<?php
if ( ! defined( 'ABSPATH' ) ) {
	exit; // Exit if accessed directly
}

/**
 * Google Analytics Integration
 *
 * Allows tracking code to be inserted into store pages.
 *
 * @class   WC_Google_Analytics
 * @extends WC_Integration
 */
class WC_Google_Analytics extends WC_Integration {

	/**
	 * Init and hook in the integration.
	 *
	 * @return void
	 */
	public function __construct() {
		$this->id                    = 'google_analytics';
		$this->method_title          = __( 'Google Analytics', 'woocommerce-google-analytics-integration' );
		$this->method_description    = __( 'Google Analytics is a free service offered by Google that generates detailed statistics about the visitors to a website.', 'woocommerce-google-analytics-integration' );
		$this->dismissed_info_banner = get_option( 'woocommerce_dismissed_info_banner' );

		// Load the settings
		$this->init_form_fields();
		$this->init_settings();
		$constructor = $this->init_options();

		// Contains snippets/JS tracking code
		include_once( 'class-wc-google-analytics-js.php' );
		WC_Google_Analytics_JS::get_instance( $constructor );

		// Display an info banner on how to configure WooCommerce
		if ( is_admin() ) {
			include_once( 'class-wc-google-analytics-info-banner.php' );
			WC_Google_Analytics_Info_Banner::get_instance( $this->dismissed_info_banner, $this->ga_id );
		}

		// Admin Options
		add_filter( 'woocommerce_tracker_data', array( $this, 'track_options' ) );
		add_action( 'woocommerce_update_options_integration_google_analytics', array( $this, 'process_admin_options') );
		add_action( 'woocommerce_update_options_integration_google_analytics', array( $this, 'show_options_info') );
		add_action( 'admin_enqueue_scripts', array( $this, 'load_admin_assets') );

		// Tracking code
		add_action( 'wp_head', array( $this, 'tracking_code_display' ), 999999 );

		// Event tracking code
		add_action( 'woocommerce_after_add_to_cart_button', array( $this, 'add_to_cart' ) );
		add_action( 'wp_footer', array( $this, 'loop_add_to_cart' ) );
		add_action( 'woocommerce_after_cart', array( $this, 'remove_from_cart' ) );
		add_action( 'woocommerce_after_mini_cart', array( $this, 'remove_from_cart' ) );
		add_filter( 'woocommerce_cart_item_remove_link', array( $this, 'remove_from_cart_attributes' ), 10, 2 );
		add_action( 'woocommerce_after_shop_loop_item', array( $this, 'listing_impression' ) );
		add_action( 'woocommerce_after_shop_loop_item', array( $this, 'listing_click' ) );
		add_action( 'woocommerce_after_single_product', array( $this, 'product_detail' ) );
		add_action( 'woocommerce_after_checkout_form', array( $this, 'checkout_process' ) );

		// utm_nooverride parameter for Google AdWords
		add_filter( 'woocommerce_get_return_url', array( $this, 'utm_nooverride' ) );
	}

	/**
	 * Loads all of our options for this plugin
	 * @return array An array of options that can be passed to other classes
	 */
	public function init_options() {
		$options = array(
			'ga_id',
			'ga_set_domain_name',
			'ga_standard_tracking_enabled',
			'ga_support_display_advertising',
			'ga_use_universal_analytics',
			'ga_anonymize_enabled',
			'ga_ecommerce_tracking_enabled',
			'ga_enhanced_ecommerce_tracking_enabled',
			'ga_enhanced_remove_from_cart_enabled',
			'ga_enhanced_product_impression_enabled',
			'ga_enhanced_product_click_enabled',
			'ga_enhanced_checkout_process_enabled',
			'ga_enhanced_product_detail_view_enabled',
			'ga_event_tracking_enabled'
		);

