($self->{factoids}->hash->{$chan}->{$keyword}->{'persist-key'}) {
    my $key = $self->{factoids}->hash->{$chan}->{$keyword}->{'persist-key'};
    if ($self->{compartments}->{$key}) {
      $safe = $self->{compartments}->{$key};
    } else {
      $new_compartment = $key;
    }
  }

  if (not defined $safe) {
    $safe = Safe->new;
    $safe->permit_only(qw/:base_core rv2gv padany rand srand concat subst join sort mapstart grepstart/);
    $safe->deny(qw/entersub/);

    # some default stuff
    $safe->reval('$" = " ";');

    $self->{compartments}->{$new_compartment} = $safe if $new_compartment;
  }

  no warnings;
  local our @args = $self->{pbot}->{commands}->parse_arguments($arguments);
  local our $nick = $nick;
  local our $channel = $from;
  use warnings;

  @args = ($nick) if not @args;
  $arguments = '';

  $safe->share(qw/@args $nick $channel/);

  my $action = eval {
    $self->{pbot}->{logger}->log("evaling [$code]\n");
    my $result = $safe->reval($code);

    if ($@) {
      my $error = $@;
      chomp $error;
      $error =~ s/trapped by operation.*/operation disallowed (we're still fine-tuning this; let us know if you think this should be allowed)/;
      $error =~ s/at \(eval \d+\) line 1.//g;
      $error = "$error (did you forget to use quotes around factoid variables?)" if $error =~ /syntax error/;
      return "/say Error in factoid code: $error";
    } else {
      return $result;
    }
  };

  if ($@) {
    my $error = $@;
    chomp $error;
    $error =~ s/at \(eval \d+\) line 1.//g;
    $action = "/say Error in factoid: $error";
  }

  %SIG = %signals;
  alarm 1;

  unless ($self->{factoids}->hash->{$chan}->{$keyword}->{interpolate} eq '0') {
    $action = $self->expand_factoid_vars($from, $nick, $root_keyword, $action);
    $action = $self->expand_action_arguments($action, $arguments, $nick);
  } else {
    $action = validate_string($action);
  }

  return $action;
}

sub execute_code_factoid_using_vm {
  my ($self, $stuff) = @_;

  unless (exists $self->{factoids}->hash->{$stuff->{channel}}->{$stuff->{keyword}}->{interpolate} and $self->{factoids}->hash->{$stuff->{channel}}->{$stuff->{keyword}}->{interpolate} eq '0') {
    $stuff->{code} = $self->expand_factoid_vars($stuff->{from}, $stuff->{nick}, $stuff->{root_keyword}, $stuff->{code});
    $stuff->{code} = $self->expand_action_arguments($stuff->{code}, $stuff->{arguments}, $stuff->{nick});
  }

  my %h = (nick => $stuff->{nick}, channel => $stuff->{from}, lang => $stuff->{lang}, code => $stuff->{code}, arguments => $stuff->{arguments}, factoid => "$stuff->{channel}:$stuff->{keyword}");

  if (exists $self->{factoids}->hash->{$stuff->{channel}}->{$stuff->{keyword}}->{'persist-key'}) {
    $h{'persist-key'} = $self->{factoids}->hash->{$stuff->{channel}}->{$stuff->{keyword}}->{'persist-key'};
  }

  # not sure why we need this here, but it seems to stop strange
  # text encoding issues in the following encode_json call
  use Encode;
  $h{arguments} = decode('utf8', $h{arguments});

  my $json = encode_json \%h;

  $stuff->{special} = 'code-factoid';
  $stuff->{root_channel} = $stuff->{channel};
  $stuff->{keyword} = 'compiler';
  $stuff->{arguments} = $json;

