index.js

const redux = require("redux")
const reduxLogger = require("redux-logger")

const createStore = redux.createStore
const combineReducers = redux.combineReducers
const applyMiddleware = redux.applyMiddleware
const logger = reduxLogger.createLogger()

const BUY_CAKE = "BUY_CAKE" 
const BUY_ICECREAM = "BUY ICECREAM"

function buyCake() {
    return {
        type: BUY_CAKE,
    }
}

function buyIceCream() {
    return {
        type: BUY_ICECREAM,
    }
}

// const initalState = {
//     numOfCakes: 10,
//     numOfIceCreams: 20
// }

const initalCakeState = {
    numOfCakes: 10,
}

const initalIceCreamState = {
    numOfCakes: 20,
}

// const reducer = (state = initalState, action) => {
//     switch(action.type) {
//         case BUY_CAKE: return {
//             ...state,
//             numOfCakes: state.numOfCakes - 1
//         }
//         case BUY_ICECREAM: return {
//             ...state,
//             numOfIceCreams: state.numOfIceCreams - 1
//         }

//         default: return state
//     }
// }

const cakeReducer = (state = initalCakeState, action) => {
    switch(action.type) {
        case BUY_CAKE: return {
            ...state,
            numOfCakes: state.numOfCakes - 1
        }

        default: return state
    }
}

const iceCreamReducer = (state = initalIceCreamState, action) => {
    switch(action.type) {
        case BUY_ICECREAM: return {
            ...state,
            numOfIceCreams: state.numOfIceCreams - 1
        }

        default: return state
    }
}

const rootReducer = combineReducers({
    cake: cakeReducer,
    iceCream: iceCreamReducer
})

const store =  createStore(rootReducer, applyMiddleware(logger))
console.log("Inital state", store.getState())
const unsubscribe = store.subscribe(() => {})
store.dispatch(buyCake())
store.dispatch(buyCake())
store.dispatch(buyIceCream())
store.dispatch(buyIceCream())
unsubscribe()