# This script is a drop-in HTML filter and parser for use with bitlbee and
# irssi. HTML that can be rendered will be, and the rest will be stripped.
# This should not interfere with other scripts for bitlbee; it is intended to be
# a transparent mangler.
#
# TO USE:
#   1) Adjust the channel and server tag settings below.
#   2) Load the script
#   3) In the bitlbee control channel (&bitlbee), type: set strip_html false
#   4) Enjoy.
#
# For use with bitlbee 1.0+. ChangeLog is available at the bottom of the file.
#
# SETTINGS
# [bitlbee]
# bitlbee_replace_html = ON
#   -> replaces HTML in incoming AIM messages
# bitlbee_replace_control_codes = OFF
#   -> replaces control codes (bold, underline, reverse) in outgoing private
#      messages to AIM users with HTML equivalents. This is turned off by
#      default due to the known bug below. If this wouldn't bother you, and you
#      would like to have this feature, there's no real harm in turning it on.
# bitlbee_strip_trailing_whitespace = OFF
#   -> removes whitespace at the end of messages
#
# KNOWN BUGS
# * This script is somewhat incompatible with splitlong.pl. When long messages
#   get split up, and bitlbee_replace_control_codes is ON, the control codes
#   will properly get replaced when they are sent to the remote user, but when
#   the subsequent split parts are displayed, they may contain the html that
#   is supposed to be hidden.
use strict;
use Irssi::TextUI;
use Data::Dumper;

use vars qw($VERSION %IRSSI);

$VERSION = '0.95';
%IRSSI = (
  authors     => 'Matt "f0rked" Sparks',
  contact     => 'ms+irssi@quadpoint.org',
  name        => 'bitlbee_html',
  description => 'Adds some HTML parsing to bitlbee messages',
  license     => 'GPLv2',
  url         => 'http://quadpoint.org',
  changed     => '2005-12-18',
);

# TODO: Make these settings (?)
my $bitlbee_channel = "&bitlbee";
my $bitlbee_server_tag = "IM";

# Time to wait to collect all parts of a message from bitlbee server
my $buffer_timeout = 200;  # milliseconds

# How long does a message have to be before we consider it a split?
my $split_length = 425;

my %buffer;
my %emitting;
my $debug = 0;


# Thanks to timing (http://the-timing.nl) for this
Irssi::signal_add_last 'channel sync' => sub
{
  my($channel) = @_;
  if ($channel->{topic} eq "Welcome to the control channel. Type \x02help\x02 for help information.") {
    $bitlbee_server_tag = $channel->{server}->{tag};
    $bitlbee_channel = $channel->{name};
  }
};


# Debug to the active window
sub adebug
{
  return if !$debug;
  my($t) = @_;
  my $w = Irssi::active_win();
  $w->print($t, MSGLEVEL_CLIENTCRAP);
}


# Debug to the status window
sub sdebug
{
  return if !$debug;
  my($t) = @_;
  print $t;
}


sub trim
{
  ($_) = @_;
  s/^\s*(.+)\s*$/$1/;
  return $_;
}


# return true if given address supports HTML, false if not.
sub does_html
{
  my($address) = @_;
  return ($address =~ /^[a-z].*\@login\.oscar\.aol\.com$/i ||
          $address =~ /^[a-z].*\@login\.icq\.com$/i) ? 1 : 0;
}


# More advanced checking in the future?
sub bee_server
{
  my($server) = @_;
  return 0 if !$server;
  return ($server->{tag} ne $bitlbee_server_tag) ? 0 : 1;
}


sub html2irc
{
  ($_) = @_;
  #print "Before: $_";

  s/<br ?\/?>/\n/isg;
  s/<font .+?>//isg;
  s/<\/font>//ig;
  s/<\/?body.*?>//isg;
  s/<\/?html>//ig;
  s/<a .*?href="(.+?)".*?>(.*?)<\/a>/handle_link($1,$2)/iesg;

  # note for <b>,<i>, and <u>, these are encapsulating tags, and they _may_
  # contain newlines. This script will split by newlines and emit message
  # signals for each part, and a part may end up looking like "<b>foo" with
  # no end tag, because the end tag is on the next message. To fix this, we
  # have to also check for <b>foo\n and ^foo</b> and put the control codes
  # in the appropriate places to avoid formatting the wrong text.
  s/<b>(.*?)<\/b>/\002$1\002/ig;  # bold
  s/<b>(.*?)\n/\002$1\n/isg;
  s/^(.*?)<\/b>/\002$1\002/isg;

  s/<u>(.*?)<\/u>/\037$1\037/ig;  # underline
  s/<u>(.*?)\n/\037$1\n/isg;
  s/^(.*?)<\/u>/\037$1\037/isg;

  s/<i>(.*?)<\/i>/\026$1\026/ig;  # reverse (for italics)
  s/<i>(.*?)\n/\026$1\n/isg;
  s/^(.*?)<\/i>/\026$1\026/isg;

  s/&quot;/"/ig;
  s/&lt;/</ig;
  s/&gt;/>/ig;
  s/&amp;/&/ig;

