<?php
/**
 * Dynamic logged-in user placeholders in menu item fields.
 *
 * @package advance-menu-manager
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

class DSAMM_Menu_User_Placeholders {

	/**
	 * Default avatar size in pixels.
	 *
	 * @var int
	 */
	const DEFAULT_AVATAR_SIZE = 32;

	/**
	 * Minimum avatar size.
	 *
	 * @var int
	 */
	const MIN_AVATAR_SIZE = 16;

	/**
	 * Maximum avatar size.
	 *
	 * @var int
	 */
	const MAX_AVATAR_SIZE = 512;

	/**
	 * Register frontend filters.
	 */
	public static function init() {
		add_filter( 'wp_nav_menu_objects', array( __CLASS__, 'replace_in_menu_items' ), 20, 2 );
	}

	/**
	 * Supported text placeholder keys mapped to user object properties / meta.
	 *
	 * @return array
	 */
	public static function get_text_placeholders() {
		return array(
			'username'     => 'user_login',
			'first_name'   => 'first_name',
			'last_name'    => 'last_name',
			'display_name' => 'display_name',
			'nickname'     => 'nickname',
			'email'        => 'user_email',
		);
	}

	/**
	 * Placeholder chips for the admin help UI.
	 *
	 * @return array
	 */
	public static function get_placeholder_examples() {
		return array(
			array(
				'code'  => '{username}',
				'label' => __( 'Username', 'advance-menu-manager' ),
			),
			array(
				'code'  => '{first_name}',
				'label' => __( 'First name', 'advance-menu-manager' ),
			),
			array(
				'code'  => '{last_name}',
				'label' => __( 'Last name', 'advance-menu-manager' ),
			),
			array(
				'code'  => '{display_name}',
				'label' => __( 'Display name', 'advance-menu-manager' ),
			),
			array(
				'code'  => '{nickname}',
				'label' => __( 'Nickname', 'advance-menu-manager' ),
			),
			array(
				'code'  => '{email}',
				'label' => __( 'Email', 'advance-menu-manager' ),
			),
			array(
				'code'  => '{avatar size="48"}',
				'label' => __( 'Avatar', 'advance-menu-manager' ),
			),
		);
	}

	/**
	 * Whether a string contains any supported placeholder.
	 *
	 * @param string $value Field value.
	 * @return bool
	 */
	public static function has_placeholders( $value ) {
		if ( ! is_string( $value ) || '' === $value ) {
			return false;
		}

		if ( false !== strpos( $value, '{avatar' ) ) {
			return true;
		}

		foreach ( array_keys( self::get_text_placeholders() ) as $key ) {
			if ( false !== strpos( $value, '{' . $key . '}' ) ) {
				return true;
			}
		}

		return false;
	}

	/**
	 * Replace placeholders in nav menu item objects on the frontend.
	 *
	 * @param array  $items Menu items.
	 * @param object $args  Menu arguments.
	 * @return array
	 */
	public static function replace_in_menu_items( $items, $args ) {
		unset( $args );

		if ( empty( $items ) || ! is_array( $items ) ) {
			return $items;
		}

		if ( is_admin() && ! wp_doing_ajax() ) {
			return $items;
		}

		$user      = wp_get_current_user();
		$logged_in = ( $user instanceof WP_User ) && 0 !== (int) $user->ID;

		foreach ( $items as $index => $item ) {
			if ( ! is_object( $item ) ) {
				continue;
			}

			if ( isset( $item->title ) && self::has_placeholders( $item->title ) ) {
				$items[ $index ]->title = $logged_in
					? self::replace_placeholders( $item->title, $user, 'title' )
					: self::strip_placeholders( $item->title );
			}

			if ( isset( $item->attr_title ) && self::has_placeholders( $item->attr_title ) ) {
				$items[ $index ]->attr_title = $logged_in
					? self::replace_placeholders( $item->attr_title, $user, 'attr_title' )
					: self::strip_placeholders( $item->attr_title );
			}

			if ( isset( $item->description ) && self::has_placeholders( $item->description ) ) {
				$items[ $index ]->description = $logged_in
					? self::replace_placeholders( $item->description, $user, 'description' )
					: self::strip_placeholders( $item->description );
			}

			if ( isset( $item->url ) && self::has_placeholders( $item->url ) ) {
				$items[ $index ]->url = $logged_in
					? self::replace_placeholders( $item->url, $user, 'url' )
					: self::strip_placeholders( $item->url );
			}
		}

		return $items;
	}

	/**
	 * Replace all placeholders in a string for the given user.
	 *
	 * @param string  $value Field value.
	 * @param WP_User $user  Current user.
	 * @param string  $context Field context: title|attr_title|description|url.
	 * @return string
	 */
	public static function replace_placeholders( $value, $user, $context = 'title' ) {
		if ( ! is_string( $value ) || '' === $value || ! ( $user instanceof WP_User ) ) {
			return $value;
		}

		$value = self::replace_text_placeholders( $value, $user );
		$value = self::replace_avatar_placeholders( $value, $user, $context );

		/**
		 * Filter the menu field value after user placeholder replacement.
		 *
		 * @param string  $value   Replaced value.
		 * @param WP_User $user    Current user.
		 * @param string  $context Field context.
		 */
		return apply_filters( 'dsamm_menu_user_placeholder_value', $value, $user, $context );
	}

	/**
	 * Replace text placeholders.
	 *
	 * @param string  $value Field value.
	 * @param WP_User $user  Current user.
	 * @return string
	 */
	private static function replace_text_placeholders( $value, $user ) {
		foreach ( self::get_text_placeholders() as $placeholder => $property ) {
			$token = '{' . $placeholder . '}';

			if ( false === strpos( $value, $token ) ) {
				continue;
			}

			$replacement = '';

			if ( 'first_name' === $property || 'last_name' === $property || 'nickname' === $property ) {
				$replacement = (string) $user->get( $property );
			} elseif ( isset( $user->{$property} ) ) {
				$replacement = (string) $user->{$property};
			}

