package notify

import (
	"net"
	"time"
)

const (
	MSG_SYS MessageType = iota
	MSG_SYS_WAIT
	MSG_SYS_REPLY
	// Deprecated: legacy RSA key-exchange control message.
	MSG_KEY_CHANGE
	MSG_ASYNC
	MSG_SYNC_ASK
	MSG_SYNC_REPLY
)

type MessageType uint8

type NetType uint8

const (
	NET_SERVER NetType = iota
	NET_CLIENT
)

type MsgVal []byte
type TransferMsg struct {
	ID    uint64
	Key   string
	Value MsgVal
	Type  MessageType
}

type Message struct {
	NetType
	LogicalConn *LogicalConn
	// Deprecated: ClientConn aliases LogicalConn for compatibility.
	ClientConn    *ClientConn
	TransportConn *TransportConn
	ServerConn    Client
	TransferMsg
	Time        time.Time
	inboundConn net.Conn
}

type WaitMsg struct {
	TransferMsg
	Time  time.Time
	Reply chan Message
	scope string
	//Ctx   context.Context
}

type messageLogicalTransferSender interface {
	sendLogical(*LogicalConn, TransferMsg) (WaitMsg, error)
}

type messageInboundTransferSender interface {
	sendTransferInbound(*LogicalConn, *TransportConn, net.Conn, TransferMsg) error
}

func (m *Message) Reply(value MsgVal) (err error) {
	logical := messageLogicalConnSnapshot(m)
	transport := messageTransportConnSnapshot(m)
	reply := TransferMsg{
		ID:    m.ID,
		Key:   m.Key,
		Value: value,
		Type:  m.Type,
	}
	if reply.Type == MSG_SYNC_ASK {
		reply.Type = MSG_SYNC_REPLY
	}
	if reply.Type == MSG_SYS_WAIT {
		reply.Type = MSG_SYS_REPLY
	}
	if m.NetType == NET_SERVER {
		if m.inboundConn != nil && logical != nil {
			server := logical.Server()
			if server == nil {
				return transportDetachedErrorForPeer(logical, transport)
			}
			sender, _ := server.(messageInboundTransferSender)
			if sender == nil {
				return transportDetachedErrorForPeer(logical, transport)
			}
			return sender.sendTransferInbound(logical, transport, m.inboundConn, reply)
		}
		if transport != nil {
			_, err = transport.sendTransfer(reply)
			return
		}
		if logical == nil {
			return transportDetachedErrorForPeer(nil, transport)
		}
		server := logical.Server()
		if server == nil {
			return transportDetachedErrorForPeer(logical, transport)
		}
		sender, _ := server.(messageLogicalTransferSender)
		if sender == nil {
			return transportDetachedErrorForPeer(logical, transport)
		}
		_, err = sender.sendLogical(logical, reply)
	}
	if m.NetType == NET_CLIENT {
		_, err = m.ServerConn.send(reply)
	}
	return
}

func (m *Message) ReplyObj(value interface{}) (err error) {
	data, err := encode(value)
	if err != nil {
		return err
	}
	return m.Reply(data)
}

func hydrateServerMessagePeerFields(message Message) Message {
	if message.LogicalConn == nil {
		message.LogicalConn = logicalConnFromClient(message.ClientConn)
	}
	if message.ClientConn == nil {
		message.ClientConn = message.LogicalConn.compatClientConn()
	}
	if message.TransportConn == nil && message.LogicalConn != nil {
		message.TransportConn = message.LogicalConn.CurrentTransportConn()
	}
	return message
}

func messageLogicalConnSnapshot(message *Message) *LogicalConn {
	if message == nil {
		return nil
	}
	if message.LogicalConn != nil {
		return message.LogicalConn
	}
	return logicalConnFromClient(message.ClientConn)
}

func messageTransportConnSnapshot(message *Message) *TransportConn {
	if message == nil {
		return nil
	}
	if message.TransportConn != nil {
		return message.TransportConn
	}
	logical := messageLogicalConnSnapshot(message)
	if logical == nil {
		return nil
	}
	return logical.CurrentTransportConn()
}