number-munchers/reducers/board/troggle.reducer.js

const Immutable = require('immutable');

import * as TroggleActions from '../../actions/board/troggle.actions';
import { SETTINGS } from '../../App';
const initial = [];

const reducer = (state = initial, action) => {
    if (action.type !== TroggleActions.TROGGLE_ACTION) {
        return state;
    }

    switch (action.action) {
        case TroggleActions.MOVE:
            // Randomize movement with boolean flags.
            const moveToAttack = Boolean(Math.round(Math.random()));
            const moveAlongXAxis = Boolean(Math.round(Math.random()));
            const moveInPositiveDirection = Boolean(Math.round(Math.random()));

            const x = state[action.index].x;
            const y = state[action.index].y;
            let newX = x;
            let newY = y;

            // DO NOT CONSOLIDATE. Attack first, ask questions later.
            if (moveAlongXAxis === true) {
                if (x === SETTINGS.GRID_WIDTH - 1 ||
                    (moveToAttack && x >= action.muncherX)) {
                    newX = x - 1;
                }
                else if (x === 0 ||
                    (moveToAttack && x < action.muncherX)) {
                    newX = x + 1;
                }
                else if (moveInPositiveDirection) {
                    newX = x + 1;
                }
                else if (!moveInPositiveDirection) {
                    newX = x - 1;
                }
            }
            else {
                if (y === SETTINGS.GRID_HEIGHT - 1 ||
                    (moveToAttack && y >= action.muncherY)) {
                    newY = y - 1;
                }
                else if (y === 0 ||
                    (moveToAttack && y < action.muncherY)) {
                    newY = y + 1;
                }
                else if (moveInPositiveDirection) {
                    newY = y + 1;
                }
                else if (!moveInPositiveDirection) {
                    newY = y - 1;
                }
            }

            return Immutable.fromJS(state)
                .setIn([action.index, 'x'], newX)
                .setIn([action.index, 'y'], newY)
                .toJS();

        case TroggleActions.CREATE:
            return Immutable.List(state).push({ x: 0, y: 0 }).toArray();
            break;
    }

    return state;
};

export default reducer;