// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0

package tencentcloudlogserviceexporter // import "github.com/open-telemetry/opentelemetry-collector-contrib/exporter/tencentcloudlogserviceexporter"

import (
	"strings"
	"unicode"
)

// The code for sanitize is mostly copied from:
//  https://github.com/open-telemetry/opentelemetry-collector/blob/2e84285efc665798d76773b9901727e8836e9d8f/exporter/prometheusexporter/sanitize.go

// sanitize replaces non-alphanumeric characters with underscores in s.
func sanitize(s string) string {
	if len(s) == 0 {
		return s
	}

	// Note: No length limit for label keys because Prometheus doesn't
	// define a length limit, thus we should NOT be truncating label keys.
	// See https://github.com/orijtech/prometheus-go-metrics-exporter/issues/4.

	s = strings.Map(sanitizeRune, s)
	if unicode.IsDigit(rune(s[0])) {
		s = "key_" + s
	}
	if s[0] == '_' {
		s = "key" + s
	}
	return s
}

// converts anything that is not a letter or digit to an underscore
func sanitizeRune(r rune) rune {
	if unicode.IsLetter(r) || unicode.IsDigit(r) {
		return r
	}
	// Everything else turns into an underscore
	return '_'
}