// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package tls

import "strconv"

// An AlertError is a TLS alert.
//
// When using a QUIC transport, QUICConn methods will return an error
// which wraps AlertError rather than sending a TLS alert.
type AlertError uint8

func (e AlertError) Error() string {
	return alert(e).String()
}

type alert uint8

const (
	// alert level
	alertLevelWarning = 1
	alertLevelError   = 2
)

const (
	alertCloseNotify                  alert = 0
	alertUnexpectedMessage            alert = 10
	alertBadRecordMAC                 alert = 20
	alertDecryptionFailed             alert = 21
	alertRecordOverflow               alert = 22
	alertDecompressionFailure         alert = 30
	alertHandshakeFailure             alert = 40
	alertBadCertificate               alert = 42
	alertUnsupportedCertificate       alert = 43
	alertCertificateRevoked           alert = 44
	alertCertificateExpired           alert = 45
	alertCertificateUnknown           alert = 46
	alertIllegalParameter             alert = 47
	alertUnknownCA                    alert = 48
	alertAccessDenied                 alert = 49
	alertDecodeError                  alert = 50
	alertDecryptError                 alert = 51
	alertExportRestriction            alert = 60
	alertProtocolVersion              alert = 70
	alertInsufficientSecurity         alert = 71
	alertInternalError                alert = 80
	alertInappropriateFallback        alert = 86
	alertUserCanceled                 alert = 90
	alertNoRenegotiation              alert = 100
	alertMissingExtension             alert = 109
	alertUnsupportedExtension         alert = 110
	alertCertificateUnobtainable      alert = 111
	alertUnrecognizedName             alert = 112
	alertBadCertificateStatusResponse alert = 113
	alertBadCertificateHashValue      alert = 114
	alertUnknownPSKIdentity           alert = 115
	alertCertificateRequired          alert = 116
	alertNoApplicationProtocol        alert = 120
	alertECHRequired                  alert = 121
)

var alertText = map[alert]string{
	alertCloseNotify:                  "close notify",
	alertUnexpectedMessage:            "unexpected message",
	alertBadRecordMAC:                 "bad record MAC",
	alertDecryptionFailed:             "decryption failed",
	alertRecordOverflow:               "record overflow",
	alertDecompressionFailure:         "decompression failure",
	alertHandshakeFailure:             "handshake failure",
	alertBadCertificate:               "bad certificate",
	alertUnsupportedCertificate:       "unsupported certificate",
	alertCertificateRevoked:           "revoked certificate",
	alertCertificateExpired:           "expired certificate",
	alertCertificateUnknown:           "unknown certificate",
	alertIllegalParameter:             "illegal parameter",
	alertUnknownCA:                    "unknown certificate authority",
	alertAccessDenied:                 "access denied",
	alertDecodeError:                  "error decoding message",
	alertDecryptError:                 "error decrypting message",
	alertExportRestriction:            "export restriction",
	alertProtocolVersion:              "protocol version not supported",
	alertInsufficientSecurity:         "insufficient security level",
	alertInternalError:                "internal error",
	alertInappropriateFallback:        "inappropriate fallback",
	alertUserCanceled:                 "user canceled",
	alertNoRenegotiation:              "no renegotiation",
	alertMissingExtension:             "missing extension",
	alertUnsupportedExtension:         "unsupported extension",
	alertCertificateUnobtainable:      "certificate unobtainable",
	alertUnrecognizedName:             "unrecognized name",
	alertBadCertificateStatusResponse: "bad certificate status response",
	alertBadCertificateHashValue:      "bad certificate hash value",
	alertUnknownPSKIdentity:           "unknown PSK identity",
	alertCertificateRequired:          "certificate required",
	alertNoApplicationProtocol:        "no application protocol",
	alertECHRequired:                  "encrypted client hello required",
}

func (e alert) String() string {
	s, ok := alertText[e]
	if ok {
		return "tls: " + s
	}
	return "tls: alert(" + strconv.Itoa(int(e)) + ")"
}

func (e alert) Error() string {
	return e.String()
}