import { server } from '../commons/server';
import { LOGOUT, AUTHENTICATED, WORKSPACE_CHANGE, WORKSPACE_CHANGING } from '../core/actions';
import { app } from '../core/app';
import SessionUtils from './session-utils';

/**
 * Initialize the session module by wiring the session to the app action dispatcher
 * @return {[type]} [description]
 */
export function initSession() {
    app.add(actionHandler);
}

function actionHandler(act, data) {
    if (act === AUTHENTICATED) {
        return data;
    }

    if (act === LOGOUT) {
        return { session: null };
    }

    if (act === WORKSPACE_CHANGE) {
        SessionUtils.gotoHome();
        return data;
    }

    return null;
}

/**
 * Check if user was already authenticated
 * @return {Boolean} True if user is already authenticated
 */
export function isAuthenticated() {
    const data = getSessionData();
    return data !== undefined && data !== null;
}

/**
 * Check if a given permission is allowed
 * @param  {string}  perm The permission code to check
 * @return {Boolean}      Return true if permission is granted
 */
export function hasPerm(perm) {
    const session = getSessionData();
    return session !== null && (session.administrator || session.permissions.indexOf(perm) >= 0);
}

/**
 * Perform a user logout in the system, forcing him to login again
 * @return {Promise} Promise that will be resolved when logout is finished
 */
export function logout() {
    const autk = app.getCookie('autk');

    // inform server to register logout of the authentication token
    if (autk) {
        // call server to register logout
        return server.get('/api/auth/logout?tk=' + autk).then(() => {
            // clear authentication token in the cookies
            app.setCookie('autk', null);

            // inform the system about the logout
            app.dispatch(LOGOUT);
        });
    }

    // return an empty promise if there is no logout information
    return new Promise(resolve => resolve(null));
}

/**
 * Request user session data to the server based on its authentication token.
 * A promise is returned and will return the result of the operation - In case the
 * authentication token is valid, it will return the session data, otherwise,
 * the promise will be rejected
 * @return {Promise} A promise containing the session data
 */
export function authenticate() {
    return server.post('/api/sys/session').then(res => {
        app.dispatch(AUTHENTICATED, { session: res });
        return res;
    });
}

export function changeWorkspace(wsid) {
    app.dispatch(WORKSPACE_CHANGING);

    return server.post('/api/sys/changews/' + wsid).then(res => {
        const authToken = res.authToken;
        app.setCookie('autk', authToken);
        const state = { session: res.session };
        app.setState(state);
        app.dispatch(WORKSPACE_CHANGE, state);
    });
}

/**
 * Return user session data stored by the application
 * @return {[type]} [description]
 */
function getSessionData() {
    return app.getState().session;
}