<?php
/**
 * Technical health checks (WordPress APIs first; loopback requests optional).
 *
 * @package SiteAuditHub
 */

namespace SiteAuditHub;

defined( 'ABSPATH' ) || exit;

/**
 * Health checks. Never exposes secrets: only versions, flags and counts.
 */
class Health {

	const TRANSIENT = 'siteaudithub_health_results';

	/**
	 * Run checks and return findings. Also caches an overview for the UI.
	 *
	 * @param bool $remote Include loopback HTTP checks.
	 * @return array Findings.
	 */
	public static function run( $remote = true ) {
		global $wp_version, $wpdb;
		$findings = array();
		$overview = array();

		// WordPress version.
		$core       = get_site_transient( 'update_core' );
		$latest     = null;
		$core_known = is_object( $core ) && ! empty( $core->updates );
		if ( $core_known ) {
			foreach ( $core->updates as $offer ) {
				if ( isset( $offer->response ) && 'upgrade' === $offer->response && ! empty( $offer->current ) ) {
					$latest = $offer->current;
					break;
				}
			}
		}
		if ( $latest && version_compare( $latest, $wp_version, '>' ) ) {
			/* translators: 1: installed, 2: available */
			$findings[] = Catalog::finding( 'health_wp_update', '', sprintf( __( 'Installed %1$s, available %2$s.', 'siteaudithub' ), $wp_version, $latest ) );
		}
		$overview[] = array(
			'label'  => __( 'WordPress version', 'siteaudithub' ),
			'value'  => $wp_version,
			'status' => $latest && version_compare( $latest, $wp_version, '>' ) ? 'warning' : ( $core_known ? 'good' : 'unknown' ),
			'note'   => $latest && version_compare( $latest, $wp_version, '>' )
				/* translators: %s: version */
				? sprintf( __( 'Update available: %s', 'siteaudithub' ), $latest )
				: ( $core_known ? __( 'Up to date according to the last update check.', 'siteaudithub' ) : __( 'Update information unavailable (no recent update check).', 'siteaudithub' ) ),
		);

		// PHP version. Active support ends ~2 years after release; security support ~3 years.
		$php_status = 'good';
		if ( version_compare( PHP_VERSION, '8.1', '<' ) ) {
			$php_status = 'warning';
			/* translators: %s: PHP version */
			$findings[] = Catalog::finding( 'health_php_version', '', sprintf( __( 'PHP %s is end-of-life upstream.', 'siteaudithub' ), PHP_VERSION ), array( 'severity' => version_compare( PHP_VERSION, '8.0', '<' ) ? 'high' : 'medium' ) );
		}
		$overview[] = array(
			'label'  => __( 'PHP version', 'siteaudithub' ),
			'value'  => PHP_VERSION,
			'status' => $php_status,
			'note'   => 'good' === $php_status ? __( 'Supported by the PHP project at the time of this release.', 'siteaudithub' ) : __( 'Consider upgrading with your host.', 'siteaudithub' ),
		);

		// Plugin and theme updates.
		$plugin_updates = get_site_transient( 'update_plugins' );
		$pcount         = is_object( $plugin_updates ) && ! empty( $plugin_updates->response ) ? count( (array) $plugin_updates->response ) : 0;
		if ( $pcount ) {
			$names = array();
			$all   = Paths::plugins();
			foreach ( array_keys( (array) $plugin_updates->response ) as $file ) {
				$names[] = isset( $all[ $file ] ) ? $all[ $file ]['Name'] : $file;
			}
			/* translators: %d: count */
			$findings[] = Catalog::finding( 'health_plugin_updates', '', sprintf( _n( '%d plugin has an update:', '%d plugins have updates:', $pcount, 'siteaudithub' ), $pcount ) . "\n" . implode( "\n", $names ) );
		}
		$overview[] = array(
			'label'  => __( 'Plugin updates', 'siteaudithub' ),
			'value'  => (string) $pcount,
			'status' => $pcount ? 'warning' : ( is_object( $plugin_updates ) ? 'good' : 'unknown' ),
			'note'   => is_object( $plugin_updates ) && ! empty( $plugin_updates->last_checked )
				/* translators: %s: human time diff */
				? sprintf( __( 'Last checked %s ago.', 'siteaudithub' ), human_time_diff( (int) $plugin_updates->last_checked ) )
				: __( 'WordPress has not checked for updates recently.', 'siteaudithub' ),
		);

