# compile time options here
const
  libp2p_pubsub_sign {.booldefine.} = true
  libp2p_pubsub_verify {.booldefine.} = true
  libp2p_pubsub_anonymize {.booldefine.} = false

import hashes, random, tables, sets, sequtils
import chronos, stew/[byteutils, results], chronos/ratelimit
import
  ../../libp2p/[
    builders,
    protocols/pubsub/errors,
    protocols/pubsub/pubsub,
    protocols/pubsub/pubsubpeer,
    protocols/pubsub/gossipsub,
    protocols/pubsub/floodsub,
    protocols/pubsub/rpc/messages,
    protocols/secure/secure,
  ]
import ../helpers
import chronicles

export builders

randomize()

type TestGossipSub* = ref object of GossipSub

proc getPubSubPeer*(p: TestGossipSub, peerId: PeerId): PubSubPeer =
  proc getConn(): Future[Connection] =
    p.switch.dial(peerId, GossipSubCodec_12)

  let pubSubPeer = PubSubPeer.new(peerId, getConn, nil, GossipSubCodec_12, 1024 * 1024)
  debug "created new pubsub peer", peerId

  p.peers[peerId] = pubSubPeer

  onNewPeer(p, pubSubPeer)
  pubSubPeer

proc randomPeerId*(): PeerId =
  try:
    PeerId.init(PrivateKey.random(ECDSA, rng[]).get()).tryGet()
  except CatchableError as exc:
    raise newException(Defect, exc.msg)

func defaultMsgIdProvider*(m: Message): Result[MessageId, ValidationResult] =
  let mid =
    if m.seqno.len > 0 and m.fromPeer.data.len > 0:
      byteutils.toHex(m.seqno) & $m.fromPeer
    else:
      # This part is irrelevant because it's not standard,
      # We use it exclusively for testing basically and users should
      # implement their own logic in the case they use anonymization
      $m.data.hash & $m.topic.hash
  ok mid.toBytes()

proc generateNodes*(
    num: Natural,
    secureManagers: openArray[SecureProtocol] = [SecureProtocol.Noise],
    msgIdProvider: MsgIdProvider = defaultMsgIdProvider,
    gossip: bool = false,
    triggerSelf: bool = false,
    verifySignature: bool = libp2p_pubsub_verify,
    anonymize: bool = libp2p_pubsub_anonymize,
    sign: bool = libp2p_pubsub_sign,
    sendSignedPeerRecord = false,
    unsubscribeBackoff = 1.seconds,
    maxMessageSize: int = 1024 * 1024,
    enablePX: bool = false,
    overheadRateLimit: Opt[tuple[bytes: int, interval: Duration]] =
      Opt.none(tuple[bytes: int, interval: Duration]),
    gossipSubVersion: string = "",
): seq[PubSub] =
  for i in 0 ..< num:
    let switch = newStandardSwitch(
      secureManagers = secureManagers, sendSignedPeerRecord = sendSignedPeerRecord
    )
    let pubsub =
      if gossip:
        let g = GossipSub.init(
          switch = switch,
          triggerSelf = triggerSelf,
          verifySignature = verifySignature,
          sign = sign,
          msgIdProvider = msgIdProvider,
          anonymize = anonymize,
          maxMessageSize = maxMessageSize,
          parameters = (
            var p = GossipSubParams.init()
            p.floodPublish = false
            p.historyLength = 20
            p.historyGossip = 20
            p.unsubscribeBackoff = unsubscribeBackoff
            p.enablePX = enablePX
            p.overheadRateLimit = overheadRateLimit
            p
          ),
        )
        # set some testing params, to enable scores
        g.topicParams.mgetOrPut("foobar", TopicParams.init()).topicWeight = 1.0
        g.topicParams.mgetOrPut("foo", TopicParams.init()).topicWeight = 1.0
        g.topicParams.mgetOrPut("bar", TopicParams.init()).topicWeight = 1.0
        if gossipSubVersion != "":
          g.codecs = @[gossipSubVersion]
        g.PubSub
      else:
        FloodSub.init(
          switch = switch,
          triggerSelf = triggerSelf,
          verifySignature = verifySignature,
          sign = sign,
          msgIdProvider = msgIdProvider,
          maxMessageSize = maxMessageSize,
          anonymize = anonymize,
        ).PubSub

    switch.mount(pubsub)
    result.add(pubsub)

proc subscribeNodes*(nodes: seq[PubSub]) {.async.} =
  for dialer in nodes:
    for node in nodes:
      if dialer.switch.peerInfo.peerId != node.switch.peerInfo.peerId:
        await dialer.switch.connect(node.peerInfo.peerId, node.peerInfo.addrs)

proc subscribeSparseNodes*(nodes: seq[PubSub], degree: int = 2) {.async.} =
  if nodes.len < degree:
    raise
      (ref CatchableError)(msg: "nodes count needs to be greater or equal to degree!")

  for i, dialer in nodes:
    if (i mod degree) != 0:
      continue

    for node in nodes:
      if dialer.switch.peerInfo.peerId != node.peerInfo.peerId:
        await dialer.switch.connect(node.peerInfo.peerId, node.peerInfo.addrs)

proc subscribeRandom*(nodes: seq[PubSub]) {.async.} =
  for dialer in nodes:
    var dialed: seq[PeerId]
    while dialed.len < nodes.len - 1:
      let node = sample(nodes)
      if node.peerInfo.peerId notin dialed:
        if dialer.peerInfo.peerId != node.peerInfo.peerId:
          await dialer.switch.connect(node.peerInfo.peerId, node.peerInfo.addrs)
          dialed.add(node.peerInfo.peerId)

proc waitSub*(sender, receiver: auto, key: string) {.async.} =
  if sender == receiver:
    return
  let timeout = Moment.now() + 5.seconds
  let fsub = GossipSub(sender)

  # this is for testing purposes only
  # peers can be inside `mesh` and `fanout`, not just `gossipsub`
  while (
    not fsub.gossipsub.hasKey(key) or
    not fsub.gossipsub.hasPeerId(key, receiver.peerInfo.peerId)
  ) and
      (
        not fsub.mesh.hasKey(key) or
        not fsub.mesh.hasPeerId(key, receiver.peerInfo.peerId)
      ) and (
    not fsub.fanout.hasKey(key) or
    not fsub.fanout.hasPeerId(key, receiver.peerInfo.peerId)
  )
  :
    trace "waitSub sleeping..."

    # await
    await sleepAsync(5.milliseconds)
    doAssert Moment.now() < timeout, "waitSub timeout!"

proc waitSubGraph*(nodes: seq[PubSub], key: string) {.async.} =
  let timeout = Moment.now() + 5.seconds
  while true:
    var
      nodesMesh: Table[PeerId, seq[PeerId]]
      seen: HashSet[PeerId]
    for n in nodes:
      nodesMesh[n.peerInfo.peerId] =
        toSeq(GossipSub(n).mesh.getOrDefault(key).items()).mapIt(it.peerId)
    var ok = 0
    for n in nodes:
      seen.clear()
      proc explore(p: PeerId) =
        if p in seen:
          return
        seen.incl(p)
        for peer in nodesMesh.getOrDefault(p):
          explore(peer)

      explore(n.peerInfo.peerId)
      if seen.len == nodes.len:
        ok.inc()
    if ok == nodes.len:
      return
    trace "waitSubGraph sleeping..."

    await sleepAsync(5.milliseconds)
    doAssert Moment.now() < timeout, "waitSubGraph timeout!"