let gtm4wp_last_selected_product_variation;
window.gtm4wp_view_item_fired_during_pageload = false;

window.gtm4wp_checkout_step_fired = []; // step 1 will be the billing section which is reported during pageload, no need to handle here

window.gtm4wp_first_container_id = "";

function gtm4wp_woocommerce_handle_cart_qty_change() {
	document.querySelectorAll( '.product-quantity input.qty' ).forEach(function( qty_el ) {
		const original_value = qty_el.defaultValue;

		let current_value  = parseInt( qty_el.value );
		if ( isNaN( current_value ) ) {
			current_value = original_value;
		}

		// is quantity changed changed?
		if ( original_value != current_value ) {
			const cart_item_temp = qty_el.closest( '.cart_item' );
			const productdata_el = cart_item_temp && cart_item_temp.querySelector( '.remove' );
			if ( !productdata_el ) {
				return;
			}

			const productdata = gtm4wp_read_json_from_node( productdata_el, "gtm4wp_product_data");
			if ( !productdata ) {
				return true;
			}

			// does the quantity increase?
			if ( original_value < current_value ) {
				// yes => handle add to cart event
				productdata.quantity = current_value - original_value;
				productdata.price    = productdata.price;

				gtm4wp_push_ecommerce( 'add_to_cart', [ productdata ], {
					'currency': gtm4wp_currency, // ga4 version
					'value': productdata.price * productdata.quantity
				});
			} else {
				// no => handle remove from cart event
				productdata.quantity = original_value - current_value;
				productdata.price    = productdata.price;

				gtm4wp_push_ecommerce( 'remove_from_cart', [ productdata ], {
					'currency': gtm4wp_currency,
					'value': productdata.price * productdata.quantity
				});
			}
		} // end if qty changed
	}); // end each qty field
} // end gtm4wp_woocommerce_handle_cart_qty_change()

function gtm4wp_woocommerce_handle_payment_method_change() {
	// do not report checkout step if already reported
	if ( gtm4wp_checkout_step_fired.indexOf( 'payment_method' ) > -1 ) {
		return;
	}

	// do not fire event during page load
	if ( 'complete' != document.readyState ) {
		return;
	}

	let payment_type = '(payment type not found)';
	let payment_el = document.querySelector( '.payment_methods input:checked' );
	if ( !payment_el ) {
		payment_el = document.querySelector( 'input[name^=payment_method]' ); // select the first input element
	}
	if ( payment_el ) {
		payment_type = payment_el.value;
	}

	gtm4wp_push_ecommerce( 'add_payment_info', window.gtm4wp_checkout_products, {
		'currency': gtm4wp_currency,
		'payment_type': payment_type,
		'value': window.gtm4wp_checkout_value
	});

	gtm4wp_checkout_step_fired.push( 'payment_method' );
} // end gtm4wp_woocommerce_handle_payment_method_change()

function gtm4wp_woocommerce_handle_shipping_method_change() {
	// do not report checkout step if already reported
	if ( gtm4wp_checkout_step_fired.indexOf( 'shipping_method' ) > -1 ) {
		return;
	}

	// do not fire event during page load
	if ( 'complete' != document.readyState ) {
		return;
	}

	let shipping_tier = '(shipping tier not found)';
	let shipping_el = document.querySelector( 'input[name^=shipping_method]:checked' );
	if ( !shipping_el ) {
		shipping_el = document.querySelector( 'input[name^=shipping_method]' ); // select the first input element
	}
	if ( shipping_el ) {
		shipping_tier = shipping_el.value;
	}

	gtm4wp_push_ecommerce( 'add_shipping_info', window.gtm4wp_checkout_products, {
		'currency': gtm4wp_currency,
		'shipping_tier': shipping_tier,
		'value': window.gtm4wp_checkout_value
	});