		$theme_updates = get_site_transient( 'update_themes' );
		$tcount        = is_object( $theme_updates ) && ! empty( $theme_updates->response ) ? count( (array) $theme_updates->response ) : 0;
		if ( $tcount ) {
			/* translators: %s: theme slugs */
			$findings[] = Catalog::finding( 'health_theme_updates', '', sprintf( __( 'Themes: %s', 'siteaudithub' ), implode( ', ', array_keys( (array) $theme_updates->response ) ) ) );
		}
		$overview[] = array(
			'label'  => __( 'Theme updates', 'siteaudithub' ),
			'value'  => (string) $tcount,
			'status' => $tcount ? 'warning' : ( is_object( $theme_updates ) ? 'good' : 'unknown' ),
			'note'   => '',
		);

		// HTTPS.
		$https = 0 === strpos( home_url(), 'https://' ) && 0 === strpos( site_url(), 'https://' );
		if ( ! $https ) {
			$findings[] = Catalog::finding( 'health_not_https', '', home_url() );
		}
		$overview[] = array(
			'label'  => __( 'HTTPS', 'siteaudithub' ),
			'value'  => $https ? __( 'Enabled', 'siteaudithub' ) : __( 'Not used', 'siteaudithub' ),
			'status' => $https ? 'good' : 'critical',
			'note'   => '',
		);

		// Debug configuration.
		$debug_display = defined( 'WP_DEBUG' ) && WP_DEBUG && ( ! defined( 'WP_DEBUG_DISPLAY' ) || WP_DEBUG_DISPLAY ) && 'production' === wp_get_environment_type();
		if ( $debug_display ) {
			$findings[] = Catalog::finding( 'health_debug_display', '' );
		}
		$overview[] = array(
			'label'  => __( 'Debug display', 'siteaudithub' ),
			'value'  => $debug_display ? __( 'On', 'siteaudithub' ) : __( 'Off', 'siteaudithub' ),
			'status' => $debug_display ? 'warning' : 'good',
			/* translators: %s: environment type */
			'note'   => sprintf( __( 'Environment type: %s', 'siteaudithub' ), wp_get_environment_type() ),
		);

		$overview[] = Login_Guard::health_row();

		if ( get_user_by( 'login', 'admin' ) ) {
			$findings[] = Catalog::finding( 'health_admin_user', '' );
		}

		// Cron.
		$cron_disabled = defined( 'DISABLE_WP_CRON' ) && DISABLE_WP_CRON;
		if ( $cron_disabled ) {
			$findings[] = Catalog::finding( 'health_cron_disabled', '' );
		}
		$overdue = 0;
		$crons   = function_exists( '_get_cron_array' ) ? _get_cron_array() : array();
		foreach ( (array) $crons as $timestamp => $hooks ) {
			if ( (int) $timestamp < time() - HOUR_IN_SECONDS ) {
				$overdue += count( (array) $hooks );
			}
		}
		if ( $overdue > 0 ) {
			/* translators: %d: count */
			$findings[] = Catalog::finding( 'health_cron_overdue', '', sprintf( __( '%d event(s) overdue by more than one hour.', 'siteaudithub' ), $overdue ) );
		}
		$overview[] = array(
			'label'  => __( 'WP-Cron', 'siteaudithub' ),
			'value'  => $cron_disabled ? __( 'Disabled (server cron expected)', 'siteaudithub' ) : __( 'Enabled', 'siteaudithub' ),
			'status' => $overdue ? 'warning' : 'good',
			/* translators: %d: count */
			'note'   => $overdue ? sprintf( __( '%d overdue event(s).', 'siteaudithub' ), $overdue ) : __( 'No events overdue by more than an hour.', 'siteaudithub' ),
		);

