/**
 * 4Ventures — Universal Attribution Script v1.0
 * Almacena parámetros UTM y Click IDs en cookie '_4v_attr' (90 días)
 * e inyecta automáticamente en formularios y enlaces de WhatsApp.
 */
(function() {
  'use strict';

  var COOKIE_NAME = '_4v_attr';
  var COOKIE_DAYS = 90;

  function getQueryParam(name) {
    var results = new RegExp('[\?&]' + name + '=([^&#]*)').exec(window.location.href);
    return results !== null ? decodeURIComponent(results[1].replace(/\+/g, ' ')) : null;
  }

  function setCookie(name, value, days) {
    var expires = '';
    if (days) {
      var date = new Date();
      date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
      expires = '; expires=' + date.toUTCString();
    }
    var secure = location.protocol === 'https:' ? '; Secure' : '';
    document.cookie = name + '=' + encodeURIComponent(JSON.stringify(value)) + expires + '; path=/; SameSite=Lax' + secure;
  }

  function getCookie(name) {
    var nameEQ = name + '=';
    var ca = document.cookie.split(';');
    for (var i = 0; i < ca.length; i++) {
      var c = ca[i];
      while (c.charAt(0) === ' ') c = c.substring(1, c.length);
      if (c.indexOf(nameEQ) === 0) {
        try {
          return JSON.parse(decodeURIComponent(c.substring(nameEQ.length, c.length)));
        } catch (e) {
          return null;
        }
      }
    }
    return null;
  }

  function detectReferrerSource() {
    var ref = document.referrer.toLowerCase();
    if (!ref) return { source: 'direct', medium: 'none' };
    if (ref.indexOf('google.') !== -1) return { source: 'google', medium: 'organic' };
    if (ref.indexOf('bing.') !== -1) return { source: 'bing', medium: 'organic' };
    if (ref.indexOf('instagram.') !== -1) return { source: 'instagram', medium: 'social' };
    if (ref.indexOf('facebook.') !== -1) return { source: 'facebook', medium: 'social' };
    if (ref.indexOf('linkedin.') !== -1) return { source: 'linkedin', medium: 'social' };
    if (ref.indexOf('tiktok.') !== -1) return { source: 'tiktok', medium: 'social' };
    if (ref.indexOf('youtube.') !== -1) return { source: 'youtube', medium: 'social' };
    try {
      var url = new URL(ref);
      return { source: url.hostname, medium: 'referral' };
    } catch(e) {
      return { source: 'referral', medium: 'referral' };
    }
  }

  function captureAttribution() {
    var utmSource = getQueryParam('utm_source');
    var utmMedium = getQueryParam('utm_medium');
    var utmCampaign = getQueryParam('utm_campaign');
    var utmContent = getQueryParam('utm_content');
    var utmTerm = getQueryParam('utm_term');
    var gclid = getQueryParam('gclid');
    var fbclid = getQueryParam('fbclid');
    var ttclid = getQueryParam('ttclid');
    var liFatId = getQueryParam('li_fat_id');

    var clickId = gclid || fbclid || ttclid || liFatId || null;
    var clickType = gclid ? 'gclid' : fbclid ? 'fbclid' : ttclid ? 'ttclid' : liFatId ? 'li_fat_id' : null;

    var existingAttr = getCookie(COOKIE_NAME);

    // Si hay nuevos parámetros en URL, actualizamos o creamos
    if (utmSource || clickId) {
      var newAttr = {
        source: utmSource || (gclid ? 'google' : fbclid ? 'meta' : ttclid ? 'tiktok' : liFatId ? 'linkedin' : 'unknown'),
        medium: utmMedium || (clickId ? 'cpc' : 'unknown'),
        campaign: utmCampaign || '',
        content: utmContent || '',
        term: utmTerm || '',
        click_id: clickId,
        click_type: clickType,
        landing_page: window.location.href,
        referrer: document.referrer || '',
        timestamp: new Date().toISOString()
      };
      setCookie(COOKIE_NAME, newAttr, COOKIE_DAYS);
      return newAttr;
    }

    // Si no hay params y ya hay cookie previa, la mantenemos
    if (existingAttr) {
      return existingAttr;
    }

    // Si es primera visita sin parámetros, deducimos del referrer
    var refData = detectReferrerSource();
    var defaultAttr = {
      source: refData.source,
      medium: refData.medium,
      campaign: '',
      content: '',
      term: '',
      click_id: null,
      click_type: null,
      landing_page: window.location.href,
      referrer: document.referrer || '',
      timestamp: new Date().toISOString()
    };
    setCookie(COOKIE_NAME, defaultAttr, COOKIE_DAYS);
    return defaultAttr;
  }

  function injectHiddenFields(attr) {
    var forms = document.querySelectorAll('form');
    var fieldKeys = ['source', 'medium', 'campaign', 'content', 'term', 'click_id', 'click_type', 'landing_page', 'referrer'];

    forms.forEach(function(form) {
      fieldKeys.forEach(function(key) {
        var inputName = 'utm_' + key;
        if (key === 'click_id' || key === 'click_type' || key === 'landing_page' || key === 'referrer') {
          inputName = key;
        }
        var val = attr[key] || '';
        var existing = form.querySelector('input[name="' + inputName + '"]');
        if (existing) {
          existing.value = val;
        } else {
          var input = document.createElement('input');
          input.type = 'hidden';
          input.name = inputName;
          input.value = val;
          form.appendChild(input);
        }
      });
    });
  }

  function injectWhatsAppLinks(attr) {
    if (!attr.click_id && !attr.source) return;
    var links = document.querySelectorAll('a[href*="wa.me"], a[href*="api.whatsapp.com"]');
    var tag = ' [ref:' + (attr.source || 'web') + (attr.click_id ? '-' + attr.click_id.substring(0, 8) : '') + ']';
    links.forEach(function(link) {
      var href = link.getAttribute('href');
      if (href && href.indexOf('[ref:') === -1) {
        if (href.indexOf('text=') !== -1) {
          link.setAttribute('href', href + encodeURIComponent(tag));
        } else {
          var sep = href.indexOf('?') !== -1 ? '&' : '?';
          link.setAttribute('href', href + sep + 'text=' + encodeURIComponent('Hola,' + tag));
        }
      }
    });
  }

  // Inicialización inmediata y en DOMContentLoaded
  var currentAttr = captureAttribution();

  function init() {
    injectHiddenFields(currentAttr);
    injectWhatsAppLinks(currentAttr);
  }

  if (document.readyState === 'loading') {
    document.addEventListener('DOMContentLoaded', init);
  } else {
    init();
  }

  // Exponer API global
  window._4v = {
    getAttribution: function() { return currentAttr; },
    refresh: captureAttribution,
    inject: init
  };
})();