=head1 NAME

Atheme::Hooks - Documentation for the Perl Hooks interface

=head1 DESCRIPTION

Atheme uses hooks as its primary mechanism for extensibility, outside of command
handlers. Almost all of the hook types used by the core and by standard modules
are available to Perl.

=head1 ADDING HOOKS

The Atheme interface provides a global C<%Hooks> tied hash as the primary Perl
interface to hooks. This is keyed on the hook name (see L</HOOK TYPES>), and the value is
a type with one method:

=head2 add_hook

    $Hooks{channel_join}->add_hook(\&channel_join_hook);

The C<add_hook> method takes one argument, which is a coderef that will be
called when the hook is triggered. Argument types vary with the particular hook,
and are described individually in L</HOOK TYPES> below.

There is no need to remove hooks; this is done automatically when the script
that added them is unloaded.

=head1 HOOK TYPES

All hook functions take a single argument or none at all. This is either an
object reference, or a hashref containing one or more named values. Some such
values are read/write; which these are, and the effects of changing them, are
described where applicable.

=head2 config_purge

Parameter: None.

Called when the current configuration info is being purged prior to reloading.

=head2 config_ready

Parameter: None.

Called when the config file has completed loading.

=head2 db_write, db_write_pre_ca

Called to allow modules to write their own persistent information to the
database file. Not currently supported in Perl.

=head2 db_saved

Parameter: None.

Called when the database has completed saving.

=head2 shutdown

Parameter: None.

Called immediately prior to shutting down services.

=head2 channel_add

Parameter: L<Atheme::Channel>

Called when a channel is created on the network.

=head2 channel_delete

Parameter: L<Atheme::Channel>

Called when a channel on the network becomes empty and is deleted.

=head2 channel_tschange

Parameter: L<Atheme::Channel>

Called when a channel's creation timestamp (TS) changes.

=head2 channel_join

Parameters: { C<cu> => L<Atheme::ChanUser> }

Called when a user joins a channel. If C<cu> is undef, then another hook
function has already kicked the user. If this function kicks the user, then it
must set C<cu> to undef.

=head2 channel_part

Parameters: { C<cu> => L<Atheme::ChanUser> }

Called when a user parts a channel. C<cu> is the user's membership of the
channel immediately before the part.

=head2 channel_topic

Parameter: L<Atheme::Channel>

Called when a channel's topic changes.

=head2 channel_can_change_topic

Parameters: { C<user> => L<Atheme::User>, C<server> => L<Atheme::Server>,
C<channel> => L<Atheme::Channel>, C<setter> => string, C<ts> => integer,
C<topic> => string, C<approved> => integer }

Called when a user is trying to change the topic of a channel. Setting
C<approved> to a non-zero value will result in services reverting the topic
change.

=head2 channel_message

Parameters: { C<user> => L<Atheme::User>, C<channel> => L<Atheme::Channel>,
C<message> => string }

Called when a user sends a message to a channel.

=head2 server_add

Parameter: L<Atheme::Server>

Called when a new server is introduced to the network.

=head2 server_eob

Parameter: L<Atheme::Server>

Called when a new server finishes linking (end-of-burst) to the network.

=head2 server_delete

Parameter: { C<server> => L<Atheme::Server> }

Called when a server delinks from the network.

=head2 user_add

Parameters: { C<user> => L<Atheme::User> }

Called when a new user appears on the network.

=head2 user_delete

Parameter: L<Atheme::User>

Called when a user is removed from the network.

=head2 user_nickchange

Parameters: { C<user> => L<Atheme::User>, C<oldnick> => string }

Called when a user changes nick.

=head2 user_away

Parameter: L<Atheme::User>

Called when a user's away status changes.

=head2 user_deoper

Parameter: L<Atheme::User>

Called when a user ceases to be an IRC Operator (sets user mode -o).

=head2 user_oper

Parameter: L<Atheme::User>

Called when a user becomes an IRC Operator (gains user mode +o).

=head2 channel_can_register

Parameters: { C<source> => L<Atheme::Sourceinfo>, C<name> => string, C<channel>
=> L<Atheme::Channel>, C<approved> => integer }

Called to decide whether a user is allowed to register a channel. Setting
C<approved> to a non-zero value will deny the registration.

=head2 channel_drop

Parameter: L<Atheme::ChannelRegistration>

Called when a channel registration is being dropped.

