import * as storage from 'redux-storage'

// Import redux and all your reducers as usual
import { createStore, applyMiddleware, combineReducers } from 'redux';
import * as reducers from './reducers';

// We need to wrap the base reducer, as this is the place where the loaded
// state will be injected.
//
// Note: The reducer does nothing special! It just listens for the LOAD
//       action and merge in the provided state :)
// Note: A custom merger function can be passed as second argument
const reducer = storage.reducer(combineReducers(reducers));

// Now it's time to decide which storage engine should be used
//
// Note: The arguments to `createEngine` are different for every engine!
import createEngine from 'redux-storage-engine-localstorage';
const engine = createEngine('my-save-key');

// And with the engine we can create our middleware function. The middleware
// is responsible for calling `engine.save` with the current state afer
// every dispatched action.
//
// Note: You can provide a list of action types as second argument, those
//       actions will be filtered and WON'T trigger calls to `engine.save`!
const middleware = storage.createMiddleware(engine);

// As everything is prepared, we can go ahead and combine all parts as usual
const createStoreWithMiddleware = applyMiddleware(middleware)(createStore);
const store = createStoreWithMiddleware(reducer);

// At this stage the whole system is in place and every action will trigger
// a save operation.
//
// BUT (!) an existing old state HAS NOT been restored yet! It's up to you to
// decide when this should happen. Most of the times you can/should do this
// right after the store object has been created.

// To load the previous state we create a loader function with our prepared
// engine. The result is a function that can be used on any store object you
// have at hand :)
const load = storage.createLoader(engine);
load(store);

// Notice that our load function will return a promise that can also be used
// to respond to the restore event.
load(store)
    .then((newState) => console.log('Loaded state:', newState))
    .catch(() => console.log('Failed to load previous state'));

import { LOAD, SAVE } from 'redux-storage';

function storageAwareReducer(state = { loaded: false }, action) {
    switch (action.type) {
        case LOAD:
            return { ...state, loaded: true };

        case SAVE:
            console.log('Something has changed and written to disk!');

        default:
            return state;
    }
}

import { createMiddleware } from 'redux-storage'

import { APP_START } from './constants';

const middleware = createMiddleware(engine, [ APP_START ]);

import { createMiddleware } from 'redux-storage'

import { SHOULD_SAVE } from './constants';

const middleware = createMiddleware(engine, [], [ SHOULD_SAVE ]);