const accessToken = localStorage.getItem('accessToken');

async function isAccessTokenOkay() {
    try {
        const response = await fetch('/auth/check_access_token', {
            method: 'GET',
            headers: {
                'Authorization': `Bearer ${accessToken}`,
            }
        });

        if (response.status === 200) return true;
        if (response.status === 401) return false;

        console.error('Error: server sent unexpected HTTP status code', response.status);
        return false;
    } catch (err) {
        console.error('Network or server error:', err);
        return false;
    }
}

(async () => {
    if (!accessToken) return;

    const valid = await isAccessTokenOkay();
    if (valid && window.location.pathname === '/web/login') {
        window.location.href = '/web/libraries';
    }

    if (!valid) {
        window.location.href = '/web/login';
    }
})();

//used in /web/login, not a general purpose function
async function getAccessToken() {
    const username = document.getElementById('username').value;
    const password = document.getElementById('password').value;

    try {
        const response = await fetch('/auth/user_and_pass', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
            },
            body: JSON.stringify({ username, password })
        });

        if (response.status === 200) {
            const data = await response.json();
            const accessToken = data.AccessToken;

            if (!accessToken) {
                alert('Login failed: no token returned');
                return;
            }

            localStorage.setItem('accessToken', accessToken);
            window.location.href = '/web/libraries';
        } else if (response.status === 401) {
            alert('Invalid username or password');
        } else {
            alert('Server error, please try again later.');
        }
    } catch (err) {
        alert('Network error, please try again later.');
    }
}