<?php
/**
 * Acoustic Connect Event Handler
 *
 * Handles all WooCommerce event tracking
 *
 * @package Acoustic_Connect_Woo
 */

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

/**
 * Event Handler Class
 */
class Acoustic_Connect_Event_Handler
{

    /**
     * Single instance
     *
     * @var Acoustic_Connect_Event_Handler
     */
    private static $instance = null;

    /**
     * Constructor
     */
    private function __construct()
    {
        $this->register_hooks();
    }

    /**
     * Get instance
     *
     * @return Acoustic_Connect_Event_Handler
     */
    public static function get_instance()
    {
        if (null === self::$instance) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    /**
     * Register hooks
     */
    private function register_hooks()
    {
        // Only register if tracking is enabled
        if (!$this->is_tracking_enabled()) {
            return;
        }

        // Page context injection
        add_action('wp_footer', array($this, 'inject_page_context'), 5);

        // Product view tracking
        add_action('woocommerce_after_single_product', array($this, 'inject_product_view_tracking'));

        // Cart events - using proper WooCommerce hooks
        add_action('woocommerce_add_to_cart', array($this, 'handle_add_to_cart'), 10, 6);
        add_action('woocommerce_cart_item_removed', array($this, 'handle_remove_from_cart'), 10, 2);

        // Fragment filters for AJAX cart events - passes data to JavaScript
        add_filter('woocommerce_add_to_cart_fragments', array($this, 'add_cart_event_fragment'), 10, 1);

        // Inject product data into cart rows for remove-from-cart tracking
        add_filter('woocommerce_cart_item_name', array($this, 'inject_cart_item_product_data'), 10, 3);

        // Checkout events
        add_action('woocommerce_before_checkout_form', array($this, 'inject_checkout_data'));
        add_action('woocommerce_checkout_order_processed', array($this, 'handle_order_placed'), 10, 3);

        // Thank you page
        add_action('woocommerce_thankyou', array($this, 'inject_order_completion_tracking'));

        // Search tracking
        add_action('pre_get_posts', array($this, 'track_search'));

        // Add product data attributes to product loops
        add_action('woocommerce_after_shop_loop_item', array($this, 'add_product_data_attributes'));
    }

    /**
     * Check if tracking is enabled
     *
     * @return bool
     */
    private function is_tracking_enabled()
    {
        $enabled = get_option('acoustic_connect_enabled', 'no');
        $app_key = get_option('acoustic_connect_app_key', '');
        $collector_url = get_option('acoustic_connect_collector_url', '');

        return ('yes' === $enabled && !empty($app_key) && !empty($collector_url));
    }

    /**
     * Inject page context data
     */
    public function inject_page_context()
    {
        $context = array(
            'pageType' => $this->get_page_type(),
            'timestamp' => time() * 1000,
            'userAgent' => isset($_SERVER['HTTP_USER_AGENT']) ? sanitize_text_field(wp_unslash($_SERVER['HTTP_USER_AGENT'])) : '',
            'language' => get_locale(),
        );

        // Add WooCommerce specific context
        if (function_exists('WC') && WC()->cart) {
            $context['cart'] = array(
                'itemCount' => WC()->cart->get_cart_contents_count(),
                'total' => WC()->cart->get_total('raw'),
            );
        }

        wp_add_inline_script(
            'acoustic-connect-wrapper',
            'window.acousticConnectPageContext = ' . wp_json_encode($context) . ';',
            'before'
        );
    }

    /**
     * Get page type
     *
     * @return string
     */
    private function get_page_type()
    {
        if (is_front_page()) {
            return 'home';
        } elseif (is_product()) {
            return 'product';
        } elseif (is_product_category()) {
            return 'category';
        } elseif (is_product_tag()) {
            return 'tag';
        } elseif (is_shop()) {
            return 'shop';
        } elseif (is_cart()) {
            return 'cart';
        } elseif (is_checkout()) {
            return 'checkout';
        } elseif (is_account_page()) {
            return 'account';
        } elseif (is_search()) {
            return 'search';
        } elseif (is_page()) {
            return 'page';
        }

        return 'unknown';
    }

    /**
     * Inject product view tracking
     */
    public function inject_product_view_tracking()
    {
        if ('yes' !== get_option('acoustic_connect_track_product_view', 'yes')) {
            return;
        }

        global $product;

        if (!$product) {
            return;
        }

        $product_data = $this->get_product_data($product);

        wp_add_inline_script(
            'acoustic-connect-wrapper',
            'window.acousticProductData = ' . wp_json_encode($product_data) . ';',
            'before'
        );
    }

