#
# Copyright 2019 Centreon (http://www.centreon.com/)
#
# Centreon is a full-fledged industry-strength solution that meets
# the needs in IT infrastructure and application monitoring for
# service performance.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

package apps::voip::3cx::restapi::custom::api;

use base qw(centreon::plugins::mode);

use strict;
use warnings;
use centreon::plugins::http;
use centreon::plugins::statefile;
use JSON::XS;
use Digest::MD5 qw(md5_hex);

sub new {
    my ($class, %options) = @_;
    my $self = $class->SUPER::new(package => __PACKAGE__, %options);
    bless $self, $class;

    if (!defined($options{output})) {
        print "Class Custom: Need to specify 'output' argument.\n";
        exit 3;
    }
    if (!defined($options{options})) {
        $options{output}->add_option_msg(short_msg => "Class Custom: Need to specify 'options' argument.");
        $options{output}->option_exit();
    }
    
    if (!defined($options{noptions})) {
        $options{options}->add_options(arguments =>  {
            "hostname:s"            => { name => 'hostname' },
            "port:s"                => { name => 'port'},
            "proto:s"               => { name => 'proto' },
            "api-username:s"        => { name => 'api_username' },
            "api-password:s"        => { name => 'api_password' },
            "timeout:s"             => { name => 'timeout', default => 30 },
        });
    }
    
    $options{options}->add_help(package => __PACKAGE__, sections => 'REST API OPTIONS', once => 1);

    $self->{output} = $options{output};
    $self->{mode} = $options{mode};
    $self->{http} = centreon::plugins::http->new(%options);
    $self->{cache} = centreon::plugins::statefile->new(%options);

    return $self;
}

sub set_options {
    my ($self, %options) = @_;

    $self->{option_results} = $options{option_results};
}

sub set_defaults {
    my ($self, %options) = @_;

    foreach (keys %{$options{default}}) {
        if ($_ eq $self->{mode}) {
            for (my $i = 0; $i < scalar(@{$options{default}->{$_}}); $i++) {
                foreach my $opt (keys %{$options{default}->{$_}[$i]}) {
                    if (!defined($self->{option_results}->{$opt}[$i])) {
                        $self->{option_results}->{$opt}[$i] = $options{default}->{$_}[$i]->{$opt};
                    }
                }
            }
        }
    }
}

sub check_options {
    my ($self, %options) = @_;

    $self->{hostname} = (defined($self->{option_results}->{hostname})) ? $self->{option_results}->{hostname} : undef;
    $self->{port} = (defined($self->{option_results}->{port})) ? $self->{option_results}->{port} : 443;
    $self->{proto} = (defined($self->{option_results}->{proto})) ? $self->{option_results}->{proto} : 'https';
    $self->{timeout} = (defined($self->{option_results}->{timeout})) ? $self->{option_results}->{timeout} : 30;
    $self->{ssl_opt} = (defined($self->{option_results}->{ssl_opt})) ? $self->{option_results}->{ssl_opt} : undef;
    $self->{api_username} = (defined($self->{option_results}->{api_username})) ? $self->{option_results}->{api_username} : undef;
    $self->{api_password} = (defined($self->{option_results}->{api_password})) ? $self->{option_results}->{api_password} : undef;

    if (!defined($self->{hostname}) || $self->{hostname} eq '') {
        $self->{output}->add_option_msg(short_msg => "Need to specify --hostname option.");
        $self->{output}->option_exit();
    }
    if (!defined($self->{api_username}) || $self->{api_username} eq '') {
        $self->{output}->add_option_msg(short_msg => "Need to specify --api-username option.");
        $self->{output}->option_exit();
    }
    if (!defined($self->{api_password}) || $self->{api_password} eq '') {
        $self->{output}->add_option_msg(short_msg => "Need to specify --api-password option.");
        $self->{output}->option_exit();
    }

    $self->{cache}->check_options(option_results => $self->{option_results});

    return 0;
}

sub build_options_for_httplib {
    my ($self, %options) = @_;

    $self->{option_results}->{hostname} = $self->{hostname};
    $self->{option_results}->{port} = $self->{port};
    $self->{option_results}->{proto} = $self->{proto};
    $self->{option_results}->{ssl_opt} = $self->{ssl_opt};
    $self->{option_results}->{timeout} = $self->{timeout};
}

sub settings {
    my ($self, %options) = @_;