  #print "After: $_";
  return $_;
}


sub irc2html
{
  ($_) = @_;
  my $ret;
  adebug "irc2html input: $_";

  if (/^<html>/) {
    # Already htmlized? This shouldn't happen. Assume that html tags were
    # manually inserted, in which case we should just escape the html and
    # return.
    s/&/&amp;/g;
    s/"/&quot;/g;
    s/</&lt;/g;
    s/>/&gt;/g;
    $ret = "<html>$_</html>";
    adebug "irc2html return: $ret";
    return $ret;
  }

  my $orig = $_;

  s/&/&amp;/g;
  s/"/&quot;/g;
  s/</&lt;/g;
  s/>/&gt;/g;

  s/\002(.*?)\002/<b>$1<\/b>/sg;  # bold
  s/\002(.*)/<b>$1<\/b>/sg;       # unended bold
  s/\037(.*?)\037/<u>$1<\/u>/sg;  # underline
  s/\037(.*)/<u>$1<\/u>/sg;
  s/\026(.*?)\026/<i>$1<\/i>/sg;  # reverse (italics)
  s/\026(.*)/<i>$1<\/i>/sg;
  s/\003/<br>/g;                  # newlines.. this is ctrl+c in irssi.

  #print "After: $_, length: ".length($_);
  my $ret = ($_ ne $orig) ? "<html>$_</html>" : $orig;
  adebug "irc2html return: $ret";
  return $ret;
}


sub handle_link
{
  my($url, $title) = @_;
  $title = html2irc($title);
  #adebug $url;
  #adebug $title;

  if ($url eq $title) {
    return $url;
  } elsif ($url eq "mailto:$title") {
    return $title;
  } else {
    my $str = "[$title]($url)";
    $str =~ s/^\[(\n)*/$1\[/;
    return $str;
  }
}


sub event_privmsg
{
  my($server, $msg, $nick, $address) = @_;
  return if !Irssi::settings_get_bool("bitlbee_replace_html");
  return if !does_html($address);
  return if $emitting{"priv_$nick"};  # don't catch if we're sending signal
  return if !bee_server($server);

  #print "Received msg: $msg";
  # Check the buffer. If it is empty, set a timeout. Fill it in either
  # case. This step is necessary because long messages will naturally
  # get split up, and to avoid the HTML cutting split up, we buffer
  # and then parse everything at once.
  if (!$buffer{"priv_$nick"}) {
    # We have no buffer, this is a new message
    my @data = ("priv", $server, $nick, $address);
    Irssi::timeout_add_once($buffer_timeout, "check_buffer", \@data);
  }

  $msg .= " ";
  sdebug "Adding part: '$msg'";
  $buffer{"priv_$nick"} .= $msg;#."\002|\002";

  # Length hack. Sometimes we get multiple messages quickly from bitlbee
  # that aren't html formatted with <br>. Detect this and add newlines
  # appropriately.
  my $length = length("$nick $address $msg");
  sdebug "Length: $length";
  if ($length < $split_length) {
    $buffer{"priv_$nick"} .= "\n";
  }

  Irssi::signal_stop;
}


sub event_pubmsg
{
  my($server, $msg, $nick, $address, $target) = @_;
  return if !Irssi::settings_get_bool("bitlbee_replace_html");
  return if !bee_server($server);
  return if !does_html($address) and $nick ne "root";  # only aim does html.
  return if $emitting{"pub_$nick"};

  if (!$buffer{"pub_$nick"}) {
    my @data = ("pub", $server, $nick, $address, $target);
    Irssi::timeout_add_once($buffer_timeout, "check_buffer", \@data);
  }

  $buffer{"pub_$nick"} .= $msg;
  if (length("$nick $address $msg $target") < $split_length) {
    $buffer{"pub_$nick"} .= "\n";
  }

  Irssi::signal_stop;
}


sub event_action
{
  my($server, $msg, $nick, $address, $target) = @_;
  #print $msg;
  return if !Irssi::settings_get_bool("bitlbee_replace_html");
  return if !does_html($address);
  return if $emitting{"act_$nick"};
  return if !bee_server($server);

  if (!$buffer{"act_$nick"}) {
    my @data = ("act", $server, $nick, $address, $target);
    Irssi::timeout_add_once($buffer_timeout, "check_buffer", \@data);
  }

  $buffer{"act_$nick"} .= $msg;
  if (length("$nick $address $msg $target") < $split_length) {
    $buffer{"act_$nick"} .= "\n";
  }

  Irssi::signal_stop;
}


sub event_send_text
{
  my($text, $server, $witem) = @_;
  return if !bee_server($server);
  return if !Irssi::settings_get_bool("bitlbee_replace_control_codes");

  # This will make sure that the person we are talking to is on AIM.
  my $address;
  my $modified_text = $text;
  if ($witem->{type} eq "CHANNEL") {
    if (my($n, $s, $m) = $text =~ /^([^ ]+):([ ]*)(.*)$/) {
      $address = $witem->nick_find($n)->{host};
      $modified_text = "$n:$s" . irc2html($m);
    }
  } else {
    $address = $witem->{address};
    $modified_text = irc2html($text);
  }
  return if !does_html($address);

