/* only run JS code when all DOM & content is loaded */
window.onload = function() {

    var agent = navigator.userAgent;
    var domain = window.location.hostname;
    var page = window.location.pathname;
    var timezone = Intl.DateTimeFormat().resolvedOptions().timeZone;
    var scrollPercentage = 0;
    var sessionId = sessionSet();
    var browserId = browserSet();
    var referrer = document.referrer;

    if (referrer === '') {
        referrer = 'direct';
    } 
    
    function isPageRefreshed() {
        return performance.navigation.type === 1;
    }

    /* get source of user i.e ppc */
    var queryString = window.location.search;
    var urlParams = new URLSearchParams(queryString);
    var squidSource = urlParams.get('squid_source');
    if(squidSource) {
        localStorage.setItem('squid_source', squidSource);
    } else {
        squidSource = localStorage.getItem('squid_source') ?? 'none';
    }
    var sources = JSON.parse(localStorage.getItem('squid_sources')) ?? [];
    if(urlParams.has('squid_source')) {
        squidSource = urlParams.get('squid_source');
        if(!sources.includes(squidSource)) {
            sources.push(squidSource);
            localStorage.setItem('squid_sources', JSON.stringify(sources));
        }
    }
    
    /* get email campaign if exists */
    var squidEmail = urlParams.get('squid_email');
    if(squidEmail) {
        localStorage.setItem('squid_email', squidEmail);
    } else {
        squidEmail = localStorage.getItem('squid_email') ?? null;
    }
    
    /* generate IDs */
    function randomString(length) {
        var chars = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
        var result = '';
        for (var i = length; i > 0; --i) result += chars[Math.floor(Math.random() * chars.length)];
        return result;
    }

    /* fetch or set sessionId */
    function sessionSet() {
        var sessionId = localStorage.getItem('session_id');
        if(!sessionId) {
            sessionId = randomString(24);
            var fetchPromise = fetch("https://icnsquid.work/api/checksessionid/"+sessionId);
            fetchPromise.then(response => {
                return response.json();
            }).then(res => {
                if(!res.OK) {
                    sessionId = res.session_id;
                } 
            });
            localStorage.setItem('session_id', sessionId);
        }
        return sessionId;
    }

    /* fetch or set browserId */
    function browserSet() {
        var browserId = localStorage.getItem('browser_id');
        if(!browserId) {
            browserId = randomString(24);
            var fetchPromise = fetch("https://icnsquid.work/api/checkbrowserid/"+browserId);
            fetchPromise.then(response => {
                return response.json();
            }).then(res => {
                if(!res.OK) {
                    browserId = res.browser_id;
                } 
            });
            localStorage.setItem('browser_id', browserId);
        }
        return browserId;
    }

    /* page views */
    function pageView() {
        setLatestEvent();
        if (!isPageRefreshed()) {
            uniqueData = {
                category: 'page_view'
            }
            sendData(uniqueData);
        } 
    }

    /* Track link clicks */
    var links = document.getElementsByTagName("a");
    for(var link of links) {
        link.addEventListener("click", function (e) {
            setLatestEvent();

            sendData({
                category: 'link',
                link: e.target.href,
            });
        });
    }

    /* Track button clicks */
    var buttons = document.getElementsByTagName("button");
    for(var button of buttons) {
        button.addEventListener("click", function (e) {
            setLatestEvent();

            sendData({
                category: 'button',
                button_text: e.target.innerText,
            });
        });
    }

    // Track Senso iframe Forms [!!] Doesn't work because of Cross-origin restrictions imposed by the external host of the source
    // var iframes = document.getElementsByTagName("iframe");
    // for(var iframe of iframes) {
        
    //     // Get the document object of the iframe
    //     var iframeDocument = iframe.contentDocument || iframe.contentWindow.document;
        
    //     // Find all form elements within the iframe document
    //     var formElements = iframeDocument.getElementsByTagName("form");
        
        
    //     // Add event listener for all iframe forms
    //     for(var ifrForm of formElements) {
    //         ifrForm.addEventListener("submit", function (e) {
    //             setLatestEvent();
    //             e.preventDefault();
    //             getFormData(e.target);
    //         });
    //     }
    // }

    /* track form submits */
    var forms = document.getElementsByTagName("form");
    for(var form of forms) {
        form.addEventListener("submit", function (e) {
            setLatestEvent();
            e.preventDefault();
            getFormData(e.target);
        });
    }
    