		$constructor = array();
		foreach ( $options as $option ) {
			$constructor[ $option ] = $this->$option = $this->get_option( $option );
		}

		return $constructor;
	}

	/**
	 * Tells WooCommerce which settings to display under the "integration" tab
	 */
	public function init_form_fields() {
		$this->form_fields = array(
			'ga_id' => array(
				'title'       => __( 'Google Analytics ID', 'woocommerce-google-analytics-integration' ),
				'description' => __( 'Log into your Google Analytics account to find your ID. e.g. <code>UA-XXXXX-X</code>', 'woocommerce-google-analytics-integration' ),
				'type'        => 'text',
				'placeholder' => 'UA-XXXXX-X',
				'default'     => get_option( 'woocommerce_ga_id' ) // Backwards compat
			),
			'ga_set_domain_name' => array(
				'title' 			=> __( 'Set Domain Name', 'woocommerce-google-analytics-integration' ),
				'description' 		=> sprintf( __( '(Optional) Sets the <code>_setDomainName</code> variable. <a href="%s">See here for more information</a>.', 'woocommerce-google-analytics-integration' ), 'https://developers.google.com/analytics/devguides/collection/gajs/gaTrackingSite#multipleDomains' ),
				'type' 				=> 'text',
				'default' 			=> ''
			),
			'ga_standard_tracking_enabled' => array(
				'title'         => __( 'Tracking Options', 'woocommerce-google-analytics-integration' ),
				'label'         => __( 'Enable Standard Tracking', 'woocommerce-google-analytics-integration' ),
				'description'   =>  __( 'This tracks session data such as demographics, system, etc. You don\'t need to enable this if you are using a 3rd party Google analytics plugin.', 'woocommerce-google-analytics-integration' ),
				'type'          => 'checkbox',
				'checkboxgroup' => 'start',
				'default'       => get_option( 'woocommerce_ga_standard_tracking_enabled' ) ? get_option( 'woocommerce_ga_standard_tracking_enabled' ) : 'no'  // Backwards compat
			),
			'ga_support_display_advertising' => array(
				'label'         => __( '"Display Advertising" Support', 'woocommerce-google-analytics-integration' ),
				'description'   => sprintf( __( 'Set the Google Analytics code to support Display Advertising. %sRead more about Display Advertising%s.', 'woocommerce-google-analytics-integration' ), '<a href="https://support.google.com/analytics/answer/2700409" target="_blank">', '</a>' ),
				'type'          => 'checkbox',
				'checkboxgroup' => '',
				'default'       => get_option( 'woocommerce_ga_support_display_advertising' ) ? get_option( 'woocommerce_ga_support_display_advertising' ) : 'no'  // Backwards compat
			),
			'ga_use_universal_analytics' => array(
				'label'         => __( 'Enable Universal Analytics', 'woocommerce-google-analytics-integration' ),
				'description'   => sprintf( __( 'Uses Universal Analytics instead of Classic Google Analytics. If you have <strong>not</strong> previously used Google Analytics on this site, check this box. Otherwise, %sfollow step 1 of the Universal Analytics upgrade guide.%s Enabling this setting will take care of step 2. %sRead more about Universal Analytics%s. Universal Analytics must be enabled to enable enhanced eCommerce.', 'woocommerce-google-analytics-integration' ), '<a href="https://developers.google.com/analytics/devguides/collection/upgrade/guide" target="_blank">', '</a>', '<a href="https://support.google.com/analytics/answer/2790010?hl=en" target="_blank">', '</a>' ),
				'type'          => 'checkbox',
				'checkboxgroup' => '',
				'default'       => get_option( 'woocommerce_ga_use_universal_analytics' ) ? get_option( 'woocommerce_ga_use_universal_analytics' ) : 'no'  // Backwards compat
			),
			'ga_anonymize_enabled' => array(
				'label'         => __( 'Anonymize IP addresses.', 'woocommerce-google-analytics-integration' ),
				'description'   => sprintf( __( 'Enabling this option is mandatory in certain countries due to national privacy laws. %sRead more about IP Anonymization%s.', 'woocommerce-google-analytics-integration' ), '<a href="https://support.google.com/analytics/answer/2763052" target="_blank">', '</a>' ),
				'type'          => 'checkbox',
				'checkboxgroup' => '',
				'default'       => 'yes'
			),
			'ga_ecommerce_tracking_enabled' => array(
				'label' 			=> __( 'Purchase Transactions', 'woocommerce-google-analytics-integration' ),
				'description' 			=> __( 'This requires a payment gateway that redirects to the thank you/order received page after payment. Orders paid with gateways which do not do this will not be tracked.', 'woocommerce-google-analytics-integration' ),
				'type' 				=> 'checkbox',
				'checkboxgroup'		=> 'start',
				'default' 			=> get_option( 'woocommerce_ga_ecommerce_tracking_enabled' ) ? get_option( 'woocommerce_ga_ecommerce_tracking_enabled' ) : 'yes'  // Backwards compat
			),
			'ga_event_tracking_enabled' => array(
				'label' 			=> __( 'Add to Cart Events', 'woocommerce-google-analytics-integration' ),
				'type' 				=> 'checkbox',
				'checkboxgroup'		=> '',
				'default' 			=> 'yes'
			),