  $self->{pbot}->{factoids}->{factoidmodulelauncher}->execute_module($stuff);
  return "";
}

sub execute_code_factoid {
  my ($self, @args) = @_;
  return $self->execute_code_factoid_using_vm(@args);
}

sub interpreter {
  my ($self, $stuff) = @_;
  my $pbot = $self->{pbot};

  if ($self->{pbot}->{registry}->get_value('general', 'debugcontext')) {
    use Data::Dumper;
    $Data::Dumper::Sortkeys  = 1;
    $self->{pbot}->{logger}->log("Factoids::interpreter\n");
    $self->{pbot}->{logger}->log(Dumper $stuff);
  }

  #$self->{pbot}->{logger}->log("enter factoid interpreter [$keyword][" . (defined $arguments ? $arguments : '') . "] referenced = $referenced\n");
  return undef if not length $stuff->{keyword} or $stuff->{interpret_depth} > $self->{pbot}->{registry}->get_value('interpreter', 'max_recursion');

  $stuff->{from} = lc $stuff->{from};

  # search for factoid against global channel and current channel (from unless ref_from is defined)
  my $original_keyword = $stuff->{keyword};
  #$self->{pbot}->{logger}->log("calling find_factoid in Factoids.pm, interpreter() to search for factoid against global/current\n");
  my ($channel, $keyword) = $self->find_factoid($stuff->{ref_from} ? $stuff->{ref_from} : $stuff->{from}, $stuff->{keyword}, $stuff->{arguments}, 1);

  if (not $stuff->{ref_from} or $stuff->{ref_from} eq '.*') {
    $stuff->{ref_from} = "";
  }

  if (defined $channel and not $channel eq '.*' and not lc $channel eq $stuff->{from}) {
    $stuff->{ref_from} = "[$channel] ";
  }

  $stuff->{arguments} = "" if not defined $stuff->{arguments};

  # if no match found, attempt to call factoid from another channel if it exists there
  if (not defined $keyword) {
    my $string = "$original_keyword $stuff->{arguments}";
    my $lc_keyword = lc $original_keyword;
    my $comma = "";
    my $found = 0;
    my $chans = "";
    my ($fwd_chan, $fwd_trig);

    # build string of which channels contain the keyword, keeping track of the last one and count
    foreach my $chan (keys %{ $self->{factoids}->hash }) {
      foreach my $trig (keys %{ $self->{factoids}->hash->{$chan} }) {
        my $type = $self->{factoids}->hash->{$chan}->{$trig}->{type};
        if (($type eq 'text' or $type eq 'module') and lc $trig eq $lc_keyword) {
          $chans .= $comma . $chan;
          $comma = ", ";
          $found++;
          $fwd_chan = $chan;
          $fwd_trig = $trig;
          last;
        }
      }
    }

    # if multiple channels have this keyword, then ask user to disambiguate
    if ($found > 1) {
      return undef if $stuff->{referenced};
      return $stuff->{ref_from} . "Ambiguous keyword '$original_keyword' exists in multiple channels (use 'fact <channel> <keyword>' to choose one): $chans";
    } 
    # if there's just one other channel that has this keyword, trigger that instance
    elsif ($found == 1) {
      $pbot->{logger}->log("Found '$original_keyword' as '$fwd_trig' in [$fwd_chan]\n");
      $stuff->{keyword} = $fwd_trig;
      $stuff->{interpret_depth}++;
      $stuff->{ref_from} = $fwd_chan;
      return $pbot->{factoids}->interpreter($stuff);
    } 
    # otherwise keyword hasn't been found, display similiar matches for all channels
    else {
      # if a non-nick argument was supplied, e.g., a sentence using the bot's nick, don't say anything
      return undef if length $stuff->{arguments} and not $self->{pbot}->{nicklist}->is_present($stuff->{from}, $stuff->{arguments});
      
      my $matches = $self->{commands}->factfind($stuff->{from}, $stuff->{nick}, $stuff->{user}, $stuff->{host}, quotemeta $original_keyword);

