// Copyright 2025 Google LLC

//

// 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 spanner

import (

"context"

"errors"

"fmt"

"cloud.google.com/go/spanner/internal"

"go.opentelemetry.io/otel"

otelcodes "go.opentelemetry.io/otel/codes"

"go.opentelemetry.io/otel/trace"

"google.golang.org/api/googleapi"

"google.golang.org/grpc/status"

)

const (

defaultTracerName = "cloud.google.com/go/spanner"

gcpClientRepo = "googleapis/google-cloud-go"

gcpClientArtifact = "cloud.google.com/go/spanner"

// GcpResourceNamePrefix is the prefix for Spanner GCP resource names span attribute.

GcpResourceNamePrefix = "//spanner.googleapis.com/"

)

func tracer() trace.Tracer {

return otel.Tracer(defaultTracerName, trace.WithInstrumentationVersion(internal.Version))

}

// startSpan creates a span and a context.Context containing the newly-created span.

// If the context.Context provided in `ctx` contains a span then the newly-created

// span will be a child of that span, otherwise it will be a root span.

func startSpan(ctx context.Context, name string, opts ...trace.SpanStartOption) (context.Context, trace.Span) {

name = prependPackageName(name)

ctx, span := tracer().Start(ctx, name, opts...)

return ctx, span

}

// endSpan retrieves the current span from ctx and completes the span.

// If an error occurs, the error is recorded as an exception span event for this span,

// and the span status is set in the form of a code and a description.

func endSpan(ctx context.Context, err error) {

span := trace.SpanFromContext(ctx)

if err != nil {

span.SetStatus(otelcodes.Error, toOpenTelemetryStatusDescription(err))

span.RecordError(err)

}

span.End()

}

// toOpenTelemetryStatus converts an error to an equivalent OpenTelemetry status description.

func toOpenTelemetryStatusDescription(err error) string {

var err2 *googleapi.Error

if ok := errors.As(err, &err2); ok {

return err2.Message

} else if s, ok := status.FromError(err); ok {

return s.Message()

} else {

return err.Error()

}

}

func prependPackageName(spanName string) string {

return fmt.Sprintf("%s.%s", gcpClientArtifact, spanName)

}