			'ga_enhanced_ecommerce_tracking_enabled' => array(
				'title'         => __( 'Enhanced eCommerce', 'woocommerce-google-analytics-integration' ),
				'label'         => __( 'Enable Enhanced eCommerce ', 'woocommerce-google-analytics-integration' ),
				'description'   => sprintf( __( 'Enhanced eCommerce allows you to measure more user interactions with your store, including: product impressions, product detail views, starting the checkout process, adding cart items, and removing cart items. Universal Analytics must be enabled for Enhanced eCommerce to work. Before enabling this setting, turn on Enhanced eCommerce in your Google Analytics dashboard. <a href="%s">See here for more information</a>.', 'woocommerce-google-analytics-integration' ), 'https://support.google.com/analytics/answer/6032539?hl=en' ),
				'type'          => 'checkbox',
				'checkboxgroup' => '',
				'default'       => 'no'
			),

			// Enhanced eCommerce Settings

			'ga_enhanced_remove_from_cart_enabled' => array(
				'label' 			=> __( 'Remove from Cart Events', 'woocommerce-google-analytics-integration' ),
				'type' 				=> 'checkbox',
				'checkboxgroup'		=> '',
				'default' 			=> 'yes',
				'class'             => 'enhanced-setting'
			),

			'ga_enhanced_product_impression_enabled' => array(
				'label' 			=> __( 'Product Impressions from Listing Pages', 'woocommerce-google-analytics-integration' ),
				'type' 				=> 'checkbox',
				'checkboxgroup'		=> '',
				'default' 			=> 'yes',
				'class'             => 'enhanced-setting'
			),

			'ga_enhanced_product_click_enabled' => array(
				'label' 			=> __( 'Product Clicks from Listing Pages', 'woocommerce-google-analytics-integration' ),
				'type' 				=> 'checkbox',
				'checkboxgroup'		=> '',
				'default' 			=> 'yes',
				'class'             => 'enhanced-setting'
			),

			'ga_enhanced_product_detail_view_enabled' => array(
				'label' 			=> __( 'Product Detail Views', 'woocommerce-google-analytics-integration' ),
				'type' 				=> 'checkbox',
				'checkboxgroup'		=> '',
				'default' 			=> 'yes',
				'class'             => 'enhanced-setting'
			),

			'ga_enhanced_checkout_process_enabled' => array(
				'label' 			=> __( 'Checkout Process Initiated', 'woocommerce-google-analytics-integration' ),
				'type' 				=> 'checkbox',
				'checkboxgroup'		=> '',
				'default' 			=> 'yes',
				'class'             => 'enhanced-setting'
			),
		);
	}

