# File: PBot.pm
# Author: pragma_
#
# Purpose: IRC Bot (3rd generation)

# 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::PBot;

use strict;
use warnings;

use feature 'unicode_strings';

# unbuffer stdout
STDOUT->autoflush(1);

use Carp ();
use PBot::Logger;
use PBot::VERSION;
use PBot::Registry;
use PBot::SelectHandler;
use PBot::StdinReader;
use PBot::IRC;
use PBot::EventDispatcher;
use PBot::IRCHandlers;
use PBot::Channels;
use PBot::BanTracker;
use PBot::NickList;
use PBot::LagChecker;
use PBot::MessageHistory;
use PBot::AntiFlood;
use PBot::AntiSpam;
use PBot::Interpreter;
use PBot::Commands;
use PBot::ChanOps;
use PBot::Factoids;
use PBot::BotAdmins;
use PBot::IgnoreList;
use PBot::BlackList;
use PBot::Timer;
use PBot::Refresher;
use PBot::Plugins;
use PBot::WebPaste;
use PBot::Utils::ParseDate;
use PBot::FuncCommand;

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

  my ($class, %conf) = @_;
  my $self = bless {}, $class;
  $self->{atexit} = PBot::Registerable->new(%conf);
  $self->register_signal_handlers;
  $self->initialize(%conf);
  return $self;
}

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

  $self->{startup_timestamp} = time;

  my $data_dir   = $conf{data_dir};
  my $module_dir = $conf{module_dir};
  my $plugin_dir = $conf{plugin_dir};

  # check command-line arguments for directory overrides
  foreach my $arg (@ARGV) {
    if ($arg =~ m/^-?(?:general\.)?((?:data|module|plugin)_dir)=(.*)$/) {
      my $override = $1;
      my $value = $2;
      $data_dir = $value if $override eq 'data_dir';
      $module_dir = $value if $override eq 'module_dir';
      $plugin_dir = $value if $override eq 'plugin_dir';
    }
  }

  # logger created first to allow other modules to log things
  $self->{logger}   = PBot::Logger->new(pbot => $self, filename => "$data_dir/log/log", %conf);

  $self->{version}  = PBot::VERSION->new(pbot => $self, %conf);
  $self->{logger}->log($self->{version}->version . "\n");
  $self->{logger}->log("Args: @ARGV\n") if @ARGV;

  return if $conf{logger_only};

  $self->{timer}    = PBot::Timer->new(timeout => 10, %conf);
  $self->{commands} = PBot::Commands->new(pbot => $self, %conf);
  $self->{func_cmd} = PBot::FuncCommand->new(pbot => $self, %conf);
  $self->{refresher} = PBot::Refresher->new(pbot => $self);

  # make sure the environment is sane
  if (not -d $data_dir) {
    $self->{logger}->log("Data directory ($data_dir) does not exist; aborting...\n");
    exit;
  }

  if (not -d $module_dir) {
    $self->{logger}->log("Modules directory ($module_dir) does not exist; aborting...\n");
    exit;
  }

  if (not -d $plugin_dir) {
    $self->{logger}->log("Plugins directory ($plugin_dir) does not exist; aborting...\n");
    exit;
  }

  $self->{logger}->log("data_dir: $data_dir\n");
  $self->{logger}->log("module_dir: $module_dir\n");
  $self->{logger}->log("plugin_dir: $plugin_dir\n");

  # create registry and set some defaults
  $self->{registry} = PBot::Registry->new(pbot => $self, filename => "$data_dir/registry", %conf);

  $self->{registry}->add_default('text', 'general', 'data_dir',    $data_dir);
  $self->{registry}->add_default('text', 'general', 'module_dir',  $module_dir);
  $self->{registry}->add_default('text', 'general', 'plugin_dir',  $plugin_dir);
  $self->{registry}->add_default('text', 'general', 'trigger',     $conf{trigger}     // '!');

