Google Drive: GFile, Export as MS-Office

// GraalJS Script (engine type: 2)

//////// START "main()" /////////////////////////////////////////////////////////////////

main();
function main(){ 

//// == Config Retrieving / 工程コンフィグの参照 ==
const strAuthzSetting     = configs.get      ( "AuthzConfU" );   /// REQUIRED
  engine.log( " AutomatedTask Config: Authz Setting: " + strAuthzSetting );
const strInputfileId      = configs.get      ( "StrConfA1" );    /// REQUIRED
  if( strInputfileId    === "" ){
    throw new Error( "\n AutomatedTask ConfigError:" +
                     " Config {A1: FileID} is empty \n" );
  }
let   strSaveas           = configs.get      ( "StrConfB1" );    // NotRequired
  if( strSaveas         === "" ){
    engine.log( " AutomatedTask ConfigWarning:" +
                " Config {B1: ExportedSaveas} is empty" );
  }
const filesPocketDownload  = configs.getObject( "SelectConfB2" ); /// REQUIRED
const strPocketNameOnDrive = configs.getObject( "SelectConfB3" ); // NotRequired
const strPocketMimetype    = configs.getObject( "SelectConfB4" ); // NotRequired


//// == Data Retrieving / ワークフローデータの参照 ==
let filesAttached = engine.findData( filesPocketDownload ); // java.util.ArrayList
if( filesAttached === null ) {
  engine.log( " AutomatedTask FilesArray {B2} (empty)" );
  filesAttached = new java.util.ArrayList();
}else{
  engine.log( " AutomatedTask FilesArray {B2}: " +
              filesAttached.size() + " files" );
}


//// == Calculating / 演算 ==
/// Gets a file's metadata by ID.
/// Google Workspace for Developers > Google Drive for Developers > v3
/// https://developers.google.com/drive/api/v3/reference/files/get
// request1, prepare
let request1Uri = "https://www.googleapis.com/drive/v3/files/" + strInputfileId;
let request1    = httpClient.begin(); // HttpRequestWrapper
    request1    = request1.authSetting( strAuthzSetting ); // with "Authorization: Bearer XX"
    // https://questetra.zendesk.com/hc/en-us/articles/360024574471-R2300#HttpRequestWrapper
    request1    = request1.queryParam( "supportsAllDrives", "true" );
// request1, try
const response1     = request1.get( request1Uri ); // HttpResponseWrapper
engine.log( " AutomatedTask ApiRequest1 Start: " + request1Uri );
const response1Code = response1.getStatusCode() + "";
const response1Body = response1.getResponseAsString() + "";
engine.log( " AutomatedTask ApiResponse Status: " + response1Code );
if( response1Code !== "200"){
  throw new Error( "\n AutomatedTask UnexpectedResponseError: " +
                    response1Code + "\n" + response1Body + "\n" );
}
// response1, parse
/* engine.log( response1Body ); // debug
{
  "kind": "drive#file",
  "id": "0BwSW_lixFpUuQ2JyV1pqU3VzTGs",
  "name": "Questetra-Intro-en.pdf",
  "mimeType": "application/pdf"
}
*/
const response1Obj = JSON.parse( response1Body );
engine.log( " AutomatedTask ApiResponse: File Name OnDrive: " + response1Obj.name );
engine.log( " AutomatedTask ApiResponse: File MIME-Type: " + response1Obj.mimeType );
if( strSaveas === "" ){
  if( response1Obj.mimeType === "application/vnd.google-apps.document" ){
    strSaveas = response1Obj.name + ".docx";
  }else if( response1Obj.mimeType === "application/vnd.google-apps.spreadsheet" ){
    strSaveas = response1Obj.name + ".xlsx";
  }else if( response1Obj.mimeType === "application/vnd.google-apps.presentation" ){
    strSaveas = response1Obj.name + ".pptx";
  }else{
    throw new Error( "\n AutomatedTask UnexpectedMimetypeError: " +
                      response1Obj.mimeType + "\n" );
  }
}