	gtm4wp_checkout_step_fired.push( 'shipping_method' );
}

function gtm4wp_woocommerce_process_pages() {
	// loop through WC blocks to set proper listname and position parameters
	const gtm4wp_product_block_names = {
		'wp-block-handpicked-products': {
			'displayname': 'Handpicked Products',
			'counter': 1
		},
		'wp-block-product-best-sellers': {
			'displayname': 'Best Selling Products',
			'counter': 1
		},
		'wp-block-product-category': {
			'displayname': 'Product Category List',
			'counter': 1
		},
		'wp-block-product-new': {
			'displayname': 'New Products',
			'counter': 1
		},
		'wp-block-product-on-sale': {
			'displayname': 'Sale Products',
			'counter': 1
		},
		'wp-block-products-by-attribute': {
			'displayname': 'Products By Attribute',
			'counter': 1
		},
		'wp-block-product-tag': {
			'displayname': 'Products By Tag',
			'counter': 1
		},
		'wp-block-product-top-rated': {
			'displayname': 'Top Rated Products',
			'counter': 1
		},
	}

	document.querySelectorAll( '.wc-block-grid .wc-block-grid__product' ).forEach( function( product_grid_item ) {

		const product_grid_container = product_grid_item.closest( '.wc-block-grid' );
		const product_data_el = product_grid_item.querySelector( '.gtm4wp_productdata' );

		if ( product_grid_container && product_data_el ) {

			const product_grid_container_classes = product_grid_container.classList;

			if ( product_grid_container_classes ) {

				for(let i in gtm4wp_product_block_names) {
					if ( product_grid_container_classes.contains( i ) ) {
						gtm4wp_update_json_in_node( product_data_el, 'gtm4wp_product_data', 'item_list_name', gtm4wp_product_block_names[i].displayname );
						gtm4wp_update_json_in_node( product_data_el, 'gtm4wp_product_data', 'index', gtm4wp_product_block_names[i].counter );

						gtm4wp_product_block_names[i].counter++;
					}
				}
			}
		}

	});

	// track impressions of products in product lists
	if ( document.querySelectorAll( '.gtm4wp_productdata,.widget-product-item' ).length > 0 ) {
		let products = [];

		document.querySelectorAll( '.gtm4wp_productdata,.widget-product-item' ).forEach( function( productdata_el ) {
			const productdata = gtm4wp_read_json_from_node( productdata_el, "gtm4wp_product_data");
			if ( !productdata ) {
				return true;
			}

			products.push(productdata);
		});

		if ( gtm4wp_product_per_impression > 0 ) {
			// Need to split the product submissions up into chunks in order to avoid the GA 16kb hit size limit
			let chunk;

			while ( products.length ) {
				chunk = products.splice( 0, gtm4wp_product_per_impression );

				gtm4wp_push_ecommerce( 'view_item_list', chunk, {
					'currency': gtm4wp_currency
				});
			}
		} else {
			// push everything in one event and let's hope the best :-)
			gtm4wp_push_ecommerce( 'view_item_list', products, {
				'currency': gtm4wp_currency
			});
		}
	}

	// manage events related to user clicks
	document.addEventListener( 'click', function( e ) {
		let event_target_element = e.target;
	
		if ( !event_target_element ) {
			// for some reason event target is not specificed
			return true;
		}
	
		// track add to cart events for simple products in product lists
		if ( event_target_element.closest( '.add_to_cart_button:not(.product_type_variable, .product_type_grouped, .single_add_to_cart_button)' ) ) {
			const product_el = event_target_element.closest( '.product,.wc-block-grid__product' );

			const productdata_el = product_el && product_el.querySelector( '.gtm4wp_productdata' );
			if ( !productdata_el ) {
				return true;
			}

			const productdata  = gtm4wp_read_json_from_node( productdata_el, "gtm4wp_product_data" );
			if ( !productdata ) {
				return true;
			}

			if ( "variable" === productdata.product_type || "grouped" === productdata.product_type ) {
				return true;
			}

			if ( productdata.productlink ) {
				delete productdata.productlink;
			}
			delete productdata.product_type;
			productdata.quantity = 1;

			gtm4wp_push_ecommerce( 'add_to_cart', [ productdata ], {
				'currency': gtm4wp_currency,
				'value': productdata.price
			});
		}
	
