var CLIENT_ID = '...';
var CLIENT_SECRET = '...';

/**
 * Authorizes and makes a request to the ChatWork API.
 */
function run() {
  var service = getService_();
  if (service.hasAccess()) {
    var response = UrlFetchApp.fetch('https://api.chatwork.com/v2/me', {
      headers: {
        Authorization: 'Bearer ' + service.getAccessToken()
      }
    });
    var result = JSON.parse(response.getContentText());
    Logger.log(JSON.stringify(result, null, 2));
  } else {
    var authorizationUrl = service.getAuthorizationUrl();
    Logger.log('Open the following URL and re-run the script: %s',
        authorizationUrl);
  }
}

/**
 * Reset the authorization state, so that it can be re-tested.
 */
function reset() {
  getService_().reset();
}

/**
 * Configures the service.
 */
function getService_() {
  var scope = 'users.profile.me:read rooms.messages:read';
  return OAuth2.createService('ChatWork')
      // Set the endpoint URLs.
      .setAuthorizationBaseUrl(
          'https://www.chatwork.com/packages/oauth2/login.php')
      .setTokenUrl('https://oauth.chatwork.com/token')

      // Set the client ID and secret.
      .setClientId(CLIENT_ID)
      .setClientSecret(CLIENT_SECRET)

      // Set the name of the callback function that should be invoked to
      // complete the OAuth flow.
      .setCallbackFunction('authCallback')

      .setScope(scope)

      .setTokenHeaders({
        'Authorization': 'Basic ' +
            Utilities.base64Encode(CLIENT_ID + ':' + CLIENT_SECRET)
      })
      // Avoid "invalid_client error".
      // This service does not support form field authentication.
      .setTokenPayloadHandler(function(tokenPayload) {
        delete tokenPayload.client_id;
        return tokenPayload;
      })
      // Set the property store where authorized tokens should be persisted.
      .setPropertyStore(PropertiesService.getUserProperties());
}

/**
 * Handles the OAuth callback.
 */
function authCallback(request) {
  var service = getService_();
  var authorized = service.handleCallback(request);
  if (authorized) {
    return HtmlService.createHtmlOutput('Success!');
  } else {
    return HtmlService.createHtmlOutput('Denied.');
  }
}

/**
 * Logs the redict URI to register.
 */
function logRedirectUri() {
  Logger.log(OAuth2.getRedirectUri());
}