NAME
    Net::Google::Drive::Simple - Simple modification of Google Drive data

SYNOPSIS
        use feature 'say';
        use Net::Google::Drive::Simple;

        # requires a ~/.google-drive.yml file with an access token,
        # see description below.
        my $gd = Net::Google::Drive::Simple->new();

        my $children = $gd->children( "/" ); # or any other folder /path/location

        foreach my $item ( @$children ) {

            # item is a Net::Google::Drive::Simple::Item object

            if ( $item->is_folder ) {
                say "** ", $item->title, " is a folder";
            } else {
                say $item->title, " is a file ", $item->mimeType;
                eval { # originalFilename not necessary available for all files
                  say $item->originalFilename(), " can be downloaded at ", $item->downloadUrl();
                };
            }
        }

DESCRIPTION
    Net::Google::Drive::Simple authenticates with a user's Google Drive and
    offers several convenience methods to list, retrieve, and modify the
    data stored in the 'cloud'. See "eg/google-drive-upsync" as an example
    on how to keep a local directory in sync with a remote directory on
    Google Drive.

  GETTING STARTED
    To get the access token required to access your Google Drive data via
    this module, you need to run the script "eg/google-drive-init" in this
    distribution.

    Before you run it, you need to register your 'app' with Google Drive and
    obtain a client_id and a client_secret from Google:

        https://developers.google.com/drive/web/enable-sdk

    Click on "Enable the Drive API and SDK", and find "Create an API project
    in the Google APIs Console". On the API console, create a new project,
    click "Services", and enable "Drive API" (leave "drive SDK" off). Then,
    under "API Access" in the navigation bar, create a client ID, and make
    sure to register a an "installed application" (not a "web application").
    "Redirect URIs" should contain "http://localhost". This will get you a
    "Client ID" and a "Client Secret".

    Then, replace the following lines in "eg/google-drive-init" with the
    values received:

          # You need to obtain a client_id and a client_secret from
          # https://developers.google.com/drive to use this.
        my $client_id     = "XXX";
        my $client_secret = "YYY";

    Then run the script. It'll start a web server on port 8082 on your local
    machine. When you point your browser at http://localhost:8082, you'll
    see a link that will lead you to Google Drive's login page, where you
    authenticate and then allow the app (specified by client_id and
    client_secret above) access to your Google Drive data. The script will
    then receive an access token from Google Drive and store it in
    ~/.google-drive.yml from where other scripts can pick it up and work on
    the data stored on the user's Google Drive account. Make sure to limit
    access to ~/.google-drive.yml, because it contains the access token that
    allows everyone to manipulate your Google Drive data. It also contains a
    refresh token that this library uses to get a new access token
    transparently when the old one is about to expire.

METHODS
    "new()"
        Constructor, creates a helper object to retrieve Google Drive data
        later.

    "my $children = $gd->children( "/path/to" )"
        Return the entries under a given path on the Google Drive as a
        reference to an array. Each entry is an object composed of the JSON
        data returned by the Google Drive API. Each object offers methods
        named like the fields in the JSON data, e.g. "originalFilename()",
        "downloadUrl", etc.

        Will return all entries found unless "maxResults" is set:

            my $children = $gd->children( "/path/to", { maxResults => 3 } )

        Due to the somewhat capricious ways Google Drive handles its
        directory structures, the method needs to traverse the path
        component by component and determine the ID of each directory to get
        to the next level. To speed up subsequent lookups, it also returns
        the ID of the last component to the caller:

            my( $children, $parent ) = $gd->children( "/path/to" );

        If the caller now wants to e.g. insert a file into the directory,
        its ID is available in $parent.

        Each child comes back as a files#resource type and gets mapped into
        an object that offers access to the various fields via methods:

            for my $child ( @$children ) {
                print $child->kind(), " ", $child->title(), "\n";
            }

        Please refer to

            https://developers.google.com/drive/v2/reference/files#resource

        for details on which fields are available.

    "my $files = $gd->files( )"
        Return all files on the drive as a reference to an array. Will
        return all entries found unless "maxResults" is set:

            my $files = $gd->files( { maxResults => 3 } )

        Note that Google limits the number of entries returned by default to
        100, and seems to restrict the maximum number of files returned by a
        single query to 3,500, even if you specify higher values for
        "maxResults".

        Each file comes back as an object that offers access to the Google
        Drive item's fields, according to the API (see "children()").

    "my $id = $gd->folder_create( "folder-name", $parent_id )"
        Create a new folder as a child of the folder with the id $parent_id.
        Returns the ID of the new folder or undef in case of an error.

