初期化タグの設定

SingularGTMのInitializationタグタイプでは、 `Global Properties `（オブジェクト）を `Key`および`Value `フィールドに 変数、データレイヤー値、またはテキストを割り当てることで設定します。 `Override `（true/false）フィールドは 必要に応じて調整してください。 `Override `が `false`の場合、既存のプロパティは変更されません。 `true`の場合、既存のプロパティは 上書きされます。

<script>
(function() {
    // singular-web-organic-search-tracking: setupOrganicSearchTracking.js
    // Tracks organic search referrals by appending wpsrc and wpcn to the URL if no campaign parameters exist and the referrer is a search engine.

    // Configuration for debugging (set to true to enable logs)
    var debug = true;

    // List of campaign parameters to check for exclusion
    var campaignParams = [
        'gclid', 'fbclid', 'ttclid', 'msclkid', 'twclid', 'li_fat_id',
        'utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content', 'wpsrc'
    ];

    // Whitelist of legitimate search engine domains (prevents false positives)
    var legitimateSearchEngines = new Set([
        // Google domains
        'google.com', 'google.co.uk', 'google.ca', 'google.com.au', 'google.de', 
        'google.fr', 'google.it', 'google.es', 'google.co.jp', 'google.co.kr',
        'google.com.br', 'google.com.mx', 'google.co.in', 'google.ru', 'google.com.sg',
        
        // Bing domains  
        'bing.com', 'bing.co.uk', 'bing.ca', 'bing.com.au', 'bing.de',
        
        // Yahoo domains
        'yahoo.com', 'yahoo.co.uk', 'yahoo.ca', 'yahoo.com.au', 'yahoo.de',
        'yahoo.fr', 'yahoo.it', 'yahoo.es', 'yahoo.co.jp',
        
        // Other search engines
        'baidu.com', 'duckduckgo.com', 'yandex.com', 'yandex.ru',
        'ask.com', 'aol.com', 'ecosia.org', 'startpage.com', 
        'qwant.com', 'seznam.cz', 'naver.com', 'daum.net'
    ]);

    // Extract main domain from hostname (removes subdomains)
    function getMainDomain(hostname) {
        if (!hostname) return '';
        
        var lowerHost = hostname.toLowerCase();
        
        // Handle special cases for known search engines with country codes
        var searchEnginePatterns = {
            'google': function(host) {
                // Match google.TLD patterns more precisely
                if (host.indexOf('google.co.') !== -1 || host.indexOf('google.com') !== -1) {
                    var parts = host.split('.');
                    for (var i = 0; i < parts.length - 1; i++) {
                        if (parts[i] === 'google') {
                            return parts.slice(i).join('.');
                        }
                    }
                }
                return null;
            },
            'bing': function(host) {
                if (host.indexOf('bing.co') !== -1 || host.indexOf('bing.com') !== -1) {
                    var parts = host.split('.');
                    for (var i = 0; i < parts.length - 1; i++) {
                        if (parts[i] === 'bing') {
                            return parts.slice(i).join('.');
                        }
                    }
                }
                return null;
            },
            'yahoo': function(host) {
                if (host.indexOf('yahoo.co') !== -1 || host.indexOf('yahoo.com') !== -1) {
                    var parts = host.split('.');
                    for (var i = 0; i < parts.length - 1; i++) {
                        if (parts[i] === 'yahoo') {
                            return parts.slice(i).join('.');
                        }
                    }
                }
                return null;
            }
        };
        
        // Try specific patterns for major search engines
        for (var engine in searchEnginePatterns) {
            if (lowerHost.indexOf(engine) !== -1) {
                var result = searchEnginePatterns[engine](lowerHost);
                if (result) return result;
            }
        }
        
        // Handle other known engines with simple mapping
        var otherEngines = {
            'baidu.com': 'baidu.com',
            'duckduckgo.com': 'duckduckgo.com', 
            'yandex.ru': 'yandex.ru',
            'yandex.com': 'yandex.com',
            'ask.com': 'ask.com',
            'aol.com': 'aol.com',
            'ecosia.org': 'ecosia.org',
            'startpage.com': 'startpage.com',
            'qwant.com': 'qwant.com',
            'seznam.cz': 'seznam.cz',
            'naver.com': 'naver.com',
            'daum.net': 'daum.net'
        };
        
        for (var domain in otherEngines) {
            if (lowerHost.indexOf(domain) !== -1) {
                return otherEngines[domain];
            }
        }
        
        // Fallback: Extract main domain by taking last 2 parts (for unknown domains)
        var parts = hostname.split('.');
        if (parts.length >= 2) {
            return parts[parts.length - 2] + '.' + parts[parts.length - 1];
        }
        
        return hostname;
    }

    // Get query parameter by name, using URL.searchParams with regex fallback for IE11
    function getParameterByName(name, url) {
        if (!url) url = window.location.href;
        try {
            return new URL(url).searchParams.get(name) || null;
        } catch (e) {
            if (debug) console.warn('URL API not supported, falling back to regex:', e);
            name = name.replace(/[\[\]]/g, '\\$&');
            var regex = new RegExp('[?&]' + name + '(=([^&#]*)|&|#|$)');
            var results = regex.exec(url);
            if (!results) return null;
            if (!results[2]) return '';
            return decodeURIComponent(results[2].replace(/\+/g, ' '));
        }
    }

