<?php
/**
 * Ensures the WordPress page-cache bootstrap is installed and enabled.
 *
 * @package NBHPerformance
 */

namespace NBH\Performance\Modules\CacheEngine;

use NBH\Performance\Modules\Core\Module;

/**
 * Ensures the WordPress page-cache bootstrap is installed and enabled.
 */
final class CacheBootstrapManager implements Module {
	/** Register bootstrap checks. */
	public function register() {
		add_action( 'admin_init', array( $this, 'ensure_if_missing' ), 2 );
		add_action( 'update_option_nbh_performance_cache_enabled', array( $this, 'ensure' ), 10, 2 );
		add_action( 'update_option_nbh_performance_safe_mode', array( $this, 'ensure' ), 10, 2 );
	}

	/**
	 * Initializes bootstrap status once on an administrator request.
	 *
	 * @return void
	 */
	public function ensure_if_missing() {
		if ( current_user_can( 'manage_options' ) && false === get_option( 'nbh_performance_cache_bootstrap_status', false ) ) {
			$this->ensure();
		}
	}

	/**
	 * Ensure WP_CACHE, the drop-in and cache directories are ready.
	 *
	 * @return array
	 */
	public function ensure() {
		$status = array(
			'wp_cache_defined'  => defined( 'WP_CACHE' ) && WP_CACHE,
			'dropin_installed'  => false,
			'directories_ready' => false,
			'checked_at'        => time(),
			'ready'             => false,
			'blockers'          => array(),
		);

		if ( ! get_option( 'nbh_performance_cache_enabled', false ) ) {
			update_option( 'nbh_performance_cache_bootstrap_status', $status, false );
			return $status;
		}

		// Avoid writing executable drop-ins until caching can actually be used.
		if ( ! $status['wp_cache_defined'] ) {
			$status['blockers'][] = 'wp_cache_disabled';
			update_option( 'nbh_performance_cache_bootstrap_status', $status, false );
			return $status;
		}
		$status['directories_ready'] = wp_mkdir_p( WP_CONTENT_DIR . '/cache/nbh-performance/pages' );
		$status['dropin_installed']  = ( new DropInInstaller() )->install();

		// WP_CACHE must be configured by the administrator or host. Never edit wp-config.php.
		if ( ! $status['directories_ready'] ) {
			$status['blockers'][] = 'cache_directory_unwritable';
		}
		if ( ! $status['dropin_installed'] ) {
			$status['blockers'][] = 'cache_dropin_unavailable';
		}
		$status['ready'] = empty( $status['blockers'] ) && ! get_option( 'nbh_performance_safe_mode', true );

		update_option( 'nbh_performance_cache_bootstrap_status', $status, false );
		return $status;
	}
}