# 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 Plugins::ActionTrigger;
use parent 'Plugins::Plugin';

# purpose: provides interface to set/remove/modify regular expression triggers
# to execute a command.
#
# Examples:
#
# Greet a nick when they join the channel:
# actiontrigger add #channel 0 0 ^(?i)([^!]+)![^\s]+.JOIN echo Hi $1, welcome to $channel!
#
# Same, but via private message (set level to 10 to use `msg` admin command):
# actiontrigger add #channel 10 0 ^(?i)([^!]+)![^\s]+.JOIN msg Hi $1, welcome to $channel!
#
# Kick a nick if they say a naughty thing. Set level to 10 to use `kick` admin command.
# actiontrigger add global 10 0 "^(?i)([^!]+)![^\s]+.PRIVMSG.*bad phrase" kick $1 Do you talk to your mother with that mouth?
#
# Say something when a keyword is seen, but only once every 5 minutes:
# actiontrigger add global 0 300 "some phrase" echo Something!
#
# Capture a part of somebody's message.
# actiontrigger add #channel 0 0 "(?i)how is the weather (?:in|for) (.*) today" weather $1
#
# These are basic examples; more complex examples can be crafted.

use warnings; use strict;
use feature 'unicode_strings';

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

use DBI;
use Time::Duration qw/duration/;
use Time::HiRes qw/gettimeofday/;

sub initialize {
  my ($self, %conf) = @_;
  $self->{pbot}->{commands}->register(sub { $self->actiontrigger(@_) }, 'actiontrigger', 1);
  $self->{pbot}->{capabilities}->add('admin', 'can-actiontrigger', 1);

  $self->{pbot}->{event_dispatcher}->register_handler('irc.public',  sub { $self->on_public(@_) });
  $self->{pbot}->{event_dispatcher}->register_handler('irc.caction', sub { $self->on_action(@_) });
  $self->{pbot}->{event_dispatcher}->register_handler('irc.join',    sub { $self->on_join(@_) });
  $self->{pbot}->{event_dispatcher}->register_handler('irc.part',    sub { $self->on_departure(@_) });
  $self->{pbot}->{event_dispatcher}->register_handler('irc.quit',    sub { $self->on_departure(@_) });
  $self->{pbot}->{event_dispatcher}->register_handler('irc.kick',    sub { $self->on_kick(@_) });

  $self->{filename} = $self->{pbot}->{registry}->get_value('general', 'data_dir') . '/triggers.sqlite3';

  $self->dbi_begin;
  $self->create_database;
}

sub unload {
  my $self = shift;
  $self->dbi_end;
  $self->{pbot}->{commands}->unregister('actiontrigger');
  $self->{pbot}->{capabilities}->remove('can-actiontrigger');
  $self->{pbot}->{event_dispatcher}->remove_handler('irc.public');
  $self->{pbot}->{event_dispatcher}->remove_handler('irc.caction');
  $self->{pbot}->{event_dispatcher}->remove_handler('irc.join');
  $self->{pbot}->{event_dispatcher}->remove_handler('irc.part');
  $self->{pbot}->{event_dispatcher}->remove_handler('irc.quit');
  $self->{pbot}->{event_dispatcher}->remove_handler('irc.kick');
}

sub create_database {
  my $self = shift;
  return if not $self->{dbh};

  eval {
    $self->{dbh}->do(<<SQL);
CREATE TABLE IF NOT EXISTS Triggers (
  channel     TEXT,
  trigger     TEXT,
  action      TEXT,
  owner       TEXT,
  level       INTEGER,
  repeatdelay INTEGER,
  lastused    NUMERIC
)
SQL
  };