		// track add to cart events for products on product detail pages
		if ( event_target_element.closest( '.single_add_to_cart_button:not(.disabled)' ) ) {
			const product_form = event_target_element.closest( 'form.cart' );
			if ( !product_form ) {
				return true;
			}
	
			let product_variant_id = product_form.querySelectorAll( '[name=variation_id]' );
			let product_is_grouped = product_form.classList && product_form.classList.contains( 'grouped_form' );
	
			if ( product_variant_id.length > 0 ) {
				if ( gtm4wp_last_selected_product_variation ) {
					const qty_el = product_form.querySelector( '[name=quantity]' );
					gtm4wp_last_selected_product_variation.quantity = (qty_el && qty_el.value) || 1;
	
					gtm4wp_push_ecommerce( 'add_to_cart', [ gtm4wp_last_selected_product_variation ], {
						'currency': gtm4wp_currency,
						'value': (gtm4wp_last_selected_product_variation.price * gtm4wp_last_selected_product_variation.quantity).toFixed(2)
					});
				}
			} else if ( product_is_grouped ) {
				const products_in_group = document.querySelectorAll( '.grouped_form .gtm4wp_productdata' );
				let products = [];
				let sum_value = 0;
	
				products_in_group.forEach( function( product_data_el ) {
					const productdata = gtm4wp_read_json_from_node(product_data_el, 'gtm4wp_product_data', ['productlink']);
					if ( !productdata ) {
						return true;
					}

					let product_qty = 0;
					const product_qty_input = document.querySelectorAll( 'input[name=quantity\\[' + productdata.internal_id + '\\]]' );
					if ( product_qty_input.length > 0 ) {
						product_qty = (product_qty_input[0] && product_qty_input[0].value) || 1;
					} else {
						return true;
					}
	
					if ( 0 == product_qty ) {
						return true;
					}
					productdata.quantity = product_qty;

					delete productdata.internal_id;
	
					products.push( productdata );
					sum_value += productdata.price * productdata.quantity;
				});
	
				if ( 0 == products.length ) {
					return true;
				}
	
				gtm4wp_push_ecommerce( 'add_to_cart', products, {
					'currency': gtm4wp_currency,
					'value': sum_value.toFixed(2)
				});
			} else {
				const product_data_el = product_form.querySelector( '[name=gtm4wp_product_data]' );
				if ( !product_data_el ) {
					return true;
				}

				let productdata = gtm4wp_read_from_json( product_data_el.value );
				productdata.quantity = product_form.querySelector( '[name=quantity]' ) && product_form.querySelector( '[name=quantity]' ).value;
				if ( isNaN( productdata.quantity ) ) {
					productdata.quantity = 1;
				}
	
				gtm4wp_push_ecommerce( 'add_to_cart', [ productdata ], {
					'currency': gtm4wp_currency,
					'value': productdata.price * productdata.quantity
				});
			}
		}
	
		// track remove links in mini cart widget and on cart page
		if ( event_target_element.closest( '.mini_cart_item a.remove,.product-remove a.remove' ) ) {
			const click_el = event_target_element;
	
			const productdata_el = click_el && click_el.closest( '.mini_cart_item a.remove,.product-remove a.remove' );
			if ( !productdata_el ) {
				return true;
			}

			const productdata = gtm4wp_read_json_from_node( productdata_el, "gtm4wp_product_data");
			if ( !productdata ) {
				return true;
			}

			let qty = 0;
			const cart_item_el = productdata_el.closest( '.cart_item' );
			let qty_element = cart_item_el && cart_item_el.querySelectorAll( '.product-quantity input.qty' );
			if ( !qty_element || ( 0 === qty_element.length ) ) {
				const mini_cart_item_el = productdata_el.closest( '.mini_cart_item' );
				qty_element = mini_cart_item_el && mini_cart_item_el.querySelectorAll( '.quantity' );
				if ( qty_element && ( qty_element.length > 0 ) ) {
					qty = parseInt( qty_element[0].textContent );
	
					if ( Number.isNaN( qty ) ) {
						qty = 0;
					}
				}
			} else {
				qty = qty_element[0].value;
			}
	
			if ( 0 === qty ) {
				return true;
			}

			productdata.quantity = qty;
	
			gtm4wp_push_ecommerce( 'remove_from_cart', [ productdata ], {
				'currency': gtm4wp_currency,
				'value': productdata.price * productdata.quantity
			});
		}
	
