<?php

/**
 * Returns the SVG elements and attributes allowed for registered icons.
 *
 * @return array[] Allowed SVG elements and attributes.
 * @phpstan-return array<non-falsy-string, array<non-falsy-string, true>>
 */
function gutenberg_get_allowed_icon_svg_tags(): array {
	$allow_attributes = static function ( string ...$attribute_names ): array {
		return array_fill_keys( $attribute_names, true );
	};

	$stroke_attributes = $allow_attributes(
		'style',
		'stroke',
		'stroke-width',
		'stroke-linecap',
		'stroke-linejoin',
		'stroke-miterlimit',
		'vector-effect',
	);

	return array(
		'svg'     => array_merge(
			$allow_attributes(
				'class',
				'xmlns',
				'width',
				'height',
				'viewbox',
				'aria-hidden',
				'role',
				'focusable',
				'fill',
				'fill-rule',
				'clip-rule',
			),
			$stroke_attributes
		),
		'path'    => array_merge(
			$allow_attributes(
				'fill',
				'fill-rule',
				'clip-rule',
				'd',
				'opacity',
				'transform',
			),
			$stroke_attributes
		),
		'polygon' => array_merge(
			$allow_attributes(
				'fill',
				'fill-rule',
				'clip-rule',
				'points',
				'transform',
				'focusable',
			),
			$stroke_attributes
		),
		'rect'    => array_merge(
			$allow_attributes(
				'fill',
				'fill-rule',
				'clip-rule',
				'x',
				'y',
				'width',
				'height',
				'rx',
				'ry',
				'transform',
			),
			$stroke_attributes
		),
		'circle'  => array_merge(
			$allow_attributes(
				'fill',
				'fill-rule',
				'clip-rule',
				'cx',
				'cy',
				'r',
				'transform',
			),
			$stroke_attributes
		),
	);
}


class WP_Icons_Registry_Gutenberg extends WP_Icons_Registry {
	/**
	 * Overridden to skip the parent's core icon registration, which uses the
	 * core manifest path. Core icons are registered via
	 * `gutenberg_register_default_icons()` using the Gutenberg manifest instead.
	 */
	protected function __construct() {}

	/**
	 * Registers an icon.
	 *
	 * @param string $icon_name       Namespaced icon name in the form "collection/icon-name"
	 *                                (e.g. "core/arrow-left").
	 * @param array  $icon_properties {
	 *     List of properties for the icon.
	 *
	 *     @type string $label     Required. A human-readable label for the icon.
	 *     @type string $content   Optional. SVG markup for the icon.
	 *                             If not provided, the content will be retrieved from the `file_path` if set.
	 *                             If both `content` and `file_path` are not set, the icon will not be registered.
	 *     @type string $file_path Optional. The full path to the file containing the icon content.
	 * }
	 * @return bool True if the icon was registered with success and false otherwise.
	 */
	public function register( $icon_name, $icon_properties ) {
		if ( ! isset( $icon_name ) || ! is_string( $icon_name ) ) {
			_doing_it_wrong(
				__METHOD__,
				__( 'Icon name must be a string.', 'gutenberg' ),
				'7.0.0'
			);
			return false;
		}

		if ( ! str_contains( $icon_name, '/' ) ) {
			_doing_it_wrong(
				__METHOD__,
				__( 'Icon name must be namespaced in the form "collection/icon-name".', 'gutenberg' ),
				'7.1.0'
			);
			return false;
		}

		list( $collection, $unqualified_name ) = explode( '/', $icon_name, 2 );

		if ( preg_match( '/[A-Z]/', $unqualified_name ) ) {
			_doing_it_wrong(
				__METHOD__,
				__( 'Icon names must not contain uppercase characters.', 'gutenberg' ),
				'7.1.0'
			);
			return false;
		}

		if ( ! preg_match( '/^[a-z0-9]([a-z0-9_-]*[a-z0-9])?$/', $unqualified_name ) ) {
			_doing_it_wrong(
				__METHOD__,
				__( 'Icon names must start and end with a lowercase letter or digit and contain only lowercase letters, digits, hyphens, and underscores.', 'gutenberg' ),
				'7.1.0'
			);
			return false;
		}

