<?php
/**
 * Storefront pixel.
 *
 * @package CortexCommerce
 */

namespace CortexCommerce\Pixel;

use CortexCommerce\Settings\Config;
use CortexCommerce\Settings\Options;
use CortexCommerce\Support\Log;

defined( 'ABSPATH' ) || exit;

/**
 * Prints the per-page pixel config and a loader that injects the hosted script (Config::pixel_src()) after the
 * page's load event, so nothing of ours can delay it. The config holds nothing about the visitor, so full-page
 * caches stay safe. Spec: docs/superpowers/specs/2026-09-25-pixel-v2-design.md §3.1, §4, §6.
 */
final class PixelModule {

	const HANDLE = 'cortexcommerce-pixel';

	/**
	 * Whether a build failure was logged in this request already.
	 *
	 * @var bool
	 */
	private static $logged = false;

	public function register(): void {
		add_action( 'wp_enqueue_scripts', array( $this, 'enqueue' ) );
	}

	public function enqueue(): void {
		try {
			if ( ! self::should_load() ) {
				return;
			}
			$loader = self::loader();
			wp_register_script( self::HANDLE, false, array(), null, array( 'in_footer' => true ) ); // phpcs:ignore WordPress.WP.EnqueuedResourceParameters.MissingVersion -- inline only, nothing to cache-bust.
			wp_enqueue_script( self::HANDLE );
			wp_add_inline_script( self::HANDLE, $loader );
		} catch ( \Throwable $e ) {
			if ( ! self::$logged ) {
				self::$logged = true;
				try {
					Log::error( 'Pixel left off for this page: ' . $e->getMessage() );
				} catch ( \Throwable $ignored ) {
					// A broken logger must not fatal the storefront either: fail closed means no pixel, quietly.
					unset( $ignored );
				}
			}
		}
	}

	/**
	 * Connected with a pixel id, switched on, not vetoed by the cortexcommerce_pixel_enabled filter, and not a page
	 * that handles payment or account details.
	 */
	public static function should_load(): bool {
		if ( is_admin() || ! Options::is_connected() || '' === Options::pixel_id() || ! Options::settings()['pixel_enabled'] ) {
			return false;
		}
		if ( self::excluded() ) {
			return false;
		}
		return (bool) apply_filters( 'cortexcommerce_pixel_enabled', true );
	}

	/**
	 * Checkout (including order received and order pay), and account pages (including login and registration).
	 */
	public static function excluded(): bool {
		return ( function_exists( 'is_checkout' ) && is_checkout() )
			|| ( function_exists( 'is_wc_endpoint_url' ) && is_wc_endpoint_url( 'order-pay' ) )
			|| ( function_exists( 'is_account_page' ) && is_account_page() )
			|| is_customize_preview();
	}

	/**
	 * @return array{v: int, id: string, endpoint: string, pt: string, p?: string, t?: string, q?: string}
	 */
	public static function config(): array {
		$type   = self::page_type();
		$config = array(
			'v'        => 2,
			'id'       => Options::pixel_id(),
			'endpoint' => Config::api_base() . '/pixel/v2/e',
			'pt'       => $type,
		);
		if ( 'product' === $type ) {
			$config['p'] = (string) get_queried_object_id();
		}
		if ( 'category' === $type || 'tag' === $type ) {
			$config['t'] = (string) get_queried_object_id();
		}
		if ( 'search' === $type ) {
			$query = trim( (string) get_search_query( false ) );
			if ( '' !== $query ) {
				$config['q'] = mb_substr( $query, 0, 100 );
			}
		}
		return $config;
	}

	public static function page_type(): string {
		if ( is_front_page() ) {
			return 'home';
		}
		if ( is_search() ) {
			return 'search';
		}
		if ( function_exists( 'is_shop' ) && is_shop() ) {
			return 'shop';
		}
		if ( function_exists( 'is_product' ) && is_product() ) {
			return 'product';
		}
		if ( function_exists( 'is_product_category' ) && is_product_category() ) {
			return 'category';
		}
		if ( function_exists( 'is_product_tag' ) && is_product_tag() ) {
			return 'tag';
		}
		if ( function_exists( 'is_cart' ) && is_cart() ) {
			return 'cart';
		}
		if ( is_page() ) {
			return 'page';
		}
		if ( is_singular( 'post' ) ) {
			return 'post';
		}
		return 'other';
	}

	/**
	 * The inline script: the config, then a loader that adds the hosted script once the page has loaded.
	 */
	public static function loader(): string {
		$flags  = JSON_UNESCAPED_SLASHES | JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_APOS | JSON_HEX_QUOT;
		$config = (string) wp_json_encode( self::config(), $flags );
		$src    = (string) wp_json_encode( Config::pixel_src(), $flags );
		return 'window.cortexcommercePixel = ' . $config . ';'
			. '(function(w,d,s){function go(){try{var e=d.createElement("script");e.src=s;e.async=true;e.id="cortexcommerce-pixel-src";'
			. '(d.head||d.documentElement).appendChild(e);}catch(x){}}'
			. 'if(d.readyState==="complete"){w.setTimeout(go,0);}else{w.addEventListener("load",function(){w.setTimeout(go,0);});}'
			. '})(window,document,' . $src . ');';
	}
}