  $self->{pbot}->{logger}->log("ActionTrigger create database failed: $@") if $@;
}

sub dbi_begin {
  my ($self) = @_;
  eval {
    $self->{dbh} = DBI->connect("dbi:SQLite:dbname=$self->{filename}", "", "", { RaiseError => 1, PrintError => 0, AutoInactiveDestroy => 1, sqlite_unicode => 1 }) or die $DBI::errstr;
  };

  if ($@) {
    $self->{pbot}->{logger}->log("Error opening ActionTrigger database: $@");
    return 0;
  } else {
    return 1;
  }
}

sub dbi_end {
  my ($self) = @_;
  return if not $self->{dbh};
  $self->{dbh}->disconnect;
  delete $self->{dbh};
}

sub add_trigger {
  my ($self, $channel, $trigger, $action, $owner, $level, $repeatdelay) = @_;

  return 0 if $self->get_trigger($channel, $trigger);

  eval {
    my $sth = $self->{dbh}->prepare('INSERT INTO Triggers (channel, trigger, action, owner, level, repeatdelay, lastused) VALUES (?, ?, ?, ?, ?, ?, 0)');
    $sth->execute(lc $channel, $trigger, $action, $owner, $level, $repeatdelay);
  };

  if ($@) {
    $self->{pbot}->{logger}->log("Add trigger failed: $@");
    return 0;
  }
  return 1;
}

sub delete_trigger {
  my ($self, $channel, $trigger) = @_;
  return 0 if not $self->get_trigger($channel, $trigger);
  my $sth = $self->{dbh}->prepare('DELETE FROM Triggers WHERE channel = ? AND trigger = ?');
  $sth->execute(lc $channel, $trigger);
  return 1;
}

sub list_triggers {
  my ($self, $channel) = @_;

  my $triggers = eval {
    my $sth;

    if ($channel eq '*') {
      $sth = $self->{dbh}->prepare('SELECT * FROM Triggers WHERE channel != ?');
      $channel = 'global';
    } else {
      $sth = $self->{dbh}->prepare('SELECT * FROM Triggers WHERE channel = ?');
    }
    $sth->execute(lc $channel);
    return $sth->fetchall_arrayref({});
  };

  if ($@) {
    $self->{pbot}->{logger}->log("List triggers failed: $@");
  }

  $triggers = [] if not defined $triggers;
  return @$triggers;
}

sub update_trigger {
  my ($self, $channel, $trigger, $data) = @_;

  eval {
    my $sql = 'UPDATE Triggers SET ';

    my $comma = '';
    foreach my $key (keys %$data) {
      $sql .= "$comma$key = ?";
      $comma = ", ";
    }

    $sql .= "WHERE trigger = ? AND channel = ?";
    my $sth = $self->{dbh}->prepare($sql);
    my $param = 1;
    foreach my $key (keys %$data) {
      $sth->bind_param($param++, $data->{$key});
    }

    $sth->bind_param($param++, $trigger);
    $sth->bind_param($param, $channel);
    $sth->execute();
  };

  $self->{pbot}->{logger}->log("Update trigger $channel/$trigger failed: $@\n") if $@;
}

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

  my $row = eval {
    my $sth = $self->{dbh}->prepare('SELECT * FROM Triggers WHERE channel = ? AND trigger = ?');
    $sth->execute(lc $channel, $trigger);
    my $row = $sth->fetchrow_hashref();
    return $row;
  };

  if ($@) {
    $self->{pbot}->{logger}->log("Get trigger failed: $@");
    return undef;
  }

  return $row;
}

sub on_kick {
  my ($self, $event_type, $event) = @_;
  my ($nick, $user, $host) = ($event->{event}->nick, $event->{event}->user, $event->{event}->host);
  my ($victim, $reason) = ($event->{event}->to, $event->{event}->{args}[1]);
  my $channel = $event->{event}->{args}[0];
  return 0 if $event->{interpreted};
  $self->check_trigger($nick, $user, $host, $channel, "KICK $victim $reason");
  return 0;
}

sub on_action {
  my ($self, $event_type, $event) = @_;
  my ($nick, $user, $host, $msg) = ($event->{event}->nick, $event->{event}->user, $event->{event}->host, $event->{event}->args);
  my $channel = $event->{event}->{to}[0];
  return 0 if $event->{interpreted};
  $msg =~ s/^\/me\s+//;
  $self->check_trigger($nick, $user, $host, $channel, "ACTION $msg");
  return 0;
}