    /**
     * Handle add to cart
     *
     * Stores event data in WC session for the fragment filter to pick up.
     * This data is then passed to JavaScript via AJAX fragments.
     *
     * @param string $cart_item_key Cart item key.
     * @param int    $product_id    Product ID.
     * @param int    $quantity      Quantity.
     * @param int    $variation_id  Variation ID.
     * @param array  $variation     Variation data.
     * @param array  $cart_item_data Cart item data.
     */
    public function handle_add_to_cart($cart_item_key, $product_id, $quantity, $variation_id, $variation, $cart_item_data)
    {
        if ('yes' !== get_option('acoustic_connect_track_add_to_cart', 'yes')) {
            return;
        }

        $product = wc_get_product($variation_id ? $variation_id : $product_id);

        if (!$product) {
            return;
        }

        // Store event in WC session for fragment filter to pick up (same request)
        $event_data = array(
            'type' => 'addToCart',
            'product' => $this->get_product_data($product),
            'quantity' => $quantity,
            'cart_item_key' => $cart_item_key,
        );

        // Use WC session instead of transients - more reliable for same-request data passing
        if (function_exists('WC') && WC()->session) {
            WC()->session->set('acoustic_last_cart_event', $event_data);
        }
    }

    /**
     * Add cart event data to AJAX fragments
     *
     * This is called after add-to-cart AJAX and passes event data to JavaScript
     * via the fragments response.
     *
     * @param array $fragments Cart fragments.
     * @return array Modified fragments.
     */
    public function add_cart_event_fragment($fragments)
    {
        if (!function_exists('WC') || !WC()->session) {
            return $fragments;
        }

        $event_data = WC()->session->get('acoustic_last_cart_event');

        if ($event_data) {
            // Clear after reading to avoid duplicate events
            WC()->session->set('acoustic_last_cart_event', null);

            // Add as a script tag that JavaScript can read from fragments
            $fragments['.acoustic-cart-event'] = '<script type="application/json" class="acoustic-cart-event">'
                . wp_json_encode($event_data) . '</script>';
        }

        return $fragments;
    }

    /**
     * Inject product data into cart item name
     *
     * Adds hidden product data span to cart rows for remove-from-cart tracking.
     *
     * @param string $product_name Product name HTML.
     * @param array  $cart_item Cart item data.
     * @param string $cart_item_key Cart item key.
     * @return string Modified product name HTML.
     */
    public function inject_cart_item_product_data($product_name, $cart_item, $cart_item_key)
    {
        $product = $cart_item['data'] ?? null;

        if (!$product) {
            return $product_name;
        }

        $product_data = $this->get_product_data($product);
        $product_data['quantity'] = $cart_item['quantity'];
        $product_data['cart_item_key'] = $cart_item_key;

        $data_span = '<span class="acoustic-product-data" style="display:none;" data-product="'
            . esc_attr(wp_json_encode($product_data)) . '"></span>';

        return $product_name . $data_span;
    }

    /**
     * Handle remove from cart
     *
     * Note: This hook fires AFTER the item is removed, so we need to get the item
     * from removed_cart_contents, not from get_cart_item().
     *
     * @param string   $cart_item_key Cart item key.
     * @param WC_Cart $cart          Cart object.
     */
    public function handle_remove_from_cart($cart_item_key, $cart)
    {
        if ('yes' !== get_option('acoustic_connect_track_remove_from_cart', 'yes')) {
            return;
        }

        // Item has already been removed, check removed_cart_contents
        $cart_item = $cart->removed_cart_contents[$cart_item_key] ?? null;

        if (!$cart_item) {
            return;
        }

        $product = wc_get_product($cart_item['product_id']);

        if (!$product) {
            return;
        }

        // Store event in WC session for potential AJAX fragment response
        $event_data = array(
            'type' => 'removeFromCart',
            'product' => $this->get_product_data($product),
            'quantity' => $cart_item['quantity'],
        );

        // Use WC session instead of transients
        if (function_exists('WC') && WC()->session) {
            WC()->session->set('acoustic_last_remove_event', $event_data);
        }
    }

    /**
     * Inject checkout data
     */
    public function inject_checkout_data()
    {
        if ('yes' !== get_option('acoustic_connect_track_checkout', 'yes')) {
            return;
        }

        $cart_data = $this->get_cart_data();

        wp_add_inline_script(
            'acoustic-connect-wrapper',
            'window.acousticConnectCartData = ' . wp_json_encode($cart_data) . ';',
            'before'
        );
    }