/// Export as MS-Office from Google Drive to BPMS.
/// Google Workspace for Developers > Google Drive for Developers > v3
/// https://developers.google.com/drive/api/v3/reference/files/export
let request2Uri = "https://www.googleapis.com/drive/v3/files/" + strInputfileId + "/export";
let request2    = httpClient.begin(); // HttpRequestWrapper
    request2    = request2.authSetting( strAuthzSetting ); // with "Authorization: Bearer XX"
    // https://questetra.zendesk.com/hc/en-us/articles/360024574471-R2300#HttpRequestWrapper
    if( response1Obj.mimeType === "application/vnd.google-apps.document" ){
      request2  = request2.queryParam( "mimeType",
                  "application/vnd.openxmlformats-officedocument.wordprocessingml.document" );
    }else if( response1Obj.mimeType === "application/vnd.google-apps.spreadsheet" ){
      request2  = request2.queryParam( "mimeType",
                  "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet" );
    }else if( response1Obj.mimeType === "application/vnd.google-apps.presentation" ){
      request2  = request2.queryParam( "mimeType",
                  "application/vnd.openxmlformats-officedocument.presentationml.presentation" );
    }
// request2, try
const response2     = request2.get( request2Uri ); // HttpResponseWrapper
engine.log( " AutomatedTask ApiRequest2 Start: " + request2Uri );
const response2Code = response2.getStatusCode() + "";
engine.log( " AutomatedTask ApiResponse Status: " + response2Code );
if( response2Code !== "200"){
  const response2Body = response2.getResponseAsString() + "";
  throw new Error( "\n AutomatedTask UnexpectedResponseError: " +
                    response2Code + "\n" + response2Body + "\n" );
}
// response2, parse
const fileTmp = new com.questetra.bpms.core.event.scripttask.NewQfile(
                 strSaveas, response2.getContentType(), response2.getResponse()
                );
filesAttached.add( fileTmp );


//// == Data Updating / ワークフローデータへの代入 ==
engine.setData( filesPocketDownload,    filesAttached );

if( strPocketNameOnDrive !== null ){
  engine.setData( strPocketNameOnDrive, response1Obj.name );
}
if( strPocketMimetype    !== null ){
  engine.setData( strPocketMimetype,    response1Obj.mimeType );
}

} //////// END "main()" /////////////////////////////////////////////////////////////////


/*
Notes:
- Proposals created with Google Docs and Slides can be automatically converted to MS-Office.
- The File ID can be obtained from the URI or the sharing settings screen.
- TimeoutException error may occur in case many pages or images.
- The exported content is limited to 10MB.
Notes-ja:
- Google ドキュメントやスライド等で作成された提案書や参考資料を自動的にMS-Office化できます。
- File ID は URI や共有設定画面等から取得します。
- Exportされるファイルのサイズ上限は 10MB です。
- ページ数や画像数が多い等の場合に TimeoutException エラーが発生する場合があります。

APPENDIX-en
- Setting example of "HTTP Authentication" (OAuth2)
    - Authorization Endpoint URL:
        - https://accounts.google.com/o/oauth2/auth?access_type=offline&approval_prompt=force
    - Token Endpoint URL:
        - https://accounts.google.com/o/oauth2/token
    - Scope:
        - https://www.googleapis.com/auth/drive.readonly
    - Client ID, Consumer Secret:
        - ( from https://console.developers.google.com/ )
        - Redirect URLs: https://s.questetra.net/oauth2callback
APPENDIX-ja
- "HTTP認証"（OAuth2）の設定例
    - Authorization Endpoint URL:
        - https://accounts.google.com/o/oauth2/auth?access_type=offline&approval_prompt=force
    - Token Endpoint URL:
        - https://accounts.google.com/o/oauth2/token
    - Scope:
        - https://www.googleapis.com/auth/drive.readonly
    - Client ID, Consumer Secret:
        - ( from https://console.developers.google.com/ )
        - Redirect URLs: https://s.questetra.net/oauth2callback
*/