		// Autoloaded options size.
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery
		$autoload = (int) $wpdb->get_var( $wpdb->prepare( 'SELECT SUM(LENGTH(option_value)) FROM %i WHERE autoload IN (%s, %s, %s, %s)', $wpdb->options, 'yes', 'on', 'auto-on', 'auto' ) );
		if ( $autoload > 1024 * 1024 ) {
			$findings[] = Catalog::finding( 'health_autoload', '', size_format( $autoload ), array( 'severity' => $autoload > 3 * 1024 * 1024 ? 'high' : 'medium' ) );
		}
		$overview[] = array(
			'label'  => __( 'Autoloaded options', 'siteaudithub' ),
			'value'  => size_format( $autoload ),
			'status' => $autoload > 1024 * 1024 ? 'warning' : 'good',
			'note'   => __( 'Loaded on every request; under 1 MB is comfortable.', 'siteaudithub' ),
		);

		// PHP environment.
		$missing = array();
		foreach ( array( 'curl', 'dom', 'mbstring', 'json', 'openssl', 'zip', 'fileinfo', 'xml' ) as $ext ) {
			if ( ! extension_loaded( $ext ) ) {
				$missing[] = $ext;
			}
		}
		if ( $missing ) {
			$findings[] = Catalog::finding( 'health_php_extensions', '', implode( ', ', $missing ) );
		}
		$overview[] = array(
			'label'  => __( 'PHP extensions', 'siteaudithub' ),
			'value'  => $missing ? implode( ', ', $missing ) . ' ' . __( 'missing', 'siteaudithub' ) : __( 'All recommended loaded', 'siteaudithub' ),
			'status' => $missing ? 'warning' : 'good',
			'note'   => '',
		);
		$memory = wp_convert_hr_to_bytes( (string) ini_get( 'memory_limit' ) );
		if ( $memory > 0 && $memory < 128 * MB_IN_BYTES ) {
			$findings[] = Catalog::finding( 'health_memory_limit', '', (string) ini_get( 'memory_limit' ) );
		}
		$overview[] = array(
			'label'  => __( 'PHP memory limit', 'siteaudithub' ),
			'value'  => (string) ini_get( 'memory_limit' ),
			'status' => ( $memory > 0 && $memory < 128 * MB_IN_BYTES ) ? 'warning' : 'good',
			/* translators: %s: seconds */
			'note'   => sprintf( __( 'max_execution_time: %s', 'siteaudithub' ), (string) ini_get( 'max_execution_time' ) ),
		);

		// Inactive plugins/themes.
		$plugins  = Paths::plugins();
		$inactive = array();
		$active   = (array) get_option( 'active_plugins', array() );
		$network  = is_multisite() ? (array) get_site_option( 'active_sitewide_plugins', array() ) : array();
		foreach ( $plugins as $file => $p ) {
			if ( ! in_array( $file, $active, true ) && ! isset( $network[ $file ] ) ) {
				$inactive[] = $p['Name'];
			}
		}
		if ( $inactive ) {
			$findings[] = Catalog::finding( 'health_inactive_plugins', '', implode( "\n", $inactive ) );
		}
		$themes          = wp_get_themes();
		$active_theme    = get_stylesheet();
		$parent_theme    = get_template();
		$inactive_themes = array();
		foreach ( $themes as $slug => $theme ) {
			if ( $slug !== $active_theme && $slug !== $parent_theme ) {
				$inactive_themes[] = $theme->get( 'Name' );
			}
		}
		if ( count( $inactive_themes ) > 1 ) {
			$findings[] = Catalog::finding( 'health_inactive_themes', '', implode( "\n", $inactive_themes ) );
		}

