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 op = form.selected.options[index].textContent;
    let res = "";
  
    function chooseOperation(oper){
      switch(oper){
        case "+":
          return "sum"
        case "-":
          return "diff"
        case "*":
          return "mul"
        case "/":
          return "div"
        case "%":
          return "ost"
        case "con":
          return "con"
      }
    }

    let operstor = chooseOperation(op)
    if(form.num2.value == 0) return;
    res = await fetch(`http://localhost:8080/${operstor}?num1=${form.num1.value}&num2=${form.num2.value}`)
    res = await res.text();
    
    // switch(op) {
    //   case "+":
    //     res = await fetch(`http://localhost:8080/sum?num1=${form.num1.value}&num2=${form.num2.value}`)
    //     res = await res.text();
    //     break;
    //   case "-":
    //     res = await fetch(`http://localhost:8080/diff?num1=${form.num1.value}&num2=${form.num2.value}`)
    //     res = await res.text();
    //     break;
  
    //   case "*":
    //       res = await fetch(`http://localhost:8080/mul?num1=${form.num1.value}&num2=${form.num2.value}`)
    //       res = await res.text();
    //       break;
          
    //   case "/":
    //       if(form.num2.value == 0) return;
    //       res = await fetch(`http://localhost:8080/div?num1=${form.num1.value}&num2=${form.num2.value}`)
    //       res = await res.text();
    //       break;

    //   case "%":
    //       if(form.num2.value == 0) return;
    //       res = await fetch(`http://localhost:8080/ost?num1=${form.num1.value}&num2=${form.num2.value}`)
    //       res = await res.text();
    //       break;

    //   case "con":
    //       res = await fetch(`http://localhost:8080/con?num1=${form.num1.value}&num2=${form.num2.value}`)
    //       res = await res.text();
    //       break;
    // }
  
    form.res.value = res;
  }