MyCrypto/common/reducers/swap.js

import {
  SWAP_DESTINATION_AMOUNT,
  SWAP_DESTINATION_KIND,
  SWAP_ORIGIN_AMOUNT,
  SWAP_ORIGIN_KIND,
  SWAP_UPDATE_BITY_RATES
} from 'actions/swap';

export const ALL_CRYPTO_KIND_OPTIONS = ['BTC', 'ETH', 'REP'];

const initialState = {
  originAmount: 0,
  destinationAmount: 0,
  originKind: 'BTC',
  destinationKind: 'ETH',
  destinationKindOptions: ALL_CRYPTO_KIND_OPTIONS.filter(
    element => element !== 'BTC'
  ),
  originKindOptions: ALL_CRYPTO_KIND_OPTIONS.filter(
    element => element !== 'REP'
  ),
  bityRates: {}
};

export function swap(state = initialState, action) {
  switch (action.type) {
    case SWAP_ORIGIN_KIND: {
      return {
        ...state,
        originKind: action.value,
        destinationKind: action.value === state.destinationKind
          ? ALL_CRYPTO_KIND_OPTIONS.filter(
              element => element !== action.value
            )[0]
          : state.destinationKind,
        destinationKindOptions: ALL_CRYPTO_KIND_OPTIONS.filter(
          element => element !== action.value
        )
      };
    }
    case SWAP_DESTINATION_KIND: {
      return {
        ...state,
        destinationKind: action.value
      };
    }
    case SWAP_ORIGIN_AMOUNT:
      return {
        ...state,
        originAmount: action.value
      };
    case SWAP_DESTINATION_AMOUNT:
      return {
        ...state,
        destinationAmount: action.value
      };
    case SWAP_UPDATE_BITY_RATES:
      return {
        ...state,
        bityRates: {
          ...state.bityRates,
          ...action.value
        }
      };
    default:
      return state;
  }
}