package model

import (
	"encoding/binary"
	"errors"
	"fmt"
	"github.com/gorilla/websocket"
	"rocommon"
	"rocommon/rpc"
	_ "rocommon/service"
	"rocommon/socket"
	"rocommon/util"
	_ "roserver/baseserver/model"
	_ "roserver/baseserver/router"
	_ "roserver/serverproto"
)

const (
	MsgIDLen   = 2             // uint16
	lenMaxLen  = 2             //包体大小2个字节 uint16
	msgIdLen   = 2             //包ID大小2个字节  uint16
	msgSeqlen  = 4             //发送序列号2个字节大小，用来断线重连
	msgFlaglen = 2             //暂定标记，加解密 1表示RSA，2表示AES
	MsgBodyIdx = 2 + 4 + 2 + 2 //->10
)

type DirectWSMessageTransmitter struct {
}

//recv直接原始数据传递到后端 / 返回消息给client
func (this *DirectWSMessageTransmitter) OnRecvMsg(s rocommon.Session) (msg interface{}, seqId uint32, err error) {
	conn, ok := s.Raw().(*websocket.Conn)
	if !ok || conn == nil {
		util.InfoF("[DirectWSMessageTransmitter] OnRecvMsg err")
		return nil, 0, nil
	}

	//opt := s.Node().(socket.SocketOption)
	//var opt socket.SocketOption
	//if s.GetSessionOptFlag() {
	//	opt = s.Node().(socket.SocketOption)
	//} else {
	//	opt = s.GetSessionOpt().(socket.SocketOption)
	//}

	messageType, raw, err1 := conn.ReadMessage()
	if err1 != nil {
		err = err1
		util.InfoF("[DirectWSMessageTransmitter] OnRecvMsg ReadMessage err=%v", err)
		return nil, 0, err1
	}
	switch messageType {
	case websocket.BinaryMessage:
		var msgId uint16
		//var seqId uint32  //包序列号，客户端发送时的序列从1开始
		var flagId uint16 //加密方式
		var msgData []byte
		var msgDataLen uint16

		if len(raw) < lenMaxLen {
			return nil, 0, nil
		}
		msgDataLen = binary.BigEndian.Uint16(raw) //msgDataLen
		raw = raw[lenMaxLen:]
		if msgDataLen >= 0 {
			//msgIdLen
			if len(raw) < msgIdLen {
				return
			}
			msgId = binary.BigEndian.Uint16(raw)
			raw = raw[msgIdLen:]

			//msgSeqlen
			if len(raw) < msgSeqlen {
				return
			}
			seqId = binary.BigEndian.Uint32(raw)
			raw = raw[msgSeqlen:]

			//msgFlaglen
			if len(raw) < msgFlaglen {
				return
			}
			flagId = binary.BigEndian.Uint16(raw)
			msgData = raw[msgFlaglen:]

			//尝试直接发送到其他后端服务器或者解析
			if err == nil {
				msg, err = FrontendPackageProc(int(msgId), seqId, flagId, msgData, s)
			}
		}
	}
	return
}

//send 直接发往客户端的消息
func (this *DirectWSMessageTransmitter) OnSendMsg(s rocommon.Session, msg interface{}) (err error) {
	conn, ok := s.Raw().(*websocket.Conn)
	if !ok || conn == nil {
		util.InfoF("[DirectWSMessageTransmitter] OnRecvMsg err")
		return nil
	}

	//opt := s.Node().(socket.SocketOption)
	var opt socket.SocketOption
	if s.GetSessionOptFlag() {
		opt = s.Node().(socket.SocketOption)
	} else {
		opt = s.GetSessionOpt().(socket.SocketOption)
	}
	aesKey := s.GetAES()

	var (
		msgData []byte
		msgId   uint16
		seqId   uint32
		msgInfo *rocommon.MessageInfo
	)
	switch m := msg.(type) {
	case *rocommon.TransmitPacket:
		msgData = m.MsgData
		msgId = uint16(m.MsgId)
		seqId = m.SeqId
	default:
		msgData, msgInfo, err = rpc.EncodeMessage(msg)
		if err != nil {
			return err
		}
		msgId = uint16(msgInfo.ID)
	}
	//todo
	// 注意上层发包不要超过最大值
	msgLen := len(msgData)
	var cryptType uint16 = 0
	//握手阶段
	if msgId == uint16(rpc.SC_HAND_SHAKE_NTFMsgId) {
		cryptType = 1
		msgData, err = rpc.RSAEncrypt(msgData, rpc.PublicClientKey)
		if err != nil {
			return err
		}
		msgLen = len(msgData)
	} else {
		if len(*aesKey) > 0 && msgId != rpc.SC_PING_ACKMsgId {
			cryptType = 2
			msgData, err = rpc.AESCtrEncrypt(msgData, *aesKey, *aesKey...)
			//msgData, err = AESCtrEncrypt(msgData, *aesKey)
			if err != nil {
				return err
			}
			msgLen = len(msgData)
		}
	}
	if msgLen > opt.MaxMsgLen() {
		err = errors.New(fmt.Sprintf("message too big msgId=%v msglen=%v maxlen=%v", msgId, msgLen, opt.MaxMsgLen()))
		util.FatalF("SendMessage err=%v", err)
		err = nil
		return
	}

	//data := make([]byte, lenMaxLen + msgIdLen + msgLen)
	data := make([]byte, lenMaxLen+msgIdLen+msgSeqlen+msgFlaglen+msgLen) //head + body
	//lenMaxLen
	binary.BigEndian.PutUint16(data, uint16(msgLen))
	//msgIdLen
	binary.BigEndian.PutUint16(data[lenMaxLen:], uint16(msgId))
	//seq 返回客户端发送的序列号
	binary.BigEndian.PutUint32(data[lenMaxLen+msgIdLen:], seqId)
	//log.Println("sendSeqId:", seqId)
	//使用的加密方式AES
	binary.BigEndian.PutUint16(data[lenMaxLen+msgIdLen+msgSeqlen:], cryptType)

	//body
	if msgLen > 0 {
		copy(data[lenMaxLen+msgIdLen+msgSeqlen+msgFlaglen:], msgData)
	}
	conn.WriteMessage(websocket.BinaryMessage, data)

	return
}