      # found factfind matches
      if ($matches !~ m/^No factoids/) {
        return undef if $stuff->{referenced};
        return "No such factoid '$original_keyword'; $matches";
      }

      # otherwise find levenshtein closest matches from all channels
      $matches = $self->{factoids}->levenshtein_matches('.*', lc $original_keyword);

      # don't say anything if nothing similiar was found
      return undef if $matches eq 'none';
      return undef if $stuff->{referenced};

      return $stuff->{ref_from} . "No such factoid '$original_keyword'; did you mean $matches?";
    }
  }

  $stuff->{keyword} = $keyword;
  $stuff->{trigger} = $keyword;
  $stuff->{channel} = $channel;
  $stuff->{original_keyword} = $original_keyword;

  return undef if $stuff->{referenced} and $self->{factoids}->hash->{$channel}->{$keyword}->{noembed};

  if (exists $self->{factoids}->hash->{$channel}->{$keyword}->{last_referenced_on}) {
    if (exists $self->{factoids}->hash->{$channel}->{$keyword}->{last_referenced_in}) {
      if ($self->{factoids}->hash->{$channel}->{$keyword}->{last_referenced_in} eq $stuff->{from}) {
        my $ratelimit = $self->{pbot}->{registry}->get_value($stuff->{from}, 'ratelimit_override');
        $ratelimit = $self->{factoids}->hash->{$channel}->{$keyword}->{rate_limit} if not defined $ratelimit;
        if (gettimeofday - $self->{factoids}->hash->{$channel}->{$keyword}->{last_referenced_on} < $ratelimit) {
          return "/msg $stuff->{nick} $stuff->{ref_from}'$keyword' is rate-limited; try again in " . duration ($ratelimit - int(gettimeofday - $self->{factoids}->hash->{$channel}->{$keyword}->{last_referenced_on})) . "." unless $self->{pbot}->{admins}->loggedin($channel, "$stuff->{nick}!$stuff->{user}\@$stuff->{host}");
        }
      }
    }
  }

  my $type = $self->{factoids}->hash->{$channel}->{$keyword}->{type};

  $self->{factoids}->hash->{$channel}->{$keyword}->{ref_count}++;
  $self->{factoids}->hash->{$channel}->{$keyword}->{ref_user} = "$stuff->{nick}!$stuff->{user}\@$stuff->{host}";
  $self->{factoids}->hash->{$channel}->{$keyword}->{last_referenced_on} = gettimeofday;
  $self->{factoids}->hash->{$channel}->{$keyword}->{last_referenced_in} = $stuff->{from} || "stdin";

  my $action;

  if (length $stuff->{arguments} and exists $self->{factoids}->hash->{$channel}->{$keyword}->{action_with_args}) {
    $action = $self->{factoids}->hash->{$channel}->{$keyword}->{action_with_args};
  } else {
    $action = $self->{factoids}->hash->{$channel}->{$keyword}->{action};
  }

  if ($action =~ m{^/code\s+([^\s]+)\s+(.+)$}i) {
    my ($lang, $code) = ($1, $2);
    $stuff->{lang} = $lang;
    $stuff->{code} = $code;
    $self->execute_code_factoid($stuff);
    return "";
  }

  return $self->handle_action($stuff, $action);
}

sub handle_action {
  my ($self, $stuff, $action) = @_;

  if ($self->{pbot}->{registry}->get_value('general', 'debugcontext')) {
    use Data::Dumper;
    $Data::Dumper::Sortkeys  = 1;
    $self->{pbot}->{logger}->log("Factoids::handle_action [$action]\n");
    $self->{pbot}->{logger}->log(Dumper $stuff);
  }

  return "" if not length $action;

  my ($channel, $keyword) = ($stuff->{channel}, $stuff->{trigger});