		$allowed_keys = array_fill_keys( array( 'label', 'content', 'file_path' ), 1 );
		foreach ( array_keys( $icon_properties ) as $key ) {
			if ( ! array_key_exists( $key, $allowed_keys ) ) {
				_doing_it_wrong(
					__METHOD__,
					sprintf(
						// translators: %s is the name of any user-provided key
						__( 'Invalid icon property: "%s".', 'gutenberg' ),
						$key
					),
					'7.0.0'
				);
				return false;
			}
		}

		if ( ! WP_Icon_Collections_Registry::get_instance()->is_registered( $collection ) ) {
			_doing_it_wrong(
				__METHOD__,
				sprintf(
					/* translators: %s: Icon collection slug. */
					__( 'Icon collection "%s" is not registered.', 'gutenberg' ),
					$collection
				),
				'7.1.0'
			);
			return false;
		}

		if ( ! isset( $icon_properties['label'] ) || ! is_string( $icon_properties['label'] ) ) {
			_doing_it_wrong(
				__METHOD__,
				__( 'Icon label must be a string.', 'gutenberg' ),
				'7.0.0'
			);
			return false;
		}

		if (
			( ! isset( $icon_properties['content'] ) && ! isset( $icon_properties['file_path'] ) ) ||
			( isset( $icon_properties['content'] ) && isset( $icon_properties['file_path'] ) )
		) {
			_doing_it_wrong(
				__METHOD__,
				__( 'Icons must provide either `content` or `file_path`.', 'gutenberg' ),
				'7.0.0'
			);
			return false;
		}

		if ( isset( $icon_properties['content'] ) ) {
			if ( ! is_string( $icon_properties['content'] ) ) {
				_doing_it_wrong(
					__METHOD__,
					__( 'Icon content must be a string.', 'gutenberg' ),
					'7.0.0'
				);
				return false;
			}

			$sanitized_icon_content = $this->sanitize_icon_content( $icon_properties['content'] );
			if ( empty( $sanitized_icon_content ) ) {
				_doing_it_wrong(
					__METHOD__,
					__( 'Icon content does not contain valid SVG markup.', 'gutenberg' ),
					'7.0.0'
				);
				return false;
			}

			$icon_properties['content'] = $sanitized_icon_content;
		}

		$qualified_name = $collection . '/' . $unqualified_name;

		if ( $this->is_registered( $qualified_name ) ) {
			_doing_it_wrong(
				__METHOD__,
				__( 'Icon is already registered.', 'gutenberg' ),
				'7.1.0'
			);
			return false;
		}

		$icon = array_merge(
			$icon_properties,
			array(
				'name'       => $qualified_name,
				'collection' => $collection,
			)
		);

		$this->registered_icons[ $qualified_name ] = $icon;

		return true;
	}

	/**
	 * Unregisters an icon.
	 *
	 * @param string $icon_name Namespaced icon name in the form "collection/icon-name"
	 *                          (e.g. "core/arrow-left").
	 * @return bool True if the icon was unregistered successfully, else false.
	 */
	public function unregister( $icon_name ) {
		if ( ! $this->is_registered( $icon_name ) ) {
			_doing_it_wrong(
				__METHOD__,
				sprintf(
					/* translators: %s: Icon name. */
					__( 'Icon "%s" is not registered.', 'gutenberg' ),
					$icon_name
				),
				'7.1.0'
			);
			return false;
		}

		unset( $this->registered_icons[ $icon_name ] );
		return true;
	}

	/**
	 * Sanitizes the icon SVG content.
	 *
	 * Overrides the base class to allow the `rect` and `circle` shapes, plus the
	 * stroke-related attributes and inline styles required by stroke-based icons.
	 *
	 * The signature is intentionally left without type declarations to stay
	 * compatible with the parent WP_Icons_Registry::sanitize_icon_content()
	 * shipped in WordPress core, which declares none.
	 *
	 * @param string $icon_content The icon SVG content to sanitize.
	 * @return string The sanitized icon SVG content.
	 */
	protected function sanitize_icon_content( $icon_content ) {
		return wp_kses( $icon_content, gutenberg_get_allowed_icon_svg_tags() );
	}

