<?php
namespace ArrayFunnel\Features\Analytics\Services;

defined( 'ABSPATH' ) || exit;

/**
 * Records conversion events in the plugin's own analytics table.
 */
final class EventTracker {

    public function __construct() {
        // Track completed orders across classic and block checkout flows.
        add_action( 'woocommerce_checkout_order_created', [ $this, 'trackOrder' ], 10, 1 );
        add_action( 'woocommerce_checkout_order_processed', [ $this, 'trackOrderProcessed' ], 10, 3 );
        add_action( 'woocommerce_store_api_checkout_order_processed', [ $this, 'trackOrder' ], 10, 1 );
        add_action( 'woocommerce_payment_complete', [ $this, 'trackOrderById' ], 10, 1 );
        add_action( 'woocommerce_order_status_processing', [ $this, 'trackOrderById' ], 10, 1 );
        add_action( 'woocommerce_order_status_completed', [ $this, 'trackOrderById' ], 10, 1 );

        // Track add to cart
        add_action( 'woocommerce_add_to_cart', [ $this, 'trackAddToCart' ], 10, 3 );

        // Track checkout page view
        add_action( 'woocommerce_before_checkout_form', [ $this, 'trackCheckoutView' ] );
    }

    public function trackOrder( $order ): void {
        if ( is_numeric( $order ) ) {
            $this->trackOrderById( (int) $order );
            return;
        }

        if ( ! $order instanceof \WC_Order ) {
            return;
        }

        if ( $this->hasTrackedOrder( (int) $order->get_id() ) ) {
            return;
        }

        $this->record( 'order_completed', [
            'order_id' => $order->get_id(),
            'revenue'  => (float) $order->get_total(),
        ] );
    }

    public function trackOrderProcessed( int $order_id ): void {
        $this->trackOrderById( $order_id );
    }

    public function trackOrderById( int $order_id ): void {
        if ( $order_id <= 0 || $this->hasTrackedOrder( $order_id ) ) {
            return;
        }

        $order = wc_get_order( $order_id );
        if ( ! $order instanceof \WC_Order ) {
            return;
        }

        $this->trackOrder( $order );
    }

    /**
     * Record a product being added to the cart.
     *
     * @param string $cart_item_key Cart item key WooCommerce generated. Unused.
     * @param int    $product_id    Product added to the cart.
     * @param int    $quantity      Quantity added.
     */
    public function trackAddToCart( string $cart_item_key, int $product_id, int $quantity ): void {
        $this->record( 'add_to_cart', [
            'product_id' => $product_id,
            'quantity'   => $quantity,
        ] );
    }

    public function trackCheckoutView(): void {
        $this->record( 'checkout_view' );
    }

    public function record( string $event_type, array $meta = [] ): void {
        global $wpdb;

        // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery
        $inserted = $wpdb->insert(
            $wpdb->prefix . 'arrayfunnel_analytics',
            [
                'event_type' => $event_type,
                'order_id'   => $meta['order_id'] ?? null,
                'user_id'    => get_current_user_id() ?: null,
                'session_id' => $this->getSessionId(),
                'revenue'    => $meta['revenue'] ?? 0.00,
                'meta'       => ! empty( $meta ) ? wp_json_encode( $meta ) : null,
                'created_at' => current_time( 'mysql', true ),
            ],
            [ '%s', '%d', '%d', '%s', '%f', '%s', '%s' ]
        );

        if ( false !== $inserted ) {
            $this->invalidateAnalyticsCache();
        }
    }

    private function hasTrackedOrder( int $order_id ): bool {
        if ( $order_id <= 0 ) {
            return false;
        }

        global $wpdb;
        // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching
        $exists = $wpdb->get_var(
            $wpdb->prepare(
                "SELECT id
                 FROM {$wpdb->prefix}arrayfunnel_analytics
                 WHERE event_type = %s
                   AND order_id = %d
                 LIMIT 1",
                'order_completed',
                $order_id
            )
        );

        return ! empty( $exists );
    }

    private function invalidateAnalyticsCache(): void {
        global $wpdb;

        $patterns = [
            '_transient_arrayfunnel_overview_%',
            '_transient_timeout_arrayfunnel_overview_%',
            '_transient_arrayfunnel_revenue_chart_%',
            '_transient_timeout_arrayfunnel_revenue_chart_%',
            '_transient_arrayfunnel_events_log_%',
            '_transient_timeout_arrayfunnel_events_log_%',
        ];

        foreach ( $patterns as $pattern ) {
            // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching
            $wpdb->query(
                $wpdb->prepare(
                    "DELETE FROM {$wpdb->options}
                     WHERE option_name LIKE %s",
                    $pattern
                )
            );
        }
    }

    private function getSessionId(): string {
        $session_id = WC()->session ? (string) WC()->session->get_customer_id() : '';
        if ( '' !== $session_id ) {
            return hash( 'sha256', 'arrayfunnel_analytics|' . $session_id );
        }

        return wp_generate_uuid4();
    }
}