  unless (exists $self->{factoids}->hash->{$channel}->{$keyword}->{interpolate} and $self->{factoids}->hash->{$channel}->{$keyword}->{interpolate} eq '0') {
    $action = $self->expand_factoid_vars($stuff->{from}, $stuff->{nick}, $stuff->{root_keyword}, $action);
  }

  if (length $stuff->{arguments}) {
    if ($action =~ m/\$args/ or $action =~ m/\$arg\[/) {
      unless (defined $self->{factoids}->hash->{$channel}->{$keyword}->{interpolate} and $self->{factoids}->hash->{$channel}->{$keyword}->{interpolate} eq '0') {
        $action = $self->expand_action_arguments($action, $stuff->{arguments}, $stuff->{nick});
      }
      $stuff->{arguments} = "";
    } else {
      if ($self->{factoids}->hash->{$channel}->{$keyword}->{type} eq 'text') {
        my $target = $self->{pbot}->{nicklist}->is_present_similar($stuff->{from}, $stuff->{arguments});


        if ($target and $action !~ /\$(?:nick|args)\b/) {
          $stuff->{nickoverride} = $target unless $stuff->{force_nickoverride};
        }
      }
    }
  } else {
    # no arguments supplied, replace $args with $nick/$tonick, etc
    $action = $self->expand_action_arguments($action, undef, $stuff->{nick});
  }

  # Check if it's an alias
  if ($action =~ /^\/call\s+(.*)$/) {
    my $command = $1;
    $command .= " $stuff->{arguments}" if length $stuff->{arguments};

    $stuff->{command} = $command;

    $self->{pbot}->{logger}->log("[" . (defined $stuff->{from} ? $stuff->{from} : "stdin") . "] ($stuff->{nick}!$stuff->{user}\@$stuff->{host}) [$keyword] aliased to: [$command]\n");
    return $self->{pbot}->{interpreter}->interpret($stuff);
  }

  $self->{pbot}->{logger}->log("(" . (defined $stuff->{from} ? $stuff->{from} : "(undef)") . "): $stuff->{nick}!$stuff->{user}\@$stuff->{host}: $keyword: action: \"$action\"\n");

  if ($self->{factoids}->hash->{$channel}->{$keyword}->{enabled} == 0) {
    $self->{pbot}->{logger}->log("$keyword disabled.\n");
    return "/msg $stuff->{nick} $stuff->{ref_from}$keyword is currently disabled.";
  }

  unless (exists $self->{factoids}->hash->{$channel}->{$keyword}->{interpolate} and $self->{factoids}->hash->{$channel}->{$keyword}->{interpolate} eq '0') {
    $action = $self->expand_factoid_vars($stuff->{from}, $stuff->{nick}, $stuff->{root_keyword}, $action);
    $action = $self->expand_action_arguments($action, $stuff->{arguments}, $stuff->{nick});
  }

  return $action if $stuff->{special} eq 'code-factoid';

  if ($self->{factoids}->hash->{$channel}->{$keyword}->{type} eq 'module') {
    my $preserve_whitespace = $self->{factoids}->hash->{$channel}->{$keyword}->{preserve_whitespace};
    $preserve_whitespace = 0 if not defined $preserve_whitespace;

    $stuff->{preserve_whitespace} = $preserve_whitespace;
    $stuff->{root_keyword} = $keyword unless defined $stuff->{root_keyword};
    $stuff->{root_channel} = $channel;

    my $result = $self->{factoidmodulelauncher}->execute_module($stuff);
    if (length $result) {
      return $stuff->{ref_from} . $result;
    } else {
      return "";
    }
  }
  elsif ($self->{factoids}->hash->{$channel}->{$keyword}->{type} eq 'text') {
    # Don't allow user-custom /msg factoids, unless factoid triggered by admin
    if (($action =~ m/^\/msg/i) and (not $self->{pbot}->{admins}->loggedin($stuff->{from}, "$stuff->{nick}!$stuff->{user}\@$stuff->{host}"))) {
      $self->{pbot}->{logger}->log("[ABUSE] Bad factoid (contains /msg): $action\n");
      return "You must login to use this command.";
    }

