package C4::External::OverDrive; # Copyright (c) 2013 ByWater # # This file is part of Koha. # # Koha 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 3 of the License, or # (at your option) any later version. # # Koha 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 Koha; if not, see . use strict; use warnings; use Koha; use JSON; use Koha::Caches; use HTTP::Request; use HTTP::Request::Common; use LWP::Authen::Basic; use LWP::UserAgent; BEGIN { require Exporter; our @ISA = qw( Exporter ) ; our @EXPORT = qw( IsOverDriveEnabled GetOverDriveToken ); } sub _request { my ( $request ) = @_; my $ua = LWP::UserAgent->new( agent => "Koha " . $Koha::VERSION ); my $response; eval { $response = $ua->request( $request ) ; }; if ( $@ ) { warn "OverDrive request failed: $@"; return; } return $response; } =head1 NAME C4::External::OverDrive - Retrieve OverDrive content availability information =head2 FUNCTIONS This module provides content search for OverDrive, =over =item IsOverDriveEnabled Returns 1 if all of the necessary system preferences for OverDrive are set. =back =cut sub IsOverDriveEnabled { return ( C4::Context->preference( 'OverDriveClientKey' ) && C4::Context->preference( 'OverDriveClientSecret' ) ); } =over =item GetOverDriveToken Fetches an OAuth2 auth token for the OverDrive API, reusing an existing token in Memcache if possible. Returns the token ( as "bearer ..." ) or undef on failure. =back =cut sub GetOverDriveToken { my $key = C4::Context->preference( 'OverDriveClientKey' ); my $secret = C4::Context->preference( 'OverDriveClientSecret' ); return unless ( $key && $secret ) ; my $cache; eval { $cache = Koha::Caches->get_instance() }; my $token; $cache and $token = $cache->get_from_cache( "overdrive_token" ) and return $token; my $request = HTTP::Request::Common::POST( 'https://oauth.overdrive.com/token', [ grant_type => 'client_credentials' ] ) ; $request->header( Authorization => LWP::Authen::Basic->auth_header( $key, $secret ) ); my $response = _request( $request ) or return; if ( $response->header('Content-Type') !~ m!application/json! ) { warn "Could not connect to OverDrive: " . $response->message; return; } my $contents = from_json( $response->decoded_content ); if ( !$response->is_success ) { warn "Could not log into OverDrive: " . ( $contents ? $contents->{'error_description'} : $response->decoded_content ); return; } $token = $contents->{'token_type'} . ' ' . $contents->{'access_token'}; # Fudge factor to prevent spurious failures $cache and $cache->set_in_cache( 'overdrive_token', $token, { expiry => $contents->{'expires_in'} - 5 } ); return $token; } 1; __END__ =head1 NOTES =cut =head1 AUTHOR Jesse Weaver =cut