			$value = str_replace( $token, $replacement, $value );
		}

		return $value;
	}

	/**
	 * Replace avatar placeholders.
	 *
	 * @param string  $value   Field value.
	 * @param WP_User $user    Current user.
	 * @param string  $context Field context.
	 * @return string
	 */
	private static function replace_avatar_placeholders( $value, $user, $context ) {
		if ( false === strpos( $value, '{avatar' ) ) {
			return $value;
		}

		return preg_replace_callback(
			'/\{avatar(?:\s+size=(["\']?)(\d+)\1)?\}/i',
			function( $matches ) use ( $user, $context ) {
				$size = ! empty( $matches[2] ) ? absint( $matches[2] ) : self::DEFAULT_AVATAR_SIZE;
				$size = max( self::MIN_AVATAR_SIZE, min( self::MAX_AVATAR_SIZE, $size ) );

				if ( 'url' === $context || 'attr_title' === $context ) {
					$url = get_avatar_url( $user->ID, array( 'size' => $size ) );
					return $url ? $url : '';
				}

				$avatar = get_avatar(
					$user->ID,
					$size,
					'',
					$user->display_name,
					array(
						'class' => 'amm-user-avatar',
					)
				);

				return is_string( $avatar ) ? $avatar : '';
			},
			$value
		);
	}

	/**
	 * Remove all supported placeholders from a string (replace with empty).
	 *
	 * Used for logged-out visitors so raw placeholder tokens are never visible.
	 *
	 * @param string $value Field value.
	 * @return string
	 */
	private static function strip_placeholders( $value ) {
		if ( ! is_string( $value ) || '' === $value ) {
			return $value;
		}

		foreach ( array_keys( self::get_text_placeholders() ) as $key ) {
			$value = str_replace( '{' . $key . '}', '', $value );
		}

		$value = preg_replace( '/\{avatar(?:\s+size=(["\']?)\d+\1)?\}/i', '', $value );

		return trim( $value );
	}

	/**
	 * Render admin help for available placeholders.
	 *
	 * @param int   $menu_item_id Menu item ID.
	 * @param array $args         Optional args.
	 */
	public static function render_help( $menu_item_id, $args = array() ) {
		$defaults = array(
			'readonly' => false,
		);
		$args = wp_parse_args( $args, $defaults );

		$menu_item_id = (int) $menu_item_id;
		$examples     = self::get_placeholder_examples();
		$toggle_id    = 'amm-user-placeholders-body-' . $menu_item_id;
		?>
		<div class="field-amm-user-placeholders description description-wide is-collapsed" data-menu-item-id="<?php echo esc_attr( $menu_item_id ); ?>">
			<div class="amm-user-placeholders-header">
				<button
					type="button"
					class="amm-user-placeholders-toggle"
					aria-expanded="false"
					aria-controls="<?php echo esc_attr( $toggle_id ); ?>"
				>
					<strong><?php esc_html_e( 'User placeholders', 'advance-menu-manager' ); ?></strong>
					<span class="amm-user-placeholders-toggle-icon" aria-hidden="true"></span>
				</button>
			</div>
			<div id="<?php echo esc_attr( $toggle_id ); ?>" class="amm-user-placeholders-body" hidden>
				<p class="description amm-user-placeholders-intro">
					<?php esc_html_e( 'Use these placeholders in the Navigation Label, Title Attribute, or Description fields. On the front end, each placeholder is automatically replaced with the logged-in user’s information, such as their username, first name, email, or avatar.', 'advance-menu-manager' ); ?>
				</p>
				<p class="description amm-user-placeholders-intro">
					<?php esc_html_e( 'For logged-out visitors, placeholders are automatically hidden. To hide the entire menu item, set the visibility to Logged In Users only.', 'advance-menu-manager' ); ?>
				</p>
				<ul class="amm-user-placeholder-list">
					<?php foreach ( $examples as $example ) : ?>
						<li>
							<?php if ( empty( $args['readonly'] ) ) : ?>
								<button
									type="button"
									class="button-link amm-user-placeholder-chip"
									data-placeholder="<?php echo esc_attr( $example['code'] ); ?>"
									title="<?php echo esc_attr( sprintf( /* translators: %s: placeholder code */ __( 'Copy %s', 'advance-menu-manager' ), $example['code'] ) ); ?>"
								>
									<code><?php echo esc_html( $example['code'] ); ?></code>
									<span class="amm-user-placeholder-chip-label"><?php echo esc_html( $example['label'] ); ?></span>
								</button>
							<?php else : ?>
								<code><?php echo esc_html( $example['code'] ); ?></code>
								<span class="amm-user-placeholder-chip-label"><?php echo esc_html( $example['label'] ); ?></span>
							<?php endif; ?>
						</li>
					<?php endforeach; ?>
				</ul>
				<p class="description amm-user-placeholders-example">
					<?php esc_html_e( 'Example:', 'advance-menu-manager' ); ?>
					<code>Hello, {first_name}</code>
					<p class="amm-user-placeholders-docs">
						<a href="<?php echo esc_url( "https://docs.thedotstore.com/article/1440-display-dynamic-user-information-in-wordpress-menu-items" ); ?>" target="_blank" rel="noopener noreferrer"><?php esc_html_e( 'Click here', 'advance-menu-manager' ); ?></a><?php esc_html_e( ' to learn more about user placeholders.', 'advance-menu-manager' ); ?>
					</p>
				</p>
			</div>
		</div>
		<?php
	}
}