NAME

    WebService::GoogleAPI::Client - API WebService OAUTH2 Client Agent to
    streamline access to GOOGLE API End-Point Services using Discovery Data

VERSION

    version 0.13.1

SYNOPSIS

    Access Google API Services Version 1 using an OAUTH2 User Agent

    assumes gapi.json configuration in working directory with scoped Google
    project redentials and user authorization created by _goauth_

        use WebService::GoogleAPI::Client;
        
        my $gapi_client = WebService::GoogleAPI::Client->new( debug => 1, gapi_json => 'gapi.json', user=> 'peter@pscott.com.au' );
        
        say $gapi_client->list_of_available_google_api_ids();
    
        my @gmail_endpoint_list =      $gapi_client->methods_available_for_google_api_id('gmail')
    
        if $gapi_agent->has_scope_to_access_api_endpoint( 'gmail.users.settings.sendAs.get' ) {
          say 'User has Access to GMail Method End-Point gmail.users.settings.sendAs.get';
        }

    Package includes _go_auth_ CLI Script to collect initial end-user
    authorisation to scoped services

EXAMPLES

 AUTOMATIC API REQUEST CONSTRUCTION - SEND EMAL

        ## using dotted API Endpoint id to invoke helper validation and default value interpolations etc to send email to self
        use Email::Simple;    ## RFC2822 formatted messages
        use MIME::Base64;
        my $my_email_address = 'peter@shotgundriver.com'
    
    
        my $raw_email_payload = encode_base64( Email::Simple->create( header => [To => $my_email_address, 
                                                                                 From => $my_email_address, 
                                                                                 Subject =>"Test email from '$my_email_address' ",], 
                                                                                 body => "This is the body of email to '$my_email_address'", 
                                                                    )->as_string 
                                            );
    
        $gapi_client->api_query( 
                                api_endpoint_id => 'gmail.users.messages.send',
                                options    => { raw => $raw_email_payload },
                            );

 MANUAL API REQUEST CONSTRUCTION - GET CALENDAR LIST

        ## Completely manually constructed API End-Point Request to obtain Perl Data Structure converted from JSON response.
        my $res = $gapi_client->api_query(
          method => 'get',
          path => 'https://www.googleapis.com/calendar/users/me/calendarList',
        )->json;

METHODS

 new

    WebService::GoogleAPI::Client->new( user => 'useremail@sdf.com',
    gapi_json => '/fullpath/gapi.json' );

 api_query

    query Google API with option to validate request before submitting

    handles user auth token inclusion in request headers and refreshes
    token if required and possible

    Required params: method, route

    Optional params: api_endpoint_id

    $self->access_token must be valid

    Examples of usage:

      $gapi->api_query({
          method => 'get',
          path => 'https://www.googleapis.com/calendar/users/me/calendarList',
        });
    
      $gapi->api_query({
          method => 'post',
          path => 'https://www.googleapis.com/calendar/v3/calendars/'.$calendar_id.'/events',
          options => { key => value }
      }
    
      ## if provide the Google API Endpoint to inform pre-query validation
      say $gapi_agent->api_query(
          api_endpoint_id => 'gmail.users.messages.send',
          options    => { raw => encode_base64( 
                                                Email::Simple->create( header => [To => $user, From => $user, Subject =>"Test email from $user",], 
                                                                        body   => "This is the body of email from $user to $user", )->as_string 
                                              ), 
                        },
      )->to_string; ##
    
      print  $gapi_agent->api_query(
                api_endpoint_id => 'gmail.users.messages.list', ## auto sets method to GET, path to 'https://www.googleapis.com/calendar'
              )->to_string;
      #print Dumper $r;
    
    
      NB: including the version in the API Endpoint Spec is not supported .. yet? eg gmail:v1.users.messages.list .. will always use the latest stable version
    
    
      if the pre-query validation fails then a 418 - I'm a Teapot error response is returned with the 
      body containing the specific description of the errors ( Tea Leaves ;^) ).   

    Returns Mojo::Message::Response object

 has_scope_to_access_api_endpoint

    Given an API Endpoint such as 'gmail.users.settings.sendAs.get' returns
    1 iff user has scope to access

        say 'User has Access'  if $gapi_agent->has_scope_to_access_api_endpoint( 'gmail.users.settings.sendAs.get' );

    Returns 0 if scope to access is not available to the user.

    warns and returns 0 on error ( eg user or config not specified etc )

 methods_available_for_google_api_id

    Returns a hashref keyed on the Google service API Endpoint in dotted
    format. The hashed content contains a structure representing the
    corresponding discovery specification for that method ( API Endpoint )

        methods_available_for_google_api_id('gmail')

    TODO: consider ? refactor to allow parameters either as a single api id
    such as 'gmail' as well as the currently accepted hash keyed on the api
    and version

    DELEGATED FROM WebService::GoogleAPI::Client::Discovery

    SEE ALSO: The following methods are delegated through to
    Client::Discovery - see perldoc WebService::Client::Discovery for
    detils

      get_method_meta 
      discover_all 
      extract_method_discovery_detail_from_api_spec 
      get_api_discovery_for_api_id

 list_of_available_google_api_ids

    Returns an array list of all the available API's described in the API
    Discovery Resource that is either fetched or cached in CHI locally for
    30 days.

    WHen called in a scalar context returns the list as a comma joined
    string.

    DELEGATED FROM WebService::GoogleAPI::Client::Discovery

FEATURES

    API Discovery with local caching using CHI File

    OAUTH app credentials (client_id, client_secret, scope, users
    access_token and refresh_tokens) stored in local file (default name =
    gapi.json)

    access_token refreshes when expires (if user has refresh_token) saving
    refreshed token back to json file

    helper api_query to streamline request composition without preventing
    manual construction if preferred.

    CLI tool (goauth) with lightweight http server to simplify OAuth2
    configuration, sccoping, authorization and obtaining access_ and
    refresh_ tokensn from users

AUTHOR

    Peter Scott <localshop@cpan.org>

COPYRIGHT AND LICENSE

    This software is Copyright (c) 2017-2018 by Peter Scott and others.

    This is free software, licensed under:

      The Apache License, Version 2.0, January 2004

