package nnet

import (
	"errors"
	"fmt"
	"git.noahlan.cn/northlan/nnet/component"
	"git.noahlan.cn/northlan/nnet/log"
	"git.noahlan.cn/northlan/nnet/pipeline"
	"git.noahlan.cn/northlan/nnet/session"
	"github.com/gorilla/websocket"
	"net"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"
)

type (
	Options struct {
		Name          string                // 服务端名，默认为n-net
		Pipeline      pipeline.Pipeline     // 消息管道
		RetryInterval time.Duration         // 消息重试间隔时长
		Components    *component.Components // 组件库

		HeartbeatInterval time.Duration // 心跳间隔，0表示不进行心跳
		WS                WSOptions     // websocket
	}

	WSOptions struct {
		IsWebsocket    bool   // 是否为websocket服务端
		WebsocketPath  string // ws地址(ws://127.0.0.1/WebsocketPath)
		TLSCertificate string // TLS 证书地址 (websocket)
		TLSKey         string // TLS 证书key地址 (websocket)
	}
)

// Server TCP-Server
type Server struct {
	// Options 参数列表
	Options
	// protocol 协议名
	// "tcp", "tcp4", "tcp6", "unix" or "unixpacket"
	// 若只想开启IPv4, 使用tcp4即可
	protocol string
	// address 服务地址
	// 地址可直接使用hostname,但强烈不建议这样做,可能会同时监听多个本地IP
	// 如果端口号不填或端口号为0，例如："127.0.0.1:" 或 ":0"，服务端将选择随机可用端口
	address string
	// handler 消息处理器
	handler *Handler
	// sessionMgr session管理器
	sessionMgr *session.Manager
}

func NewServer(protocol, addr string, opts ...Option) *Server {
	options := Options{
		Components: &component.Components{},
		WS:         WSOptions{},
	}
	s := &Server{
		Options:  options,
		protocol: protocol,
		address:  addr,
	}

	for _, opt := range opts {
		opt(&s.Options)
	}

	s.handler = NewHandler()
	s.sessionMgr = session.NewManager()

	initPool(0)

	return s
}

func (s *Server) Serve() {
	components := s.Components.List()
	for _, c := range components {
		err := s.handler.register(c.Comp, c.Opts)
		if err != nil {
			// TODO Log and return
			return
		}
	}

	// Initialize components
	for _, c := range components {
		c.Comp.OnInit()
	}

	go func() {
		if s.WS.IsWebsocket {
			if len(s.WS.TLSCertificate) != 0 && len(s.WS.TLSKey) != 0 {
				s.listenAndServeWSTLS()
			} else {
				s.listenAndServeWS()
			}
		} else {
			s.listenAndServe()
		}
	}()

	sg := make(chan os.Signal)
	signal.Notify(sg, syscall.SIGINT, syscall.SIGQUIT, syscall.SIGKILL, syscall.SIGTERM)

	select {
	//case <-env.Die:
	//	log.Println("The app will shutdown in a few seconds")
	case s := <-sg:
		log.Infof("server got signal", s)
	}

	log.Infof("server is stopping...")
	s.Shutdown()
	// TODO close
}

func (s *Server) Shutdown() {
	components := s.Components.List()
	compLen := len(components)
	for i := compLen - 1; i >= 0; i-- {
		components[i].Comp.OnShutdown()
	}
}

func (s *Server) listenAndServe() {
	listener, err := net.Listen(s.protocol, s.address)
	if err != nil {
		panic(err)
	}

	// 监听成功，服务已启动
	// TODO log
	defer listener.Close()

	go func() {
		for {
			conn, err := listener.Accept()
			if err != nil {
				if errors.Is(err, net.ErrClosed) {
					log.Error("服务器网络错误", err)
					return
				}
				log.Errorf("监听错误 %v", err)
				continue
			}

			err = pool.SubmitConn(func() {
				r := newRequest(conn, s.Pipeline)
				s.handler.handle(r)
			})
			if err != nil {
				// TODO Log
				continue
			}
		}
	}()
}

func (s *Server) listenAndServeWS() {
	upgrade := websocket.Upgrader{
		ReadBufferSize:    1024,
		WriteBufferSize:   1024,
		CheckOrigin:       nil,
		EnableCompression: false,
	}
	http.HandleFunc(fmt.Sprintf("/%s/", "path"), func(w http.ResponseWriter, r *http.Request) {
		conn, err := upgrade.Upgrade(w, r, nil)
		if err != nil {
			// TODO upgrade failure, uri=r.requestURI err=err.Error()
			return
		}
		// TODO s.handler.handleWS(conn)
	})
	if err := http.ListenAndServe(s.address, nil); err != nil {
		panic(err)
	}
}

func (s *Server) listenAndServeWSTLS() {
	upgrade := websocket.Upgrader{
		ReadBufferSize:    1024,
		WriteBufferSize:   1024,
		CheckOrigin:       nil,
		EnableCompression: false,
	}
	http.HandleFunc(fmt.Sprintf("/%s/", "path"), func(w http.ResponseWriter, r *http.Request) {
		conn, err := upgrade.Upgrade(w, r, nil)
		if err != nil {
			// TODO upgrade failure, uri=r.requestURI err=err.Error()
			return
		}
		// TODO s.handler.handleWS(conn)
	})
	if err := http.ListenAndServeTLS(s.address, "", "", nil); err != nil {
		panic(err)
	}
}