  #print Dumper $witem;
  #print "Sending: $modified_text";
  Irssi::signal_stop;
  Irssi::signal_continue($modified_text, $server, $witem);
}


sub event_send_command
{
    my($args, $server, $witem) = @_;
    return if !bee_server($server);
    adebug "send command: $args";
}


sub event_message_own
{
  my($server, $msg, $target, $orig_target) = @_;
  return if !bee_server($server);
  return if !Irssi::settings_get_bool("bitlbee_replace_control_codes");
  return if !Irssi::settings_get_bool("bitlbee_replace_html");

  if ($msg =~ /^<html>/ || $msg =~ /^([^ ]+):[ ]*<html>/) {
    # If we're on the bitlbee server and the message looks like html,
    # we're here.
    #print "$server '$msg' $target $orig_target";

    if ($orig_target && (my $qu = $server->query_find($target))) {
      #print "orig target, found query.";
      if ($qu->{address} && !does_html($qu->{address})) {
        # The person we're talking to is not using an HTML-compatible
        # protocol. Don't treat this as html.
        return;
      }
    } elsif (!$orig_target &&
             (my $ch = $server->channel_find($target)) &&
             (my($t) = $msg =~ /^([^ ]+):/)) {
      my $to_nick = $ch->nick_find($t);
      if ($to_nick->{address} && !does_html($to_nick->{address})) {
        # We're talking to someone in a particular channel on
        # bitlbee, but they don't support HTML.
        return;
      }
    }

    # If we made it this far, treat the message as HTML.
    Irssi::signal_stop;
    Irssi::signal_continue($server, html2irc($msg), $target, $orig_target);
  }
}


sub check_buffer
{
  my($type, $server, $nick, $address, $target) = @{@_[0]};
  # We should now have a full buffer for $nick, we can examine it, parse
  # it, and re-emit the appropriate signals without any HTML splitting
  # problems.
  my $msg = $buffer{"${type}_${nick}"};
  sdebug "Complete msg: $msg";
  return if !$msg;
  $msg = html2irc($msg);
  $msg =~ s/[\s]*$//
    if Irssi::settings_get_bool("bitlbee_strip_trailing_whitespace");

  # $msg is now in the appropriate format, we can emit the signal.
  $emitting{"${type}_${nick}"} = 1;
  my $sig = "message ";
  if ($type eq "priv") {
    $sig.="private";
  } elsif ($type eq "pub") {
    $sig.="public";
  } else {
    $sig.="irc action";
  }
  #print "Emitting $sig";
  for (split /\n/, $msg) {
    Irssi::signal_emit($sig, $server, $_, $nick, $address, $target);
  }

  delete($buffer{"${type}_${nick}"});
  delete($emitting{"${type}_${nick}"});
}


sub event_301
{
  return if !Irssi::settings_get_bool("bitlbee_replace_html");
  my($server, $data, $foo, $bar)=@_;
  return if !bee_server($server);
  my($me, $them, @msg) = split / /, $data;
  my $msg = join " ", @msg;
  $msg = html2irc($msg);
  $msg = ~s/[\s]*$//
    if Irssi::settings_get_bool("bitlbee_strip_trailing_whitespace");
  Irssi::signal_stop;
  Irssi::signal_continue($server, "$me $them $msg", $foo, $bar);
}


Irssi::signal_add_first("message private", "event_privmsg");
Irssi::signal_add_first("message public", "event_pubmsg");
Irssi::signal_add_first("event 301", "event_301");
Irssi::signal_add_first("message irc action", "event_action");

Irssi::signal_add_first("send text", "event_send_text");
Irssi::signal_add_first("send command", "event_send_command");
Irssi::signal_add_first("message own_private", "event_message_own");
Irssi::signal_add_first("message own_public", "event_message_own");
Irssi::signal_add_first("message irc own_action", "event_message_own");

# Settings
Irssi::settings_add_bool("bitlbee", "bitlbee_replace_html", 1);
Irssi::settings_add_bool("bitlbee", "bitlbee_replace_control_codes", 0);
Irssi::settings_add_bool("bitlbee", "bitlbee_strip_trailing_whitespace", 0);


### ChangeLog ###
# Version 0.95
#   - fixed a small bug causing links to sometimes not be properly formatted
# Version 0.94
#   - fixed bug causing a script error when typing in the status window and on
#     startup of irssi
# Version 0.93
#   - fixed a stupid case issue in address recognization.
# Version 0.92
#   - code cleanups
#   - control codes are allowed in control channel, but targets must be used
#     (remoteuser: I'm talking to you) (this is the default)
# Version 0.91
#   - more intelligent checking for HTML support
#   - allowed html from AIM users over ICQ connections
# Version 0.9
#   - removed html parsing for non-AIM connections
#   - added support for replacing control codes (created by ctrl+b, ctrl+v, and
#     cltr+-) with html equivalents. Disabled by default.
#
# Version 0.8 (2005-12-02)
#   - Initial public release