package protocol

import (
	"encoding/json"
	"fmt"
	"git.noahlan.cn/noahlan/nnet/core"
	"git.noahlan.cn/noahlan/nnet/entity"
	"git.noahlan.cn/noahlan/ntools-go/core/nlog"
	"time"
)

type (
	handshakeData struct {
		Version string `json:"version"` // 客户端版本号，服务器以此判断是否合适与客户端通信
		Type    string `json:"type"`    // 客户端类型，与客户端版本号一起来确定客户端是否合适

		// 透传信息
		Payload interface{} `json:"payload,optional,omitempty"`
	}
	handshakeAckData struct {
		Heartbeat int64 `json:"heartbeat"` // 心跳间隔，单位秒 0表示不需要心跳
		// 路由
		Routes map[string]uint16 `json:"routes"` // route map to code
		Codes  map[uint16]string `json:"codes"`  // code map to route

		// 服务端支持的body部分消息传输协议
		//Protocol string `json:"protocol,options=[plain,json,protobuf]"` // plain/json/protobuf

		// 透传信息
		Payload interface{} `json:"payload,optional,omitempty"`
	}
)

func WithNNetPipeline(heartbeatInterval time.Duration, handshakeValidator func([]byte) error) core.RunOption {
	handshakeAck := &handshakeAckData{}
	data, err := json.Marshal(handshakeAck)
	nlog.Must(err)

	packer := NewNNetPacker()
	hrd, _ := packer.Pack(Handshake, data)

	return func(server *core.Server) {
		server.Pipeline().Inbound().PushFront(func(entity entity.NetworkEntity, v interface{}) error {
			pkg, ok := v.(*NNetPacket)
			if !ok {
				return ErrWrongPacketType
			}
			conn, _ := entity.Conn()

			switch pkg.PacketType {
			case Handshake:
				if err := handshakeValidator(pkg.Data); err != nil {
					return err
				}
				if err := entity.SendBytes(hrd); err != nil {
					return err
				}
				entity.SetStatus(core.StatusPrepare)
				nlog.Debugf("connection handshake Id=%d, Remote=%s", entity.Session().ID(), conn.RemoteAddr())
			case HandshakeAck:
				entity.SetStatus(core.StatusPending)
				nlog.Debugf("receive handshake ACK Id=%d, Remote=%s", entity.Session().ID(), conn.RemoteAddr())
			case Heartbeat:
				// Expected
			case Data:
				if entity.Status() < core.StatusPending {
					return errors.New(fmt.Sprintf("receive data on socket which not yet ACK, session will be closed immediately, remote=%s",
						conn.RemoteAddr()))
				}
				entity.SetStatus(core.StatusWorking)

				var lastMid uint64
				switch pkg.MsgType {
				case Request:
					lastMid = pkg.ID
				case Notify:
					lastMid = 0
				default:
					return fmt.Errorf("Invalid message type: %s ", pkg.MsgType.String())
				}
				entity.SetLastMID(lastMid)
			}
			return nil
		})
	}
}