		// track clicks in product lists
		if ( event_target_element.closest(
			'.products li:not(.product-category) a:not(.add_to_cart_button):not(.quick-view-button),'
			+'.wc-block-grid__products li:not(.product-category) a:not(.add_to_cart_button):not(.quick-view-button),'
			+'.products>div:not(.product-category) a:not(.add_to_cart_button):not(.quick-view-button),'
			+'.widget-product-item,'
			+'.woocommerce-grouped-product-list-item__label a' )
		) {
			// do nothing if GTM is blocked for some reason
			if ( 'undefined' == typeof google_tag_manager ) {
				return true;
			}
	
			const event_target_element = e.target;
			const matching_link_element = event_target_element.closest(
				'.products li:not(.product-category) a:not(.add_to_cart_button):not(.quick-view-button),'
				+'.wc-block-grid__products li:not(.product-category) a:not(.add_to_cart_button):not(.quick-view-button),'
				+'.products>div:not(.product-category) a:not(.add_to_cart_button):not(.quick-view-button),'
				+'.widget-product-item,'
				+'.woocommerce-grouped-product-list-item__label a'
			);
	
			if ( !matching_link_element ) {
				return true;
			}
	
			let temp_selector = event_target_element.closest( '.product,.wc-block-grid__product' );
			let productdata_el;
	
			if ( temp_selector ) {
				productdata_el = temp_selector.querySelector( '.gtm4wp_productdata' );
	
			} else {
				temp_selector = event_target_element.closest( '.products li' );
	
				if ( temp_selector ) {
					productdata_el = temp_selector.querySelector( '.gtm4wp_productdata' );
	
				} else {
					temp_selector = event_target_element.closest( '.products>div' );
	
					if ( temp_selector ) {
						productdata_el = temp_selector.querySelector( '.gtm4wp_productdata' );
	
					} else {
						temp_selector = event_target_element.closest( '.woocommerce-grouped-product-list-item__label' );
	
						if ( temp_selector ) {
							productdata_el = temp_selector.querySelector( '.gtm4wp_productdata' );
						} else {
							productdata_el = event_target_element;
						}
					}
				}
			}
			
			const productdata = gtm4wp_read_json_from_node( productdata_el, 'gtm4wp_product_data', ['internal_id'] );
			if ( !productdata ) {
				return true;
			}
	
			// only act on links pointing to the product detail page
			if ( productdata.productlink != matching_link_element.getAttribute( 'href' ) ) {
				return true;
			}
	
			// Look at first GTM container ID in case there are multiple GTM containers live on the page
			// since eventCallback is called on every container and we only need this executed once in this case.
			for (let i in window.google_tag_manager) {
				if (i.substring(0,4).toLowerCase() == "gtm-") {
					window.gtm4wp_first_container_id = i;
					break;
				}
			}
	
			// do not do anything if GTM was not loaded
			// and window.google_tag_manager is for some reason initialized (GA4 only setup?)
			if ( "" === window.gtm4wp_first_container_id ) {
				return true;
			}
	
			const ctrl_key_pressed = e.ctrlKey || e.metaKey;
			const target_new_tab = ( '_blank' === matching_link_element.target );
			
			// save this info to prevent redirection if another plugin already prevented to event for some reason
			let event_already_prevented = e.defaultPrevented;
			if ( !event_already_prevented ) {
				e.preventDefault();
			}
			
			if ( ctrl_key_pressed || target_new_tab ) {
				// we need to open the new tab/page here so that popup blocker of the browser doesn't block our code
				window.productpage_window = window.open( 'about:blank', '_blank' );
			}

			const productlink_to_redirect = productdata.productlink;
			delete productdata.productlink;
	