sub on_public {
  my ($self, $event_type, $event) = @_;
  my ($nick, $user, $host, $msg) = ($event->{event}->nick, $event->{event}->user, $event->{event}->host, $event->{event}->args);
  my $channel = $event->{event}->{to}[0];
  return 0 if $event->{interpreted};
  $self->check_trigger($nick, $user, $host, $channel, "PRIVMSG $msg");
  return 0;
}

sub on_join {
  my ($self, $event_type, $event) = @_;
  my ($nick, $user, $host, $channel, $args) = ($event->{event}->nick, $event->{event}->user, $event->{event}->host, $event->{event}->to, $event->{event}->args);
  $channel = lc $channel;
  $self->check_trigger($nick, $user, $host, $channel, "JOIN");
  return 0;
}

sub on_departure {
  my ($self, $event_type, $event) = @_;
  my ($nick, $user, $host, $channel, $args) = ($event->{event}->nick, $event->{event}->user, $event->{event}->host, $event->{event}->to, $event->{event}->args);
  $channel = lc $channel;
  $self->check_trigger($nick, $user, $host, $channel, (uc $event->{event}->type) . " $args");
  return 0;
}

sub check_trigger {
  my ($self, $nick, $user, $host, $channel, $text) = @_;
  return 0 if not $self->{dbh};

  my @triggers = $self->list_triggers($channel);
  my @globals = $self->list_triggers('global');
  push @triggers, @globals;

  $text = "$nick!$user\@$host $text";
  my $now = gettimeofday;

  foreach my $trigger (@triggers) {
    eval {
      $trigger->{lastused} = 0 if not defined $trigger->{lastused};
      $trigger->{repeatdelay} = 0 if not defined $trigger->{repeatdelay};
      if ($now - $trigger->{lastused} >= $trigger->{repeatdelay} and $text  =~ m/$trigger->{trigger}/) {
        $trigger->{lastused} = $now;
        my $data = { lastused => $now };
        $self->update_trigger($trigger->{channel}, $trigger->{trigger}, $data);

        my $action = $trigger->{action};
        my @stuff = ($1, $2, $3, $4, $5, $6, $7, $8, $9);
        my $i;
        map { ++$i; $action =~ s/\$$i/$_/g; } @stuff;

        my $delay = 0;

        my ($n, $u, $h) = $trigger->{owner} =~ /^([^!]+)!([^@]+)\@(.*)$/;
        my $command = {
          nick => $n,
          user => $u,
          host => $h,
          command => $action,
          level => $trigger->{level} // 0
        };
        $self->{pbot}->{logger}->log("ActionTrigger: ($channel) $trigger->{trigger} -> $action [$command->{level}]\n");
        $self->{pbot}->{interpreter}->add_to_command_queue($channel, $command, $delay);
      }
    };

    if ($@) {
      $self->{pbot}->{logger}->log("Skipping bad trigger $trigger->{trigger}: $@");
    }
  }
  return 0;
}

sub actiontrigger {
  my ($self, $from, $nick, $user, $host, $arguments, $stuff) = @_;
  return "Internal error." if not $self->{dbh};

  my $command = $self->{pbot}->{interpreter}->shift_arg($stuff->{arglist});
  my $result;
  given ($command) {
    when ('list') {
      my $channel = $self->{pbot}->{interpreter}->shift_arg($stuff->{arglist});
      if (not defined $channel) {
        if ($from !~ /^#/) {
          $channel = 'global';
        } else {
          $channel = $from;
        }
      } elsif ($channel !~ m/^#/ and $channel ne 'global') {
        return "Invalid channel $channel. Usage: actiontrigger list [#channel or global]";
      }

      my @triggers = $self->list_triggers($channel);

      if (not @triggers) {
        $result = "No action triggers set for $channel.";
      } else {
        $result = "Triggers for $channel:\n";
        my $comma = '';
        foreach my $trigger (@triggers) {
          $trigger->{level} //= 0;
          $trigger->{repeatdelay} //= 0;
          $result .= "$comma$trigger->{trigger} -> $trigger->{action}";
          $result .= " (level=$trigger->{level})" if $trigger->{level} != 0;
          $result .= " (repeatdelay=$trigger->{repeatdelay})" if $trigger->{repeatdelay} != 0;
          $comma = ",\n";
        }
      }
    }

