<?php
/**
 * MU Plugins check.
 *
 * @package advanced-analytics
 *
 * @since 4.9.0
 */

declare(strict_types=1);

namespace ADVAN\Checks\Migration;

use ADVAN\Checks\Abstract_Check;

// Exit if accessed directly.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

if ( ! class_exists( 'ADVAN\Checks\Migration\MU_Plugins_Check' ) ) {

	/**
	 * MU Plugins check class.
	 *
	 * @since 4.9.0
	 */
	class MU_Plugins_Check extends Abstract_Check {

		/**
		 * Check identifier (slug).
		 *
		 * @var string Check identifier (slug).
		 *
		 * @since 4.9.0
		 */
		protected static string $id = 'mu-plugins';

		/**
		 * Check category.
		 *
		 * @var string Check category.
		 *
		 * @since 4.9.0
		 */
		protected static string $category = 'resources';

		/**
		 * Check weight (1-10).
		 *
		 * @var int Check weight (1-10).
		 *
		 * @since 4.9.0
		 */
		protected static int $weight = 4;

		/**
		 * Check title (translatable).
		 *
		 * @return string Check title.
		 *
		 * @since 4.9.0
		 */
		public static function get_title(): string {
			return __( 'Must-Use Plugins', '0-day-analytics' );
		}

		/**
		 * Check description (translatable).
		 *
		 * @return string Check description.
		 *
		 * @since 4.9.0
		 */
		public static function get_description(): string {
			return __( 'Checks for must-use plugins that need manual migration.', '0-day-analytics' );
		}

		/**
		 * Run the check.
		 *
		 * @return array Check result.
		 *
		 * @since 4.9.0
		 */
		public static function run(): array {
			$mu_plugins_dir = WPMU_PLUGIN_DIR;
			$mu_plugins     = array();
			$host_specific  = array();

			if ( is_dir( $mu_plugins_dir ) ) {
				$files = scandir( $mu_plugins_dir );

				foreach ( $files as $file ) {
					if ( '.' === $file || '..' === $file ) {
						continue;
					}

					$filepath = $mu_plugins_dir . '/' . $file;
					$real = realpath( $filepath );

					// Only count PHP files.
					if ( $real && str_starts_with( $real, WPMU_PLUGIN_DIR ) && is_file( $real ) && pathinfo( $file, PATHINFO_EXTENSION ) === 'php' ) {
						$mu_plugins[] = $file;

						// Check for hosting-specific plugins.
						// Limit file read to 1MB to prevent memory exhaustion.
						$filesize = filesize( $real );
						if ( false === $filesize || $filesize > 1048576 ) {
							continue; // Skip files larger than 1MB or unreadable.
						}
						// phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents -- Local file read with size check.
						$contents = file_get_contents( $real, false, null, 0, 1048576 );
						if ( $contents ) {
							$hosting_patterns = array(
								'wpengine'   => 'WP Engine',
								'godaddy'    => 'GoDaddy',
								'bluehost'   => 'Bluehost',
								'siteground' => 'SiteGround',
								'kinsta'     => 'Kinsta',
								'flywheel'   => 'Flywheel',
								'pantheon'   => 'Pantheon',
								'cloudways'  => 'Cloudways',
							);

							foreach ( $hosting_patterns as $pattern => $host ) {
								if ( stripos( $contents, $pattern ) !== false || stripos( $file, $pattern ) !== false ) {
									$host_specific[ $file ] = $host;
									break;
								}
							}
						}
					}
				}
			}

			$mu_count     = count( $mu_plugins );
			$host_count   = count( $host_specific );
			$custom_count = $mu_count - $host_count;

			$details = array(
				'mu_plugins_dir' => $mu_plugins_dir,
				'mu_plugins'     => $mu_plugins,
				'host_specific'  => $host_specific,
				'total_count'    => $mu_count,
				'custom_count'   => $custom_count,
			);

			if ( 0 === $mu_count ) {
				return static::pass(
					__( 'No must-use plugins found. Your migration won\'t need to account for any MU-plugins.', '0-day-analytics' ),
					$details
				);
			}

			if ( ! empty( $host_specific ) ) {
				return static::warning(
					sprintf(
					/* translators: 1: number of MU-plugins, 2: hosting provider names */
						__( 'Found %1$d must-use plugins, including hosting-specific ones from %2$s. These are typically installed by your host and should NOT be copied to a new server.', '0-day-analytics' ),
						$mu_count,
						implode( ', ', array_unique( array_values( $host_specific ) ) )
					),
					__( 'Only migrate your custom MU-plugins, not the ones provided by your hosting company. The new host may have their own MU-plugins.', '0-day-analytics' ),
					$details
				);
			}

			if ( $mu_count > 5 ) {
				return static::info(
					sprintf(
					/* translators: %d: number of MU-plugins */
						__( 'Found %d must-use plugins. Remember to manually copy the mu-plugins folder during migration - most automated tools skip this directory.', '0-day-analytics' ),
						$mu_count
					),
					$details
				);
			}

			return static::info(
				sprintf(
				/* translators: %d: number of MU-plugins */
					__( 'Found %d must-use plugin(s). Make sure to manually copy the mu-plugins folder to your new server - automated migration tools often skip this directory.', '0-day-analytics' ),
					$mu_count
				),
				$details
			);
		}
	}
}