/*
   Copyright 2017 the original author or authors.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/

package openflow

import (
	"encoding/json"
	"fmt"
	"time"

	"github.com/donNewtonAlpha/goloxi"
	ofp "github.com/donNewtonAlpha/goloxi/of13"
	pb "github.com/opencord/voltha-protos/v2/go/voltha"

	"log"
	"net"
)

var conn net.Conn
var volthaClient *pb.VolthaServiceClient
var packetOutChannel chan pb.PacketOut

type Client struct {
	OfServerAddress string
	Port            uint16
	DeviceId        string
	KeepRunning     bool
}

func NewClient(ofServerAddress string, port uint16, deviceId string, keepRunning bool) *Client {
	client := Client{OfServerAddress: ofServerAddress, Port: port, DeviceId: deviceId, KeepRunning: keepRunning}
	go client.Start()
	return &client
}

func (client *Client) End() {
	client.KeepRunning = false
}
func (client *Client) Start() {
	addressLine := fmt.Sprintf("%s:%d", client.OfServerAddress, client.Port)
	raddr, e := net.ResolveTCPAddr("tcp", addressLine)
	if e != nil {
		errMessage := fmt.Errorf("Unable to resolve %s", addressLine)
		fmt.Println(errMessage)
		return
	}
	for {
		if client.KeepRunning {
			connection, e := net.DialTCP("tcp", nil, raddr)
			conn = connection
			if e != nil {
				log.Fatalf("unable to connect to %v", raddr)
			}
			defer conn.Close()
			client.sayHello()
			for {
				if !client.KeepRunning {
					return
				}
				buf := make([]byte, 1500)
				read, e := conn.Read(buf)
				if e != nil {
					log.Printf("Connection has died %v", e)
					break
				}
				decoder := goloxi.NewDecoder(buf)
				header, e := ofp.DecodeHeader(decoder)

				if e != nil {
					log.Printf("decodeheader threw error %v", e)
				}
				message, _ := json.Marshal(header)
				log.Printf("message %s\n", message)
				client.parseHeader(header, buf) //first one is ready
				len := header.GetLength()
				if len < uint16(read) {
					for {
						read = read - int(len)
						newBuf := buf[len:]
						decoder = goloxi.NewDecoder(newBuf)
						newHeader, e := ofp.DecodeHeader(decoder)
						message, _ := json.Marshal(newHeader)
						log.Printf("message %s\n", message)
						if e != nil {

						}
						len = newHeader.GetLength()
						client.parseHeader(newHeader, newBuf)
						if read == int(len) {
							break
						} else {
						}
						buf = newBuf
					}
				}
				if e != nil {
					log.Println("Decode Header error ", e)
				}
			}
		}
		break
	}
}
func (client *Client) sayHello() {

	hello := ofp.NewHello()
	hello.Xid = uint32(GetXid())
	var elements []ofp.IHelloElem

	elem := ofp.NewHelloElemVersionbitmap()
	elem.SetType(ofp.OFPHETVersionbitmap)
	elem.SetLength(8)
	var bitmap = ofp.Uint32{Value: 16}
	bitmaps := []*ofp.Uint32{&bitmap}

	elem.SetBitmaps(bitmaps)

	elements = append(elements, elem)

