// Copyright 2019-2025 The Wait4X Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package checker

import (
	"errors"
	"net"
	"syscall"
)

// IsConnectionRefused attempts to determine if the given error was caused by a failure to establish a connection.
func IsConnectionRefused(err error) bool {
	for err != nil {
		switch t := err.(type) {
		case *net.OpError:
			if t.Op == "dial" || t.Op == "read" {
				return true
			}
		case syscall.Errno:
			if t == syscall.ECONNREFUSED {
				return true
			}
		}

		err = errors.Unwrap(err)
	}

	return false
}
