script.js

const userName = localStorage.getItem("username");
const target = parseInt(localStorage.getItem("target"));
const submitButton = document.getElementById("submit-button");
const resetButton = document.getElementById('reset');
let answer = document.getElementById('answer');
let needed = 0;

if (!userName) {
    window.location.href = "index.html";
} else {
    document.getElementById("first-name").textContent = `${userName}'s homepage`;
}

document.getElementById('calculator').addEventListener("submit", (e) => {
    e.preventDefault();

    const carbs = parseInt(document.getElementById('carbs').value);
    const currentBs = parseInt(document.getElementById('insulin').value);

    if (currentBs <= 70) {
        answer.style.color = "red";
        answer.textContent = "Blood sugar is too low- do not take any insulin";
        return;
    } else if (currentBs <= 90) {
        answer.style.color = "yellow";
    } else {
        answer.style.color = "#43cea2";
    }

    let insulinForCarbs = 0;
    if (carbs >= 10 || currentBs > target) {
        insulinForCarbs = Math.floor(carbs / document.getElementById('ratio').value); // 1 unit per 14g
    }
    let correction = (currentBs - target) / 50;

    if (correction < 0) correction = 0;

    let totalInsulin = Math.round((insulinForCarbs + correction) * 2) / 2;
    if (currentBs < target) {
        needed = Math.floor((target - currentBs) / 50);
        totalInsulin -= needed;
    }

    answer.textContent = `${totalInsulin} is the correct amount`;
});

resetButton.addEventListener('click', () => {
    localStorage.removeItem("username");
    localStorage.removeItem("target");
    location.reload();
})