<?php
/**
 * Optional logging for AAL Connector For LACRM.
 *
 * @package LACRM_Forms
 */

declare(strict_types=1);

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Class LACRM_Forms_Logger
 */
final class LACRM_Forms_Logger {

	/**
	 * @var self|null
	 */
	private static ?self $instance = null;

	/**
	 * Log option name.
	 */
	private const OPTION_NAME = 'lacrm_forms_log';

	/**
	 * Max log entries to keep.
	 */
	private const MAX_ENTRIES = 500;

	/**
	 * @return self
	 */
	public static function instance(): self {
		if ( self::$instance === null ) {
			self::$instance = new self();
		}
		return self::$instance;
	}

	/**
	 * Log a message (only if logging is enabled in settings).
	 *
	 * @param string $message Message.
	 * @param string $level   Level: 'info', 'error', 'debug'.
	 * @param array  $context Optional context (e.g. form id, contact id).
	 */
	public function log( string $message, string $level = 'info', array $context = array() ): void {
		if ( ! function_exists( 'lacrm_forms_get_option' ) ) {
			return;
		}
		if ( ! lacrm_forms_get_option( 'enable_logging', true ) ) {
			return;
		}

		$entry = array(
			'time'    => current_time( 'mysql' ),
			'level'   => sanitize_key( $level ),
			'message' => sanitize_text_field( $message ),
			'context' => $this->sanitize_log_context( $context ),
		);

		$log = get_option( self::OPTION_NAME, array() );
		$log = is_array( $log ) ? $log : array();
		$log[] = $entry;

		if ( count( $log ) > self::MAX_ENTRIES ) {
			$log = array_slice( $log, -self::MAX_ENTRIES, null, true );
		}

		update_option( self::OPTION_NAME, $log, false );
	}

	/**
	 * Sanitize context for storage (scalars only).
	 *
	 * @param array $context Raw context.
	 * @return array
	 */
	private function sanitize_log_context( array $context ): array {
		$out = array();
		foreach ( $context as $k => $v ) {
			if ( is_scalar( $v ) ) {
				$out[ sanitize_key( (string) $k ) ] = $v;
			}
		}
		return $out;
	}

	/**
	 * Get total number of log entries.
	 *
	 * @return int
	 */
	public function get_log_count(): int {
		$log = get_option( self::OPTION_NAME, array() );
		$log = is_array( $log ) ? $log : array();
		return count( $log );
	}

	/**
	 * Get a page of log entries (newest first).
	 *
	 * @param int $per_page Entries per page.
	 * @param int $page     Page number (1-based).
	 * @return array{items: array, total: int}
	 */
	public function get_log_page( int $per_page = 20, int $page = 1 ): array {
		$log   = get_option( self::OPTION_NAME, array() );
		$log   = is_array( $log ) ? $log : array();
		$total = count( $log );
		$reversed = array_reverse( $log );
		$offset   = max( 0, ( $page - 1 ) * $per_page );
		$items    = array_slice( $reversed, $offset, $per_page );
		return array(
			'items' => $items,
			'total' => $total,
		);
	}

	/**
	 * Get recent log entries (for backward compatibility).
	 *
	 * @param int $limit Max entries.
	 * @return array
	 */
	public function get_log( int $limit = 100 ): array {
		$result = $this->get_log_page( $limit, 1 );
		return $result['items'];
	}

	/**
	 * Clear the log.
	 */
	public function clear(): void {
		delete_option( self::OPTION_NAME );
	}
}