package main

import (
	"context"
	"fmt"
	"gitee.com/micro-tools/micro"
	"gitee.com/micro-tools/micro/module"
	"gitee.com/micro-tools/wf/extend/utils/gmicro/registry"
	"gitee.com/micro-tools/wf/extend/utils/gmicro/registry/etcd"
	"gitee.com/micro-tools/wf/frame/g"
	"gitee.com/micro-tools/wf/os/glog"
	"gitee.com/micro-tools/wf/text/gstr"
	"gitee.com/micro-tools/wf/util/gconv"
	consulapi "github.com/hashicorp/consul/api"
	"github.com/mitchellh/consulstructure"
	"go.etcd.io/etcd/clientv3"
	"reflect"
)

const (
	TracingName = "Blocking Query"
	TracingURL  = "172.16.13.6:6831"
	ConsulURL   = "127.0.0.1:8500"
	EtcdURL     = "127.0.0.1:2379"
)

func main() {
	go func() {
		type Config struct {
			Blocking string `json:"blocking,omitempty"`
		}
		EtcdBlockingQuery(&Config{}, "/corex/", func(value interface{}) {
			var val Config
			_ = gconv.Struct(value, &val)
			glog.Info(val)
		})
		//ConsulBlockingQuery(&Config{}, func(value interface{}) {
		//	var val Config
		//	_ = gconv.Struct(value, &val)
		//	glog.Info(val)
		//})
	}()
	rs := etcd.NewRegistry(func(options *registry.Options) {
		options.Address = []string{EtcdURL}
	})

	app := micro.Create(
		module.Debug(false),
		module.Tracing(module.Trace{
			Status: true,
			Name:   TracingName,
			URL:    TracingURL,
		}),
		module.Registry(rs), //指定服务发现
	)

	err := app.Run(New())
	if err != nil {
		app.Logger().Errorf("%s", err.Error())
	}
}

func ConsulBlockingQuery(targetPointer interface{}, prefix string, call func(value interface{})) {
	// Create our decoder
	updateCh := make(chan interface{})
	errCh := make(chan error)
	decoder := &consulstructure.Decoder{
		Target:   targetPointer,
		UpdateCh: updateCh,
		ErrCh:    errCh,
		Prefix:   prefix,
		Consul:   &consulapi.Config{Address: ConsulURL},
	}

	// Run the decoder and wait for changes
	go decoder.Run()
	for {
		select {
		case v := <-updateCh:
			call(v)
		case err := <-errCh:
			fmt.Printf("Error: %s\n", err)
		}
	}
}

func EtcdBlockingQuery(targetPointer interface{}, prefix string, call func(value interface{})) {
	raw := GetStructTagName(targetPointer)
	if len(raw) == 0 {
		return
	}
	cli, err := clientv3.New(clientv3.Config{
		Endpoints: []string{EtcdURL},
	})
	if err != nil {
		return
	}
	var wkey string
	var opts []clientv3.OpOption
	if prefix != "" {
		wkey = prefix
		opts = append(opts, clientv3.WithPrefix())
	} else {
		wkey = ""
		opts = append(opts, clientv3.WithPrefix())
	}
	ctx := context.Background()
	for {
		select {
		case r := <-cli.Watch(ctx, wkey, opts...):
			for _, v := range r.Events {
				mk := gconv.String(v.Kv.Key)
				mk = gstr.Replace(mk, prefix, "")
				for _, k := range raw {
					if k == mk {
						call(g.Map{k: interface{}(v.Kv.Value)})
						break
					}
				}
			}
		}
	}
}

// GetStructTagName 获取struct的field的tag内容
func GetStructTagName(pointer interface{}) []string {
	types := reflect.TypeOf(pointer)
	numField := types.Elem().NumField()
	var tagValues = make([]string, numField)
	for i := 0; i < numField; i++ {
		tagValue := types.Elem().Field(i).Tag.Get("json")
		if tagValue == "" {
			continue
		}
		tagValues[i] = gstr.Split(tagValue, ",")[0]
	}
	return tagValues
}