(function () {
    'use strict';

    var configurationElement = document.getElementById('analytics-configuration');
    var banner = document.getElementById('analytics-consent');
    var settingsButton = document.getElementById('analytics-consent-settings');

    if (!configurationElement || !banner || !settingsButton) {
        return;
    }

    var configuration;
    try {
        configuration = JSON.parse(configurationElement.textContent || '');
    } catch (error) {
        return;
    }

    var cookieName = configuration.consentCookie;
    var consentVersion = configuration.consentVersion;
    var matomoStarted = false;

    function readDecision() {
        var cookies = document.cookie ? document.cookie.split(';') : [];
        for (var index = 0; index < cookies.length; index += 1) {
            var parts = cookies[index].trim().split('=');
            var name = decodeURIComponent(parts.shift() || '');
            if (name !== cookieName) {
                continue;
            }

            var value = decodeURIComponent(parts.join('='));
            var expectedPrefix = consentVersion + ':';
            if (value.indexOf(expectedPrefix) !== 0) {
                return null;
            }

            var decision = value.slice(expectedPrefix.length);
            return decision === 'granted' || decision === 'denied' ? decision : null;
        }

        return null;
    }

    function cookieSuffix() {
        var suffix = '; Path=/; Max-Age=' + String(configuration.consentMaxAge) + '; SameSite=Lax';
        if (configuration.cookieDomain) {
            suffix += '; Domain=' + configuration.cookieDomain;
        }
        if (configuration.secureCookies || window.location.protocol === 'https:') {
            suffix += '; Secure';
        }
        return suffix;
    }

    function writeDecision(decision) {
        document.cookie = encodeURIComponent(cookieName)
            + '=' + encodeURIComponent(consentVersion + ':' + decision)
            + cookieSuffix();
    }

    function URLWithoutParameters(value) {
        try {
            var url = new URL(value, window.location.href);
            return url.origin + url.pathname;
        } catch (error) {
            return '';
        }
    }

    function startMatomo() {
        window._paq = window._paq || [];

        if (matomoStarted) {
            window._paq.push(['setConsentGiven']);
            window._paq.push(['trackPageView']);
            return;
        }
        matomoStarted = true;

        var trackerUrl = configuration.matomoUrl + 'matomo.php';
        window._paq.push(['requireConsent']);
        window._paq.push(['setTrackerUrl', trackerUrl]);
        window._paq.push(['setSiteId', configuration.siteId]);
        window._paq.push(['setDoNotTrack', true]);
        window._paq.push(['disableBrowserFeatureDetection']);
        window._paq.push(['disablePerformanceTracking']);
        window._paq.push(['setCookiePath', '/']);
        window._paq.push(['setCookieSameSite', 'Lax']);
        window._paq.push(['setSecureCookie', window.location.protocol === 'https:']);
        window._paq.push(['setVisitorCookieTimeout', configuration.consentMaxAge]);
        window._paq.push(['setReferralCookieTimeout', configuration.consentMaxAge]);
        window._paq.push(['setCustomUrl', URLWithoutParameters(window.location.href)]);

        var referrer = URLWithoutParameters(document.referrer);
        if (referrer) {
            window._paq.push(['setReferrerUrl', referrer]);
        }
        if (configuration.cookieDomain) {
            window._paq.push(['setCookieDomain', configuration.cookieDomain]);
        }

        window._paq.push(['setConsentGiven']);
        window._paq.push(['trackPageView']);

        var script = document.createElement('script');
        script.async = true;
        script.src = configuration.matomoUrl + 'matomo.js';
        script.referrerPolicy = 'strict-origin-when-cross-origin';
        document.head.appendChild(script);
    }

    function expireCookie(name, domain) {
        var value = encodeURIComponent(name) + '=; Path=/; Max-Age=0; SameSite=Lax';
        if (domain) {
            value += '; Domain=' + domain;
        }
        if (configuration.secureCookies || window.location.protocol === 'https:') {
            value += '; Secure';
        }
        document.cookie = value;
    }

    function removeMatomoCookies() {
        var cookies = document.cookie ? document.cookie.split(';') : [];
        cookies.forEach(function (cookie) {
            var name = decodeURIComponent(cookie.trim().split('=')[0] || '');
            if (name.indexOf('_pk_') !== 0 && name.indexOf('mtm_') !== 0) {
                return;
            }
            expireCookie(name, '');
            if (configuration.cookieDomain) {
                expireCookie(name, configuration.cookieDomain);
            }
        });
    }

    function stopMatomo() {
        if (window._paq) {
            window._paq.push(['forgetConsentGiven']);
            window._paq.push(['deleteCookies']);
        }
        removeMatomoCookies();
    }

    function closeBanner() {
        banner.hidden = true;
        settingsButton.hidden = false;
    }

    function choose(decision) {
        writeDecision(decision);
        closeBanner();
        if (decision === 'granted') {
            startMatomo();
        } else {
            stopMatomo();
        }
        window.dispatchEvent(new CustomEvent('kaffeeliste:analytics-consent', {
            detail: {analytics: decision}
        }));
    }

    banner.querySelectorAll('[data-analytics-consent]').forEach(function (button) {
        button.addEventListener('click', function () {
            choose(button.getAttribute('data-analytics-consent'));
        });
    });

    settingsButton.addEventListener('click', function () {
        banner.hidden = false;
        settingsButton.hidden = true;
        var firstButton = banner.querySelector('[data-analytics-consent="denied"]');
        if (firstButton) {
            firstButton.focus();
        }
    });

    var initialDecision = readDecision();
    if (initialDecision === 'granted') {
        settingsButton.hidden = false;
        startMatomo();
    } else if (initialDecision === 'denied') {
        settingsButton.hidden = false;
        stopMatomo();
    } else {
        banner.hidden = false;
    }
}());