<?php
/**
 * Editor looks like the site: brings the styles of a block theme (theme.json) into the classic editor.
 * The option also holds the switch for clean paste (class-paste.php); both are in the tab "Writing".
 *
 * Block themes style the block editor only, so the classic editor shows posts in its own font and width.
 * This sends the theme's global styles and font files into the editor frame. Themes without theme.json
 * keep their own editor stylesheet. On by default, own option and settings group like the privacy tab.
 *
 * @package ThreeCE
 */

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

/**
 * Editor appearance.
 */
class ThreeCE_Editor_Look {

	const OPTION = 'threece_look';
	const GROUP  = 'threece_look';
	const HANDLE = 'threece-editor-look';

	/**
	 * Hooks.
	 */
	public static function init(): void {
		add_action( 'init', array( __CLASS__, 'register_setting' ) );
		add_action( 'admin_enqueue_scripts', array( __CLASS__, 'enqueue' ) );
	}

	/**
	 * 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,
			)
		);
	}

	/**
	 * Checkboxes of the tab "Writing": 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 defaults.
	 *
	 * @param mixed $input Raw value.
	 * @return array{theme_styles: bool, clean_paste: bool}
	 */
	public static function sanitize( $input ) {
		$settings = array(
			'theme_styles' => true,
			'clean_paste'  => true,
		);
		if ( ! is_array( $input ) ) {
			return $settings;
		}
		foreach ( array_keys( $settings ) as $key ) {
			$value            = $input[ $key ] ?? '';
			$settings[ $key ] = true === $value || '1' === $value || 1 === $value;
		}
		return $settings;
	}

	/**
	 * Settings with the factory defaults (all on) when nothing valid is stored.
	 *
	 * @return array{theme_styles: bool, clean_paste: bool}
	 */
	public static function settings() {
		$stored = get_option( self::OPTION, null );
		return self::sanitize( is_array( $stored ) ? $stored : null );
	}

	/**
	 * CSS for the editor frame: font files and global styles of the theme, plus its content width.
	 * Empty when switched off or when the theme has no theme.json.
	 *
	 * @return string
	 */
	public static function css() {
		if ( ! self::settings()['theme_styles'] || ! wp_theme_has_theme_json() ) {
			return '';
		}
		ob_start();
		wp_print_font_faces();
		$fonts = (string) preg_replace( '#</?style[^>]*>#i', '', (string) ob_get_clean() );
		$width = 'html body.mce-content-body{max-width:var(--wp--style--global--content-size, none);margin-left:auto;margin-right:auto;}';
		return trim( $fonts . "\n" . wp_get_global_stylesheet() . "\n" . $width );
	}

	/**
	 * Passes the CSS to the TinyMCE plugin on the classic edit screen.
	 *
	 * @param string $hook_suffix Admin page.
	 */
	public static function enqueue( $hook_suffix ): void {
		if ( ! in_array( $hook_suffix, array( 'post.php', 'post-new.php' ), true ) || ! current_user_can( 'edit_posts' ) ) {
			return;
		}
		$screen = function_exists( 'get_current_screen' ) ? get_current_screen() : null;
		if ( $screen && $screen->is_block_editor() ) {
			return;
		}
		$css = self::css();
		if ( '' === $css ) {
			return;
		}
		wp_register_script( self::HANDLE, false, array(), THREECE_VERSION, true );
		wp_enqueue_script( self::HANDLE );
		wp_add_inline_script( self::HANDLE, 'window.threeceEditorLook = ' . wp_json_encode( array( 'css' => $css ) ) . ';' );
	}
}