package main

import (
	"context"
	"flag"
	"fmt"
	"os"
	"strconv"
	"strings"
	"time"

	"github.com/apache/thrift/lib/go/thrift"
	"github.com/lightstep/lightstep-tracer-go"
	stdopentracing "github.com/opentracing/opentracing-go"
	zipkin "github.com/openzipkin/zipkin-go-opentracing"
	"google.golang.org/grpc"
	"sourcegraph.com/sourcegraph/appdash"
	appdashot "sourcegraph.com/sourcegraph/appdash/opentracing"

	"github.com/go-kit/kit/examples/addsvc"
	grpcclient "github.com/go-kit/kit/examples/addsvc/client/grpc"
	httpclient "github.com/go-kit/kit/examples/addsvc/client/http"
	thriftclient "github.com/go-kit/kit/examples/addsvc/client/thrift"
	thriftadd "github.com/go-kit/kit/examples/addsvc/thrift/gen-go/addsvc"
	"github.com/go-kit/kit/log"
)

func main() {
	// The addcli presumes no service discovery system, and expects users to
	// provide the direct address of an addsvc. This presumption is reflected in
	// the addcli binary and the the client packages: the -transport.addr flags
	// and various client constructors both expect host:port strings. For an
	// example service with a client built on top of a service discovery system,
	// see profilesvc.

	var (
		httpAddr         = flag.String("http.addr", "", "HTTP address of addsvc")
		grpcAddr         = flag.String("grpc.addr", "", "gRPC (HTTP) address of addsvc")
		thriftAddr       = flag.String("thrift.addr", "", "Thrift address of addsvc")
		thriftProtocol   = flag.String("thrift.protocol", "binary", "binary, compact, json, simplejson")
		thriftBufferSize = flag.Int("thrift.buffer.size", 0, "0 for unbuffered")
		thriftFramed     = flag.Bool("thrift.framed", false, "true to enable framing")
		zipkinAddr       = flag.String("zipkin.addr", "", "Enable Zipkin tracing via a Zipkin HTTP Collector endpoint")
		zipkinKafkaAddr  = flag.String("zipkin.kafka.addr", "", "Enable Zipkin tracing via a Kafka server host:port")
		appdashAddr      = flag.String("appdash.addr", "", "Enable Appdash tracing via an Appdash server host:port")
		lightstepToken   = flag.String("lightstep.token", "", "Enable LightStep tracing via a LightStep access token")
		method           = flag.String("method", "sum", "sum, concat")
	)
	flag.Parse()

	if len(flag.Args()) != 2 {
		fmt.Fprintf(os.Stderr, "usage: addcli [flags] <a> <b>\n")
		os.Exit(1)
	}

	// This is a demonstration client, which supports multiple tracers.
	// Your clients will probably just use one tracer.
	var tracer stdopentracing.Tracer
	{
		if *zipkinAddr != "" {
			// endpoint typically looks like: http://zipkinhost:9411/api/v1/spans
			collector, err := zipkin.NewHTTPCollector(*zipkinAddr)
			if err != nil {
				fmt.Fprintf(os.Stderr, "%v\n", err)
				os.Exit(1)
			}
			defer collector.Close()

			tracer, err = zipkin.NewTracer(
				zipkin.NewRecorder(collector, false, "0.0.0.0:0", "addcli"),
			)
			if err != nil {
				fmt.Fprintf(os.Stderr, "%v\n", err)
				os.Exit(1)
			}
		} else if *zipkinKafkaAddr != "" {
			collector, err := zipkin.NewKafkaCollector(
				strings.Split(*zipkinKafkaAddr, ","),
				zipkin.KafkaLogger(log.NewNopLogger()),
			)
			if err != nil {
				fmt.Fprintf(os.Stderr, "%v\n", err)
				os.Exit(1)
			}
			defer collector.Close()

			tracer, err = zipkin.NewTracer(
				zipkin.NewRecorder(collector, false, "0.0.0.0:0", "addcli"),
			)
			if err != nil {
				fmt.Fprintf(os.Stderr, "%v\n", err)
				os.Exit(1)
			}
		} else if *appdashAddr != "" {
			tracer = appdashot.NewTracer(appdash.NewRemoteCollector(*appdashAddr))
		} else if *lightstepToken != "" {
			tracer = lightstep.NewTracer(lightstep.Options{
				AccessToken: *lightstepToken,
			})
			defer lightstep.FlushLightStepTracer(tracer)
		} else {
			tracer = stdopentracing.GlobalTracer() // no-op
		}
	}