  $self->{registry}->add_default('text', 'irc',     'debug',       $conf{irc_debug}   // 0);
  $self->{registry}->add_default('text', 'irc',     'show_motd',   $conf{show_motd}   // 1);
  $self->{registry}->add_default('text', 'irc',     'max_msg_len', $conf{max_msg_len} // 425);
  $self->{registry}->add_default('text', 'irc',     'server',      $conf{server}      // "irc.freenode.net");
  $self->{registry}->add_default('text', 'irc',     'port',        $conf{port}        // 6667);
  $self->{registry}->add_default('text', 'irc',     'SSL',         $conf{SSL}         // 0);
  $self->{registry}->add_default('text', 'irc',     'SSL_ca_file', $conf{SSL_ca_file} // 'none');
  $self->{registry}->add_default('text', 'irc',     'SSL_ca_path', $conf{SSL_ca_path} // 'none');
  $self->{registry}->add_default('text', 'irc',     'botnick',     $conf{botnick}     // "");
  $self->{registry}->add_default('text', 'irc',     'username',    $conf{username}    // "pbot3");
  $self->{registry}->add_default('text', 'irc',     'realname',    $conf{realname}    // "https://github.com/pragma-/pbot");
  $self->{registry}->add_default('text', 'irc',     'identify_password', $conf{identify_password} // '');
  $self->{registry}->add_default('text', 'irc',     'log_default_handler', 1);

  $self->{registry}->set_default('irc', 'SSL_ca_file',       'private', 1);
  $self->{registry}->set_default('irc', 'SSL_ca_path',       'private', 1);
  $self->{registry}->set_default('irc', 'identify_password', 'private', 1);

  # load existing registry entries from file (if exists) to overwrite defaults
  if (-e $self->{registry}->{registry}->{filename}) {
    $self->{registry}->load;
  }

  # update important paths
  $self->{registry}->set('general', 'data_dir',   'value', $data_dir,   0, 1);
  $self->{registry}->set('general', 'module_dir', 'value', $module_dir, 0, 1);
  $self->{registry}->set('general', 'plugin_dir', 'value', $plugin_dir, 0, 1);

  # override registry entries with command-line arguments, if any
  foreach my $arg (@ARGV) {
    next if $arg =~ m/^-?(?:general\.)?(?:config|data|module|plugin)_dir=.*$/; # already processed
    my ($item, $value) = split /=/, $arg, 2;

    if (not defined $item or not defined $value) {
      $self->{logger}->log("Fatal error: unknown argument `$arg`; arguments must be in the form of `section.key=value` (e.g.: irc.botnick=newnick)\n");
      exit;
    }

    my ($section, $key) = split /\./, $item, 2;

    if (not defined $section or not defined $key) {
      $self->{logger}->log("Fatal error: bad argument `$arg`; registry entries must be in the form of section.key (e.g.: irc.botnick)\n");
    }

    $section =~ s/^-//; # remove a leading - to allow arguments like -irc.botnick due to habitual use of -args

    $self->{logger}->log("Overriding $section.$key to $value\n");
    $self->{registry}->set($section, $key, 'value', $value, 0, 1);
  }

  # registry triggers fire when value changes
  $self->{registry}->add_trigger('irc', 'botnick', sub { $self->change_botnick_trigger(@_) });
  $self->{registry}->add_trigger('irc', 'debug',   sub { $self->irc_debug_trigger(@_)      });

  # ensure user has attempted to configure the bot
  if (not length $self->{registry}->get_value('irc', 'botnick')) {
    $self->{logger}->log("Fatal error: IRC nickname not defined; please set registry key irc.botnick in $data_dir/registry to continue.\n");
    exit;
  }

  $self->{event_dispatcher}   = PBot::EventDispatcher->new(pbot => $self, %conf);
  $self->{irchandlers}        = PBot::IRCHandlers->new(pbot => $self, %conf);
  $self->{select_handler}     = PBot::SelectHandler->new(pbot => $self, %conf);
  $self->{stdin_reader}       = PBot::StdinReader->new(pbot => $self, %conf);
  $self->{admins}             = PBot::BotAdmins->new(pbot => $self, filename => "$data_dir/admins", %conf);
  $self->{bantracker}         = PBot::BanTracker->new(pbot => $self, %conf);
  $self->{lagchecker}         = PBot::LagChecker->new(pbot => $self, %conf);
  $self->{messagehistory}     = PBot::MessageHistory->new(pbot => $self, filename => "$data_dir/message_history.sqlite3", %conf);
  $self->{antiflood}          = PBot::AntiFlood->new(pbot => $self, %conf);
  $self->{antispam}           = PBot::AntiSpam->new(pbot => $self, %conf);
  $self->{ignorelist}         = PBot::IgnoreList->new(pbot => $self, filename => "$data_dir/ignorelist", %conf);
  $self->{blacklist}          = PBot::BlackList->new(pbot => $self, filename => "$data_dir/blacklist", %conf);
  $self->{irc}                = PBot::IRC->new();
  $self->{channels}           = PBot::Channels->new(pbot => $self, filename => "$data_dir/channels", %conf);
  $self->{chanops}            = PBot::ChanOps->new(pbot => $self, %conf);
  $self->{nicklist}           = PBot::NickList->new(pbot => $self, %conf);
  $self->{webpaste}           = PBot::WebPaste->new(pbot => $self, %conf);
  $self->{parsedate}          = PBot::Utils::ParseDate->new(pbot => $self, %conf);

