package servlet

import (
	"crypto/rsa"
	"fmt"

	"git.loafle.net/commons/logging-go"
	"git.loafle.net/commons/server-go"
	"git.loafle.net/commons/server-go/socket"
	og "git.loafle.net/overflow/gateway"
	ogs "git.loafle.net/overflow/gateway/subscribe"
	ogrs "git.loafle.net/overflow/gateway_rpc/servlet"
	"git.loafle.net/overflow/member_gateway_rpc/subscribe"

	"github.com/dgrijalva/jwt-go"
	"github.com/satori/go.uuid"
	"github.com/valyala/fasthttp"
)

type WebappServlet interface {
	ogrs.RPCServlet
}

type WebappServlets struct {
	ogrs.RPCServlets

	VerifyKey *rsa.PublicKey
	SignKey   *rsa.PrivateKey
}

func (s *WebappServlets) Init(serverCtx server.ServerCtx) error {
	if err := s.RPCServlets.Init(serverCtx); nil != err {
		return err
	}

	return nil
}

func (s *WebappServlets) OnStart(serverCtx server.ServerCtx) error {
	if err := s.RPCServlets.OnStart(serverCtx); nil != err {
		return err
	}

	subscribeChan, err := subscribe.Subscriber.Subscribe("/webapp")
	if nil != err {
		return err
	}
	go s.handleSubscribe(serverCtx, subscribeChan)

	return nil
}

func (s *WebappServlets) OnStop(serverCtx server.ServerCtx) {
	if err := subscribe.Subscriber.Unsubscribe("/webapp"); nil != err {
		logging.Logger().Warn(err)
	}

	s.RPCServlets.OnStop(serverCtx)
}

func (s *WebappServlets) Destroy(serverCtx server.ServerCtx) {

	s.RPCServlets.Destroy(serverCtx)
}

func (s *WebappServlets) Handshake(servletCtx server.ServletCtx, ctx *fasthttp.RequestCtx) (*fasthttp.ResponseHeader, error) {
	var ok bool

	tokenString := string(ctx.QueryArgs().Peek("authToken"))
	token, err := jwt.Parse(tokenString, func(token *jwt.Token) (interface{}, error) {
		// Don't forget to validate the alg is what you expect:
		if _, ok := token.Method.(*jwt.SigningMethodRSA); !ok {
			return nil, fmt.Errorf("Unexpected signing method: %v", token.Header["alg"])
		}
		// hmacSampleSecret is a []byte containing your secret, e.g. []byte("my_secret_key")
		return s.VerifyKey, nil
	})

	if nil != err {
		return nil, err
	}

	var claims jwt.MapClaims
	if claims, ok = token.Claims.(jwt.MapClaims); !ok || !token.Valid {
		return nil, fmt.Errorf("Token is not valid %v", token)
	}

	userEmail := claims["sub"].(string)
	sessionID := uuid.NewV4().String()

	servletCtx.SetAttribute(og.SessionIDKey, sessionID)
	servletCtx.SetAttribute(og.SessionClientTypeKey, og.MEMBER)
	servletCtx.SetAttribute(og.SessionTargetIDKey, userEmail)

	return nil, nil
}

func (s *WebappServlets) OnConnect(servletCtx server.ServletCtx, conn socket.Conn) {
	s.RPCServlets.OnConnect(servletCtx, conn)
}

func (s *WebappServlets) OnDisconnect(servletCtx server.ServletCtx) {
	s.RPCServlets.OnDisconnect(servletCtx)
}

func (s *WebappServlets) handleSubscribe(serverCtx server.ServerCtx, subscribeChan <-chan *ogs.Message) {
	var sessions []*ogrs.Session

LOOP:
	for {
		select {
		case msg, ok := <-subscribeChan:
			if !ok {
				return
			}

			switch msg.TargetType {
			case ogs.MEMBER:
				sessions = s.GetSessionsByTargetIDs(msg.Targets)
			case ogs.MEMBER_SESSION:
				sessions = s.GetSessions(msg.Targets)
			default:
				logging.Logger().Warnf("Subscriber: Unknown TargetType %s", msg.TargetType)
				continue LOOP
			}

			if nil == sessions || 0 == len(sessions) {
				continue LOOP
			}

			for _, session := range sessions {
				_writeChan := session.ServletCtx.GetAttribute(og.SessionWriteChanKey)
				if nil != _writeChan {
					writeChan := _writeChan.(chan<- []byte)
					writeChan <- *msg.Message
				}
			}
		}
	}
}