    /**
     * Handle order placed
     *
     * @param int      $order_id    Order ID.
     * @param array    $posted_data Posted data.
     * @param WC_Order $order       Order object.
     */
    public function handle_order_placed($order_id, $posted_data, $order)
    {
        if ('yes' !== get_option('acoustic_connect_track_checkout', 'yes')) {
            return;
        }

        $order_data = array(
            'order_id' => $order_id,
            'cart_value' => $order->get_total(),
            'subtotal' => $order->get_subtotal(),
            'shipping_cost' => $order->get_shipping_total(),
            'tax' => $order->get_total_tax(),
            'currency' => $order->get_currency(),
            'payment_method' => $order->get_payment_method(),
            'line_items' => array(),
        );

        foreach ($order->get_items() as $item) {
            $product = $item->get_product();

            if ($product) {
                $quantity = max(1, $item->get_quantity());
                $order_data['line_items'][] = array(
                    'product_id' => $product->get_id(),
                    'product_name' => $product->get_name(),
                    'quantity' => $quantity,
                    'base_price' => $product->get_price(),
                    'purchase_price' => $item->get_total() / $quantity,
                );
            }
        }

        // Store in transient for thank you page
        set_transient('acoustic_order_' . $order_id, $order_data, 3600);
    }

    /**
     * Inject order completion tracking on thank you page
     *
     * @param int $order_id Order ID.
     */
    public function inject_order_completion_tracking($order_id)
    {
        if (!$order_id) {
            return;
        }

        $order_data = get_transient('acoustic_order_' . $order_id);

        if (!$order_data) {
            return;
        }

        wp_add_inline_script(
            'acoustic-connect-wrapper',
            'window.acousticOrderData = ' . wp_json_encode($order_data) . ';',
            'before'
        );

        // Delete transient
        delete_transient('acoustic_order_' . $order_id);
    }

    /**
     * Track search
     *
     * Note: Search tracking is now handled entirely by JavaScript which extracts
     * the search term from URL parameters and counts results from the DOM.
     * This method is kept for potential future server-side enhancements.
     *
     * @param WP_Query $query Query object.
     */
    public function track_search($query)
    {
        // Search tracking is handled client-side in acoustic-connect-wrapper.js
        // This hook is kept for potential future server-side search analytics
        return;
    }

    /**
     * Add product data attributes
     */
    public function add_product_data_attributes()
    {
        global $product;

        if (!$product) {
            return;
        }

        $product_data = $this->get_product_data($product);

        echo '<div class="acoustic-product-data" style="display:none;" data-product="' . esc_attr(wp_json_encode($product_data)) . '"></div>';
    }

    /**
     * Get product data
     *
     * @param WC_Product $product Product object.
     * @return array
     */
    private function get_product_data($product)
    {
        $categories = array();
        $terms = get_the_terms($product->get_id(), 'product_cat');

        if ($terms && !is_wp_error($terms)) {
            foreach ($terms as $term) {
                $categories[] = $term->name;
            }
        }

        $data = array(
            'product_id' => $product->get_id(),
            'product_name' => $product->get_name(),
            'sale_price' => $product->get_price(),
            'regular_price' => $product->get_regular_price(),
            'discount_price' => $product->get_sale_price(),
            'currency' => get_woocommerce_currency(),
            'sku' => $product->get_sku(),
            'category_names' => $categories,
            'in_stock' => $product->is_in_stock(),
            'product_type' => $product->get_type(),
            'product_url' => $product->get_permalink(),
        );

        return apply_filters('acoustic_connect_product_data', $data, $product);
    }

    /**
     * Get cart data
     *
     * @return array
     */
    private function get_cart_data()
    {
        if (!function_exists('WC') || !WC()->cart) {
            return array();
        }

        $items = array();

        foreach (WC()->cart->get_cart() as $cart_item) {
            $product = $cart_item['data'];

            if ($product) {
                $items[] = array(
                    'id' => $product->get_id(),
                    'name' => $product->get_name(),
                    'quantity' => $cart_item['quantity'],
                    'price' => $product->get_price(),
                    'total' => $cart_item['line_total'],
                );
            }
        }

        $data = array(
            'items' => $items,
            'itemCount' => WC()->cart->get_cart_contents_count(),
            'subtotal' => WC()->cart->get_cart_subtotal(),
            'total' => WC()->cart->get_total('raw'),
            'currency' => get_woocommerce_currency(),
        );

        return apply_filters('acoustic_connect_cart_data', $data);
    }
}