<?php
/**
 * Components and metrics for keepwatch-report.v2.
 *
 * @package Keepwatch
 */

namespace Keepwatch\Cloud;

use Keepwatch\Checks\DatabaseCheck;

defined( 'ABSPATH' ) || exit;

/**
 * Installed WordPress core, plugins and themes with versions and available updates, plus a few site metrics.
 * Built from data WordPress already has locally (update transients, option table); no remote requests. Sent only after
 * the administrator agreed to it (consent version 2). No user, order or file content is included.
 */
final class SiteInventory {

	public const MAX_PLUGINS = 150;
	public const MAX_THEMES  = 30;

	/**
	 * Installed components.
	 *
	 * @return array{core: array{version: string, update: string|null}, plugins: list<array{slug: string, name: string, version: string, active: bool, update: string|null}>, themes: list<array{slug: string, name: string, version: string, active: bool, update: string|null}>}
	 */
	public static function components(): array {
		global $wp_version;

		if ( ! function_exists( 'get_plugins' ) ) {
			require_once ABSPATH . 'wp-admin/includes/plugin.php';
		}

		$core_update = null;
		$core        = get_site_transient( 'update_core' );
		if ( is_object( $core ) && isset( $core->updates ) && is_array( $core->updates ) ) {
			foreach ( $core->updates as $offer ) {
				if ( is_object( $offer ) && isset( $offer->response, $offer->current ) && 'upgrade' === $offer->response ) {
					$core_update = self::version( (string) $offer->current );
					break;
				}
			}
		}

		$plugin_updates = get_site_transient( 'update_plugins' );
		$plugin_updates = is_object( $plugin_updates ) && isset( $plugin_updates->response ) && is_array( $plugin_updates->response ) ? $plugin_updates->response : array();
		$plugins        = array();
		foreach ( get_plugins() as $file => $data ) {
			if ( count( $plugins ) >= self::MAX_PLUGINS ) {
				break;
			}
			$file      = (string) $file;
			$update    = isset( $plugin_updates[ $file ] ) && is_object( $plugin_updates[ $file ] ) && isset( $plugin_updates[ $file ]->new_version )
				? self::version( (string) $plugin_updates[ $file ]->new_version ) : null;
			$plugins[] = array(
				'slug'    => self::slug( false !== strpos( $file, '/' ) ? dirname( $file ) : basename( $file, '.php' ) ),
				'name'    => self::text( isset( $data['Name'] ) ? (string) $data['Name'] : $file ),
				'version' => self::version( isset( $data['Version'] ) ? (string) $data['Version'] : '' ),
				'active'  => is_plugin_active( $file ),
				'update'  => $update,
			);
		}

		$theme_updates = get_site_transient( 'update_themes' );
		$theme_updates = is_object( $theme_updates ) && isset( $theme_updates->response ) && is_array( $theme_updates->response ) ? $theme_updates->response : array();
		$active_theme  = get_stylesheet();
		$themes        = array();
		foreach ( wp_get_themes() as $stylesheet => $theme ) {
			if ( count( $themes ) >= self::MAX_THEMES ) {
				break;
			}
			$stylesheet = (string) $stylesheet;
			$offer      = $theme_updates[ $stylesheet ] ?? null;
			$themes[]   = array(
				'slug'    => self::slug( $stylesheet ),
				'name'    => self::text( (string) $theme->get( 'Name' ) ),
				'version' => self::version( (string) $theme->get( 'Version' ) ),
				'active'  => $stylesheet === $active_theme,
				'update'  => is_array( $offer ) && isset( $offer['new_version'] ) ? self::version( (string) $offer['new_version'] ) : null,
			);
		}

		return array(
			'core'    => array(
				'version' => self::version( (string) $wp_version ),
				'update'  => $core_update,
			),
			'plugins' => $plugins,
			'themes'  => $themes,
		);
	}

	/**
	 * Site metrics. A value that cannot be read is null.
	 *
	 * @return array{memory_limit_mb: int|null, autoload_kb: int|null, db_size_mb: int|null, cron_overdue: int}
	 */
	public static function metrics(): array {
		$facts = ( new DatabaseCheck() )->facts();

		$overdue = 0;
		$cutoff  = time() - HOUR_IN_SECONDS;
		foreach ( _get_cron_array() as $timestamp => $hooks ) {
			if ( (int) $timestamp < $cutoff ) {
				$overdue += count( $hooks );
			}
		}

		$memory = wp_convert_hr_to_bytes( (string) ini_get( 'memory_limit' ) );

		return array(
			'memory_limit_mb' => $memory > 0 ? (int) round( $memory / MB_IN_BYTES ) : null,
			'autoload_kb'     => null === $facts['autoload_bytes'] ? null : (int) round( $facts['autoload_bytes'] / KB_IN_BYTES ),
			'db_size_mb'      => null === $facts['db_bytes'] ? null : (int) round( $facts['db_bytes'] / MB_IN_BYTES ),
			'cron_overdue'    => min( 100000, $overdue ),
		);
	}

	/**
	 * Lowercase slug as the schema expects.
	 *
	 * @param string $value Raw slug.
	 */
	private static function slug( string $value ): string {
		$clean = (string) preg_replace( '/[^a-z0-9_.-]/', '', strtolower( $value ) );
		return strlen( $clean ) > 100 ? substr( $clean, 0, 100 ) : $clean;
	}

	/**
	 * Version string (max 32 characters).
	 *
	 * @param string $value Raw version.
	 */
	private static function version( string $value ): string {
		$value = trim( wp_strip_all_tags( $value ) );
		return strlen( $value ) > 32 ? substr( $value, 0, 32 ) : $value;
	}

	/**
	 * Display name (max 80 characters, tags removed).
	 *
	 * @param string $value Raw name.
	 */
	private static function text( string $value ): string {
		$value = trim( wp_strip_all_tags( $value ) );
		return function_exists( 'mb_substr' ) ? mb_substr( $value, 0, 80 ) : substr( $value, 0, 80 );
	}
}