package micro

import (
	"context"
	"crypto/md5"
	"encoding/hex"
	"git.nspix.com/golang/micro/gateway"
	"git.nspix.com/golang/micro/gateway/http"
	"git.nspix.com/golang/micro/log"
	"git.nspix.com/golang/micro/registry"
	"git.nspix.com/golang/micro/utils/docker"
	"git.nspix.com/golang/micro/utils/net/ip"
	"git.nspix.com/golang/micro/utils/unsafestr"
	"net"
	"os"
	"os/signal"
	"strings"
	"sync"
	"syscall"
	"time"
)

type Service struct {
	opts       *Options
	ctx        context.Context
	cancelFunc context.CancelFunc
	registry   registry.Registry
	node       *registry.ServiceNode
	listener   net.Listener
	gateway    *gateway.Gateway
	wg         sync.WaitGroup
	httpSvr    *http.Server
	upTime     time.Time
}

func (svr *Service) wrapSync(f func()) {
	svr.wg.Add(1)
	go func() {
		f()
		svr.wg.Done()
	}()
}

func (svr *Service) eventLoop() {
	var (
		err    error
		ticker *time.Ticker
	)
	ticker = time.NewTicker(time.Second * 10)
	defer ticker.Stop()
	for {
		select {
		case <-ticker.C:
			if err = svr.registry.Register(svr.node); err != nil {
				log.Warnf("registry service %s error: %s", svr.opts.Name, err.Error())
			}
		case <-svr.ctx.Done():
			return
		}
	}
}

func (svr *Service) Handle(method string, cb HandleFunc) {
	if svr.opts.EnableHttp {
		//convert url
		path := strings.ReplaceAll(method, ".", "/")
		if path[0] != '/' {
			path = "/" + path
		}
		svr.httpSvr.Handle("POST", path, func(ctx *http.Context) (err error) {
			return cb(ctx)
		})
	}
	//启动RPC功能
	if svr.opts.EnableRPC {

	}
	return
}

func (svr *Service) generateInstance() {
	var (
		err      error
		id       string
		dockerID string
		tcpAddr  *net.TCPAddr
	)

	if id, err = docker.SelfContainerID(); err != nil {
		//生成唯一ID
		e5 := md5.New()
		e5.Write(unsafestr.StringToBytes(svr.opts.Name))
		e5.Write(unsafestr.StringToBytes(svr.opts.Version))
		id = hex.EncodeToString(e5.Sum(nil))
	} else {
		dockerID = id
	}
	svr.node = &registry.ServiceNode{
		ID:        id,
		Name:      svr.opts.Name,
		Version:   svr.opts.Version,
		Metadata:  map[string]string{},
		Addresses: make(map[string]registry.Addr),
	}
	ipLocal := ip.InternalIP()
	svr.node.Address = ipLocal
	if tcpAddr, err = net.ResolveTCPAddr("tcp", svr.listener.Addr().String()); err == nil {
		svr.node.Port = tcpAddr.Port
	}
	svr.node.Metadata["docker-id"] = dockerID
	if svr.opts.EnableHttp {
		svr.node.Metadata["enable-http"] = "true"
	}
	if svr.opts.EnableRPC {
		svr.node.Metadata["enable-rpc"] = "true"
	}
}

func (svr *Service) prepare() (err error) {
	log.Prefix(svr.opts.Name)
	if svr.listener, err = net.ListenTCP("tcp", nil); err != nil {
		return
	}
	log.Infof("listener on: %s", svr.listener.Addr())
	svr.gateway = gateway.New(svr.listener)
	svr.generateInstance()
	svr.wrapSync(func() {
		svr.gateway.Run(svr.ctx)
	})
	svr.wrapSync(func() {
		svr.eventLoop()
	})
	if svr.opts.EnableHttp {
		l := gateway.NewListener(svr.listener.Addr())
		if err = svr.gateway.Attaches([][]byte{[]byte("GET"), []byte("POST"), []byte("PUT"), []byte("DELETE"), []byte("OPTIONS")}, l); err == nil {
			svr.wrapSync(func() {
				_ = svr.httpSvr.Serve(l)
			})
			svr.httpSvr.Handle("GET", "/healthy", func(ctx *http.Context) (err error) {
				return ctx.Success(map[string]interface{}{
					"healthy": "healthy",
					"uptime":  time.Now().Sub(svr.upTime).String(),
				})
			})
			log.Infof("attach http server success")
		} else {
			log.Warnf("attach http listener error: %s", err.Error())
		}
	}
	if svr.opts.EnableHttp {
		l := gateway.NewListener(svr.listener.Addr())
		if err = svr.gateway.Attach([]byte("RPC"), l); err == nil {
			serve := http.New()
			svr.wrapSync(func() {
				_ = serve.Serve(l)
			})
		}
	}
	if err = svr.registry.Register(svr.node); err == nil {
		log.Infof("register service %s successful", svr.opts.Name)
	}
	return
}

func (svr *Service) destroy() (err error) {
	log.Infof("stopping")
	svr.cancelFunc()
	if err = svr.registry.Deregister(svr.node); err != nil {
		log.Warnf("deregister service %s error: %s", svr.opts.Name, err.Error())
	} else {
		log.Infof("deregister service %s successful", svr.opts.Name)
	}
	if svr.listener != nil {
		if err = svr.listener.Close(); err != nil {
			log.Warnf(err.Error())
		}
	}
	log.Infof("stopped")
	return
}

func (svr *Service) Run() (err error) {
	if err = svr.prepare(); err != nil {
		return
	}
	//start server
	if svr.opts.Server != nil {
		if err = svr.opts.Server.Start(svr.ctx); err != nil {
			return
		}
	}
	//waiting
	ch := make(chan os.Signal, 1)
	signal.Notify(ch, syscall.SIGTERM, syscall.SIGINT, syscall.SIGQUIT, syscall.SIGKILL)
	select {
	case <-ch:
	case <-svr.ctx.Done():
	}
	//stop server
	if svr.opts.Server != nil {
		err = svr.opts.Server.Stop()
	}
	return svr.destroy()
}

func New(opts ...OptionMiddleware) *Service {
	o := NewOptions()
	for _, opt := range opts {
		opt(o)
	}
	svr := &Service{
		opts:     o,
		upTime:   time.Now(),
		httpSvr:  http.New(),
		registry: registry.DefaultRegistry,
	}
	svr.ctx, svr.cancelFunc = context.WithCancel(o.Context)
	return svr
}