# TODO: use GetOpt flags instead of positional arguments
    when ('add') {
      my $channel;
      if ($from =~ m/^#/) {
        $channel = $from;
      } else {
        $channel = $self->{pbot}->{interpreter}->shift_arg($stuff->{arglist});

        if (not defined $channel) {
          return "To use this command from private message the <channel> argument is required. Usage: actiontrigger add <#channel or global> <level> <repeat delay (in seconds)> <regex trigger> <command>";
        } elsif ($channel !~ m/^#/ and $channel ne 'global') {
          return "Invalid channel $channel. Usage: actiontrigger add <#channel or global> <level> <repeat delay (in seconds)> <regex trigger> <command>";
        }
      }

      my ($level, $repeatdelay, $trigger, $action) = $self->{pbot}->{interpreter}->split_args($stuff->{arglist}, 4, 0, 1);

      if (not defined $trigger or not defined $action) {
        if ($from !~ m/^#/) {
          $result = "To use this command from private message the <channel> argument is required. Usage: actiontrigger add <#channel or global> <level> <repeat delay (in seconds)> <regex trigger> <command>";
        } else {
          $result = "Usage: actiontrigger add <level> <repeat delay (in seconds)> <regex trigger> <command>";
        }
        return $result;
      }

      my $exists = $self->get_trigger($channel, $trigger);

      if (defined $exists) {
        return "Trigger already exists.";
      }

      if ($level !~ m/^\d+$/) {
        return "$nick: Missing level argument?\n";
      }

      if ($repeatdelay !~ m/^\d+$/) {
        return "$nick: Missing repeat delay argument?\n";
      }

      if ($level > 0) {
        my $admin = $self->{pbot}->{users}->find_admin($channel, "$nick!$user\@$host");
        if (not defined $admin or $level > $admin->{level}) {
          return "You may not set a level higher than your own.";
        }
      }

      if ($self->add_trigger($channel, $trigger, $action, "$nick!$user\@$host", $level, $repeatdelay)) {
        $result = "Trigger added.";
      } else {
        $result = "Failed to add trigger.";
      }
    }

    when ('delete') {
      my $channel;
      if ($from =~ m/^#/) {
        $channel = $from;
      } else {
        $channel = $self->{pbot}->{interpreter}->shift_arg($stuff->{arglist});
        if ($channel !~ m/^#/ and $channel ne 'global') {
          return "To use this command from private message the <channel> argument is required. Usage: actiontrigger delete <#channel or global> <regex trigger>";
        }
      }

      my ($trigger) = $self->{pbot}->{interpreter}->split_args($stuff->{arglist}, 1);

      if (not defined $trigger) {
        if ($from !~ m/^#/) {
          $result = "To use this command from private message the <channel> argument is required. Usage: from private message: actiontrigger delete <channel> <regex trigger>";
        } else {
          $result = "Usage: actiontrigger delete <regex trigger>";
        }
        return $result;
      }

      my $exists = $self->get_trigger($channel, $trigger);

      if (not defined $exists) {
        $result = "No such trigger.";
      } else {
        $self->delete_trigger($channel, $trigger);
        $result = "Trigger deleted.";
      }
    }

    default {
      if ($from !~ m/^#/) {
        $result = "Usage from private message: actiontrigger list [#channel or global] | actiontrigger add <#channel or global> <level> <repeat delay (in seconds)> <regex trigger> <command> | actiontrigger delete <#channel or global> <regex trigger>";
      } else {
        $result = "Usage: actiontrigger list [#channel or global] | actiontrigger add <level> <repeat delay (in seconds)> <regex trigger> <command> | actiontrigger delete <regex>";
      }
    }
  }
  return $result;
}

1;