dyaskur / google-chat-poll

import BaseHandler from './BaseHandler';

import NewPollFormCard from '../cards/NewPollFormCard';

import {addOptionToState} from '../helpers/option';

import {callMessageApi} from '../helpers/api';

import {createDialogActionResponse, createStatusActionResponse} from '../helpers/response';

import PollCard from '../cards/PollCard';

import {PollState, Voter, Votes} from '../helpers/interfaces';

import AddOptionFormCard from '../cards/AddOptionFormCard';

import {saveVotes} from '../helpers/vote';

import {MAX_NUM_OF_OPTIONS} from '../config/default';

/*

This list methods are used in the poll chat message

 */

interface PollAction {

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

  getEventPollState(): PollState;

}

export default class ActionHandler extends BaseHandler implements PollAction {

  constructor(event: chatV1.Schema$DeprecatedEvent) {

    super(event);

  }

  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':

        return {

          actionResponse: {

            type: 'DIALOG',

            dialogAction: {

              dialog: {

                body: new NewPollFormCard({topic: '', choices: []}).create(),

              },

            },

          },

        };

      default:

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

    }

  }

  }

  /**

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

   * the user's vote then rerenders the card.

   *

   * @param {object} event - chat event

   * @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 = JSON.parse(parameters['state']);

    // Add or update the user's selected option

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

    const card = new PollCard(state);

    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.

   *

   * @param {object} event the event object from Google Chat.

   *

   * @returns {object} open a dialog.

   */

  addOptionForm() {

    const card = this.event.message!.cardsV2?.[0]?.card;

    // @ts-ignore: because too long

    const stateJson = (card.sections[0].widgets[0].decoratedText?.button?.onClick?.action?.parameters[0].value || card.sections[1].widgets[0].decoratedText?.button?.onClick?.action?.parameters[0].value) ?? '';

    const state = JSON.parse(stateJson);

    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).createMessage();

    const request = {

      name: this.event.message!.name,

      requestBody: cardMessage,

      updateMask: 'cardsV2',

    };

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

    if (apiResponse) {

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

    } else {

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

    }

  }

  getEventPollState(): PollState {

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

    const state = parameters?.['state'];

    if (!state) {

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

    }

    return JSON.parse(state);

  }

}