/**
 * Floating Cart Button — shows when header cart icon scrolls out of view.
 * Updates count + total on add-to-cart and cart changes.
 */
(function ($) {
  'use strict';

  var $btn       = $('#matreshka-floating-cart');
  var $badge     = $btn.find('.mfc__badge');
  var $total     = $btn.find('.mfc__total');
  var $headerCart = $('.acounts-icons .cart-icon-wrapper');
  var visible    = false;
  var lastCartCount = parseInt($badge.attr('data-count'), 10) || 0;

  if (!$btn.length) return;

  /* ── Intersection Observer: watch header cart icon ── */
  function initObserver() {
    if (!$headerCart.length || !('IntersectionObserver' in window)) {
      // Fallback: show when scrolled past 300px
      $(window).on('scroll.mfc', throttle(function () {
        toggle($(window).scrollTop() > 300);
      }, 100));
      return;
    }

    var observer = new IntersectionObserver(function (entries) {
      entries.forEach(function (entry) {
        // Show floating btn when header cart is NOT visible AND cart has items
        toggle(!entry.isIntersecting);
      });
    }, { threshold: 0 });

    observer.observe($headerCart[0]);
  }

  /* ── Show / Hide ── */
  function toggle(shouldShow) {
    var count = parseInt($badge.attr('data-count'), 10) || 0;
    var show  = shouldShow && count > 0;

    if (show === visible) return;
    visible = show;

    if (show) {
      $btn.css('display', 'flex').addClass('mfc--visible');
    } else {
      $btn.removeClass('mfc--visible');
      setTimeout(function () {
        if (!visible) $btn.css('display', 'none');
      }, 300);
    }
  }

  /* ── Update data ── */
  function updateCart(count, totalHtml, options) {
    options = options || {};
    count = parseInt(count, 10) || 0;

    if (options.allowDecrease === false && count < lastCartCount) {
      return;
    }

    lastCartCount = count;
    $badge.text(count).attr('data-count', count);
    if (totalHtml) {
      $total.html(totalHtml);
    }
    // Also update header badge
    var $headerBadge = $('.cart-count-badge');
    if (count > 0) {
      if ($headerBadge.length) {
        $headerBadge.text(count);
      }
    }
    // Pulse animation
    $btn.addClass('mfc--pulse');
    setTimeout(function () { $btn.removeClass('mfc--pulse'); }, 400);
    // Re-evaluate visibility (hide if empty)
    if (count <= 0) {
      toggle(false);
    }
  }

  $(document.body).on('matreshka_cart_count_updated', function (event, data) {
    if (!data || data.cart_count === undefined) {
      return;
    }

    updateCart(data.cart_count, data.cart_total_html, {
      allowDecrease: data.allow_decrease !== false,
    });
  });

  /* ── Listen for add-to-cart AJAX responses ── */
  $(document).ajaxComplete(function (event, xhr, settings) {
    if (!settings || !settings.data) return;
    var data = typeof settings.data === 'string' ? settings.data : '';
    // Match our custom AJAX actions
    var isAddToCart = data.indexOf('matreshka_add_to_cart') !== -1;
    if (!isAddToCart &&
        data.indexOf('matreshka_remove_cart_item') === -1 &&
        data.indexOf('matreshka_update_cart_item') === -1) {
      return;
    }
    try {
      var response = JSON.parse(xhr.responseText);
      if (response.success && response.data) {
        var c = response.data.cart_count;
        var t = response.data.cart_total_html || null;
        if (c !== undefined) {
          updateCart(c, t, { allowDecrease: !isAddToCart });
        }
      }
    } catch (e) {}
  });

  /* ── Also listen for cart removals ── */
  $(document.body).on('removed_from_cart', function () {
    // Fetch fresh data
    if (typeof matreshka_ajax !== 'undefined') {
      $.post(matreshka_ajax.ajax_url, {
        action: 'matreshka_get_cart_count',
        nonce: matreshka_ajax.nonce,
      }, function (response) {
        if (response.success && response.data) {
          updateCart(response.data.cart_count, response.data.cart_total_html, { allowDecrease: true });
        }
      });
    }
  });

  /* ── Throttle helper ── */
  function throttle(fn, wait) {
    var last = 0;
    return function () {
      var now = Date.now();
      if (now - last >= wait) {
        last = now;
        fn.apply(this, arguments);
      }
    };
  }

  /* ── Init ── */
  initObserver();

})(jQuery);