<?php
/**
 * Advanced logging system.
 *
 * @package AceloraSiteAccelerator
 */

namespace Acelora\SiteAccelerator\Includes;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * File-backed structured logger.
 */
class Logger {

	const OPTION = 'acelora_site_accelerator_logs';

	/**
	 * Settings.
	 *
	 * @var Settings
	 */
	private $settings;

	/**
	 * Constructor.
	 *
	 * @param Settings $settings Settings.
	 */
	public function __construct( Settings $settings ) {
		$this->settings = $settings;
	}

	/**
	 * Write a log entry.
	 *
	 * @param string $level   Log level.
	 * @param string $message Message.
	 * @param array  $context Context.
	 * @return void
	 */
	public function log( $level, $message, $context = array() ) {
		if ( ! $this->settings->get( 'logging.enabled', 1 ) ) {
			return;
		}

		$entries   = get_option( self::OPTION, array() );
		$entries   = is_array( $entries ) ? $entries : array();
		$entries[] = array(
			'time'    => current_time( 'mysql' ),
			'level'   => sanitize_key( $level ),
			'message' => sanitize_text_field( $message ),
			'context' => $this->sanitize_context( $context ),
		);

		if ( count( $entries ) > 300 ) {
			$entries = array_slice( $entries, -300 );
		}

		update_option( self::OPTION, $entries, false );
	}

	/**
	 * Read recent logs.
	 *
	 * @param int $limit Max entries.
	 * @return array
	 */
	public function recent( $limit = 100 ) {
		$entries = get_option( self::OPTION, array() );
		$entries = is_array( $entries ) ? array_reverse( $entries ) : array();

		return array_slice( $entries, 0, max( 1, absint( $limit ) ) );
	}

	/**
	 * Remove old log files.
	 *
	 * @return int Removed files.
	 */
	public function prune() {
		$retention = max( 1, absint( $this->settings->get( 'logging.retention_days', 14 ) ) );
		$cutoff    = time() - ( DAY_IN_SECONDS * $retention );
		$entries   = get_option( self::OPTION, array() );
		$entries   = is_array( $entries ) ? $entries : array();
		$kept      = array();

		foreach ( $entries as $entry ) {
			$time = isset( $entry['time'] ) ? strtotime( $entry['time'] ) : time();

			if ( $time >= $cutoff ) {
				$kept[] = $entry;
			}
		}

		update_option( self::OPTION, $kept, false );

		return count( $entries ) - count( $kept );
	}

	/**
	 * Sanitize context values for database storage.
	 *
	 * @param mixed $context Context.
	 * @return mixed
	 */
	private function sanitize_context( $context ) {
		if ( is_array( $context ) ) {
			return array_map( array( $this, 'sanitize_context' ), $context );
		}

		if ( is_scalar( $context ) || null === $context ) {
			return sanitize_text_field( (string) $context );
		}

		return '';
	}
}