// UKNova Cookie/AJAX authentication

// Send entered username/password to server using an XMLHTTPRequest. If they
// are OK, will receive a time-limited authentication cookie to set for future
// requests.

var login_usepermanentcookie= true;

function login_bind() {
    var form= document.getElementById('login');
    if (!form) return;

    // Check we can actually use cookies/ajax - no point in making a form
    // the user can't do anything with. Also check whether a permanent cookie
    // can be used - usually yes, if IE is set to block-but-allow-session-cookies
    // we have to use session cookies - it doesn't auto-degrade them because
    // it's a bit stupid like that.
    //
    var test= Math.floor(Math.random()*10000);
    document.cookie= 'test='+test;
    if (document.cookie.indexOf('test='+test)==-1) return;
    test= Math.floor(Math.random()*10000);
    document.cookie= 'test='+test+';expires=Thu, 01-Jan-2030 00:00:00 GMT';
    if (document.cookie.indexOf('test='+test)==-1) login_usepermanentcookie= false;
    document.cookie= 'test=delete;expires=Sat, 01-Jan-2000 00:00:00 GMT';
    if (xmlhttp_make()==null) return;

    // Add controls to login form
    //
    var table= form.getElementsByTagName('table')[0];
    var usernameinput= document.createElement('input');
    var passwordinput= document.createElement('input');
    var usernamelabel= document.createElement('label');
    var passwordlabel= document.createElement('label');
    var submitbutton= document.createElement('input');
    usernameinput.type= 'text';
    passwordinput.type= 'password';
    submitbutton.type= 'submit';
    submitbutton.value= 'Login';
    submitbutton.className= 'default';
    submitbutton.id= 'login-submit-button';
    usernamelabel.htmlFor=usernameinput.id= 'login-username-field';
    passwordlabel.htmlFor=passwordinput.id= 'login-password-field';
    usernamelabel.appendChild(document.createTextNode('Username'));
    passwordlabel.appendChild(document.createTextNode('Password'));

    document.getElementById('login-username-label').appendChild(usernamelabel);
    document.getElementById('login-password-label').appendChild(passwordlabel);
    document.getElementById('login-username').appendChild(usernameinput);
    document.getElementById('login-password').appendChild(passwordinput);
    document.getElementById('login-submit').appendChild(submitbutton);
    form.onsubmit= login_submit;
    if (!document.getElementById('drop-login'))
        usernameinput.focus();
}


function login_submit() {
    var username=  document.getElementById('login-username-field').value;
    var password= document.getElementById('login-password-field').value;
    if (username=='' || password=='') {
        alert('You must enter a user name and password');
        return false;
    }
    if (!login_isascii(username) || !login_isascii(password)) {
        alert('User name and password must contain only standard ASCII (English) characters');
        return false;
    }
    new AuthRequest().send(username, password);
    return false;
}


js_class('AuthRequest', 'AsyncRequest', function() {
    this.send= function(username, password) {
        document.getElementById('login-submit-button').disabled= true;
        this.setstatus('Connecting...');
        var pars= Object();
        pars.username= username;
        pars.password= password;
        this.open(true, '/wsgi/auth', pars, 10000); // timeout after 10s
    };
    this.oncancel= function() {
        this.setstatus('Connection failed');
        document.getElementById('login-submit-button').disabled= false;
    };
    this.oncomplete= function(results) {
        if (!results.ok) {
            this.setstatus(results.error);
            document.getElementById('login-submit-button').disabled= false;
        } else {
            this.setstatus('Logging in...');
            var cookie= 'auth='+results.cookie+';path=/';
            if (login_usepermanentcookie)
                cookie+= ';expires='+results.expires;
            document.cookie= cookie;
            location.reload();
        }
    };
    this.setstatus= function(status) {
        var td= document.getElementById('login-status');
        dom_emptyNode(td);
        td.appendChild(document.createTextNode(status));
    };
})


function login_isascii(s) {
  for (var i= s.length; i-->0;) {
    var c= s.charCodeAt(i);
    if (c<32 || c>=127) return false;
  }
  return true;
}

login_bind();