// Copyright 2018-2021 CERN
//
// 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.
//
// In applying this license, CERN does not waive the privileges and immunities
// granted to it by virtue of its status as an Intergovernmental Organization
// or submit itself to any jurisdiction.

package trace

import (
	"context"

	"go.opentelemetry.io/otel/trace"
	"go.opentelemetry.io/otel/trace/noop"
)

type ctxKey struct{}

// ContextSetTracerProvider returns a copy of ctx with p associated.
func ContextSetTracerProvider(ctx context.Context, p trace.TracerProvider) context.Context {
	if tp, ok := ctx.Value(ctxKey{}).(trace.TracerProvider); ok {
		if tp == p {
			return ctx
		}
	}
	return context.WithValue(ctx, ctxKey{}, p)
}

// ContextGetTracerProvider returns the TracerProvider associated with the ctx.
// If no TracerProvider is associated is associated, the global default TracerProvider
// is returned
func ContextGetTracerProvider(ctx context.Context) trace.TracerProvider {
	if p, ok := ctx.Value(ctxKey{}).(trace.TracerProvider); ok {
		return p
	}
	return noop.NewTracerProvider()
}
