
=head1 NAME

Net::SIP::Simple - Simple interface for using Net::SIP

=head1 SYNOPSIS

  use Net::SIP;

  # create new agent
  my $ua = Net::SIP::Simple->new(
	outgoing_proxy => '192.168.0.10',
	registrar => '192.168.0.10',
	domain => 'example.com',
	from => 'me',
	auth => [ 'me','secret' ],
  );

  # Register agent
  $ua->register;

  # Invite other party, send anncouncement once connected
  $ua->invite( 'you',
	init_media => $ua->rtp( 'send_recv', 'announcement.pcmu-8000' ),
	asymetric_rtp => 1,
  );

  # Mainloop
  $ua->loop;

=head1 DESCRIPTION

This package implements a simple layer on top of L<Net::SIP::Endpoint>,
L<Net::SIP::Registrar> and L<Net::SIP::StatelessProxy>.
With the help of this package it is possible to write simple SIP applications
with a few lines perl code.

=head1 CONSTRUCTOR

=over 4

=item new ( %ARGS )

Creates new Net::SIP::Simple object. %ARGS can be:

=over 8

=item outgoing_proxy|proxy

C<< "ip:port" >> of outgoing proxy. The necessary L<Net::SIP::Leg> to
the proxy will be created if no leg exists.

=item registrar

C<< "ip:port" >> of registrar. Used in method B<register> if there is no
other registrar given.

=item legs|leg

\@List of legs or single leg. Leg can be an existing L<Net::SIP::Leg> (or derived)
object, an L<IO::Handle> (existing socket), a hash reference which can be used
in the constructor of L<Net::SIP::Leg> or a string of C<< "proto:ip:port" >>.
In the latter case C<proto> can be ommitted (including the colon) and defaults
to 'udp' and C<port> can be ommitted to (including the colon) defaulting to 5060.

Either B<legs> or B<outgoing_proxy> has to be provided, e.g. it needs at least one
leg.

=item auth

Authorization data, see method B<authorize> in L<Net::SIP::Request> for details
about the format.

=item domain

Default domain for not fully qualified SIP addresses in C<from> and C<to> (method
B<invite>).

=item from

SIP address of local sender, either full SIP address or only part before \@, in which
case B<domain> has to be provided.

=item options

This is a hash reference containing headers (header-key,value) for replies to an 
OPTIONS request. If not or only partly given defaults will be used for the headers
B<Allow>, B<Accept>, B<Accept-Encoding>, B<Accept-Language> and B<Supported>.

=item route

Optional list of SIP routes which will be added to route requests.

=item loop

Eventloop object for dispatcher, see L<Net::SIP::Dispatcher::Eventloop>. Usually
not given, because the loop from the dispatcher will be used, but can be given
if no dispatcher was given.

=item dispatcher

L<Net::SIP::Dispatcher> object. Usually not given and will be created, but
sometimes one need to share the same dispatcher between multiple L<Net::SIP::Simple>
objects.

=item domain2proxy|d2p

Hash with mapping between domain and upstream proxy. See same key in the constructor
of L<Net::SIP::Dispatcher> for more details.

=back

=back

=head1 METHODS

=over 4

=item error ( ERROR )

Either sets current error (used internally) or returns last error.

=item loop ( [ TIMEOUT, @STOPVAR ] )

Calls the event loops (key B<loop> in constructor> B<loop> method.
TIMEOUT is the timeout for the loop in seconds. If not given it will
not stop because of timeout. @STOPVAR is a list of scalar references,
will stop the loop if any of these references contains TRUE.
See method B<loop> in L<Net::SIP::Dispatcher::Eventloop> for more
details.

The order of TIMEOUT or the STOPVARs is insignificant, e.g. if it
finds a reference it will use it as stopvar, otherwise it's used as
timeout.

=item add_timer ( WHEN, CALLBACK, [ REPEAT ] )

Calls same method from the L<Net::SIP::Dispatcher> object in C<$self>.
See there for details on arguments.

=item rtp ( METHOD,@ARGS )

Calls the method METHOD in L<Net::SIP::Simple::RTP> with arguments
@ARGS. Currently only does this and thus works as a shortcut.
In the future one might add more ways to find the right method
for RTP handling (e.g. plugins or similar).

=item register ( %ARGS )

Registers the user agent. %ARGS can have the key B<registrar> which
has precedence over the same key in the constructor.
B<leg> specifies the leg where the register request will be send through.
If not given it will pick the right leg.

If B<cb_final> is specified it is a callback usable by B<invoke_callback>
in L<Net::SIP::Util> which will be called, once the registration is
completed (e.g. it succeeded or failed). If no B<cb_final> is specified
the method will wait, until the registration is completed and return
either the expires time given by the registrar or C<()> if registration
failed.

All other keys, like B<contact>, B<expires>
will be forwarded to method B<register> in L<Net::SIP::Endpoint>.
B<from> and B<auth> will be used from %ARGS or if not in %ARGS from
the constructor.

=item invite ( TO,%ARGS )

Invite party TO. Creates a new L<Net::SIP::Simple::Call> object with
TO and creates an INVITE request for this call using %ARGS.
See B<reinvite> in L<Net::SIP::Simple::Call> for more info on %ARGS.

Returns with the newly created L<Net::SIP::Simple::Call> object,
which can later be used for reINVITEs or BYE etc.

=item listen ( %ARGS )

Sets up waiting on all legs in C<$self> for incoming calls, e.g. new INVITE
requests. All other incoming packets will be dropped.
If a call comes in a new L<Net::SIP::Simple::Call> object will
be created using %ARGS.

The method does not wait for the calls, its setting only the callback
on the legs up. Thus it has to be followed by a call to B<loop>.

Special keys not described in L<Net::SIP::Simple::Call>:

=over 8

=item filter

A callback usable by B<invoke_callback> in L<Net::SIP::Util> which gets
called with the value of the B<From> header and the L<Net::SIP::Request>
object from the incoming request.
If the callback returns TRUE the call gets accepted, otherwise not.

=item cb_create

Callback which will be called on accepting the call. Will be called
with C<< CALL,REQUEST,LEG,FROM >> where CALL is the newly created 
L<Net::SIP::Simple::Call> object, REQUEST the creating L<Net::SIP::Request> 
packet, LEG the incoming leg and FROM the C<< "ip:port" >> of the sender.

Must return TRUE or the call gets not answered.

=item cb_established

Callback which will be called, after the call is established, e.g.
after receiving the ACK from the peer. Will be invoked with 'OK'
and the L<Net::SIP::Simple::Call> object as argument.

=item cb_cleanup

Callback which will be called when the call gets closed to clean up
allocated resources. Will be invoked with the  L<Net::SIP::Simple::Call>
object as argument.

=back

=item create_registrar ( %ARGS )

Sets up a simple registrar using L<Net::SIP::Registrar>.
See there for the meaning of %ARGS.

Like with B<listen> you need to B<loop> after calling this
method, the method itself will not wait.

=item create_stateless_proxy ( %ARGS )

Sets up a simple proxy using L<Net::SIP::StatelessProxy>.
See there for the meaning of %ARGS.

Like with B<listen> you need to B<loop> after calling this
method, the method itself will not wait.

=item create_chain ( OBJECTS, %ARGS )

Sets up a chain using L<Net::SIP::ReceiveChain>.
See there for the meaning of OBJECT and %ARGS.

Like with B<listen> you need to B<loop> after calling this
method, the method itself will not wait.

=back

