<?php
namespace QWSpeedCache\Stats;

defined( 'ABSPATH' ) || exit;

/**
 * Ring-buffer event log in options (purges, media, schedule, etc.).
 */
class Logger {

	const OPTION = 'qwsc_event_log';
	const MAX    = 100;

	/**
	 * @param string $type    Type key (a-z0-9_).
	 * @param string $message Short message.
	 */
	public static function log( $type, $message ) {
		$log = get_option( self::OPTION, array() );
		if ( ! is_array( $log ) ) {
			$log = array();
		}
		$log[] = array(
			'time'    => time(),
			'type'    => sanitize_key( $type ),
			'message' => sanitize_text_field( $message ),
		);
		if ( count( $log ) > self::MAX ) {
			$log = array_slice( $log, -self::MAX );
		}
		update_option( self::OPTION, $log, false );
	}

	/**
	 * @return array<int,array{time:int,type:string,message:string}>
	 */
	public static function all() {
		$log = get_option( self::OPTION, array() );
		return is_array( $log ) ? $log : array();
	}

	/**
	 * Newest-first slice, optional type filter.
	 *
	 * @param int         $limit Max rows.
	 * @param string|null $type  Type filter or empty for all.
	 * @return array
	 */
	public static function recent( $limit = 50, $type = null ) {
		$events = array_reverse( self::all() );
		$type   = $type ? sanitize_key( $type ) : '';
		if ( $type ) {
			$events = array_values(
				array_filter(
					$events,
					function ( $ev ) use ( $type ) {
						return isset( $ev['type'] ) && $ev['type'] === $type;
					}
				)
			);
		}
		$limit = max( 1, min( self::MAX, (int) $limit ) );
		return array_slice( $events, 0, $limit );
	}

	/**
	 * Distinct types present in the log.
	 *
	 * @return string[]
	 */
	public static function types() {
		$types = array();
		foreach ( self::all() as $ev ) {
			if ( ! empty( $ev['type'] ) ) {
				$types[ $ev['type'] ] = true;
			}
		}
		$keys = array_keys( $types );
		sort( $keys );
		return $keys;
	}

	/**
	 * Empty the log.
	 */
	public static function clear() {
		delete_option( self::OPTION );
	}

	/**
	 * Human label for a type key.
	 *
	 * @param string $type Type.
	 * @return string
	 */
	public static function type_label( $type ) {
		$map = array(
			'purge_all'       => __( 'Purge all', 'qw-optimize' ),
			'purge_url'       => __( 'Purge URL', 'qw-optimize' ),
			'purge'           => __( 'Purge', 'qw-optimize' ),
			'missed_schedule' => __( 'Missed schedule', 'qw-optimize' ),
			'unpublish'       => __( 'Unpublish', 'qw-optimize' ),
			'media'           => __( 'Media', 'qw-optimize' ),
			'preload'         => __( 'Preload', 'qw-optimize' ),
			'cdn'             => __( 'CDN', 'qw-optimize' ),
			'settings'        => __( 'Settings', 'qw-optimize' ),
		);
		$type = sanitize_key( $type );
		return isset( $map[ $type ] ) ? $map[ $type ] : $type;
	}
}