let form = document.getElementById("form");
let info = document.getElementById("res");


form.onsubmit = async (e) => {
  e.preventDefault();

  if(form.num1.value === "") return;
  if(form.num2.value === "") return;

  let index = form.selected.selectedIndex;
  let indexType = form.type.selectedIndex;

  let op = form.selected.options[index].textContent;
  let type = form.type.options[indexType].textContent;
  let res = "";

    function calc() {
      switch(op) {
        case "+":
          return "sum";
          break;

        case "-":
          return "diff";
          break;

        case "*":
            return "mul";
            break;

        case "/":
          return "div";
          break;
      }
  }

  function typeOfCalc() {
    switch(type) {
        case "Int":
        return "int";
        break;

        case "String":
        return "string";
        break;

        case "FloatArray":
        return "floatArray";
        break;
    }
  }

  if (form.num2.value == 0 && calc(op) == "divide") return;
  res = await fetch(`http://localhost:8080/${calc()}?num1=${form.num1.value}&num2=${form.num2.value}&operationType=${typeOfCalc()}`)
  res = await res.text();

  info.textContent = res;
}