#
# Copyright 2021 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::cisco::ssms::restapi::custom::api;

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  = {};
    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 => {
            'client-id:s'            => { name => 'client_id' },
            'client-secret:s'        => { name => 'client_secret' },
            'hostname:s'             => { name => 'hostname' },
            'port:s'                 => { name => 'port' },
            'proto:s'                => { name => 'proto' },
            'timeout:s'              => { name => 'timeout' },
            'unknown-http-status:s'  => { name => 'unknown_http_status' },
            'warning-http-status:s'  => { name => 'warning_http_status' },
            'critical-http-status:s' => { name => 'critical_http_status' }
        });
    }
    $options{options}->add_help(package => __PACKAGE__, sections => 'REST API OPTIONS', once => 1);

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

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

    $self->{hostname} = (defined($self->{option_results}->{hostname})) ? $self->{option_results}->{hostname} : '';
    $self->{port} = (defined($self->{option_results}->{port})) ? $self->{option_results}->{port} : 8443;
    $self->{proto} = (defined($self->{option_results}->{proto})) ? $self->{option_results}->{proto} : 'https';
    $self->{timeout} = (defined($self->{option_results}->{timeout})) ? $self->{option_results}->{timeout} : 10;
    $self->{client_id} = (defined($self->{option_results}->{client_id})) ? $self->{option_results}->{client_id} : '';
    $self->{client_secret} = (defined($self->{option_results}->{client_secret})) ? $self->{option_results}->{client_secret} : '';
    $self->{unknown_http_status} = (defined($self->{option_results}->{unknown_http_status})) ? $self->{option_results}->{unknown_http_status} : '%{http_code} < 200 or %{http_code} >= 300';
    $self->{warning_http_status} = (defined($self->{option_results}->{warning_http_status})) ? $self->{option_results}->{warning_http_status} : '';
    $self->{critical_http_status} = (defined($self->{option_results}->{critical_http_status})) ? $self->{option_results}->{critical_http_status} : '';

    if ($self->{hostname} eq '') {
        $self->{output}->add_option_msg(short_msg => "Need to specify --hostname option.");
        $self->{output}->option_exit();
    }
    if ($self->{client_id} eq '') {
        $self->{output}->add_option_msg(short_msg => "Need to specify --client-id option.");
        $self->{output}->option_exit();
    }
    if ($self->{client_secret} eq '') {
        $self->{output}->add_option_msg(short_msg => "Need to specify --client-secret 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}->{timeout} = $self->{timeout};
    $self->{option_results}->{port} = $self->{port};
    $self->{option_results}->{proto} = $self->{proto};
    $self->{option_results}->{timeout} = $self->{timeout};
}

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

    return $self->{hostname};
}

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

    $self->build_options_for_httplib();
    $self->{http}->add_header(key => 'Content-Type', value => 'application/json');
    $self->{http}->add_header(key => 'Accept', value => 'application/json');
    if (defined($self->{access_token})) {
        $self->{http}->add_header(key => 'Authorization', value => 'Bearer ' . $self->{access_token});
    }
    $self->{http}->set_options(%{$self->{option_results}});
}

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

    my $has_cache_file = $options{statefile}->read(
        statefile =>
            'cisco_ssms_api_' .
            $self->get_hostname() . '_' .
            md5_hex($self->{client_id})
    );
    my $expires_on = $options{statefile}->get(name => 'expires_on');
    my $access_token = $options{statefile}->get(name => 'access_token');

    if ($has_cache_file == 0 || !defined($access_token) || (($expires_on - time()) < 10)) {
        my $json_request = {
            grant_type => 'client_credentials', 
            client_id => $self->{client_id},
            client_secret => $self->{client_secret}
        };
        my $encoded;
        eval {
            $encoded = encode_json($json_request);
        };
        if ($@) {
            $self->{output}->add_option_msg(short_msg => "Cannot encode json request");
            $self->{output}->option_exit();
        }

        $self->settings();

        my ($content) = $self->{http}->request(
            method => 'POST',
            url_path => '/backend/oauth/token',
            query_form_post => $encoded,
            unknown_status => $self->{unknown_http_status},
            warning_status => $self->{warning_http_status},
            critical_status => $self->{critical_http_status}
        );

        my $decoded;
        eval {
            $decoded = JSON::XS->new->utf8->decode($content);
        };
        if ($@) {
            $self->{output}->add_option_msg(short_msg => "Cannot decode response (add --debug option to display returned content)");
            $self->{output}->option_exit();
        }

        $access_token = $decoded->{access_token};
        my $datas = { last_timestamp => time(), access_token => $decoded->{access_token}, expires_on => (time() + $decoded->{expires_in}) };
        $options{statefile}->write(data => $datas);
    }

    return $access_token;
}

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

    if (!defined($self->{access_token})) {
        $self->{access_token} = $self->get_access_token(statefile => $self->{cache});
    }

    $self->settings();

    my ($content) = $self->{http}->request(
        method => 'POST',
        url_path => $options{endpoint},
        query_form_post => encode_json({ limit => -1 }),
        unknown_status => $self->{unknown_http_status},
        warning_status => $self->{warning_http_status},
        critical_status => $self->{critical_http_status}
    );

    my $decoded;
    eval {
        $decoded = JSON::XS->new->utf8->decode($content);
    };
    if ($@) {
        $self->{output}->add_option_msg(short_msg => "Cannot decode response (add --debug option to display returned content)");
        $self->{output}->option_exit();
    }

    return $decoded;
}

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

    return $self->request_api(endpoint => '/api/v1/accounts/' . $options{account} . '/alerts');
}

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

    return $self->request_api(endpoint => '/api/v1/accounts/' . $options{account} . '/licenses');
}

1;

__END__

=head1 NAME

Cisco SSMS Rest API

=head1 REST API OPTIONS

Cisco SSMS Rest API

=over 8

=item B<--hostname>

Set hostname.

=item B<--port>

Port used (Default: 8443)

=item B<--proto>

Specify https if needed (Default: 'https')

=item B<--client-id>

Set client ID.

=item B<--client-secret>

Set client secret.

=item B<--timeout>

Set timeout in seconds (Default: 10).

=back

=head1 DESCRIPTION

B<custom>.

=cut