    if ($stuff->{ref_from}) {
      if ($action =~ s/^\/say\s+/$stuff->{ref_from}/i || $action =~ s/^\/me\s+(.*)/\/me $1 $stuff->{ref_from}/i
        || $action =~ s/^\/msg\s+([^ ]+)/\/msg $1 $stuff->{ref_from}/i) {
        return $action;
      } else {
        return $stuff->{ref_from} . "$keyword is $action";
      }
    } else {
      if ($action =~ m/^\/(?:say|me|msg)/i) {
        return $action;
      } elsif ($action =~ s/^\/kick\s+//) {
        if (not exists $self->{factoids}->hash->{$channel}->{$keyword}->{'effective-level'}) {
          $stuff->{authorized} = 0;
          return "/say $stuff->{nick}: $keyword doesn't have the effective-level to do that.";
        }
        my $level = 10;
        if ($self->{factoids}->hash->{$channel}->{$keyword}->{'effective-level'} >= $level) {
          $stuff->{authorized} = 1;
          return "/kick " . $action;
        } else {
          $stuff->{authorized} = 0;
          return "/say $stuff->{nick}: My effective-level isn't high enough to do that.";
        }
      } else {
        return "/say $keyword is $action";
      }
    }
  } elsif($self->{factoids}->hash->{$channel}->{$keyword}->{type} eq 'regex') {
    my $result = eval {
      my $string = "$stuff->{original_keyword}" . (defined $stuff->{arguments} ? " $stuff->{arguments}" : "");
      my $cmd;
      if ($string =~ m/$keyword/i) {
        $self->{pbot}->{logger}->log("[$string] matches [$keyword] - calling [" . $action . "$']\n");
        $cmd = $action . $';
        my ($a, $b, $c, $d, $e, $f, $g, $h, $i, $before, $after) = ($1, $2, $3, $4, $5, $6, $7, $8, $9, $`, $');
        $cmd =~ s/\$1/$a/g;
        $cmd =~ s/\$2/$b/g;
        $cmd =~ s/\$3/$c/g;
        $cmd =~ s/\$4/$d/g;
        $cmd =~ s/\$5/$e/g;
        $cmd =~ s/\$6/$f/g;
        $cmd =~ s/\$7/$g/g;
        $cmd =~ s/\$8/$h/g;
        $cmd =~ s/\$9/$i/g;
        $cmd =~ s/\$`/$before/g;
        $cmd =~ s/\$'/$after/g;
        $cmd =~ s/^\s+//;
        $cmd =~ s/\s+$//;
      } else {
        $cmd = $action;
      }

      $stuff->{command} = $cmd;
      return $self->{pbot}->{interpreter}->interpret($stuff);
    };

    if($@) {
      $self->{pbot}->{logger}->log("Regex fail: $@\n");
      return "";
    }

    if (length $result) {
      return $stuff->{ref_from} . $result;
    } else {
      return "";
    }
  } else {
    $self->{pbot}->{logger}->log("($stuff->{from}): $stuff->{nick}!$stuff->{user}\@$stuff->{host}): Unknown command type for '$keyword'\n"); 
    return "/me blinks." . " $stuff->{ref_from}";
  }
}

sub export_path {
  my $self = shift;

  if(@_) { $self->{export_path} = shift; }
  return $self->{export_path};
}

sub logger {
  my $self = shift;
  if(@_) { $self->{logger} = shift; }
  return $self->{logger};
}

sub export_site {
  my $self = shift;
  if(@_) { $self->{export_site} = shift; }
  return $self->{export_site};
}

sub factoids {
  my $self = shift;
  return $self->{factoids};
}

sub filename {
  my $self = shift;

  if(@_) { $self->{filename} = shift; }
  return $self->{filename};
}

1;