	/**
	 * Shows some additional help text after saving the Google Analytics settings
	 */
	function show_options_info() {
		$this->method_description .= "<div class='notice notice-info'><p>" . __( 'Please allow Google Analytics 24 hours to start displaying results.', 'woocommerce-google-analytics-integration' ) . "</p></div>";

		if ( isset( $_REQUEST['woocommerce_google_analytics_ga_ecommerce_tracking_enabled'] ) && true === (bool) $_REQUEST['woocommerce_google_analytics_ga_ecommerce_tracking_enabled'] ) {
			$this->method_description .= "<div class='notice notice-info'><p>" . __( 'Please note, for transaction tracking to work properly, you will need to use a payment gateway that redirects the customer back to a WooCommerce order received/thank you page.', 'woocommerce-google-analytics-integration' ) . "</div>";
		}
	}

	/**
	 * Hooks into woocommerce_tracker_data and tracks some of the analytic settings (just enabled|disabled status)
	 * only if you have opted into WooCommerce tracking
	 * http://www.woothemes.com/woocommerce/usage-tracking/
	 */
	function track_options( $data ) {
		$data['wc-google-analytics'] = array(
			'standard_tracking_enabled'   => $this->ga_standard_tracking_enabled,
			'support_display_advertising' => $this->ga_support_display_advertising,
			'use_universal_analytics'     => $this->ga_use_universal_analytics,
			'anonymize_enabled'           => $this->ga_anonymize_enabled,
			'ecommerce_tracking_enabled'  => $this->ga_ecommerce_tracking_enabled,
			'event_tracking_enabled'      => $this->ga_event_tracking_enabled
		);
		return $data;
	}

	/**
	 *
	 */
	function load_admin_assets() {
		$screen = get_current_screen();
		if ( 'woocommerce_page_wc-settings' !== $screen->id ) {
			return;
		}

		if ( empty( $_GET['tab'] ) ) {
			return;
		}

		if ( 'integration' !== $_GET['tab'] ) {
			return;
		}

		wp_enqueue_script( 'wc-google-analytics-admin-enhanced-settings', plugins_url(  '/assets/js/admin-enhanced-settings.js', dirname(__FILE__) ) );
	}

	/**
	 * Display the tracking codes
	 * Acts as a controller to figure out which code to display
	 */
	public function tracking_code_display() {
		global $wp;
		$display_ecommerce_tracking = false;

		if ( is_admin() || current_user_can( 'manage_options' ) || ! $this->ga_id ) {
			return;
		}

		// Check if is order received page and stop when the products and not tracked
		if ( is_order_received_page() && 'yes' === $this->ga_ecommerce_tracking_enabled ) {
			$order_id = isset( $wp->query_vars['order-received'] ) ? $wp->query_vars['order-received'] : 0;
			if ( 0 < $order_id && 1 != get_post_meta( $order_id, '_ga_tracked', true ) ) {
				$display_ecommerce_tracking = true;
				echo $this->get_ecommerce_tracking_code( $order_id );
			}
		}

		if ( is_woocommerce() || is_cart() || ( is_checkout() && ! $display_ecommerce_tracking ) ) {
			$display_ecommerce_tracking = true;
			echo $this->get_standard_tracking_code();
		}

		if ( ! $display_ecommerce_tracking && 'yes' === $this->ga_standard_tracking_enabled ) {
			echo $this->get_standard_tracking_code();
		}
	}

	/**
	 * Standard Google Analytics tracking
	 */
	protected function get_standard_tracking_code() {
		return "<!-- WooCommerce Google Analytics Integration -->
		" . WC_Google_Analytics_JS::get_instance()->header() . "
		<script type='text/javascript'>" . WC_Google_Analytics_JS::get_instance()->load_analytics() . "</script>
		<!-- /WooCommerce Google Analytics Integration -->";
	}

	/**
	 * eCommerce tracking
	 *
	 * @param int $order_id
	 */
	protected function get_ecommerce_tracking_code( $order_id ) {
		// Get the order and output tracking code
		$order = new WC_Order( $order_id );

