Box: Create Shared Link to File

main();
function main(){
  // get OAuth2 Setting
  const oauth2 = configs.get("conf_OAuth2");
  const fileId = decideFileId();
  const unsharedDateDef = configs.getObject("conf_UnsharedAt");
  const passwordDef = configs.getObject("conf_Password");
  
  let unsharedDate = null;
  if (unsharedDateDef !== null){
    unsharedDate = engine.findData(unsharedDateDef);
  }

  let password = "";
  if (passwordDef !== null){
    password = engine.findData(passwordDef);
  }

  checkExistingSharedLink(oauth2, fileId);
  const sharedlinkUrl = createSharedLink(oauth2, fileId, unsharedDate, password);

  const urlDef = configs.getObject( "conf_SharedLink" );
  if (urlDef !== null) {
    engine.setData(urlDef,sharedlinkUrl);
  }
}


/**
  * ファイルのIDをconfigから読み出して出力する。
  * @return {String} fileId ファイルの ID
  */
function decideFileId(){
  let fileId = "";
  const fileIdDef = configs.getObject("conf_FileId");
  if(fileIdDef === null){
    fileId = configs.get( "conf_FileId");
  }else{
    fileId = engine.findData(fileIdDef);
  }
  if (fileId === "" || fileId === null) {
    throw "File ID is blank";
  }
  return fileId;
}


/**
  * ファイルが既に共有リンク作成されているか調べ、既に共有リンクがある場合はエラーにする
  * @param {String} oauth OAuth2 設定
  * @param {String} fileId ファイルの ID
  */
function checkExistingSharedLink(oauth2, fileId) {
  const url = `https://api.box.com/2.0/files/${fileId}?fields=shared_link`;
  const response = httpClient.begin()
    .authSetting(oauth2)
    .get(url);

  const status = response.getStatusCode();
  const responseTxt = response.getResponseAsString();

  if (status !== 200) {
    engine.log(responseTxt);
    throw `Failed to get file information. status:${status}`;
  }
  const jsonRes = JSON.parse(responseTxt);

  if (jsonRes.shared_link !== null){
    throw `Shared link(${jsonRes.shared_link.url}) was already created.`;
  }
}


/**
  * Create Shared Link to File on Box  共有リンク作成
  * @param {String} oauth OAuth2 設定
  * @param {String} fileId ファイルの ID
  * @param {AddableTimestamp} unsharedDate 有効期限
  * @param {String} password パスワード
  * @return {String}  ファイルの共有リンクURL
  */
function createSharedLink(oauth2, fileId, unsharedDate, password) {
  let timezone = engine.getTimeZoneId();
  if (timezone === "GMT"){
    timezone += "+00:00";
  }

  const jsonBody = {};

  jsonBody["shared_link"] = {"access": "open"};
  if(unsharedDate !== null){
    jsonBody["shared_link"]["unshared_at"] = unsharedDate.toString() + timezone.slice(3);
  }
  if(password !== "" && password !== null){
    jsonBody["shared_link"]["password"] = password;
  }
  
  jsonBody["shared_link"]["permissions"] = {"can_download": true };
  
  const url = `https://api.box.com/2.0/files/${fileId}?fields=shared_link`;
  const response = httpClient.begin()
    .authSetting(oauth2)
    .body(JSON.stringify(jsonBody), "application/json; charset=UTF-8")
    .put(url);

  const status = response.getStatusCode();
  const responseTxt = response.getResponseAsString();

  if (status !== 200) {
    engine.log(responseTxt);
    throw `Failed to create Shared Link. status:${status}`;
  }
  const jsonRes = JSON.parse(responseTxt);
  return jsonRes.shared_link.url;
}