  $self->{interpreter}        = PBot::Interpreter->new(pbot => $self, %conf);
  $self->{interpreter}->register(sub { return $self->{commands}->interpreter(@_); });
  $self->{interpreter}->register(sub { return $self->{factoids}->interpreter(@_); });

  $self->{factoids} = PBot::Factoids->new(pbot => $self, filename => "$data_dir/factoids", %conf);

  $self->{plugins} = PBot::Plugins->new(pbot => $self, %conf);

  # load available plugins
  $self->{plugins}->autoload(%conf);

  # create implicit bot-admin account for bot
  my $botnick = $self->{registry}->get_value('irc', 'botnick');
  $self->{admins}->add_admin($botnick, '.*', "*!stdin\@pbot", 100, 'notused', 1);
  $self->{admins}->login($botnick, "$botnick!stdin\@pbot", 'notused');

  # start timer
  $self->{timer}->start();
}

sub random_nick {
  my @chars = ("A".."Z", "a".."z", "0".."9");
  my $nick = $chars[rand @chars - 10]; # nicks cannot start with a digit
  $nick .= $chars[rand @chars] for 1..9;
  return $nick;
}

# TODO: add disconnect subroutine
sub connect {
  my ($self, $server) = @_;

  if ($self->{connected}) {
    # TODO: disconnect, clean-up, etc
  }

  $server = $self->{registry}->get_value('irc', 'server') if not defined $server;

  $self->{logger}->log("Connecting to $server ...\n");

  while (not $self->{conn} = $self->{irc}->newconn(
      Nick         => $self->{registry}->get_value('irc', 'randomize_nick') ? random_nick : $self->{registry}->get_value('irc', 'botnick'),
      Username     => $self->{registry}->get_value('irc', 'username'),
      Ircname      => $self->{registry}->get_value('irc', 'realname'),
      Server       => $server,
      Pacing       => 1,
      UTF8         => 1,
      SSL          => $self->{registry}->get_value('irc', 'SSL'),
      SSL_ca_file  => $self->{registry}->get_value('irc', 'SSL_ca_file'),
      SSL_ca_path  => $self->{registry}->get_value('irc', 'SSL_ca_path'),
      Port         => $self->{registry}->get_value('irc', 'port'))) {
    $self->{logger}->log("$0: Can't connect to $server:" . $self->{registry}->get_value('irc', 'port') . ". Retrying in 15 seconds...\n");
    sleep 15;
  }

  $self->{connected} = 1;

  #set up handlers for the IRC engine
  $self->{conn}->add_default_handler(sub { $self->{irchandlers}->default_handler(@_) }, 1);
  $self->{conn}->add_handler([ 251,252,253,254,255,302 ], sub { $self->{irchandlers}->on_init(@_) });

  # ignore these events
  $self->{conn}->add_handler(['whoisserver',
                              'whoiscountry',
                              'whoischannels',
                              'whoisidle',
                              'motdstart',
                              'endofmotd',
                              'away',
                              'endofbanlist'], sub {});
}

#main loop
sub do_one_loop {
  my $self = shift;
  $self->{irc}->do_one_loop();
  $self->{select_handler}->do_select();
}

sub start {
  my $self = shift;
  while (1) {
    $self->connect() if not $self->{connected};
    $self->do_one_loop() if $self->{connected};
  }
}

sub register_signal_handlers {
  my $self = shift;
  $SIG{INT} = sub { $self->atexit; exit 0; };
}

sub atexit {
  my $self = shift;
  $self->{atexit}->execute_all;
}

sub irc_debug_trigger {
  my ($self, $section, $item, $newvalue) = @_;
  $self->{irc}->debug($newvalue);
  $self->{conn}->debug($newvalue) if $self->{connected};
}

sub change_botnick_trigger {
  my ($self, $section, $item, $newvalue) = @_;
  $self->{conn}->nick($newvalue) if $self->{connected};
}

1;