		$code = WC_Google_Analytics_JS::get_instance()->load_analytics( $order );
		$code .= WC_Google_Analytics_JS::get_instance()->add_transaction( $order );

		// Mark the order as tracked
		update_post_meta( $order_id, '_ga_tracked', 1 );

		return "
		<!-- WooCommerce Google Analytics Integration -->
		" . WC_Google_Analytics_JS::get_instance()->header() . "
		<script type='text/javascript'>$code</script>
		<!-- /WooCommerce Google Analytics Integration -->
		";
	}

	/**
	 * Check if tracking is disabled
	 *
	 * @param string $type The setting to check
	 *
	 * @return bool True if tracking for a certain setting is disabled
	 */
	private function disable_tracking( $type ) {
		if ( is_admin() || current_user_can( 'manage_options' ) || ( ! $this->ga_id ) || 'no' === $type ) {
			return true;
		}
	}

	/**
	 * Google Analytics event tracking for single product add to cart
	 *
	 * @return void
	 */
	public function add_to_cart() {
		if ( $this->disable_tracking( $this->ga_event_tracking_enabled ) ) {
			return;
		}
		if ( ! is_single() ) {
			return;
		}

		global $product;

		// Add single quotes to allow jQuery to be substituted into _trackEvent parameters
		$parameters = array();
		$parameters['category'] = "'" . __( 'Products', 'woocommerce-google-analytics-integration' ) . "'";
		$parameters['action']   = "'" . __( 'Add to Cart', 'woocommerce-google-analytics-integration' ) . "'";
		$parameters['label']    = "'" . esc_js( $product->get_sku() ? __( 'SKU:', 'woocommerce-google-analytics-integration' ) . ' ' . $product->get_sku() : "#" . $product->id ) . "'";

		if ( ! $this->disable_tracking( $this->ga_enhanced_ecommerce_tracking_enabled ) ) {
			$code = "" . WC_Google_Analytics_JS::get_instance()->tracker_var() . "( 'ec:addProduct', {";
			$code .= "'id': '" . esc_js( $product->get_sku() ? $product->get_sku() : $product->id ) . "',";
			$code .= "'quantity': $( 'input.qty' ).val() ? $( 'input.qty' ).val() : '1'";
			$code .= "} );";
			$parameters['enhanced'] = $code;
		}

		WC_Google_Analytics_JS::get_instance()->event_tracking_code( $parameters, '.single_add_to_cart_button' );
	}

	/**
	 * Enhanced Analytics event tracking for removing a product from the cart
	 */
	public function remove_from_cart() {
		if ( $this->disable_tracking( $this->ga_use_universal_analytics ) ) {
			return;
		}

		if ( $this->disable_tracking( $this->ga_enhanced_ecommerce_tracking_enabled ) ) {
			return;
		}

		if ( $this->disable_tracking( $this->ga_enhanced_remove_from_cart_enabled ) ) {
			return;
		}

		WC_Google_Analytics_JS::get_instance()->remove_from_cart();
	}

	/**
	 * Adds the product ID and SKU to the remove product link if not present
	 */
	public function remove_from_cart_attributes( $url, $key ) {
		if ( strpos( $url,'data-product_id' ) !== false ) {
			return $url;
		}

		$item = WC()->cart->get_cart_item( $key );
		$product = $item['data'];
		$url = str_replace( 'href=', 'data-product_id="' . esc_attr( $product->id ) . '" data-product_sku="' . esc_attr( $product->get_sku() )  . '" href=', $url );
		return $url;
	}

	/**
	 * Google Analytics event tracking for loop add to cart
	 *
	 * @return void
	 */
	public function loop_add_to_cart() {
		if ( $this->disable_tracking( $this->ga_event_tracking_enabled ) ) {
			return;
		}

