/*
 * Copyright 2024 gRPC authors.
 *
 * 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 opentelemetry

import (
	"context"
	"strings"

	"go.opentelemetry.io/otel/trace"
	"google.golang.org/grpc"
	otelinternaltracing "google.golang.org/grpc/stats/opentelemetry/internal/tracing"
)

const tracerName = "grpc-go"

// traceTagRPC populates provided context with a new span using the
// TextMapPropagator supplied in trace options and internal itracing.carrier.
// It creates a new outgoing carrier which serializes information about this
// span into gRPC Metadata, if TextMapPropagator is provided in the trace
// options. if TextMapPropagator is not provided, it returns the context as is.
func (h *clientStatsHandler) traceTagRPC(ctx context.Context, ai *attemptInfo) (context.Context, *attemptInfo) {
	mn := "Attempt." + strings.Replace(ai.method, "/", ".", -1)
	tracer := h.options.TraceOptions.TracerProvider.Tracer(tracerName, trace.WithInstrumentationVersion(grpc.Version))
	ctx, span := tracer.Start(ctx, mn)
	carrier := otelinternaltracing.NewOutgoingCarrier(ctx)
	h.options.TraceOptions.TextMapPropagator.Inject(ctx, carrier)
	ai.traceSpan = span
	return carrier.Context(), ai
}

// createCallTraceSpan creates a call span to put in the provided context using
// provided TraceProvider. If TraceProvider is nil, it returns context as is.
func (h *clientStatsHandler) createCallTraceSpan(ctx context.Context, method string) (context.Context, trace.Span) {
	if h.options.TraceOptions.TracerProvider == nil {
		logger.Error("TraceProvider is not provided in trace options")
		return ctx, nil
	}
	mn := strings.Replace(removeLeadingSlash(method), "/", ".", -1)
	tracer := h.options.TraceOptions.TracerProvider.Tracer(tracerName, trace.WithInstrumentationVersion(grpc.Version))
	ctx, span := tracer.Start(ctx, mn, trace.WithSpanKind(trace.SpanKindClient))
	return ctx, span
}