wp_prepare_themes_for_js() WordPress Function

function wp_prepare_themes_for_js( $themes = null ) {
	$current_theme = get_stylesheet();

	/**
	 * Filters theme data before it is prepared for JavaScript.
	 *
	 * Passing a non-empty array will result in wp_prepare_themes_for_js() returning
	 * early with that value instead.
	 *
	 * @since 4.2.0
	 *
	 * @param array           $prepared_themes An associative array of theme data. Default empty array.
	 * @param WP_Theme[]|null $themes          An array of theme objects to prepare, if any.
	 * @param string          $current_theme   The active theme slug.
	 */
	$prepared_themes = (array) apply_filters( 'pre_prepare_themes_for_js', array(), $themes, $current_theme );

	if ( ! empty( $prepared_themes ) ) {
		return $prepared_themes;
	}

	// Make sure the active theme is listed first.
	$prepared_themes[ $current_theme ] = array();

	if ( null === $themes ) {
		$themes = wp_get_themes( array( 'allowed' => true ) );
		if ( ! isset( $themes[ $current_theme ] ) ) {
			$themes[ $current_theme ] = wp_get_theme();
		}
	}

	$updates    = array();
	$no_updates = array();
	if ( ! is_multisite() && current_user_can( 'update_themes' ) ) {
		$updates_transient = get_site_transient( 'update_themes' );
		if ( isset( $updates_transient->response ) ) {
			$updates = $updates_transient->response;
		}
		if ( isset( $updates_transient->no_update ) ) {
			$no_updates = $updates_transient->no_update;
		}
	}

	WP_Theme::sort_by_name( $themes );

	$parents = array();

	$auto_updates = (array) get_site_option( 'auto_update_themes', array() );

	foreach ( $themes as $theme ) {
		$slug         = $theme->get_stylesheet();
		$encoded_slug = urlencode( $slug );

		$parent = false;
		if ( $theme->parent() ) {
			$parent           = $theme->parent();
			$parents[ $slug ] = $parent->get_stylesheet();
			$parent           = $parent->display( 'Name' );
		}

		$customize_action = null;

		$can_edit_theme_options = current_user_can( 'edit_theme_options' );
		$can_customize          = current_user_can( 'customize' );
		$is_block_theme         = $theme->is_block_theme();

		if ( $is_block_theme && $can_edit_theme_options ) {
			$customize_action = esc_url( admin_url( 'site-editor.php' ) );
		} elseif ( ! $is_block_theme && $can_customize && $can_edit_theme_options ) {
			$customize_action = esc_url(
				add_query_arg(
					array(
						'return' => urlencode( esc_url_raw( remove_query_arg( wp_removable_query_args(), wp_unslash( $_SERVER['REQUEST_URI'] ) ) ) ),
					),
					wp_customize_url( $slug )
				)
			);
		}

		$update_requires_wp  = isset( $updates[ $slug ]['requires'] ) ? $updates[ $slug ]['requires'] : null;
		$update_requires_php = isset( $updates[ $slug ]['requires_php'] ) ? $updates[ $slug ]['requires_php'] : null;

		$auto_update        = in_array( $slug, $auto_updates, true );
		$auto_update_action = $auto_update ? 'disable-auto-update' : 'enable-auto-update';

		if ( isset( $updates[ $slug ] ) ) {
			$auto_update_supported      = true;
			$auto_update_filter_payload = (object) $updates[ $slug ];
		} elseif ( isset( $no_updates[ $slug ] ) ) {
			$auto_update_supported      = true;
			$auto_update_filter_payload = (object) $no_updates[ $slug ];
		} else {
			$auto_update_supported = false;
			/*
			 * Create the expected payload for the auto_update_theme filter, this is the same data
			 * as contained within $updates or $no_updates but used when the Theme is not known.
			 */
			$auto_update_filter_payload = (object) array(
				'theme'        => $slug,
				'new_version'  => $theme->get( 'Version' ),
				'url'          => '',
				'package'      => '',
				'requires'     => $theme->get( 'RequiresWP' ),
				'requires_php' => $theme->get( 'RequiresPHP' ),
			);
		}

		$auto_update_forced = wp_is_auto_update_forced_for_item( 'theme', null, $auto_update_filter_payload );

		$prepared_themes[ $slug ] = array(
			'id'             => $slug,
			'name'           => $theme->display( 'Name' ),
			'screenshot'     => array( $theme->get_screenshot() ), // @todo Multiple screenshots.
			'description'    => $theme->display( 'Description' ),
			'author'         => $theme->display( 'Author', false, true ),
			'authorAndUri'   => $theme->display( 'Author' ),
			'tags'           => $theme->display( 'Tags' ),
			'version'        => $theme->get( 'Version' ),
			'compatibleWP'   => is_wp_version_compatible( $theme->get( 'RequiresWP' ) ),
			'compatiblePHP'  => is_php_version_compatible( $theme->get( 'RequiresPHP' ) ),
			'updateResponse' => array(
				'compatibleWP'  => is_wp_version_compatible( $update_requires_wp ),
				'compatiblePHP' => is_php_version_compatible( $update_requires_php ),
			),
			'parent'         => $parent,
			'active'         => $slug === $current_theme,
			'hasUpdate'      => isset( $updates[ $slug ] ),
			'hasPackage'     => isset( $updates[ $slug ] ) && ! empty( $updates[ $slug ]['package'] ),
			'update'         => get_theme_update_available( $theme ),
			'autoupdate'     => array(
				'enabled'   => $auto_update || $auto_update_forced,
				'supported' => $auto_update_supported,
				'forced'    => $auto_update_forced,
			),
			'actions'        => array(
				'activate'   => current_user_can( 'switch_themes' ) ? wp_nonce_url( admin_url( 'themes.php?action=activate&stylesheet=' . $encoded_slug ), 'switch-theme_' . $slug ) : null,
				'customize'  => $customize_action,
				'delete'     => ( ! is_multisite() && current_user_can( 'delete_themes' ) ) ? wp_nonce_url( admin_url( 'themes.php?action=delete&stylesheet=' . $encoded_slug ), 'delete-theme_' . $slug ) : null,
				'autoupdate' => wp_is_auto_update_enabled_for_type( 'theme' ) && ! is_multisite() && current_user_can( 'update_themes' )
					? wp_nonce_url( admin_url( 'themes.php?action=' . $auto_update_action . '&stylesheet=' . $encoded_slug ), 'updates' )
					: null,
			),
			'blockTheme'     => $theme->is_block_theme(),
		);
	}

	// Remove 'delete' action if theme has an active child.
	if ( ! empty( $parents ) && array_key_exists( $current_theme, $parents ) ) {
		unset( $prepared_themes[ $parents[ $current_theme ] ]['actions']['delete'] );
	}

	/**
	 * Filters the themes prepared for JavaScript, for themes.php.
	 *
	 * Could be useful for changing the order, which is by name by default.
	 *
	 * @since 3.8.0
	 *
	 * @param array $prepared_themes Array of theme data.
	 */
	$prepared_themes = apply_filters( 'wp_prepare_themes_for_js', $prepared_themes );
	$prepared_themes = array_values( $prepared_themes );
	return array_filter( $prepared_themes );
}