			// fire ga4 version
			gtm4wp_push_ecommerce( 'select_item', [ productdata ], {
				'currency': gtm4wp_currency
			}, function( container_id ) {
				if ( "undefined" !== typeof container_id && window.gtm4wp_first_container_id != container_id) {
					// only call this for the first loaded container
					return true;
				}

				if ( !event_already_prevented ) {
					if ( ( target_new_tab || ctrl_key_pressed ) && productpage_window ) {
						productpage_window.location.href = productlink_to_redirect;
					} else {
						document.location.href = productlink_to_redirect;
					}
				}
			});
		}
	});

	// track variable products on their detail pages
	// currently, we need to use jQuery here since WooCommerce is firing this event using jQuery
	// that can not be catched using vanilla JS
	jQuery( document ).on( 'found_variation', function( event, product_variation ) {
		if ( "undefined" == typeof product_variation ) {
			// some ither plugins trigger this event without variation data
			return;
		}

		if ( (document.readyState === "interactive") && gtm4wp_view_item_fired_during_pageload ) {
			// some custom attribute rendering plugins fire this event multiple times during page load
			return;
		}

		// event target is the <form> element of the add to cart button.
		const product_form    = event.target;
		if ( !product_form ) {
			return true;
		}

		const product_data_el = product_form.querySelector( '[name=gtm4wp_product_data]' );
		if ( !product_data_el ) {
			return true;
		}

		let current_product_detail_data;
		try {
			current_product_detail_data = JSON.parse( product_data_el.value );
		} catch(e) {
			console && console.error && console.error( e.message );
			return true;
		}

		current_product_detail_data.price = gtm4wp_make_sure_is_float( current_product_detail_data.price );

		current_product_detail_data.item_group_id = current_product_detail_data.id;
		current_product_detail_data.id = product_variation.variation_id;
		current_product_detail_data.item_id = product_variation.variation_id;
		current_product_detail_data.sku = product_variation.sku;
		if ( gtm4wp_use_sku_instead && product_variation.sku && ('' !== product_variation.sku) ) {
			current_product_detail_data.id = product_variation.sku;
			current_product_detail_data.item_id = product_variation.sku;
		}
		current_product_detail_data.price = gtm4wp_make_sure_is_float( product_variation.display_price );

		let product_variation_attribute_values = [];
		for( let attrib_key in product_variation.attributes ) {
			product_variation_attribute_values.push( product_variation.attributes[ attrib_key ] );
		}
		current_product_detail_data.item_variant = product_variation_attribute_values.join(',');
		gtm4wp_last_selected_product_variation = current_product_detail_data;

		delete current_product_detail_data.internal_id;

		// fire ga4 version
		gtm4wp_push_ecommerce( 'view_item', [ current_product_detail_data ], {
			'currency': gtm4wp_currency,
			'value': current_product_detail_data.price
		});

		if ( document.readyState === "interactive" ) {
			gtm4wp_view_item_fired_during_pageload = true;
		}
	});
	jQuery( '.variations select' ).trigger( 'change' );

	// initiate codes in WooCommere Quick View
	// currently, we need to use jQuery here since WooCommerce Quick View is showing the popup using
	// jQuery AJAX calls that can not be catched using vanilla JS
	jQuery( document ).ajaxSuccess( function( event, xhr, settings ) {
		if(typeof settings !== 'undefined') {
			if (settings.url.indexOf( 'wc-api=WC_Quick_View' ) > -1 ) {
				setTimeout( function() {

					const dl_data = document.querySelector('#gtm4wp_quickview_data');
					if ( dl_data && dl_data.dataset && dl_data.dataset.gtm4wp_datalayer ) {
						try {
							const dl_data_obj = JSON.parse( dl_data.dataset.gtm4wp_datalayer );
							if ( dl_data_obj && window.dataLayer ) {
								window.dataLayer.push(dl_data_obj);
							}
						} catch(e) {
							console && console.error && console.error( e.message );
						}
					}

