async function checkAuth() {
    try {
        const user = await get("/api/auth/me");
        const userInfo = document.getElementById("user-info");
        if (userInfo) {
            userInfo.textContent = user.username;
        }
        const adminLink = document.getElementById("admin-link");
        if (adminLink && user.role === "admin") {
            adminLink.style.display = "inline";
        }
        return user;
    } catch (error) {
        window.location.href = "/login";
        return null;
    }
}

async function handleLogin(event) {
    event.preventDefault();
    const form = event.target;
    const errorMessage = document.getElementById("error-message");
    errorMessage.textContent = "";

    const username = form.username.value.trim();
    const password = form.password.value;

    try {
        await post("/api/auth/login", { username, password });
        window.location.href = "/goals";
    } catch (error) {
        errorMessage.textContent = error.message;
    }
}

async function handleRegister(event) {
    event.preventDefault();
    const form = event.target;
    const errorMessage = document.getElementById("error-message");
    errorMessage.textContent = "";

    const username = form.username.value.trim();
    const password = form.password.value;
    const confirmPassword = form["confirm-password"].value;

    if (password !== confirmPassword) {
        errorMessage.textContent = "Passwords do not match";
        return;
    }

    if (password.length < 6) {
        errorMessage.textContent = "Password must be at least 6 characters";
        return;
    }

    try {
        await post("/api/auth/register", { username, password });
        window.location.href = "/goals";
    } catch (error) {
        errorMessage.textContent = error.message;
    }
}

async function handleLogout() {
    try {
        await post("/api/auth/logout");
        window.location.href = "/login";
    } catch (error) {
        console.error("Logout failed:", error);
    }
}

document.addEventListener("DOMContentLoaded", () => {
    const loginForm = document.getElementById("login-form");
    if (loginForm) {
        loginForm.addEventListener("submit", handleLogin);
    }

    const registerForm = document.getElementById("register-form");
    if (registerForm) {
        registerForm.addEventListener("submit", handleRegister);
    }

    const logoutBtn = document.getElementById("logout-btn");
    if (logoutBtn) {
        logoutBtn.addEventListener("click", handleLogout);
    }

    if (!document.body.classList.contains("auth-page")) {
        checkAuth();
    }
});