	/**
	 * Retrieves the content of a registered icon.
	 *
	 * Overridden so that the file validation is applied even when the base
	 * `WP_Icons_Registry` is provided by WordPress core rather than the
	 * Gutenberg compat shim.
	 *
	 * @param string $icon_name Icon name including namespace.
	 * @return string|null The content of the icon, if found.
	 */
	protected function get_content( $icon_name ) {
		if ( ! isset( $this->registered_icons[ $icon_name ]['content'] ) ) {
			$file_path  = $this->registered_icons[ $icon_name ]['file_path'] ?? '';
			$is_stringy = is_string( $file_path ) || ( is_object( $file_path ) && method_exists( $file_path, '__toString' ) );
			$icon_path  = $is_stringy ? realpath( (string) $file_path ) : false;

			if (
				! is_string( $icon_path ) ||
				! str_ends_with( $icon_path, '.svg' ) ||
				! is_file( $icon_path ) ||
				! is_readable( $icon_path )
			) {
				wp_trigger_error(
					__METHOD__,
					__( 'Icon file is missing or unreadable.', 'gutenberg' )
				);
				return null;
			}

			$content = $this->sanitize_icon_content( file_get_contents( $icon_path ) );

			if ( empty( $content ) ) {
				wp_trigger_error(
					__METHOD__,
					__( 'Icon content does not contain valid SVG markup.', 'gutenberg' )
				);
				return null;
			}

			$this->registered_icons[ $icon_name ]['content'] = $content;
		}
		return $this->registered_icons[ $icon_name ]['content'];
	}

	/**
	 * Modified to also search in icon labels
	 */
	public function get_registered_icons( $search = '' ) {
		$icons = array();

		foreach ( $this->registered_icons as $icon ) {
			if ( ! empty( $search )
				&& false === stripos( $icon['name'], $search )
				&& false === stripos( $icon['label'], $search )
			) {
				continue;
			}

			$icon['content'] = $icon['content'] ?? $this->get_content( $icon['name'] );
			$icons[]         = $icon;
		}

		return $icons;
	}

	/**
	 * Returns the shared registry instance.
	 *
	 * The base `$instance` slot is intentionally not redefined, so both
	 * `WP_Icons_Registry::get_instance()` (used by core) and this method share
	 * one instance. An existing base registry is upgraded, replaying any
	 * non-`core/` and non-`core-admin/` icons so they are not lost.
	 */
	public static function get_instance() {
		if ( ! self::$instance instanceof self ) {
			$original_registry  = self::$instance;
			$gutenberg_registry = new self();

			if ( null !== $original_registry ) {
				foreach ( $original_registry->get_registered_icons() as $icon ) {
					if ( str_starts_with( $icon['name'], 'core/' ) || str_starts_with( $icon['name'], 'core-admin/' ) ) {
						continue;
					}
					$icon_properties = array( 'label' => $icon['label'] );
					if ( ! empty( $icon['content'] ) ) {
						$icon_properties['content'] = $icon['content'];
					} elseif ( ! empty( $icon['file_path'] ) ) {
						$icon_properties['file_path'] = $icon['file_path'];
					} else {
						continue;
					}
					$gutenberg_registry->register( $icon['name'], $icon_properties );
				}
			}

			self::$instance = $gutenberg_registry;
		}

		return self::$instance;
	}
}

/**
 * Overrides the base `WP_Icons_Registry` singleton with the Gutenberg registry so
 * that all code using `WP_Icons_Registry::{method_name}()` receives it.
 */
function gutenberg_override_wp_icons_registry() {
	WP_Icons_Registry_Gutenberg::get_instance();
}
add_action( 'init', 'gutenberg_override_wp_icons_registry', 1 );