    // Check if any campaign parameters exist in the URL
    function hasAnyParameter(url, params) {
        for (var i = 0; i < params.length; i++) {
            if (getParameterByName(params[i], url) !== null) {
                return true;
            }
        }
        return false;
    }

    // Improved search engine detection - only checks hostname, uses whitelist
    function isSearchEngineReferrer(referrer) {
        if (!referrer) return false;
        
        var hostname = '';
        try {
            hostname = new URL(referrer).hostname.toLowerCase();
        } catch (e) {
            // Fallback regex for hostname extraction (IE11 compatibility)
            var match = referrer.match(/^(?:https?:\/\/)?([^\/\?#]+)/i);
            hostname = match ? match[1].toLowerCase() : '';
        }
        
        if (!hostname) return false;
        
        // First check: exact match against whitelist
        if (legitimateSearchEngines.has(hostname)) {
            if (debug) console.log('Exact match found for:', hostname);
            return true;
        }
        
        // Second check: subdomain of legitimate search engine
        var hostParts = hostname.split('.');
        if (hostParts.length >= 3) {
            // Try domain.tld combination (e.g., google.com from www.google.com)
            var mainDomain = hostParts[hostParts.length - 2] + '.' + hostParts[hostParts.length - 1];
            if (legitimateSearchEngines.has(mainDomain)) {
                if (debug) console.log('Subdomain match found for:', hostname, '-> main domain:', mainDomain);
                return true;
            }
            
            // Try last 3 parts for country codes (e.g., google.co.uk from www.google.co.uk)
            if (hostParts.length >= 3) {
                var ccDomain = hostParts[hostParts.length - 3] + '.' + hostParts[hostParts.length - 2] + '.' + hostParts[hostParts.length - 1];
                if (legitimateSearchEngines.has(ccDomain)) {
                    if (debug) console.log('Country code domain match found for:', hostname, '-> cc domain:', ccDomain);
                    return true;
                }
            }
        }
        
        if (debug) {
            console.log('Hostname not recognized as legitimate search engine:', hostname);
        }
        
        return false;
    }

    // Main function to update URL with organic search tracking parameters
    function setupOrganicSearchTracking() {
        var url = window.location.href;
        var referrer = document.referrer || '';

        // Store URL and referrer in localStorage
        try {
            localStorage.setItem('sng_url', url);
            localStorage.setItem('sng_ref', referrer);
        } catch (e) {
            if (debug) console.warn('localStorage not available:', e);
        }

        if (debug) {
            console.log('Current URL:', url);
            console.log('Referrer:', referrer);
        }

        // Skip if campaign parameters exist or referrer is not a search engine
        var hasCampaignParams = hasAnyParameter(url, campaignParams);
        if (hasCampaignParams || !isSearchEngineReferrer(referrer)) {
            if (debug) console.log('Skipping URL update: Campaign params exist or referrer is not a legitimate search engine');
            return;
        }

        // Extract and validate referrer hostname
        var referrerHostname = '';
        try {
            referrerHostname = new URL(referrer).hostname;
        } catch (e) {
            if (debug) console.warn('Invalid referrer URL, falling back to regex:', e);
            var match = referrer.match(/^(?:https?:\/\/)?([^\/]+)/i);
            referrerHostname = match ? match[1] : '';
        }

        // Extract main domain from hostname
        var mainDomain = getMainDomain(referrerHostname);
        
        if (debug) {
            console.log('Full hostname:', referrerHostname);
            console.log('Main domain:', mainDomain);
        }

        // Only proceed if main domain is valid and contains safe characters
        if (!mainDomain || !/^[a-zA-Z0-9.-]+$/.test(mainDomain)) {
            if (debug) console.log('Skipping URL update: Invalid or unsafe main domain');
            return;
        }

        // Update URL with wpsrc and wpcn parameters
        var urlObj;
        try {
            urlObj = new URL(url);
        } catch (e) {
            if (debug) console.warn('URL API not supported, cannot modify URL:', e);
            return;
        }
        
        // Set wpsrc to the main domain (e.g., google.com instead of tagassistant.google.com)
        urlObj.searchParams.set('wpsrc', mainDomain);
        
        // Set wpcn to 'Organic Search' to identify the campaign type
        urlObj.searchParams.set('wpcn', 'Organic Search');

        // Update the URL without reloading (check if history API is available)
        if (window.history && window.history.replaceState) {
            try {
                window.history.replaceState({}, '', urlObj.toString());
                if (debug) console.log('Updated URL with organic search tracking:', urlObj.toString());
            } catch (e) {
                if (debug) console.warn('Failed to update URL:', e);
            }
        } else {
            if (debug) console.warn('History API not supported, cannot update URL');
        }
    }

    // Execute the function
    setupOrganicSearchTracking();
})();
</script>