	hello.SetElements(elements)
	e := client.SendMessage(hello)
	if e != nil {
		log.Fatal(e)
	}
}
func (client *Client) parseHeader(header ofp.IHeader, buf []byte) {
	switch header.GetType() {
	case ofp.OFPTHello:
		//x := header.(*ofp.Hello)
	case ofp.OFPTError:
		errMsg := header.(*ofp.ErrorMsg)
		go handleErrMsg(errMsg)
	case ofp.OFPTEchoRequest:
		echoReq := header.(*ofp.EchoRequest)
		go handleEchoRequest(echoReq, client)
	case ofp.OFPTEchoReply:
	case ofp.OFPTExperimenter:
	case ofp.OFPTFeaturesRequest:
		featReq := header.(*ofp.FeaturesRequest)
		go handleFeatureRequest(featReq, client.DeviceId, client)
	case ofp.OFPTFeaturesReply:
	case ofp.OFPTGetConfigRequest:
		configReq := header.(*ofp.GetConfigRequest)
		go handleGetConfigRequest(configReq, client)
	case ofp.OFPTGetConfigReply:
	case ofp.OFPTSetConfig:
		setConf := header.(*ofp.SetConfig)
		go handleSetConfig(setConf)
	case ofp.OFPTPacketIn:
	case ofp.OFPTFlowRemoved:
	case ofp.OFPTPortStatus:
	case ofp.OFPTPacketOut:
		packetOut := header.(*ofp.PacketOut)
		go handlePacketOut(packetOut, client.DeviceId)
	case ofp.OFPTFlowMod:
		flowModType := uint8(buf[25])
		switch flowModType {
		case ofp.OFPFCAdd:
			flowAdd := header.(*ofp.FlowAdd)
			go handleFlowAdd(flowAdd, client.DeviceId)
		case ofp.OFPFCModify:
			flowMod := header.(*ofp.FlowMod)
			go handleFlowMod(flowMod, client.DeviceId)
		case ofp.OFPFCModifyStrict:
			flowModStrict := header.(*ofp.FlowModifyStrict)
			go handleFlowModStrict(flowModStrict, client.DeviceId)
		case ofp.OFPFCDelete:
			flowDelete := header.(*ofp.FlowDelete)
			go handleFlowDelete(flowDelete, client.DeviceId)
		case ofp.OFPFCDeleteStrict:
			flowDeleteStrict := header.(*ofp.FlowDeleteStrict)
			go handleFlowDeleteStrict(flowDeleteStrict, client.DeviceId)
		}
	case ofp.OFPTStatsRequest:
		var statType = uint16(buf[8])<<8 + uint16(buf[9])
		log.Println("statsType", statType)
		go handleStatsRequest(header, statType, client.DeviceId, client)
	case ofp.OFPTBarrierRequest:
		barRequest := header.(*ofp.BarrierRequest)
		go handleBarrierRequest(barRequest, client)
	case ofp.OFPTRoleRequest:
		roleReq := header.(*ofp.RoleRequest)
		go handleRoleRequest(roleReq, client)
	case ofp.OFPTMeterMod:
		meterMod := header.(*ofp.MeterMod)
		go handleMeterModRequest(meterMod, client)

	}
}

//openFlowMessage created to allow for a single SendMessage
type OpenFlowMessage interface {
	Serialize(encoder *goloxi.Encoder) error
}

func (client *Client) SendMessage(message OpenFlowMessage) error {
	jsonMessage, _ := json.Marshal(message)
	log.Printf("send message called %s\n", jsonMessage)
	enc := goloxi.NewEncoder()
	message.Serialize(enc)
	jMessage, _ := json.Marshal(message)
	bytes := enc.Bytes()
	log.Printf("message after serialize %d for message %s", bytes, jMessage)

	for {
		if conn == nil {
			log.Println("CONN IS NIL")
			time.Sleep(10 * time.Millisecond)
		} else {
			break
		}
	}
	_, err := conn.Write(bytes)
	if err != nil {
		log.Printf("SendMessage had error %v \n %s\n********", err, jMessage)
		return err
	} else {
		log.Printf("message after send %s", jMessage)
	}
	return nil
}
func SetGrpcClient(client *pb.VolthaServiceClient) {
	volthaClient = client
}
func getGrpcClient() *pb.VolthaServiceClient {
	return volthaClient
}
func test(hello ofp.IHello) {
	fmt.Println("works")
}
func SetPacketOutChannel(pktOutChan chan pb.PacketOut) {
	packetOutChannel = pktOutChan
}