dyaskur / google-chat-poll

export default class ActionHandler extends BaseHandler implements PollAction {

  async process(): Promise<chatV1.Schema$Message> {

    const action = this.event.common?.invokedFunction;

    switch (action) {

      case 'start_poll':

        return await this.startPoll();

      case 'vote':

        return this.recordVote();

      case 'add_option_form':

        return this.addOptionForm();

      case 'add_option':

        return await this.saveOption();

      case 'show_form':

        const pollForm = new NewPollFormCard({topic: '', choices: []}, this.getUserTimezone()).create();

        return createDialogActionResponse(pollForm);

      case 'new_poll_on_change':

        return this.newPollOnChange();

      case 'close_poll_form':

        return this.closePollForm();

      case 'close_poll':

        return await this.closePoll();

      default:

        return createStatusActionResponse('Unknown action!', 'UNKNOWN');

    }

  }

  /**

   * Handle the custom start_poll action.

   *

   * @returns {object} Response to send back to Chat

   */

  async startPoll() {

    // Get the form values

    const formValues: PollFormInputs = this.event.common!.formInputs! as PollFormInputs;

    const config = getConfigFromInput(formValues);

    if (!config.topic || config.choices.length === 0) {

      // Incomplete form submitted, rerender

      const dialog = new NewPollFormCard(config, this.getUserTimezone()).create();

      return createDialogActionResponse(dialog);

    }

    if (config.closedTime) {

      // because previously we marked up the time with user timezone offset

      config.closedTime -= this.getUserTimezone()?.offset ?? 0;

    }

    const pollCardMessage = new PollCard({author: this.event.user, ...config}, this.getUserTimezone()).createMessage();

    const request = {

      parent: this.event.space?.name,

      requestBody: pollCardMessage,

    };

    const apiResponse = await callMessageApi('create', request);

    if (apiResponse.data?.name) {

      if (config.autoclose && config.closedTime) {

        const taskPayload: taskEvent = {'id': apiResponse.data.name, 'action': 'close_poll', 'type': 'TASK'};

        await createTask(JSON.stringify(taskPayload), config.closedTime);

      }

      return createStatusActionResponse('Poll started.', 'OK');

    } else {

      return createStatusActionResponse('Failed to start poll.', 'UNKNOWN');

    }

  }

  /**

   * Handle the custom vote action. Updates the state to record

   * the user's vote then rerenders the card.

   *

   * @returns {object} Response to send back to Chat

   */

  recordVote() {

    const parameters = this.event.common?.parameters;

    if (!(parameters?.['index'])) {

      throw new Error('Index Out of Bounds');

    }

    const choice = parseInt(parameters['index']);

    const userId = this.event.user?.name ?? '';

    const userName = this.event.user?.displayName ?? '';

    const voter: Voter = {uid: userId, name: userName};

    const state = this.getEventPollState();

    // Add or update the user's selected option

    state.votes = saveVotes(choice, voter, state.votes!, state.anon);

    const card = new PollCard(state, this.getUserTimezone());

    return {

      thread: this.event.message?.thread,

      actionResponse: {

        type: 'UPDATE_MESSAGE',

      },

      cardsV2: [card.createCardWithId()],

    };

  }

  /**

   * Opens and starts a dialog that allows users to add details about a contact.

   *

   * @returns {object} open a dialog.

   */

  addOptionForm() {

    const state = this.getEventPollState();

    const dialog = new AddOptionFormCard(state).create();

    return createDialogActionResponse(dialog);

  };

  /**

   * Handle add new option input to the poll state

   * the user's vote then rerenders the card.

   *

   * @returns {object} Response to send back to Chat

   */

  async saveOption(): Promise<chatV1.Schema$Message> {

    const userName = this.event.user?.displayName ?? '';

    const state = this.getEventPollState();

    const formValues = this.event.common?.formInputs;

    const optionValue = formValues?.['value']?.stringInputs?.value?.[0]?.trim() || '';

    addOptionToState(optionValue, state, userName);

    const cardMessage = new PollCard(state, this.getUserTimezone()).createMessage();

    const request = {

      name: this.event.message!.name,

      requestBody: cardMessage,

      updateMask: 'cardsV2',

    };

    const apiResponse = await callMessageApi('update', request);

    if (apiResponse.status === 200) {

      return createStatusActionResponse('Option is added', 'OK');

    } else {

      return createStatusActionResponse('Failed to add option.', 'UNKNOWN');

    }

  }

  getEventPollState(): PollState {

    const stateJson = getStateFromCard(this.event);

    if (!stateJson) {

      throw new ReferenceError('no valid state in the event');

    }

    return JSON.parse(stateJson);

  }

  async closePoll(): Promise<chatV1.Schema$Message> {

    const state = this.getEventPollState();

    state.closedTime = Date.now();

    state.closedBy = this.event.user?.displayName ?? '';

    const cardMessage = new PollCard(state, this.getUserTimezone()).createMessage();

    const request = {

      name: this.event.message!.name,

      requestBody: cardMessage,

      updateMask: 'cardsV2',

    };

    const apiResponse = await callMessageApi('update', request);

    if (apiResponse.status === 200) {

      return createStatusActionResponse('Poll is closed', 'OK');

    } else {

      return createStatusActionResponse('Failed to close poll.', 'UNKNOWN');

    }

  }

  closePollForm() {

    const state = this.getEventPollState();

    if (state.type === ClosableType.CLOSEABLE_BY_ANYONE || state.author!.name === this.event.user?.name) {

      return createDialogActionResponse(new ClosePollFormCard().create());

    }

    const dialogConfig: MessageDialogConfig = {

      title: 'Sorry, you can not close this poll',

      message: `The poll setting restricts the ability to close the poll to only the creator(${state.author!.displayName}).`,

      imageUrl: PROHIBITED_ICON_URL,

    };

    return createDialogActionResponse(new MessageDialogCard(dialogConfig).create());

  }

  newPollOnChange() {

    const formValues: PollFormInputs = this.event.common!.formInputs! as PollFormInputs;

    const config = getConfigFromInput(formValues);

    return createDialogActionResponse(new NewPollFormCard(config, this.getUserTimezone()).create());