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

package log_test

import (
	"context"
	"strings"

	"go.opentelemetry.io/otel/log"
	logsdk "go.opentelemetry.io/otel/sdk/log"
)

// Use a processor which redacts sensitive data from some attributes.
func ExampleProcessor_redact() {
	// Existing processor that emits telemetry.
	var processor logsdk.Processor = logsdk.NewBatchProcessor(nil)

	// Wrap the processor so that it redacts values from token attributes.
	processor = &RedactTokensProcessor{processor}

	// The created processor can then be registered with
	// the OpenTelemetry Logs SDK using the WithProcessor option.
	_ = logsdk.NewLoggerProvider(
		logsdk.WithProcessor(processor),
	)
}

// RedactTokensProcessor is a [logsdk.Processor] decorator that redacts values
// from attributes containing "token" in the key.
type RedactTokensProcessor struct {
	logsdk.Processor
}

// OnEmit redacts values from attributes containing "token" in the key
// by replacing them with a REDACTED value.
func (s *RedactTokensProcessor) OnEmit(ctx context.Context, record logsdk.Record) error {
	record.WalkAttributes(func(kv log.KeyValue) bool {
		if strings.Contains(strings.ToLower(kv.Key), "token") {
			record.AddAttributes(log.String(kv.Key, "REDACTED"))
		}
		return true
	})
	return s.Processor.OnEmit(ctx, record)
}