/**
 * AttractOS Tracking Snippet
 * Tracks LLM referrals and conversions
 * ~2KB minified
 */
(function(w, d) {
  'use strict';

  // Get site key from script tag
  var scripts = d.getElementsByTagName('script');
  var currentScript = scripts[scripts.length - 1];
  var siteKey = currentScript.getAttribute('data-key');

  if (!siteKey) {
    console.warn('[AttractOS] Missing data-key attribute');
    return;
  }

  var ENDPOINT = 'https://attractos.com/api/t';
  var STORAGE_KEY = 'attractos_v';
  var SESSION_KEY = 'attractos_s';

  // LLM referrer patterns - domain to source mapping
  var LLM_REFERRERS = {
    'chat.openai.com': 'chatgpt',
    'chatgpt.com': 'chatgpt',
    'openai.com': 'chatgpt',
    'claude.ai': 'claude',
    'anthropic.com': 'claude',
    'perplexity.ai': 'perplexity',
    'gemini.google.com': 'gemini',
    'bard.google.com': 'gemini',
    'copilot.microsoft.com': 'copilot',
    'bing.com': 'copilot',
    'meta.ai': 'meta-ai',
    'grok.x.ai': 'grok',
    'you.com': 'you',
    'phind.com': 'phind',
    'kagi.com': 'kagi',
    'search.brave.com': 'brave-leo',
    'duckduckgo.com': 'duckduckgo-ai'
  };

  // Known LLM source values for UTM/param detection
  var LLM_SOURCES = [
    'chatgpt', 'openai', 'claude', 'anthropic', 'perplexity',
    'gemini', 'bard', 'copilot', 'bing-chat', 'meta-ai', 'llama',
    'grok', 'xai', 'you', 'phind', 'kagi', 'brave-leo', 'duckduckgo-ai'
  ];

  /**
   * Detect LLM source from referrer
   */
  function detectFromReferrer() {
    var ref = d.referrer;
    if (!ref) return null;

    try {
      var hostname = new URL(ref).hostname.toLowerCase();
      for (var pattern in LLM_REFERRERS) {
        if (hostname.indexOf(pattern) !== -1) {
          return { source: LLM_REFERRERS[pattern], method: 'referrer' };
        }
      }
    } catch (e) {}

    return null;
  }

  /**
   * Detect LLM source from URL parameters
   */
  function detectFromParams() {
    var params = new URLSearchParams(w.location.search);
    var checkParams = ['utm_source', 'via', 'ref', 'source'];

    for (var i = 0; i < checkParams.length; i++) {
      var val = params.get(checkParams[i]);
      if (val) {
        val = val.toLowerCase();
        for (var j = 0; j < LLM_SOURCES.length; j++) {
          if (val === LLM_SOURCES[j] || val.indexOf(LLM_SOURCES[j]) !== -1) {
            return { source: LLM_SOURCES[j], method: 'param' };
          }
        }
      }
    }

    return null;
  }

  /**
   * Get or create visitor ID
   */
  function getVisitorId() {
    var vid = null;
    try {
      vid = localStorage.getItem(STORAGE_KEY);
      if (!vid) {
        vid = Math.random().toString(36).substr(2, 9) + Date.now().toString(36);
        localStorage.setItem(STORAGE_KEY, vid);
      }
    } catch (e) {
      // localStorage not available, generate ephemeral ID
      vid = Math.random().toString(36).substr(2, 9);
    }
    return vid;
  }

  /**
   * Get or set session LLM source (persist across page views)
   */
  function getSessionSource(newSource) {
    try {
      if (newSource) {
        sessionStorage.setItem(SESSION_KEY, JSON.stringify(newSource));
        return newSource;
      }
      var stored = sessionStorage.getItem(SESSION_KEY);
      return stored ? JSON.parse(stored) : null;
    } catch (e) {
      return newSource || null;
    }
  }

  /**
   * Send tracking data
   */
  function send(data) {
    data.k = siteKey;
    data.p = w.location.pathname;
    data.ts = Date.now();

    // Use sendBeacon if available, fallback to fetch
    var payload = JSON.stringify(data);

    if (navigator.sendBeacon) {
      navigator.sendBeacon(ENDPOINT, payload);
    } else {
      fetch(ENDPOINT, {
        method: 'POST',
        body: payload,
        keepalive: true
      }).catch(function() {});
    }
  }

  // Initialize
  var visitorId = getVisitorId();

  // Detect LLM source (check params first, then referrer)
  var llmSource = detectFromParams() || detectFromReferrer();

  // Persist LLM source in session (so it survives navigation)
  if (llmSource) {
    getSessionSource(llmSource);
  } else {
    llmSource = getSessionSource();
  }

  // Track referral if LLM source detected
  if (llmSource) {
    send({
      t: 'referral',
      v: visitorId,
      s: llmSource.source,
      m: llmSource.method
    });
  }

  // Expose public API
  w.attractos = {
    /**
     * Track a conversion event
     * @param {string} eventName - Name of the event (e.g., 'signup', 'purchase')
     * @param {object} props - Optional properties (e.g., { value: 99.99 })
     */
    track: function(eventName, props) {
      props = props || {};
      send({
        t: 'conversion',
        v: visitorId,
        e: eventName,
        val: props.value,
        s: llmSource ? llmSource.source : null
      });
    },

    /**
     * Get the detected LLM source (if any)
     */
    getSource: function() {
      return llmSource;
    },

    /**
     * Get the visitor ID
     */
    getVisitorId: function() {
      return visitorId;
    }
  };

  // Debug mode
  if (w.location.search.indexOf('attractos_debug=1') !== -1) {
    console.log('[AttractOS] Initialized', {
      siteKey: siteKey,
      visitorId: visitorId,
      llmSource: llmSource
    });
  }

})(window, document);