		// Add single quotes to allow jQuery to be substituted into _trackEvent parameters
		$parameters = array();
		$parameters['category'] = "'" . __( 'Products', 'woocommerce-google-analytics-integration' ) . "'";
		$parameters['action']   = "'" . __( 'Add to Cart', 'woocommerce-google-analytics-integration' ) . "'";
		$parameters['label']    = "($(this).data('product_sku')) ? ('SKU: ' + $(this).data('product_sku')) : ('#' + $(this).data('product_id'))"; // Product SKU or ID

		if ( ! $this->disable_tracking( $this->ga_enhanced_ecommerce_tracking_enabled ) ) {
			$code = "" . WC_Google_Analytics_JS::get_instance()->tracker_var() . "( 'ec:addProduct', {";
			$code .= "'id': ($(this).data('product_sku')) ? ('SKU: ' + $(this).data('product_sku')) : ('#' + $(this).data('product_id')),";
			$code .= "'quantity': $(this).data('quantity')";
			$code .= "} );";
			$parameters['enhanced'] = $code;
		}

		WC_Google_Analytics_JS::get_instance()->event_tracking_code( $parameters, '.add_to_cart_button:not(.product_type_variable, .product_type_grouped)' );
	}

	/**
	 * Measures a listing impression (from search results)
	 */
	public function listing_impression() {
		if ( $this->disable_tracking( $this->ga_use_universal_analytics ) ) {
			return;
		}

		if ( $this->disable_tracking( $this->ga_enhanced_ecommerce_tracking_enabled ) ) {
			return;
		}

		if ( $this->disable_tracking( $this->ga_enhanced_product_impression_enabled ) ) {
			return;
		}

		global $product, $woocommerce_loop;
		WC_Google_Analytics_JS::get_instance()->listing_impression( $product, $woocommerce_loop['loop'] );
	}

	/**
	 * Measure a product click from a listing page
	 */
	public function listing_click() {
		if ( $this->disable_tracking( $this->ga_use_universal_analytics ) ) {
			return;
		}

		if ( $this->disable_tracking( $this->ga_enhanced_ecommerce_tracking_enabled ) ) {
			return;
		}

		if ( $this->disable_tracking( $this->ga_enhanced_product_click_enabled ) ) {
			return;
		}

		global $product, $woocommerce_loop;
		WC_Google_Analytics_JS::get_instance()->listing_click( $product, $woocommerce_loop['loop'] );
	}

	/**
	 * Measure a product detail view
	 */
	public function product_detail() {
		if ( $this->disable_tracking( $this->ga_use_universal_analytics ) ) {
			return;
		}

		if ( $this->disable_tracking( $this->ga_enhanced_ecommerce_tracking_enabled ) ) {
			return;
		}

		if ( $this->disable_tracking( $this->ga_enhanced_product_detail_view_enabled ) ) {
			return;
		}

		global $product;
		WC_Google_Analytics_JS::get_instance()->product_detail( $product );
	}

	/**
	 * Tracks when the checkout form is loaded
	 */
	public function checkout_process( $checkout ) {
		if ( $this->disable_tracking( $this->ga_use_universal_analytics ) ) {
			return;
		}

		if ( $this->disable_tracking( $this->ga_enhanced_ecommerce_tracking_enabled ) ) {
			return;
		}

		if ( $this->disable_tracking( $this->ga_enhanced_checkout_process_enabled ) ) {
			return;
		}

		WC_Google_Analytics_JS::get_instance()->checkout_process( WC()->cart->get_cart() );
	}

	/**
	 * Add the utm_nooverride parameter to any return urls. This makes sure Google Adwords doesn't mistake the offsite gateway as the referrer.
	 *
	 * @param  string $return_url WooCommerce Return URL
	 *
	 * @return string URL
	 */
	public function utm_nooverride( $return_url ) {
		// We don't know if the URL already has the parameter so we should remove it just in case
		$return_url = remove_query_arg( 'utm_nooverride', $return_url );

		// Now add the utm_nooverride query arg to the URL
		$return_url = add_query_arg( 'utm_nooverride', '1', $return_url );

		return $return_url;
	}
}