Marko
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Homework.10


			
				
					
						
						
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							<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>A-Level</title>
</head>
<body>
    <div id="assortment"></div>
<select id="fruits">
    <option value="apples">apples</option>
    <option value="oranges">oranges</option>
    <option value="bananas">bananas</option>
</select>
<input type="number" id="quantity" placeholder="quantity of goods">
<input type="number" id="cash" placeholder="give me your cash">
<button id="btn">Buy</button>

<script>
    function fruitBuyer(state, {type, whatFruits, howMany, cash}){ 
    if (!state){ 
        return {
            
            apples: {
                quantity: 100,
                price: 15
            },

            oranges: {
                quantity: 100,
                price: 25
            },

            bananas:{
                quantity: 100,
                price: 20
            },
            cashBox: 0
        }
    }
    if (type === 'buy'){  
        return {
            ...state, 
            [whatFruits]: {
                quantity: ((state[whatFruits].quantity - howMany) < 0 || cash < state[whatFruits].price ) ? state[whatFruits].quantity  : state[whatFruits].quantity - howMany,
                price: state[whatFruits].price
            },
                cashBox:  ((state[whatFruits].quantity - howMany) < 0 || cash < state[whatFruits].price ) ? state.cashBox : (cash * howMany) + state.cashBox
            
        }
    }
    return state 

}

function createStore(reducer){
    let state       = reducer(undefined, {})
    let cbs         = []                     
    
    const getState  = () => state            
    const subscribe = cb => (cbs.push(cb),   
                             () => cbs = cbs.filter(c => c !== cb)) 
    const dispatch  = action => { 
    const newState = reducer(state, action) 
        if (newState !== state){ 
            state = newState  
            for (let cb of cbs)  cb() 
        }
    }
    
    return {
        getState, 
        dispatch,
        subscribe 
    }
}
const store = createStore(fruitBuyer);
store.subscribe(() => assortment.innerHTML = JSON.stringify(store.getState()));
const buyFruits = (whatFruits, howMany, cash) => ({type: 'buy', whatFruits:`${whatFruits}`, howMany, cash});
btn.addEventListener('click', () =>{
    const whatFruits = fruits.value;
    const howMany = quantity.value;
    const cashValue = cash.value
    store.dispatch(buyFruits(whatFruits, howMany, cashValue))
})
store.dispatch(buyFruits('apples',0, 0));

</script>
</body>
</html>