		$uploads = wp_get_upload_dir();
		if ( empty( $uploads['error'] ) && ! wp_is_writable( $uploads['basedir'] ) ) {
			$findings[] = Catalog::finding( 'health_uploads_writable', '' );
		}

		// Loopback checks.
		if ( $remote ) {
			$rest       = Http::fetch( rest_url(), array( 'max_bytes' => 256 * 1024 ) );
			$rest_ok    = $rest['status'] >= 200 && $rest['status'] < 300;
			if ( ! $rest_ok ) {
				$findings[] = Catalog::finding( 'health_rest_api', '', $rest['status'] ? 'HTTP ' . $rest['status'] : $rest['error'] );
			}
			$overview[] = array(
				'label'  => __( 'REST API', 'siteaudithub' ),
				'value'  => $rest['status'] ? 'HTTP ' . $rest['status'] : __( 'No response', 'siteaudithub' ),
				'status' => $rest_ok ? 'good' : 'warning',
				'note'   => $rest_ok ? '' : $rest['error'],
			);

			$robots = Http::fetch( home_url( '/robots.txt' ), array( 'max_bytes' => 64 * 1024 ) );
			if ( 200 !== $robots['status'] ) {
				$findings[] = Catalog::finding( 'health_robots_missing', '', $robots['status'] ? 'HTTP ' . $robots['status'] : $robots['error'] );
			}
			$overview[] = array(
				'label'  => __( 'robots.txt', 'siteaudithub' ),
				'value'  => $robots['status'] ? 'HTTP ' . $robots['status'] : __( 'No response', 'siteaudithub' ),
				'status' => 200 === $robots['status'] ? 'good' : 'notice',
				'note'   => '',
			);

			// Only probe the default log location; never read its contents into reports.
			if ( file_exists( Paths::content() . 'debug.log' ) ) {
				$content_url = content_url( '/debug.log' );
				$log         = Http::fetch(
					$content_url,
					array(
						'method'    => 'HEAD',
						'max_bytes' => 1024,
					)
				);
				$public      = $log['status'] >= 200 && $log['status'] < 300;
				if ( $public ) {
					$findings[] = Catalog::finding( 'health_debug_log_public', '', $content_url );
				}
				$overview[] = array(
					'label'  => __( 'debug.log', 'siteaudithub' ),
					'value'  => $public ? __( 'Publicly accessible', 'siteaudithub' ) : __( 'Present, not publicly served', 'siteaudithub' ),
					'status' => $public ? 'critical' : 'good',
					'note'   => '',
				);
			}

			if ( ! $https ) {
				$https_url = set_url_scheme( home_url( '/' ), 'https' );
				$probe     = Http::fetch(
					$https_url,
					array(
						'method'        => 'HEAD',
						'max_redirects' => 2,
						'timeout'       => 8,
					)
				);
				if ( 0 === $probe['status'] ) {
					$findings[] = Catalog::finding( 'health_https_unavailable', '', $probe['error'] );
				}
			}
		}

		set_transient(
			self::TRANSIENT,
			array(
				'time'     => time(),
				'remote'   => $remote,
				'overview' => $overview,
				'findings' => $findings,
			),
			WEEK_IN_SECONDS
		);
		return $findings;
	}

	/**
	 * Cached results for the UI (runs local-only checks if nothing cached).
	 *
	 * @return array
	 */
	public static function cached() {
		$cached = get_transient( self::TRANSIENT );
		if ( ! is_array( $cached ) ) {
			self::run( false );
			$cached = get_transient( self::TRANSIENT );
		}
		return is_array( $cached ) ? $cached : array(
			'time'     => 0,
			'remote'   => false,
			'overview' => array(),
			'findings' => array(),
		);
	}
}