const calculateButton = document.getElementById("calculate");
const first = document.getElementById("first");
const second = document.getElementById("second");
const select = document.getElementById("operation");
const result = document.getElementById("result");

calculateButton.onclick = function() {
    calculate();
};

function calculate() {
    switch (parseInt(select.value)) {
        case 1:
            doSmth("plus")
            break;
        case 2:
            doSmth("minus")
            break;
        case 3:
            doSmth("mult")
            break;
        case 4:
            doSmth("div")
            break;
    };
}

function checkNum(res) {
    if (res.indexOf(".") != -1) 
        return parseInt(res)
    else
        return res
}

function doSmth(address) {
    fetch(`http://localhost:8080/${address}?first=${first.value}&second=${second.value}`)
        .then(response => response.text())
        .then(res => result.innerHTML = checkNum(res));
}