    "my $id = $gd->file_create( "folder-name", "mime-type", $parent_id )"
        Create a new file with the given mime type as a child of the folder
        with the id $parent_id. Returns the ID of the new file or undef in
        case of an error.

        Example to create an empty google spreadsheet:

            my $id = $gd->file_create( "Quarter Results", "application/vnd.google-apps.spreadsheet", "root" );

    "$gd->file_upload( $file, $dir_id )"
        Uploads the content of the file $file into the directory with the ID
        $dir_id on Google Drive. Uses $file as the file name.

        To overwrite an existing file on Google Drive, specify the file's ID
        as an optional parameter:

            $gd->file_upload( $file, $dir_id, $file_id );

    "$gd->rename( $file_id, $name )"
        Renames the file or folder with $file_id to the specified $name.

    "$gd->download( $item, [$local_filename] )"
        Downloads an item found via "files()" or "children()". Also accepts
        the downloadUrl of an item. If $local_filename is not specified,
        "download()" will return the data downloaded (this might be
        undesirable for large files). If $local_filename is specified,
        "download()" will store the downloaded data under the given file
        name.

            my $gd = Net::Google::Drive::Simple->new();
            my $files = $gd->files( { maxResults => 20 }, { page => 0 } );
            for my $file ( @$files ) {
                my $name = $file->originalFilename();
                print "Downloading $name\n";
                $gd->download( $file, $name ) or die "failed: $!";
            }

        Be aware that only documents like PDF or png can be downloaded
        directly. Google Drive Documents like spreadsheets or (text)
        documents need to be exported into one of the available formats.
        Check for "exportLinks" on a file given. In case of a document that
        can be exported you will receive a hash in the form:

            {
                'format_1' => 'download_link_1',
                'format_2' => 'download_link_2',
                ...
            }

        Choose your download link and use it as an argument to the
        download() function which can also take urls directly.

            my $gd = Net::Google::Drive::Simple->new();
            my $children = $gd->children( '/path/to/folder/on/google/drive' );
            for my $child ( @$children ) {
                if ($child->can( 'exportLinks' )){
                    my $type_chosen;
                    foreach my $type (keys %{$child->exportLinks()}){
                        # Take any type you can get..
                        $type_chosen = $type;
                        # ..but choose your preferred format, opendocument here:
                        last if $type =~/oasis\.opendocument/;
                    }
                    my $url = $child->exportLinks()->{$type_chosen};

                    $gd->download($url, 'my/local/file');

                }
            }

    "my $files = $gd->search( )"
            my $children= $gd->search({ maxResults => 20 },{ page => 0 },
                                      "title contains 'Futurama'");

        Search files for attributes. See
        <https://developers.google.com/drive/web/search-parameters> for a
        definition of the attributes.

        To list all available files, those on the drive, those directly
        shared with the user, and those generally available to the user, use
        an empty search:

          my $children= $gd->search({},{ page => 0 },"");

    "$gd->file_delete( file_id )"
        Delete the file with the specified ID from Google Drive.

    "$gd->drive_mvdir( "/gdrive/path/to/file", "/path/to/new/folder" )"
        Move an existing file to a new folder. Removes the file's "parent"
        setting (pointing to the old folder) and then adds the new folder as
        a new parent.

    "my $metadata_hash_ref = $gd->file_metadata( file_id )"
        Return metadata about the file with the specified ID from Google
        Drive.

    "api_test"
        Used at init time to check that the connection is correct.

    "children_by_folder_id"
    "data_factory"
    "error"
    "file_mime_type"
    "file_mvdir"
    "file_url"
    "http_delete"
    "http_json"
    "http_loop"
    "http_put"
    "init"
        Internal initialization to setup the connection.

    "item_iterator"
    "path_resolve"

Error handling
    In case of an error while retrieving information from the Google Drive
    API, the methods above will return "undef" and a more detailed error
    message can be obtained by calling the "error()" method:

        print "An error occurred: ", $gd->error();

LOGGING/DEBUGGING
    Net::Google::Drive::Simple is Log4perl-enabled. To find out what's going
    on under the hood, turn on Log4perl:

        use Log::Log4perl qw(:easy);
        Log::Log4perl->easy_init($DEBUG);

LEGALESE
    Copyright 2012-2019 by Mike Schilli, all rights reserved. This program
    is free software, you can redistribute it and/or modify it under the
    same terms as Perl itself.

AUTHOR
    2019, Nicolas R. <cpan@atoomic.org> 2012-2019, Mike Schilli
    <cpan@perlmeister.com>