	// This is a demonstration client, which supports multiple transports.
	// Your clients will probably just define and stick with 1 transport.

	var (
		service addsvc.Service
		err     error
	)
	if *httpAddr != "" {
		service, err = httpclient.New(*httpAddr, tracer, log.NewNopLogger())
	} else if *grpcAddr != "" {
		conn, err := grpc.Dial(*grpcAddr, grpc.WithInsecure(), grpc.WithTimeout(time.Second))
		if err != nil {
			fmt.Fprintf(os.Stderr, "error: %v", err)
			os.Exit(1)
		}
		defer conn.Close()
		service = grpcclient.New(conn, tracer, log.NewNopLogger())
	} else if *thriftAddr != "" {
		// It's necessary to do all of this construction in the func main,
		// because (among other reasons) we need to control the lifecycle of the
		// Thrift transport, i.e. close it eventually.
		var protocolFactory thrift.TProtocolFactory
		switch *thriftProtocol {
		case "compact":
			protocolFactory = thrift.NewTCompactProtocolFactory()
		case "simplejson":
			protocolFactory = thrift.NewTSimpleJSONProtocolFactory()
		case "json":
			protocolFactory = thrift.NewTJSONProtocolFactory()
		case "binary", "":
			protocolFactory = thrift.NewTBinaryProtocolFactoryDefault()
		default:
			fmt.Fprintf(os.Stderr, "error: invalid protocol %q\n", *thriftProtocol)
			os.Exit(1)
		}
		var transportFactory thrift.TTransportFactory
		if *thriftBufferSize > 0 {
			transportFactory = thrift.NewTBufferedTransportFactory(*thriftBufferSize)
		} else {
			transportFactory = thrift.NewTTransportFactory()
		}
		if *thriftFramed {
			transportFactory = thrift.NewTFramedTransportFactory(transportFactory)
		}
		transportSocket, err := thrift.NewTSocket(*thriftAddr)
		if err != nil {
			fmt.Fprintf(os.Stderr, "error: %v\n", err)
			os.Exit(1)
		}
		transport, err := transportFactory.GetTransport(transportSocket)
		if err != nil {
			fmt.Fprintf(os.Stderr, "error: %v\n", err)
			os.Exit(1)
		}
		if err := transport.Open(); err != nil {
			fmt.Fprintf(os.Stderr, "error: %v\n", err)
			os.Exit(1)
		}
		defer transport.Close()
		client := thriftadd.NewAddServiceClientFactory(transport, protocolFactory)
		service = thriftclient.New(client)
	} else {
		fmt.Fprintf(os.Stderr, "error: no remote address specified\n")
		os.Exit(1)
	}
	if err != nil {
		fmt.Fprintf(os.Stderr, "error: %v\n", err)
		os.Exit(1)
	}

	switch *method {
	case "sum":
		a, _ := strconv.ParseInt(flag.Args()[0], 10, 64)
		b, _ := strconv.ParseInt(flag.Args()[1], 10, 64)
		v, err := service.Sum(context.Background(), int(a), int(b))
		if err != nil {
			fmt.Fprintf(os.Stderr, "error: %v\n", err)
			os.Exit(1)
		}
		fmt.Fprintf(os.Stdout, "%d + %d = %d\n", a, b, v)

	case "concat":
		a := flag.Args()[0]
		b := flag.Args()[1]
		v, err := service.Concat(context.Background(), a, b)
		if err != nil {
			fmt.Fprintf(os.Stderr, "error: %v\n", err)
			os.Exit(1)
		}
		fmt.Fprintf(os.Stdout, "%q + %q = %q\n", a, b, v)

	default:
		fmt.Fprintf(os.Stderr, "error: invalid method %q\n", method)
		os.Exit(1)
	}
}