    /* get form fill data */
    function getFormData(form) {
        var formName = form.id;
        var formData = {};
        Object.assign(formData, {form_class: formName});

        var inputs = form.getElementsByTagName('INPUT');
        var textAreas = form.getElementsByTagName('TEXTAREA');

        for(var input of inputs) {  
            var labels = input.labels;
            for(var label of Object.keys(labels || {})) {
                var labelName = labels[label].textContent;
                formData[labelName] = input.value;
            }
        }
        for(var textArea of textAreas) {
            var labels = textArea.labels;
            for(var label of Object.keys(labels || {})) {
                var labelName = labels[label].textContent;
                formData[labelName] = textArea.value;
            }
        }

        sendData({
            category: 'form',
            form: formData,
        });
    }

    /**  
     * track page scrolls
     * get current browser viewpane heigtht
     */
    function getWindowHeight() {
        return window.innerHeight || 
            document.documentElement.clientHeight ||
            document.body.clientHeight || 0;
    }

    /**
     * get current absolute window scroll position
     */
    function getWindowYScroll() {
        return window.pageYOffset || 
            document.body.scrollTop ||
            document.documentElement.scrollTop || 0;
    }

    /**
     * get current absolute document height
     */
    function getDocHeight() {
        return Math.max(
            document.body.scrollHeight || 0, 
            document.documentElement.scrollHeight || 0,
            document.body.offsetHeight || 0, 
            document.documentElement.offsetHeight || 0,
            document.body.clientHeight || 0, 
            document.documentElement.clientHeight || 0
        );
    }

    /**
     * get current vertical scroll percentage
     */
    function getScrollPercentage() {
        return (
            (getWindowYScroll() + getWindowHeight()) / getDocHeight()
        ) * 100;
    }

    var throttledListener = throttle(scrollListener, 25);
    window.addEventListener('scroll', throttledListener, {passive: true});
    function throttle(func, delay) { // allows [func] to run once every [delay] ms
        var func = func.bind(func),
            last = Date.now();
        return function() {
            if (Date.now() - last > delay) {
                func();
                last = Date.now();
            }
        }
    }
    function scrollListener() {
        if(scrollPercentage < Math.round(getScrollPercentage())) {

            scrollPercentage = Math.round(getScrollPercentage());
            var threshold = document.body.clientHeight * 0.6;

            if (window.pageYOffset >= threshold) {      
                window.removeEventListener('scroll', throttledListener);
            }

            sendData({
                category: 'scroll',
                scroll_percentage: scrollPercentage,
            });
        }
    }

    /* track video */
    var timer = null;
    var totalTime = 0;

    var players = document.getElementsByTagName("video");

    for(var player of players) {
        player.addEventListener("play", startPlaying);
        player.addEventListener("pause", pausePlaying);
    }

    function startPlaying() {
        timer = window.setInterval(function() {
            totalTime += 10;
        }, 10);
    }

    function pausePlaying() {
        if (timer) clearInterval(timer);

        sendData({
            category: 'video',
            'duration': totalTime
        });
    }
    
    /* reset session_id */
    function sessionReset() {
        localStorage.removeItem("session_id");
        sessionId = sessionSet();
    }

    /* track last event time */
    function setLatestEvent() {
        var now = Date.now();
        var latestEvent = localStorage.getItem("last_event") || now;

        if(now - latestEvent > 1800000) {
            sessionReset();
        }
        
        localStorage.setItem("last_event", now);
    }

    /* send all data to SQUID */
    async function sendData(uniqueData) {
        eventData = {
            'squid': {
                time: Date.now(),
                timezone: timezone,
                page: page,
                domain: domain,
                referrer: referrer,
                source: squidSource,
                sources: sources,
                email: squidEmail,
                user_agent: agent,
                session_id: sessionId,
                browser_id: browserId
            }
        }

        Object.assign(eventData['squid'], uniqueData);
        
        console.log(eventData);
        
        var headersList = {
            "Accept": "*/*",
            "Content-Type": "application/json"
        }
        
        var blob = new Blob([JSON.stringify(eventData)], { type: 'application/json; charset=UTF-8' });

        var response = await fetch("https://icnsquid.work/api/UKbkUbuiYTc", { 
            method: "POST",
            body: blob,
            headers: headersList
        });

        var res = await response.text();
        console.log(res);
    }
    
    pageView();
}