/*

Copyright 2021 The CloudEvents Authors

SPDX-License-Identifier: Apache-2.0

*/

package event

import (

"errors"

"fmt"

"strings"

)

const (

// DataContentEncodingKey is the key to DeprecatedDataContentEncoding for versions that do not support data content encoding

// directly.

DataContentEncodingKey = "datacontentencoding"

)

var (

// This determines the behavior of validateExtensionName(). For MaxExtensionNameLength > 0, an error will be returned,

// if len(key) > MaxExtensionNameLength

MaxExtensionNameLength = 0

)

func caseInsensitiveSearch(key string, space map[string]interface{}) (interface{}, bool) {

lkey := strings.ToLower(key)

for k, v := range space {

if strings.EqualFold(lkey, strings.ToLower(k)) {

return v, true

}

}

return nil, false

}

func IsExtensionNameValid(key string) bool {

if err := validateExtensionName(key); err != nil {

return false

}

return true

}

func validateExtensionName(key string) error {

if len(key) < 1 {

return errors.New("bad key, CloudEvents attribute names MUST NOT be empty")

}

if MaxExtensionNameLength > 0 && len(key) > MaxExtensionNameLength {

return fmt.Errorf("bad key, CloudEvents attribute name '%s' is longer than %d characters", key, MaxExtensionNameLength)

}

for _, c := range key {

if !((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9')) {

return errors.New("bad key, CloudEvents attribute names MUST consist of lower-case letters ('a' to 'z') or digits ('0' to '9') from the ASCII character set")

}

}

return nil

}