# -*- perl -*-
#
# Copyright (C) 2004-2005 Daniel P. Berrange
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# $Id: MockConnection.pm,v 1.5 2006/02/03 13:30:14 dan Exp $

=pod

=head1 NAME

Net::DBus::Test::MockConnection - Fake a connection to the bus unit testing

=head1 SYNOPSIS

  use Net::DBus;

  my $bus = Net::DBus->test

  # Register a service, and the objec to be tested
  use MyObject
  my $service = $bus->export_service("org.example.MyService");
  my $object = MyObject->new($service);


  # Acquire the service & do tests
  my $remote_service = $bus->get_service('org.example.MyService');
  my $remote_object = $service->get_object("/org/example/MyObjct");

  # This traverses the mock connection, eventually
  # invoking 'testSomething' on the $object above.
  $remote_object->testSomething()

=head1 DESCRIPTION

This object provides a fake implementation of the L<Net::DBus::Binding::Connection>
enabling a pure 'in-memory' message bus to be mocked up. This is intended to
facilitate creation of unit tests for services which would otherwise need to 
call out to other object on a live message bus. It is used as a companion to
the L<Net::DBus::Test::MockObject> module which is how fake objects are to be
provided on the fake bus.

=head1 METHODS

=over 4

=cut

package Net::DBus::Test::MockConnection;

use strict;
use warnings;

use Net::DBus::Binding::Message::MethodReturn;

=item my $con = Net::DBus::Test::MockConnection->new()

Create a new mock connection object instance. It is not usually
neccessary to create instances of this object directly, instead
the C<test> method on the L<Net::DBus> object can be used to
get a handle to a test bus.

=cut

sub new {
    my $class = shift;
    my $self = {};
    
    $self->{replies} = [];
    $self->{signals} = [];
    $self->{objects} = {};
    $self->{objectTrees} = {};
    $self->{filters} = [];
    
    bless $self, $class;
    
    return $self;
}

=item $con->send($message)

Send a message over the mock connection. If the message is
a method call, it will be dispatched straight to any corresponding
mock object registered. If the mesage is an error or method return
it will be made available as a return value for the C<send_with_reply_and_block>
method. If the message is a signal it will be queued up for processing
by the C<dispatch> method. 

=cut


sub send {
    my $self = shift;
    my $msg = shift;
    
    if ($msg->isa("Net::DBus::Binding::Message::MethodCall")) {
	$self->_call_method($msg);
    } elsif ($msg->isa("Net::DBus::Binding::Message::MethodReturn") ||
	     $msg->isa("Net::DBus::Binding::Message::Error")) {
	push @{$self->{replies}}, $msg;
    } elsif ($msg->isa("Net::DBus::Binding::Message::Signal")) {
	push @{$self->{signals}}, $msg;
    } else {
	die "unhandled type of message " . ref($msg);
    }
}


=item $bus->request_name($service_name)

Pretend to send a request to the bus registering the well known 
name specified in the C<$service_name> parameter. In reality
this is just a no-op giving the impression that the name was
successfully registered.

=cut

sub request_name {
    my $self = shift;
    my $name = shift;
    my $flags = shift;
    
    # XXX do we care about this for test cases? probably not...
    # ....famous last words
}

=item my $reply = $con->send_with_reply_and_block($msg)

Send a message over the mock connection and wait for a
reply. The C<$msg> should be an instance of C<Net::DBus::Binding::Message::MethodCall>
and the return C<$reply> will be an instance of C<Net::DBus::Binding::Message::MethodReturn>.
It is also possible that an error will be thrown, with
the thrown error being blessed into the C<Net::DBus::Error>
class.