=head2 channel_info

Parameters: { C<channel> => L<Atheme::ChannelRegistration>, C<source> =>
L<Atheme::Sourceinfo> }

Called when requesting ChanServ INFO output about a channel. Can be used by
modules to add extra lines to this output.

=head2 channel_register

Parameters: { C<channel> => L<Atheme::ChannelRegistration>, C<source> =>
L<Atheme::Sourceinfo> }

Called when a channel has been registered.

=head2 channel_check_expire

Parameters: { C<channel> => L<Atheme::ChannelRegistration>, C<do_expire> =>
integer }

Called when a channel is about to expire. Setting C<do_expire> to 0 will cause
the channel not to expire during this round of checking.

=head2 channel_acl_change

Parameter: L<Atheme::ChanAcs>

Called when a channel access list entry changes.

=head2 nick_can_register

Parameters: { C<source> => L<Atheme::Sourceinfo>, C<account> => string,
C<approved> => integer }

Called to decide whether a user can register the given nickname. Setting
C<approved> to a non-zero value will deny the registration.

=head2 nick_group

Parameters: { C<source> => L<Atheme::Sourceinfo>, C<account> =>
L<Atheme::Account>, C<nick> => L<Atheme::NickRegistration> }

Called when a user groups a new nickname.

=head2 nick_check

Parameter: L<Atheme::User>

Called whenever a user begins to use a new nick. This could be when he connects,
changes nick, or any number of other actions. Use this hook if you want to do
any sort of pattern matching on all clients.

=head2 nick_enforce

Parameters: { C<user> => L<Atheme::User>, C<nick> => L<Atheme::NickRegistration> }

Used by the C<nickserv/enforce> module. Called when a user begins to use a
registered nickname they do not own, so that the enforcement timer should start.
Of questionable use to anyone else.

=head2 nick_ungroup

Parameters: { C<source> => L<Atheme::Sourceinfo>, C<account> =>
L<Atheme::Account>, C<nick> => L<Atheme::NickRegistration> }

Called when a user ungroups a nickname that they previously had grouped.

=head2 nick_check_expire

Parameters: { C<nick> => L<Atheme::NickRegistration>, C<do_expire> => integer }

Called when a nickname is about to expire. Setting C<do_expire> to 0 will cause
the nickname not to expire during this round of checking.

=head2 service_introduce

Parameter: L<Atheme::Service>

Called when a new service client is introduced to the network.

=head2 user_can_register

Parameters: { C<source> => L<Atheme::Sourceinfo>, C<account> => string, C<email>
=> string, C<password> => string, C<approved> => integer }

Called to decide whether the given user can register the given account name.
Setting C<approved> to a non-zero value will deny the registration.

=head2 user_drop

Parameter: L<Atheme::Account>

Called when a user drops his account.

=head2 user_identify

Parameter: L<Atheme::User>

Called when a user on IRC identifies to an account.

=head2 user_info

Parameters: C<source> => L<Atheme::Sourceinfo>, C<account> =>
L<Atheme::Account>, C<nick> => L<Atheme::NickRegistration> }

Called when processing a NickServ INFO request for the given nick registration
and account. Used for modules to provide extra information where appropriate.

=head2 user_register

Parameter: L<Atheme::Account>

Called when a user registers a new account.

=head2 user_verify_register

Parameters: C<source> => L<Atheme::Sourceinfo>, C<account> => L<Atheme::Account> }

Called when a user completes email verification of a new account.

=head2 user_check_expire

Parameters: { C<account> => L<Atheme::Account>, C<do_expire> =>
integer }

Called when an account is about to expire. Setting C<do_expire> to 0 will cause
the account not to expire during this round of checking.

=head2 user_rename

Parameters: { C<account> => L<Atheme::Account>, C<oldname> => string }

Called when an account is renamed, such as via NickServ SET ACCOUNTNAME.

=head2 myuser_delete

Parameter: L<Atheme::Account>

Called when an account is about to be deleted, for any reason.

=head2 metadata_change

Parameters: { C<target> => L<Atheme::Account>, C<name> => string, C<value> => string }

Called when a user's public metadata changes.

=head2 channel_pick_successor

Parameters: { C<channel> => L<Atheme::ChannelRegistration>, C<account> =>
L<Atheme::Account> }

Called to choose a channel's successor. Does not imply that the owner is about
to drop or expire.

Change C<account> to select a new successor. This may be overwritten by
subsequent hook functions.

=head2 operserv_info

Parameter: L<Atheme::Sourceinfo>

Called when a user runs the OperServ INFO command. Use this to add in any
relevant information.

