=head1 NAME

Monitoring::Icinga2::Client::REST - REST integration with icinga2

=head1 SYNOPSIS

    use strict;
    use warnings;

    use Monitoring::Icinga2::Client::REST;

    my $icinga = new Monitoring::Icinga2::Client::REST("fqdn",
	port => $port,
	path => $path,
	version => $version,
	cacert => $cacert_file,
    );
    $icinga->login("username","password") or die $icinga->login_status;

    my $host_object = {
	attrs => {
	    address => "127.0.0.1",
            check_command => "hostalive"
        }
    };


    my $put_result = $icinga->do_request("PUT", "/objects/hosts/localhost.example.com", "", $host_object)
        or warn sprintf("%s: %s", $icinga->request_code, $icinga->request_status_line);

    my $post_result = $icinga->do_request("POST", "/objects/hosts/localhost.example.com", "",$host_object)
        or warn sprintf("%s: %s", $icinga->request_code, $icinga->request_status_line);

    my $get_result = $icinga->do_request("GET", "/objects/hosts/localhost.example.com")
        or warn sprintf("%s: %s", $icinga->request_code, $icinga->request_status_line);

    my $delete_result = $icinga->do_request("DELETE", "/objects/hosts/localhost.example.com")
        or warn sprintf("%s: %s", $icinga->request_code, $icinga->request_status_line);

    $icinga->logout;

=head1 DESCRIPTION

Module used to integrate with the REST API that Icinga2 provides.

=head1 CONSTRUCTOR

=over

=item new (FQDN, PORT, PATH, VERSION, INSECURE)

=item new (FQDN, PORT, PATH, VERSION, [ INSECURE ])

Monitoring::Icinga2::Client::REST object.

The former calling convention with four mandatory arguments is the old one. If a
port number is present after the Icinga host, the constructor assumes you want
this form. The arguments are:

=over

=item * FQDN is your Icinga monitoring host.

=item * PORT is the port the REST API runs on.

=item * PATH is the URI where to find the API, usually "/".

=item * VERSION should be set to the API version, usually 1.

=item * INSECURE is optional and makes this module skip certificate verification if set.

=back

The latter form treats only the FQDN as mandatory and allows all other arguments
to be passed hash style with the following keys:

=over

=item * C<port> see above; defaults to C<5665>.

=item * C<path> see above; defaults to C</>.

=item * C<version> see above; defaults to 1 and is therefore completely
redundant as long as there is only one API version.

=item * C<insecure> see above; defaults to false

=item * C<cacert> The file name of a PEM-format file containing the certificate
of the CA that issued the server's HTTPS certificate. As internal monitoring
servers often use certs from in-house CAs, this still allows for secure peer
identification instead of using insecure mode.

=back

=back

=head1 METHODS

=over

=item login (USERNAME, PASSWORD)

Configures and validates credentials. Please note that user needs at least the permission
"status/query". This methos does nothing if it has been called on the sameobject
before unless L</logout> was called before.

=item logout

Destroys the login session.

=item login_status

Returns a human readable login status of the current session.

=item logged_in

Returns true when logged in, otherwise returns undef.

=item do_request (HTTP METHOD, URI, PARAMS, DATA)

Performs the actual request.

"PARAMS" is optional and can be any parameters that the Icinga API supports.

"DATA" is optional and is a Perl data structure that will be converted to JSON.

Returns the result in a perl reference.

=item export (FULL, API_ONLY)

Returns a Perl Data structure without unnecessary meta data. $icinga->export can
only be called after do_request. The name of the object is stored in 
$object->{attrs}{vars}{__export_name} so that you can access if you need it, please 
note that you can't use this variable name for other things if you whis to use this library
as it will be overwritten in the exported object.

"FULL" is optional and if it is true, write once attributes will be included in
the export. Objects exported with FULL set to true can be converted to json and be
used for PUT requests, but not necessarily for POST requests.

"API_ONLY" is optional and if it is true only objects created via the API
will be exported.

=item request_code

Returns the last HTTP status code.

=item request_status_line

Returns the last HTTP status line.

=back

=head1 DEPENDS

L<LWP::UserAgent>,
L<HTTP::Request>,
L<URI::Escape>,
L<JSON>,
L<Encode>

=head1 LICENSE

Copyright (c) 2016-, IT Services, Stockholm University

All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following
disclaimer.

Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following
disclaimer in the documentation and/or other materials provided with the distribution.

Neither the name of Stockholm University nor the names of its contributors may be used to endorse or promote products
derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

=head1 AUTHOR

Johan Wassberg <jocar@su.se>,
Mikael Nordin <mikael.nordin@su.se>
Bits and pieces by Matthias Bethke <matthias@towiski.de>