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

package trace // import "go.opentelemetry.io/collector/receiver/otlpreceiver/internal/trace"

import (
	"context"

	"go.opentelemetry.io/collector/consumer"
	"go.opentelemetry.io/collector/obsreport"
	"go.opentelemetry.io/collector/pdata/ptrace/ptraceotlp"
)

const dataFormatProtobuf = "protobuf"

// Receiver is the type used to handle spans from OpenTelemetry exporters.
type Receiver struct {
	ptraceotlp.UnimplementedGRPCServer
	nextConsumer consumer.Traces
	obsrecv      *obsreport.Receiver
}

// New creates a new Receiver reference.
func New(nextConsumer consumer.Traces, obsrecv *obsreport.Receiver) *Receiver {
	return &Receiver{
		nextConsumer: nextConsumer,
		obsrecv:      obsrecv,
	}
}

// Export implements the service Export traces func.
func (r *Receiver) Export(ctx context.Context, req ptraceotlp.ExportRequest) (ptraceotlp.ExportResponse, error) {
	td := req.Traces()
	// We need to ensure that it propagates the receiver name as a tag
	numSpans := td.SpanCount()
	if numSpans == 0 {
		return ptraceotlp.NewExportResponse(), nil
	}

	ctx = r.obsrecv.StartTracesOp(ctx)
	err := r.nextConsumer.ConsumeTraces(ctx, td)
	r.obsrecv.EndTracesOp(ctx, dataFormatProtobuf, numSpans, err)

	return ptraceotlp.NewExportResponse(), err
}
