nwaku/waku/waku_core/peers.nim

when (NimMajor, NimMinor) < (1, 4):
  {.push raises: [Defect].}
else:
  {.push raises: [].}

import
  std/[options, sequtils, strutils, uri],
  stew/results,
  stew/shims/net,
  chronos,
  eth/keys,
  eth/p2p/discoveryv5/enr,
  libp2p/crypto/crypto,
  libp2p/crypto/secp,
  libp2p/errors,
  libp2p/multiaddress,
  libp2p/multicodec,
  libp2p/peerid,
  libp2p/peerinfo,
  libp2p/routing_record,
  json_serialization

type
  Connectedness* = enum
    # NotConnected: default state for a new peer. No connection and no further information on connectedness.
    NotConnected,
    # CannotConnect: attempted to connect to peer, but failed.
    CannotConnect,
    # CanConnect: was recently connected to peer and disconnected gracefully.
    CanConnect,
    # Connected: actively connected to peer.
    Connected

  PeerOrigin* = enum
    UnknownOrigin,
    Discv5,
    Static,
    PeerExcahnge,
    Dns

  PeerDirection* = enum
    UnknownDirection,
    Inbound,
    Outbound

type RemotePeerInfo* = ref object
    peerId*: PeerID
    addrs*: seq[MultiAddress]
    enr*: Option[enr.Record]
    protocols*: seq[string]

    agent*: string
    protoVersion*: string
    publicKey*: crypto.PublicKey
    connectedness*: Connectedness
    disconnectTime*: int64
    origin*: PeerOrigin
    direction*: PeerDirection
    lastFailedConn*: Moment
    numberFailedConn*: int

func `$`*(remotePeerInfo: RemotePeerInfo): string =
  $remotePeerInfo.peerId

proc writeValue*(w: var JsonWriter, value: RemotePeerInfo) {.inline, raises: [IOError].} =
  w.writeValue $value

proc init*(
  T: typedesc[RemotePeerInfo],
  peerId: PeerID,
  addrs: seq[MultiAddress] = @[],
  enr: Option[enr.Record] = none(enr.Record),
  protocols: seq[string] = @[]): T =

  RemotePeerInfo(peerId: peerId, addrs: addrs, enr: enr, protocols: protocols)

proc init*(T: typedesc[RemotePeerInfo],
           peerId: string,
           addrs: seq[MultiAddress] = @[],
           enr: Option[enr.Record] = none(enr.Record),
           protocols: seq[string] = @[]): T
           {.raises: [Defect, ResultError[cstring], LPError].} =

  let peerId = PeerID.init(peerId).tryGet()
  RemotePeerInfo(peerId: peerId, addrs: addrs, enr: enr, protocols: protocols)


## Parse

proc validWireAddr*(ma: MultiAddress): bool =
  ## Check if wire Address is supported
  const
    ValidTransports = mapOr(TCP, WebSockets)
  return ValidTransports.match(ma)

proc parsePeerInfo*(peer: RemotePeerInfo): Result[RemotePeerInfo, string] =
  ## Parses a fully qualified peer multiaddr, in the
  ## format `(ip4|ip6)/tcp/p2p`, into dialable PeerInfo
  ok(peer)

proc parsePeerInfo*(peer: MultiAddress): Result[RemotePeerInfo, string] =
  ## Parses a fully qualified peer multiaddr, in the
  ## format `(ip4|ip6)/tcp/p2p`, into dialable PeerInfo
  var p2pPart: MultiAddress
  var wireAddr = MultiAddress()
  for addrPart in peer.items():
    case addrPart[].protoName()[]
    # All protocols listed here: https://github.com/multiformats/multiaddr/blob/b746a7d014e825221cc3aea6e57a92d78419990f/protocols.csv
    of "p2p":
      p2pPart = ? addrPart.mapErr(proc(err: string): string = "Error getting p2pPart [" & err & "]")
    of "ip4", "ip6", "dns", "dnsaddr", "dns4", "dns6", "tcp", "ws", "wss":
      let val = ? addrPart.mapErr(proc(err: string): string = "Error getting addrPart [" & err & "]")
      ? wireAddr.append(val).mapErr(proc(err: string): string = "Error appending addrPart [" & err & "]")

  let p2pPartStr = p2pPart.toString().get()
  if not p2pPartStr.contains("/"):
    let msg = "Error in parsePeerInfo: p2p part should contain / [p2pPartStr:" & p2pPartStr & "] [peer:" & $peer & "]"
    return err(msg)

  let peerId = ? PeerID.init(p2pPartStr.split("/")[^1])
                        .mapErr(proc(e: cstring): string = $e)

  if not wireAddr.validWireAddr():
    return err("invalid multiaddress: no supported transport found")

  return ok(RemotePeerInfo.init(peerId, @[wireAddr]))

proc parsePeerInfo*(peer: string): Result[RemotePeerInfo, string] =
  ## Parses a fully qualified peer multiaddr, in the
  ## format `(ip4|ip6)/tcp/p2p`, into dialable PeerInfo
  let multiAddr = ? MultiAddress.init(peer)
                    .mapErr(proc(err: string): string = "MultiAddress.init [" & err & "]")

