// Licensed to Apache Software Foundation (ASF) under one or more contributor
// license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright
// ownership. Apache Software Foundation (ASF) licenses this file to you 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 grpc

import (
	"github.com/apache/skywalking-go/plugins/core/operator"
	"github.com/apache/skywalking-go/plugins/core/tracing"
)

type ClientFinishInterceptor struct {
}

func (h *ClientFinishInterceptor) BeforeInvoke(invocation operator.Invocation) error {
	csEnhanced, ok := invocation.CallerInstance().(operator.EnhancedInstance)
	if !ok || csEnhanced.GetSkyWalkingDynamicField() == nil {
		return nil
	}
	contextdata := csEnhanced.GetSkyWalkingDynamicField().(*contextData)
	if !finishStreamSpan(contextdata) {
		return nil
	}
	cs := invocation.CallerInstance().(*nativeclientStream)
	method := cs.callHdr.Method
	activeSpan := tracing.ActiveSpan()
	if activeSpan == nil {
		return nil
	}
	activeSpan.SetOperationName(formatOperationName(method, "/Client/Response/CloseRecv"))
	return nil
}

func (h *ClientFinishInterceptor) AfterInvoke(invocation operator.Invocation, result ...interface{}) error {
	return nil
}

// finishStreamSpan consumes the one-shot finish flag and finishes the async
// stream span. Only the first caller wins: either RecvMsg never armed the
// finish, or a concurrent Finish already consumed it - so two racing Finish
// calls can never both run the AsyncFinish.
func finishStreamSpan(contextdata *contextData) bool {
	if !contextdata.interceptFinish.CompareAndSwap(true, false) {
		return false
	}
	if contextdata.asyncSpan != nil {
		contextdata.asyncSpan.AsyncFinish()
	}
	return true
}
