<?php
namespace QWSpeedCache\Compatibility;

defined( 'ABSPATH' ) || exit;

/**
 * Local GA4 / GTM measurement snippets with optional weekly script mirror.
 */
class LocalAnalytics {

	public function __construct() {
		add_action( 'wp_enqueue_scripts', array( $this, 'dequeue_remote' ), 100 );
		add_action( 'wp_enqueue_scripts', array( $this, 'print_ga' ), 20 );
	}

	/**
	 * Call from Plugin::activate only.
	 */
	public static function schedule_event() {
		// Stop previously scheduled mirrors: remote executable JavaScript must
		// not be downloaded into a web-accessible cache directory.
		wp_clear_scheduled_hook( 'qwsc_mirror_ga_script' );
		wp_clear_scheduled_hook( 'qwsc_mirror_gtm_script' );
	}

	public function dequeue_remote() {
		$s = \QWSpeedCache\Plugin::instance()->get_all_settings();
		if ( empty( $s['local_ga_enabled'] ) && empty( $s['local_gtm_id'] ) ) {
			return;
		}
		wp_dequeue_script( 'google-analytics' );
		wp_deregister_script( 'google-analytics' );
	}

	public function print_ga() {
		$s = \QWSpeedCache\Plugin::instance()->get_all_settings();
		if ( ! empty( $s['cookie_consent_enabled'] ) && ! empty( $s['consent_block_analytics'] ) ) {
			$ok = isset( $_COOKIE['qwsc_consent'] ) && is_string( $_COOKIE['qwsc_consent'] ) && '1' === sanitize_text_field( wp_unslash( $_COOKIE['qwsc_consent'] ) );
			if ( ! $ok ) {
				return;
			}
		}

		$s = \QWSpeedCache\Plugin::instance()->get_all_settings();
		$gtm = isset( $s['local_gtm_id'] ) && is_string( $s['local_gtm_id'] ) ? trim( $s['local_gtm_id'] ) : '';
		if ( ! preg_match( '/^GTM-[A-Z0-9]{4,20}$/', $gtm ) ) {
			$gtm = '';
		}
		if ( $gtm && 0 === strpos( $gtm, 'GTM-' ) ) {
			$src = 'https://www.googletagmanager.com/gtm.js?id=' . rawurlencode( $gtm );
			// Register a dependency-free handle so WordPress owns the inline snippet.
			// Keep GTM's original dynamic loader semantics (including dataLayer).
			wp_register_script( 'qwsc-local-gtm-bootstrap', false, array(), QWSC_VERSION, false );
			wp_enqueue_script( 'qwsc-local-gtm-bootstrap' );
			$inline = '(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({"gtm.start":new Date().getTime(),event:"gtm.js"});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!=="dataLayer"?"&l="+l:"";j.async=true;j.src=' . wp_json_encode( $src ) . '+dl;f.parentNode.insertBefore(j,f);})(window,document,"script","dataLayer",' . wp_json_encode( $gtm ) . ');';
			wp_add_inline_script( 'qwsc-local-gtm-bootstrap', $inline, 'after' );
			return;
		}
		if ( empty( $s['local_ga_enabled'] ) || empty( $s['local_ga_id'] ) ) {
			return;
		}
		$id = is_string( $s['local_ga_id'] ) ? trim( $s['local_ga_id'] ) : '';
		if ( ! preg_match( '/^G-[A-Z0-9]{4,20}$/', $id ) ) {
			return;
		}
		// Load the vendor-hosted asset using WordPress's enqueue API.
		// Arbitrary custom script URLs and cached downloaded JS are not executed.
		$src = 'https://www.googletagmanager.com/gtag/js?id=' . rawurlencode( $id );
		wp_enqueue_script( 'qwsc-local-ga', esc_url_raw( $src ), array(), QWSC_VERSION, false );
		wp_script_add_data( 'qwsc-local-ga', 'async', true );
		$inline = 'window.dataLayer=window.dataLayer||[];function gtag(){dataLayer.push(arguments);}gtag("js",new Date());gtag("config",' . wp_json_encode( $id ) . ',{anonymize_ip:true});';
		wp_add_inline_script( 'qwsc-local-ga', $inline, 'after' );
	}

	/**
	 * Retained compatibility entry point; executable remote mirrors are disabled.
	 *
	 * @return null
	 */
	public static function local_file_url() {
		return null;
	}

	/** @return null */
	public static function local_gtm_url() {
		return null;
	}

	/** Legacy cron callback: no longer downloads executable JavaScript. */
	public function mirror_script() {}

	/** Legacy cron callback: no longer downloads executable JavaScript. */
	public function mirror_gtm() {}
}