(function() {
    const SSO_IFRAME_URL = 'https://sso.erickson.it/account/bc/status.php';
    const SSO_ORIGIN = 'https://sso.erickson.it';
    const SSO_IS_LOGGED_STORAGE_KEY = "sso_is_logged";
    const SSO_STATE_KEY = "sso_state_key";
    const SSO_CHECK_URL = 'https://sso.erickson.it/account/bc/check.php';

    let statusChangeCallback = null;
    let loginCallback = null;
    let logoutCallback = null;

    window.SSOManager = {
        initialStatusCheck: 1,
        init: function() {
            if (document.readyState === 'loading') {
                document.addEventListener('DOMContentLoaded', createSsoIframe);
            } else {
                createSsoIframe();
            }

            if (this.initialStatusCheck == 2) {
                checkByRedirect();
            }
        },
        onLogin: function(callback) {
            if (typeof callback === 'function') {
                loginCallback = callback;
            }
        },
        onLogout: function(callback) {
            if (typeof callback === 'function') {
                logoutCallback = callback;
            }
        },
    };

    function createSsoIframe() {
        const iframe = document.createElement('iframe');
        iframe.style.display = 'none';
        const parentOrigin = window.location.origin;
        iframe.src = `${SSO_IFRAME_URL}?parentOrigin=${encodeURIComponent(parentOrigin)}&initialStatusCheck=${SSOManager.initialStatusCheck}`;
        iframe.title = 'SSO Status Checker';
        document.body.appendChild(iframe);
    }

    window.addEventListener('message', function(event) {
        if (event.origin !== SSO_ORIGIN) {
            return; // Ignora messaggi da origini sconosciute
        }

        if (!event.data){
            return;
        }

        if (typeof event.data.idLogged !== 'undefined') {
            if (typeof statusChangeCallback === 'function') {
                statusChangeCallback(event.data);
            }

            const isLogged = event.data.idLogged;
            sendLocalEvent(isLogged);    
        } else if (typeof event.data.action !== 'undefined') {
            const action = event.data.action;
            if (action == "checkByRedirect"){
                checkByRedirect();
            }
        }
    });

    function sendLocalEvent(isLogged){
        sessionStorage.setItem(SSO_IS_LOGGED_STORAGE_KEY, isLogged);

        if (isLogged) {
            if (typeof loginCallback === 'function') {
                loginCallback();
            }
        } else {
            if (typeof logoutCallback === 'function') {
                logoutCallback();
            }
        }
    }

    function checkByRedirect() {
        if (handleRedirectResponse()) {
            return;
        }

        if (isInSessionStorage()) {
            return;
        }

        let state = sessionStorage.getItem(SSO_STATE_KEY);
        if (typeof state == 'undefined' || state == null) {
            state = Math.random().toString(36).substring(2, 15);
            sessionStorage.setItem(SSO_STATE_KEY, state);
        } else {
            sessionStorage.removeItem(SSO_STATE_KEY);
            return;
        }
        
        const currentUrl = window.location.href;
        const currentUrlWithState = `${currentUrl}${currentUrl.includes('?') ? '&' : '?'}state=${encodeURIComponent(state)}`;

        let redirectUrl = `${SSO_CHECK_URL}?redirectTo=${encodeURIComponent(currentUrlWithState)}`;
        window.location.replace(redirectUrl);
    }

    function isInSessionStorage() {
        resetSessionstorage();

        const isLogged = sessionStorage.getItem(SSO_IS_LOGGED_STORAGE_KEY);
        if (typeof isLogged == 'undefined' || isLogged == null) {
            return false;
        }

        sendLocalEvent(isLogged === 'true');

        return true;
    }

    function resetSessionstorage(){
        const referrer = document.referrer;
        const currentOrigin = window.location.origin;

        let shouldReset = false;

        if (!referrer) {
            shouldReset = true;
        } else {
            try {
                const referrerUrl = new URL(referrer);
                if (referrerUrl.origin !== currentOrigin) {
                    shouldReset = true;
                    console.log(`Referrer da origine diversa (${referrerUrl.origin}). Resetto.`);
                } else {
                    console.log(`Referrer dalla stessa origine (${referrerUrl.origin}). Non resetto.`);
                }
            } catch (e) {
                shouldReset = true; // Considera un'entrata esterna in caso di dubbio
                console.log("Errore nell'analisi del referrer. Presunto accesso esterno. Resetto.");
            }
        }

        if (shouldReset) {
            sessionStorage.removeItem(SSO_IS_LOGGED_STORAGE_KEY);
        }
    }

    function handleRedirectResponse() {
        const urlParams = new URLSearchParams(window.location.search);
        const ssoIsLogged = urlParams.get('SsoIsLogged');

        if (ssoIsLogged === null) {
            return false;
        }

        const cleanUrlSearchParams = new URLSearchParams(window.location.search);
        cleanUrlSearchParams.delete('SsoIsLogged');
        const cleanSearch = cleanUrlSearchParams.toString();
        const cleanUrl = window.location.pathname + (cleanSearch ? '?' + cleanSearch : '') + window.location.hash;

        try {
            window.history.replaceState({}, document.title, cleanUrl);
        } catch (e) {
            
        }

        sendLocalEvent(ssoIsLogged === "1");
        return true;
    }

})(); // Fine IIFE