package node

import (
	"fmt"
	"io"
	"log"
	"net"
	"net/netip"
	"runtime/debug"
)

var (
	network  = []byte{10, 1, 1, 0}
	serverIP = byte(1)
	clientIP = byte(2)
	port     = uint16(5151)
	netName  = "testnet"
)

func must(err error) {
	if err != nil {
		panic(err)
	}
}

type TmpNode struct {
	network []byte
	localIP byte
	peers   peerRepo
	port    uint16
	netName string
	iface   io.ReadWriteCloser
	w       *connWriter
	r       *connReader
}

func NewTmpNodeServer() *TmpNode {
	n := &TmpNode{
		localIP: serverIP,
		network: network,
		peers:   newPeerRepo(),
		port:    port,
		netName: netName,
	}

	var err error
	n.iface, err = openInterface(n.network, n.localIP, n.netName)
	must(err)

	myAddr, err := net.ResolveUDPAddr("udp", fmt.Sprintf(":%d", n.port))
	must(err)

	conn, err := net.ListenUDP("udp", myAddr)
	must(err)

	n.w = newConnWriter(conn, n.localIP, n.peers.Get)
	n.r = newConnReader(conn, n.localIP, n.peers.Get)

	return n
}

func NewTmpNodeClient() *TmpNode {
	n := &TmpNode{
		localIP: clientIP,
		network: network,
		peers:   newPeerRepo(),
		port:    port,
		netName: netName,
	}

	var err error
	n.iface, err = openInterface(n.network, n.localIP, n.netName)
	must(err)

	myAddr, err := net.ResolveUDPAddr("udp", fmt.Sprintf(":%d", n.port))
	must(err)

	conn, err := net.ListenUDP("udp", myAddr)
	must(err)

	n.w = newConnWriter(conn, n.localIP, n.peers.Get)
	n.r = newConnReader(conn, n.localIP, n.peers.Get)

	return n
}

func (n *TmpNode) RunServer() {
	defer func() {
		if r := recover(); r != nil {
			fmt.Printf("%v", r)
			debug.PrintStack()
		}
	}()

	// Get remoteAddr from a packet.
	buf := make([]byte, bufferSize)
	remoteAddr, h, _, err := n.r.Read(buf)
	must(err)
	log.Printf("Got remote addr: %d -> %v", h.SourceIP, remoteAddr)
	must(err)

	n.peers.Set(h.SourceIP, &peer{
		IP:   h.SourceIP,
		Addr: &remoteAddr,
	})

	go n.readFromIFace()
	n.readFromConn()
}

func (n *TmpNode) RunClient(srvAddrStr string) {
	defer func() {
		if r := recover(); r != nil {
			fmt.Printf("%v", r)
			debug.PrintStack()
		}
	}()

	serverAddr, err := netip.ParseAddrPort(fmt.Sprintf("%s:%d", srvAddrStr, port))
	must(err)

	log.Printf("Setting %d => %v", serverIP, serverAddr)
	n.peers.Set(serverIP, &peer{
		IP:   serverIP,
		Addr: &serverAddr,
	})

	must(n.w.WriteTo(serverIP, 1, []byte{1, 2, 3, 4, 5, 6, 7, 8}))

	go n.readFromIFace()
	n.readFromConn()
}

func (n *TmpNode) readFromIFace() {
	var (
		buf      = make([]byte, bufferSize)
		packet   []byte
		remoteIP byte
		err      error
	)

	for {
		packet, remoteIP, err = readNextPacket(n.iface, buf)
		must(err)
		must(n.w.WriteTo(remoteIP, 1, packet))
	}
}

func (node *TmpNode) readFromConn() {
	var (
		buf    = make([]byte, bufferSize)
		packet []byte
		err    error
	)

	for {
		_, _, packet, err = node.r.Read(buf)
		must(err)
		// We assume that we're only receiving packets from one source.

		_, err = node.iface.Write(packet)
		must(err)
	}
}