				}, 500);
			}
		}
	});

	let gtm4wp_is_cart     = false;
	let gtm4wp_is_checkout = false;

	const doc_body = document.querySelector( 'body' );
	if ( doc_body ) {
		gtm4wp_is_cart     = doc_body.classList && doc_body.classList.contains( 'woocommerce-cart' );
		gtm4wp_is_checkout = doc_body.classList && doc_body.classList.contains( 'woocommerce-checkout' );
	}

	// codes for ecommerce events on cart page
	if ( gtm4wp_is_cart ) {
		document.addEventListener( 'click', function( e ) {
			let event_target_element = e.target;

			if ( !event_target_element ) {
				// for some reason event target is not specificed
				return true;
			}

			if ( !event_target_element.closest( '[name=update_cart]' ) ) {
				return true;
			}

			gtm4wp_woocommerce_handle_cart_qty_change();
		});

		document.addEventListener( 'keypress', function( e ) {
			let event_target_element = e.target;

			if ( !event_target_element ) {
				// for some reason event target is not specificed
				return true;
			}

			if ( !event_target_element.closest( '.woocommerce-cart-form input[type=number]' ) ) {
				return true;
			}

			gtm4wp_woocommerce_handle_cart_qty_change();
		});
	}

	// codes for ecommerce events on checkout page
	if ( gtm4wp_is_checkout ) {
		window.gtm4wp_checkout_value        = window.gtm4wp_checkout_value || 0;
		window.gtm4wp_checkout_products     = window.gtm4wp_checkout_products || [];
		window.gtm4wp_checkout_products_ga4 = window.gtm4wp_checkout_products_ga4 || [];

		document.addEventListener( 'change', function( e ) {
			let event_target_element = e.target;

			if ( !event_target_element ) {
				// for some reason event target is not specificed
				return true;
			}

			if ( !event_target_element.closest( 'input[name^=shipping_method]' ) ) {
				return true;
			}

			gtm4wp_woocommerce_handle_shipping_method_change();
		});

		document.addEventListener( 'change', function( e ) {
			let event_target_element = e.target;

			if ( !event_target_element ) {
				// for some reason event target is not specificed
				return true;
			}

			if ( !event_target_element.closest( 'input[name=payment_method]' ) ) {
				return true;
			}

			gtm4wp_woocommerce_handle_payment_method_change();
		});

		// We need to use jQuery where since the checkout_place_order event is only triggered using jQuery
		const checkout_form = jQuery('form.checkout');
		checkout_form.on('checkout_place_order', function () {
			if ( gtm4wp_checkout_step_fired.indexOf( 'shipping_method' ) == -1 ) {
				// shipping methods are not visible if only one is available
				// and if the user has already a pre-selected method, no click event will fire to report the checkout step
				gtm4wp_woocommerce_handle_shipping_method_change();
			}

			if ( gtm4wp_checkout_step_fired.indexOf( 'payment_method' ) == -1 ) {
				// if the user has already a pre-selected method, no click event will fire to report the checkout step
				gtm4wp_woocommerce_handle_payment_method_change();
			}
		});
	}
};

function gtm4wp_woocommerce_page_loading_completed() {
	document.removeEventListener( "DOMContentLoaded", gtm4wp_woocommerce_page_loading_completed );
	window.removeEventListener( "load", gtm4wp_woocommerce_page_loading_completed );
	gtm4wp_woocommerce_process_pages();
}

// code and idea borrowed from jQuery:
// https://github.com/jquery/jquery/blob/main/src/core/ready.js
if ( document.readyState !== "loading" ) {
	window.setTimeout( gtm4wp_woocommerce_process_pages );
} else {
	document.addEventListener( "DOMContentLoaded", gtm4wp_woocommerce_page_loading_completed );
	window.addEventListener( "load", gtm4wp_woocommerce_page_loading_completed );
}
