<?php

namespace App\Services;

use CodeIgniter\Database\BaseConnection;

class AuditService {
  protected BaseConnection $db;

  public function __construct() {
    $this->db = \Config\Database::connect();
  }

    public static function logData(
    string $operation,
    string $entityType,
    string $entityId,
    ?string $tableName = null,
    ?string $fieldName = null,
    ?array $previousValue = null,
    ?array $newValue = null,
    ?string $reason = null,
    ?array $context = null
  ): void {
    self::log('data_audit_log', [
      'operation' => $operation,
      'entity_type' => $entityType,
      'entity_id' => $entityId,
      'table_name' => $tableName,
      'field_name' => $fieldName,
      'previous_value' => self::normalizeAuditValue($previousValue),
      'new_value' => self::normalizeAuditValue($newValue),
      'mechanism' => 'MANUAL',
      'application_id' => 'CLQMS-WEB',
      'web_page' => self::getUri(),
      'session_id' => self::getSessionId(),
      'event_type' => strtoupper($entityType) . '_' . strtoupper($operation),
      'site_id' => self::getSiteId(),
      'workstation_id' => self::getWorkstationId(),
      'pc_name' => self::getPcName(),
      'ip_address' => self::getIpAddress(),
      'user_id' => self::getUserId(),
      'reason' => $reason,
      'context' => self::normalizeAuditValue($context),
      'created_at' => date('Y-m-d H:i:s')
    ]);
  }

  public static function logService(
    string $operation,
    string $entityType,
    string $entityId,
    string $serviceClass,
    ?string $resourceType = null,
    ?array $resourceDetails = null,
    ?array $previousValue = null,
    ?array $newValue = null,
    ?string $serviceName = null,
    ?array $context = null
  ): void {
    self::log('service_audit_log', [
      'operation' => $operation,
      'entity_type' => $entityType,
      'entity_id' => $entityId,
      'service_class' => $serviceClass,
      'resource_type' => $resourceType,
      'resource_details' => self::normalizeAuditValue($resourceDetails),
      'previous_value' => self::normalizeAuditValue($previousValue),
      'new_value' => self::normalizeAuditValue($newValue),
      'mechanism' => 'AUTOMATIC',
      'application_id' => $serviceName ?? 'SYSTEM-SERVICE',
      'service_name' => $serviceName,
      'session_id' => self::getSessionId() ?: 'service_session',
      'event_type' => strtoupper($serviceClass) . '_' . strtoupper($operation),
      'site_id' => self::getSiteId(),
      'workstation_id' => self::getWorkstationId(),
      'pc_name' => self::getPcName(),
      'ip_address' => self::getIpAddress(),
      'port' => $resourceDetails['port'] ?? null,
      'user_id' => 'SYSTEM',
      'reason' => null,
      'context' => self::normalizeAuditValue($context),
      'created_at' => date('Y-m-d H:i:s')
    ]);
  }

  public static function logSecurity(
    string $operation,
    string $entityType,
    string $entityId,
    string $securityClass,
    ?string $eventType = 'SUCCESS',
    ?string $resourcePath = null,
    ?array $previousValue = null,
    ?array $newValue = null,
    ?string $reason = null,
    ?array $context = null
  ): void {
    self::log('security_audit_log', [
      'operation' => $operation,
      'entity_type' => $entityType,
      'entity_id' => $entityId,
      'security_class' => $securityClass,
      'resource_path' => $resourcePath,
      'previous_value' => self::normalizeAuditValue($previousValue),
      'new_value' => self::normalizeAuditValue($newValue),
      'mechanism' => 'MANUAL',
      'application_id' => 'CLQMS-WEB',
      'web_page' => self::getUri(),
      'session_id' => self::getSessionId(),
      'event_type' => $eventType,
      'site_id' => self::getSiteId(),
      'workstation_id' => self::getWorkstationId(),
      'pc_name' => self::getPcName(),
      'ip_address' => self::getIpAddress(),
      'user_id' => self::getUserId() ?? 'UNKNOWN',
      'reason' => $reason,
      'context' => self::normalizeAuditValue($context),
      'created_at' => date('Y-m-d H:i:s')
    ]);
  }

  public static function logError(
    string $entityType,
    string $entityId,
    string $errorCode,
    string $errorMessage,
    string $eventType,
    ?array $errorDetails = null,
    ?array $previousValue = null,
    ?array $newValue = null,
    ?string $reason = null,
    ?array $context = null
  ): void {
    self::log('error_audit_log', [
      'operation' => 'ERROR',
      'entity_type' => $entityType,
      'entity_id' => $entityId,
      'error_code' => $errorCode,
      'error_message' => $errorMessage,
      'error_details' => self::normalizeAuditValue($errorDetails),
      'previous_value' => self::normalizeAuditValue($previousValue),
      'new_value' => self::normalizeAuditValue($newValue),
      'mechanism' => 'AUTOMATIC',
      'application_id' => 'CLQMS-WEB',
      'web_page' => self::getUri(),
      'session_id' => self::getSessionId() ?: 'system',
      'event_type' => $eventType,
      'site_id' => self::getSiteId(),
      'workstation_id' => self::getWorkstationId(),
      'pc_name' => self::getPcName(),
      'ip_address' => self::getIpAddress(),
      'user_id' => self::getUserId() ?? 'SYSTEM',
      'reason' => $reason,
      'context' => self::normalizeAuditValue($context),
      'created_at' => date('Y-m-d H:i:s')
    ]);
  }

  private static function log(string $table, array $data): void {
    $db = \Config\Database::connect();
    if (!$db->tableExists($table)) {
        return;
    }
    $db->table($table)->insert($data);
  }

  private static function normalizeAuditValue($value)
  {
      if ($value === null || is_scalar($value)) {
          return $value;
      }

      $json = json_encode($value, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
      return $json !== false ? $json : null;
  }

  private static function getUri(): ?string {
    return $_SERVER['REQUEST_URI'] ?? null;
  }

  private static function getSessionId(): ?string {
    $session = session();
    return $session->get('session_id');
  }

  private static function getSiteId(): ?string {
    $session = session();
    return $session->get('site_id');
  }

  private static function getWorkstationId(): ?string {
    $session = session();
    return $session->get('workstation_id');
  }

  private static function getPcName(): ?string {
    return gethostname();
  }

  private static function getIpAddress(): ?string {
    return $_SERVER['REMOTE_ADDR'] ?? null;
  }

  private static function getUserId(): ?string {
    $session = session();
    return $session->get('user_id');
  }
}