// @flow
import type {Action, State, Config} from '../types';
import updateVariables from '../rule-engine/apply-instructions';

const variables = (config: Config) => (_state: State, action: Action): State => {
  const state: State = _state.variables ? _state : {..._state, variables: {}};
  switch (action.type) {
    case 'answer':
    case 'move': {
      const {instructions} = action.payload;
      if (!instructions) return state;
      return updateVariables(instructions)(state);
    }
    default: {
      return state;
    }
  }
};

export default variables;