<?php
/**
 * Privacy switch: turns off the WordPress emoji script, which loads images from s.w.org.
 *
 * Current browsers draw emoji themselves; the script only helps very old systems. On by default.
 * Own option; saved from the tab "Writing" together with the writing settings, never with the editor settings.
 *
 * @package ThreeCE
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Privacy settings.
 */
class ThreeCE_Privacy {

	const OPTION = 'threece_privacy';

	/**
	 * Settings group: the switch lives in the tab "Writing" (since 1.0.1), in one form with ThreeCE_Editor_Look.
	 */
	const GROUP = ThreeCE_Editor_Look::GROUP;

	/**
	 * Hooks. Core adds its front-end emoji hooks before plugins load and its admin hooks
	 * (wp-admin/includes/admin-filters.php) after them, so the admin ones go on admin_init.
	 */
	public static function init(): void {
		add_action( 'init', array( __CLASS__, 'register_setting' ) );
		if ( self::settings()['disable_emoji'] ) {
			self::disable_emoji();
			add_action( 'admin_init', array( __CLASS__, 'disable_emoji' ) );
		}
	}

	/**
	 * Removes every place where WordPress prints the emoji script or swaps emoji for s.w.org images.
	 */
	public static function disable_emoji(): void {
		remove_action( 'wp_head', 'print_emoji_detection_script', 7 );
		remove_action( 'embed_head', 'print_emoji_detection_script' );
		remove_action( 'admin_print_scripts', 'print_emoji_detection_script' );
		remove_action( 'wp_enqueue_scripts', 'wp_enqueue_emoji_styles' );
		remove_action( 'enqueue_embed_scripts', 'wp_enqueue_emoji_styles' );
		remove_action( 'admin_enqueue_scripts', 'wp_enqueue_emoji_styles' );
		remove_action( 'wp_print_styles', 'print_emoji_styles' );
		remove_action( 'admin_print_styles', 'print_emoji_styles' );
		remove_filter( 'the_content_feed', 'wp_staticize_emoji' );
		remove_filter( 'comment_text_rss', 'wp_staticize_emoji' );
		remove_filter( 'wp_mail', 'wp_staticize_emoji_for_email' );
		add_filter( 'tiny_mce_plugins', array( __CLASS__, 'without_tinymce_emoji' ) );
	}

	/**
	 * Drops the TinyMCE plugin that swaps emoji for images in the classic editor.
	 *
	 * @param mixed $plugins TinyMCE plugin names.
	 * @return mixed
	 */
	public static function without_tinymce_emoji( $plugins ) {
		return is_array( $plugins ) ? array_values( array_diff( $plugins, array( 'wpemoji' ) ) ) : $plugins;
	}

	/**
	 * Registers the setting so every save goes through sanitize().
	 */
	public static function register_setting(): void {
		register_setting(
			self::GROUP,
			self::OPTION,
			array(
				'type'              => 'array',
				'sanitize_callback' => array( __CLASS__, 'sanitize' ),
				'show_in_rest'      => false,
			)
		);
	}

	/**
	 * A checkbox: on only for "1" (or true); a missing field means unticked. Anything that is not
	 * an array is not a form at all and keeps the factory default.
	 *
	 * @param mixed $input Raw value.
	 * @return array{disable_emoji: bool}
	 */
	public static function sanitize( $input ) {
		if ( ! is_array( $input ) ) {
			return array( 'disable_emoji' => true );
		}
		$value = $input['disable_emoji'] ?? '';
		return array( 'disable_emoji' => true === $value || '1' === $value || 1 === $value );
	}

	/**
	 * Settings with the factory default (emoji script off) when nothing valid is stored.
	 *
	 * @return array{disable_emoji: bool}
	 */
	public static function settings() {
		$stored = get_option( self::OPTION, null );
		return is_array( $stored ) ? self::sanitize( $stored ) : array( 'disable_emoji' => true );
	}
}