=cut

sub send_with_reply_and_block {
    my $self = shift;
    my $msg = shift;
    my $timeout = shift;
    
    $self->send($msg);
    
    if ($#{$self->{replies}} == -1) {
	die "no reply for " . $msg->get_path . "->" . $msg->get_member . " received within timeout";
    }
    
    my $reply = shift @{$self->{replies}};
    if ($#{$self->{replies}} != -1) {
	die "too many replies received";
    }

    if (ref($reply) eq "Net::DBus::Binding::Message::Error") {
	my $iter = $reply->iterator;
	my $desc = $iter->get_string;
	my $err = { name => $reply->get_error_name,
		    message => $desc };
	bless $err, "Net::DBus::Error";
	die $err;
    }
    return $reply;
}

=item $con->dispatch;

Dispatches any pending messages in the incoming queue
to their message handlers. This method should be called
by test suites whenever they anticipate that there are
pending signals to be dealt with.

=cut

sub dispatch {
    my $self = shift;
    
    my @signals = @{$self->{signals}};
    $self->{signals} = [];
    foreach my $msg (@signals) {
	foreach my $cb (@{$self->{filters}}) {
	    # XXX we should worry about return value...
	    &$cb($self, $msg);
	}
    }
}

=item $con->add_filter($coderef);

Adds a filter to the connection which will be invoked whenever a
message is received. The C<$coderef> should be a reference to a
subroutine, which returns a true value if the message should be
filtered out, or a false value if the normal message dispatch
should be performed.

=cut

sub add_filter {
    my $self = shift;
    my $cb = shift;
    
    push @{$self->{filters}}, $cb;
}

=item $con->register_object_path($path, \&handler)

Registers a handler for messages whose path matches
that specified in the C<$path> parameter. The supplied
code reference will be invoked with two parameters, the
connection object on which the message was received,
and the message to be processed (an instance of the
C<Net::DBus::Binding::Message> class).

=cut

sub register_object_path {
    my $self = shift;
    my $path = shift;
    my $code = shift;
    
    $self->{objects}->{$path} = $code;
}

=item $con->register_fallback($path, \&handler)

Registers a handler for messages whose path starts with 
the prefix specified in the C<$path> parameter. The supplied
code reference will be invoked with two parameters, the
connection object on which the message was received,
and the message to be processed (an instance of the
C<Net::DBus::Binding::Message> class).

=cut

sub register_fallback {
    my $self = shift;
    my $path = shift;
    my $code = shift;
    
    $self->{objects}->{$path} = $code;
    $self->{objectTrees}->{$path} = $code;
}

=item $con->unregister_object_path($path)

Unregisters the handler associated with the object path C<$path>. The
handler would previously have been registered with the C<register_object_path>
or C<register_fallback> methods.

=cut

sub unregister_object_path {
    my $self = shift;
    my $path = shift;
    
    delete $self->{objects}->{$path};
}

sub _call_method {
    my $self = shift;
    my $msg = shift;

    if (exists $self->{objects}->{$msg->get_path}) {
	my $cb = $self->{objects}->{$msg->get_path};
	&$cb($self, $msg);
    } else {
	foreach my $path (reverse sort { $a cmp $b } keys %{$self->{objectTrees}}) {
	    if ((index $msg->get_path, $path) == 0) {
		my $cb = $self->{objects}->{$path};
		&$cb($self, $msg);
		return;
	    }
	}
	if ($msg->get_path eq "/org/freedesktop/DBus") {
	    if ($msg->get_member eq "GetNameOwner") {
		my $reply = Net::DBus::Binding::Message::MethodReturn->new(call => $msg);
		my $iter = $reply->iterator(1);
		$iter->append(":1.1");
		$self->send($reply);
	    }
	}
    }
}

1;

=pod

=back

=head1 BUGS

It doesn't completely replicate the API of L<Net::DBus::Binding::Connection>, 
merely enough to make the high level bindings work in a test scenario.

=head1 SEE ALSO

L<Net::DBus>, L<Net::DBus::Test::MockObject>, L<Net::DBus::Binding::Connection>,
L<http://www.mockobjects.com/Faq.html>

=head1 COPYRIGHT

Copyright 2005 Daniel Berrange <dan@berrange.com>

=cut