    $self->build_options_for_httplib();
    $self->{http}->add_header(key => 'Content-Type', value => 'application/json;charset=UTF-8');
    if (defined($self->{cookie}) && defined($self->{xsrf})) {
        $self->{http}->add_header(key => 'Cookie', value => '.AspNetCore.Cookies=' . $self->{cookie});
        $self->{http}->add_header(key => 'X-XSRF-TOKEN', value => $self->{xsrf});
    }
    $self->{http}->set_options(%{$self->{option_results}});
}

sub authenticate {
    my ($self, %options) = @_;

    my $has_cache_file = $options{statefile}->read(statefile => '3cx_api_' . md5_hex($self->{option_results}->{hostname}) . '_' . md5_hex($self->{option_results}->{api_username}));
    my $cookie = $options{statefile}->get(name => 'cookie');
    my $xsrf = $options{statefile}->get(name => 'xsrf');
    my $expires_on = $options{statefile}->get(name => 'expires_on');
    
    if ($has_cache_file == 0 || !defined($cookie) || !defined($xsrf) || (($expires_on - time()) < 10)) {
        my $post_data = '{"Username":"' . $self->{api_username} . '",' .
            '"Password":"' . $self->{api_password} . '"}';
        
        $self->settings();

        my $content = $self->{http}->request(
            method => 'POST', query_form_post => $post_data,
            url_path => '/api/login',
            warning_status => '', unknown_status => '', critical_status => '%{http_code} < 200 or %{http_code} >= 300'
        );

        my $header = $self->{http}->get_header(name => 'Set-Cookie');
        if (defined ($header) && $header =~ /(?:^| ).AspNetCore.Cookies=([^;]+);.*/) {
            $cookie = $1;
        } else {
            $self->{output}->output_add(long_msg => $content, debug => 1);
            $self->{output}->add_option_msg(short_msg => "Error retrieving cookie");
            $self->{output}->option_exit();
        }
        if (defined ($header) && $header =~ /(?:^| )XSRF-TOKEN=([^;]+);.*/) {
            $xsrf = $1;
        } else {
            $self->{output}->output_add(long_msg => $content, debug => 1);
            $self->{output}->add_option_msg(short_msg => "Error retrieving xsrf-token");
            $self->{output}->option_exit();
        }

        my $datas = { last_timestamp => time(), cookie => $cookie, xsrf => $xsrf, expires_on => time() + (3600 * 24) };
        $options{statefile}->write(data => $datas);
    }

    $self->{cookie} = $cookie;
    $self->{xsrf} = $xsrf;
}

sub request_api {
    my ($self, %options) = @_;

    if (!defined($self->{cookie})) {
        $self->authenticate(statefile => $self->{cache});
    }

    $self->settings();

    my $content = $self->{http}->request(%options, 
        warning_status => '', unknown_status => '', critical_status => '%{http_code} < 200 or %{http_code} >= 300'
    );

    my $decoded;
    eval {
        $decoded = JSON::XS->new->utf8->decode($content);
    };
    if ($@) {
        $self->{output}->output_add(long_msg => $content, debug => 1);
        $self->{output}->add_option_msg(short_msg => "Cannot decode json response: $@");
        $self->{output}->option_exit();
    }
    if (!defined($decoded)) {
        $self->{output}->output_add(long_msg => $decoded, debug => 1);
        $self->{output}->add_option_msg(short_msg => "Error while retrieving data (add --debug option for detailed message)");
        $self->{output}->option_exit();
    }

    return $decoded;
}

sub internal_single_status {
    my ($self, %options) = @_;

    my $status = $self->request_api(method => 'GET', url_path =>'/api/SystemStatus/GetSingleStatus');
    return $status;
}

sub api_single_status {
    my ($self, %options) = @_;

    my $status = $self->internal_single_status();
    return $status->{Health};
}

sub internal_system_status {
    my ($self, %options) = @_;
    
    my $status = $self->request_api(method => 'GET', url_path =>'/api/SystemStatus');
    return $status;
}

sub api_system_status {
    my ($self, %options) = @_;

    my $status = $self->internal_system_status();
    return $status;
}

1;

__END__

=head1 NAME

3CX Rest API

=head1 REST API OPTIONS

=over 8

=item B<--hostname>

Set hostname or IP of 3CX server.

=item B<--port>

Set 3CX Port (Default: '443').

=item B<--proto>

Specify https if needed (Default: 'https').

=item B<--api-username>

Set 3CX Username.

=item B<--api-password>

Set 3CX Password.

=item B<--timeout>

Threshold for HTTP timeout (Default: '30').

=back

=cut