import { call, select, take, takeEvery } from 'redux-saga/effects';

import { drizzle } from '../../index';
import { orbitSagaPut } from '../../utils/orbitUtils';
import { DRIZZLE_UTILS_SAGA_INITIALIZED } from '../actions/drizzleUtilsActions';
import { CONTRACT_EVENT_FIRED } from './eventSaga';
import { getCurrentAccount } from './drizzleUtilsSaga';

const transactionsHistory = Object.create(null);

function* initTransaction(action) {
  const account = yield call(getCurrentAccount);
  const dataKey = drizzle.contracts[action.transactionDescriptor.contract]
    .methods[action.transactionDescriptor.method].cacheSend(
    ...action.transactionDescriptor.params, { from: account }
  );
  transactionsHistory[dataKey] = action;
  transactionsHistory[dataKey].state = 'initialized';
}

function* handleEvent(action) {
  const transactionStack = yield select(state => state.transactionStack);
  const dataKey = transactionStack.indexOf(action.event.transactionHash);
  switch (action.event.event) {
    case 'TopicCreated':
      if (dataKey !== -1
          && transactionsHistory[dataKey]
          && transactionsHistory[dataKey].state === 'initialized') {
        transactionsHistory[dataKey].state = 'success';
        // Gets orbit
        const orbit = yield select(state => state.orbit);
        // And saves the topic
        yield call(orbitSagaPut, orbit.topicsDB,
          action.event.returnValues.topicID,
          {
            subject: transactionsHistory[dataKey].userInputs.topicSubject
          });
        yield call(orbitSagaPut, orbit.postsDB,
          action.event.returnValues.postID,
          {
            subject: transactionsHistory[dataKey].userInputs.topicSubject,
            content: transactionsHistory[dataKey].userInputs.topicMessage
          });
      }
      break;
    case 'PostCreated':
      if (dataKey !== -1
          && transactionsHistory[dataKey]
          && transactionsHistory[dataKey].state === 'initialized') {
        transactionsHistory[dataKey].state = 'success';
        // Gets orbit
        const orbit = yield select(state => state.orbit);
        // And saves the topic
        yield call(orbitSagaPut, orbit.postsDB,
          action.event.returnValues.postID,
          {
            subject: transactionsHistory[dataKey].userInputs.postSubject,
            content: transactionsHistory[dataKey].userInputs.postMessage
          });
      }
      break;
    default:
      // Nothing to do here
  }
}

function* handleError() {
  const transactionStack = yield select(state => state.transactionStack);
  transactionStack.forEach((transaction, index) => {
    if (transaction.startsWith('TEMP_')) {
      transactionsHistory[index].state = 'error';
    }
  });
}

function* transactionsSaga() {
  yield take(DRIZZLE_UTILS_SAGA_INITIALIZED);
  yield takeEvery('INIT_TRANSACTION', initTransaction);
  yield takeEvery(CONTRACT_EVENT_FIRED, handleEvent);
  yield takeEvery('TX_ERROR', handleError);
}

export default transactionsSaga;