<?php
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * MetaForge_Logger — Lightweight audit trail for MetaForge Engine.
 * All events are written to the WP debug log and optionally
 * to a custom DB table for future UI display.
 */
class MetaForge_Logger {

	/**
	 * Log an audit event.
	 *
	 * @param string $event   e.g. 'field_group_saved', 'field_group_deleted'
	 * @param array  $context Optional key=>value context pairs
	 */
	public static function log( $event, $context = array() ) {
		$user_id  = get_current_user_id();
		$user     = $user_id ? get_userdata( $user_id ) : null;
		$username = $user ? $user->user_login : 'system';
		$time     = current_time( 'Y-m-d H:i:s' );

		$ctx_parts = array();
		foreach ( $context as $k => $v ) {
			$ctx_parts[] = $k . ':' . ( is_scalar( $v ) ? $v : wp_json_encode( $v ) );
		}
		$ctx_string = ! empty( $ctx_parts ) ? ' | ' . implode( ' | ', $ctx_parts ) : '';

		$message = sprintf(
			'[MFE AUDIT] %s | %s | user:%s%s',
			$time,
			strtoupper( $event ),
			$username,
			$ctx_string
		);

        // phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_error_log -- System audit logging output.
		error_log( $message );

		// Optionally persist to wp_options for a future admin UI
		$log_history   = get_option( 'metaforge_audit_log', array() );
		$log_history[] = array(
			'time'  => $time,
			'event' => $event,
			'user'  => $username,
			'ctx'   => $context,
		);

		// Keep only the last 200 entries to avoid bloating the options table
		if ( count( $log_history ) > 200 ) {
			$log_history = array_slice( $log_history, -200 );
		}

		update_option( 'metaforge_audit_log', $log_history, false );
	}

	/**
	 * Retrieve stored audit logs with optional filter.
	 *
	 * @param int    $limit        Max number of log entries to return.
	 * @param string $event_filter Optional event type filter.
	 * @return array
	 */
	public static function get_logs( $limit = 100, $event_filter = '' ) {
		$log_history = get_option( 'metaforge_audit_log', array() );
		if ( ! is_array( $log_history ) ) {
			$log_history = array();
		}

		if ( ! empty( $event_filter ) ) {
			$log_history = array_filter(
				$log_history,
				function ( $entry ) use ( $event_filter ) {
					return isset( $entry['event'] ) && stripos( $entry['event'], $event_filter ) !== false;
				}
			);
		}

		$log_history = array_reverse( $log_history );
		return array_slice( $log_history, 0, $limit );
	}

	/**
	 * Clear all stored audit logs.
	 *
	 * @return bool
	 */
	public static function clear_logs() {
		return update_option( 'metaforge_audit_log', array(), false );
	}

	/**
	 * Format logs as plain text for copy-to-clipboard or export.
	 *
	 * @return string
	 */
	public static function get_raw_log_string() {
		$logs = self::get_logs( 200 );
		if ( empty( $logs ) ) {
			return 'No audit logs recorded yet.';
		}

		$lines = array();
		foreach ( $logs as $l ) {
			$ctx     = ! empty( $l['ctx'] ) ? wp_json_encode( $l['ctx'] ) : '{}';
			$lines[] = sprintf(
				'[%s] [%s] User: %s | Data: %s',
				$l['time'] ?? 'N/A',
				strtoupper( $l['event'] ?? 'INFO' ),
				$l['user'] ?? 'system',
				$ctx
			);
		}
		return implode( "\n", $lines );
	}
}