/*
 * Licensed to the 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.
 * The 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 main

import (
	"fmt"
	"os"
	"os/signal"
	"syscall"
	"time"
)

import (
	hessian "github.com/apache/dubbo-go-hessian2"
	_ "github.com/apache/dubbo-go/cluster/cluster_impl"
	_ "github.com/apache/dubbo-go/cluster/loadbalance"
	"github.com/apache/dubbo-go/common/logger"
	_ "github.com/apache/dubbo-go/common/proxy/proxy_factory"
	"github.com/apache/dubbo-go/config"
	_ "github.com/apache/dubbo-go/filter/filter_impl"
	_ "github.com/apache/dubbo-go/protocol/dubbo"
	_ "github.com/apache/dubbo-go/registry/protocol"
	_ "github.com/apache/dubbo-go/registry/zookeeper"

	"github.com/opentracing/opentracing-go"

	zipkinot "github.com/openzipkin-contrib/zipkin-go-opentracing"

	"github.com/openzipkin/zipkin-go"
	zipkinhttp "github.com/openzipkin/zipkin-go/reporter/http"
)

var (
	survivalTimeout = int(3e9)
)

// they are necessary:
// 		export CONF_PROVIDER_FILE_PATH="xxx"
// 		export APP_LOG_CONF_FILE="xxx"
func main() {

	hessian.RegisterPOJO(&User{})
	config.Load()

	initZipkin()
	initSignal()
}

func initSignal() {
	signals := make(chan os.Signal, 1)
	// It is not possible to block SIGKILL or syscall.SIGSTOP
	signal.Notify(signals, os.Interrupt, os.Kill, syscall.SIGHUP, syscall.SIGQUIT, syscall.SIGTERM, syscall.SIGINT)
	for {
		sig := <-signals
		logger.Infof("get signal %s", sig.String())
		switch sig {
		case syscall.SIGHUP:
			// reload()
		default:
			time.AfterFunc(time.Duration(survivalTimeout), func() {
				logger.Warnf("app exit now by force...")
				os.Exit(1)
			})

			// The program exits normally or timeout forcibly exits.
			fmt.Println("provider app exit now...")
			return
		}
	}
}

func initZipkin() {
	// set up a span reporter
	reporter := zipkinhttp.NewReporter("http://localhost:9411/api/v2/spans")

	// create our local service endpoint
	endpoint, err := zipkin.NewEndpoint("myService", "myservice.mydomain.com:80")
	if err != nil {
		logger.Errorf("unable to create local endpoint: %+v\n", err)
	}

	// initialize our tracer
	nativeTracer, err := zipkin.NewTracer(reporter, zipkin.WithLocalEndpoint(endpoint))
	if err != nil {
		logger.Errorf("unable to create tracer: %+v\n", err)
	}

	// use zipkin-go-opentracing to wrap our tracer
	tracer := zipkinot.Wrap(nativeTracer)

	// optionally set as Global OpenTracing tracer instance
	opentracing.SetGlobalTracer(tracer)
}