  parsePeerInfo(multiAddr)


func getTransportProtocol(typedR: TypedRecord): Option[IpTransportProtocol] =
  if typedR.tcp6.isSome() or typedR.tcp.isSome():
    return some(IpTransportProtocol.tcpProtocol)

  if typedR.udp6.isSome() or typedR.udp.isSome():
    return some(IpTransportProtocol.udpProtocol)

  return none(IpTransportProtocol)

proc parseUrlPeerAddr*(peerAddr: Option[string]): Result[Option[RemotePeerInfo], string] =
  # Checks whether the peerAddr parameter represents a valid p2p multiaddress.
  # The param must be in the format `(ip4|ip6)/tcp/p2p/$peerId` but URL-encoded
  if not peerAddr.isSome() or peerAddr.get() == "":
    return ok(none(RemotePeerInfo))

  let parsedAddr = decodeUrl(peerAddr.get())
  let parsedPeerInfo = parsePeerInfo(parsedAddr)
  if parsedPeerInfo.isErr():
    return err("Failed parsing remote peer info [" & parsedPeerInfo.error & "]")

  return ok(some(parsedPeerInfo.value))

proc toRemotePeerInfo*(enr: enr.Record): Result[RemotePeerInfo, cstring] =
  ## Converts an ENR to dialable RemotePeerInfo
  let typedR = ? enr.toTypedRecord()
  if not typedR.secp256k1.isSome():
    return err("enr: no secp256k1 key in record")

  let
    pubKey = ? keys.PublicKey.fromRaw(typedR.secp256k1.get())
    peerId = ? PeerID.init(crypto.PublicKey(scheme: Secp256k1,
                                            skkey: secp.SkPublicKey(pubKey)))

  let transportProto = getTransportProtocol(typedR)
  if transportProto.isNone():
    return err("enr: could not determine transport protocol")

  var addrs = newSeq[MultiAddress]()
  case transportProto.get()
  of tcpProtocol:
    if typedR.ip.isSome() and typedR.tcp.isSome():
      let ip = ipv4(typedR.ip.get())
      addrs.add MultiAddress.init(ip, tcpProtocol, Port(typedR.tcp.get()))

    if typedR.ip6.isSome():
      let ip = ipv6(typedR.ip6.get())
      if typedR.tcp6.isSome():
        addrs.add MultiAddress.init(ip, tcpProtocol, Port(typedR.tcp6.get()))
      elif typedR.tcp.isSome():
        addrs.add MultiAddress.init(ip, tcpProtocol, Port(typedR.tcp.get()))
      else:
        discard

  of udpProtocol:
    if typedR.ip.isSome() and typedR.udp.isSome():
      let ip = ipv4(typedR.ip.get())
      addrs.add MultiAddress.init(ip, udpProtocol, Port(typedR.udp.get()))

    if typedR.ip6.isSome():
      let ip = ipv6(typedR.ip6.get())
      if typedR.udp6.isSome():
        addrs.add MultiAddress.init(ip, udpProtocol, Port(typedR.udp6.get()))
      elif typedR.udp.isSome():
        addrs.add MultiAddress.init(ip, udpProtocol, Port(typedR.udp.get()))
      else:
        discard

  if addrs.len == 0:
    return err("enr: no addresses in record")

  return ok(RemotePeerInfo.init(peerId, addrs, some(enr)))

converter toRemotePeerInfo*(peerRecord: PeerRecord): RemotePeerInfo =
  ## Converts peer records to dialable RemotePeerInfo
  ## Useful if signed peer records have been received in an exchange
  RemotePeerInfo.init(
    peerRecord.peerId,
    peerRecord.addresses.mapIt(it.address)
  )

converter toRemotePeerInfo*(peerInfo: PeerInfo): RemotePeerInfo =
  ## Converts the local peerInfo to dialable RemotePeerInfo
  ## Useful for testing or internal connections
  RemotePeerInfo.init(
    peerInfo.peerId,
    peerInfo.listenAddrs,
    none(enr.Record),
    peerInfo.protocols
  )

proc hasProtocol*(ma: MultiAddress, proto: string): bool =
  ## Checks if a multiaddress contains a given protocol
  ## Useful for filtering multiaddresses based on their protocols
  ##
  ## Returns ``true`` if ``ma`` contains protocol ``proto``.
  let proto = MultiCodec.codec(proto)

  let protos = ma.protocols()
  if protos.isErr():
    return false

  return protos.get().anyIt(it == proto)

func hasUdpPort*(peer: RemotePeerInfo): bool =
  if peer.enr.isNone():
   return false

  let
    enr = peer.enr.get()
    typedEnrRes = enr.toTypedRecord()

  if typedEnrRes.isErr():
    return false

  let typedEnr = typedEnrRes.get()
  typedEnr.udp.isSome() or typedEnr.udp6.isSome()