{.used.}

import
  std/[options, sequtils],
  testutils/unittests,
  chronos,
  chronicles,
  stew/shims/net,
  libp2p/switch,
  libp2p/peerId,
  libp2p/crypto/crypto,
  eth/keys,
  eth/p2p/discoveryv5/enr
import
  ../../waku/v2/node/waku_node,
  ../../waku/v2/node/peer_manager,
  ../../waku/v2/node/discv5/waku_discv5,
  ../../waku/v2/protocol/waku_peer_exchange,
  ../../waku/v2/protocol/waku_peer_exchange/rpc,
  ../../waku/v2/protocol/waku_peer_exchange/rpc_codec,
  ../test_helpers,
  ./utils,
  ./testlib/testutils


# TODO: Extend test coverage
procSuite "Waku Peer Exchange":

  asyncTest "encode and decode peer exchange response":
    ## Setup
    var
      enr1 = enr.Record(seqNum: 0, raw: @[])
      enr2 = enr.Record(seqNum: 0, raw: @[])

    check enr1.fromUri("enr:-JK4QPmO-sE2ELiWr8qVFs1kaY4jQZQpNaHvSPRmKiKcaDoqYRdki2c1BKSliImsxFeOD_UHnkddNL2l0XT9wlsP0WEBgmlkgnY0gmlwhH8AAAGJc2VjcDI1NmsxoQIMwKqlOl3zpwnrsKRKHuWPSuFzit1Cl6IZvL2uzBRe8oN0Y3CC6mKDdWRwgiMqhXdha3UyDw")
    check enr2.fromUri("enr:-Iu4QK_T7kzAmewG92u1pr7o6St3sBqXaiIaWIsFNW53_maJEaOtGLSN2FUbm6LmVxSfb1WfC7Eyk-nFYI7Gs3SlchwBgmlkgnY0gmlwhI5d6VKJc2VjcDI1NmsxoQLPYQDvrrFdCrhqw3JuFaGD71I8PtPfk6e7TJ3pg_vFQYN0Y3CC6mKDdWRwgiMq")

    let peerInfos = @[
      PeerExchangePeerInfo(enr: enr1.raw),
      PeerExchangePeerInfo(enr: enr2.raw),
    ]

    var rpc = PeerExchangeRpc(
      response: PeerExchangeResponse(
        peerInfos: peerInfos
      )
    )

    ## When
    let
      rpcBuffer: seq[byte] = rpc.encode().buffer
      res = PeerExchangeRpc.decode(rpcBuffer)

    ## Then
    check:
      res.isOk
      res.get().response.peerInfos == peerInfos

    ## When
    var
      resEnr1 = enr.Record(seqNum: 0, raw: @[])
      resEnr2 = enr.Record(seqNum: 0, raw: @[])

    discard resEnr1.fromBytes(res.get().response.peerInfos[0].enr)
    discard resEnr2.fromBytes(res.get().response.peerInfos[1].enr)

    ## Then
    check:
      resEnr1 == enr1
      resEnr2 == enr2

  asyncTest "retrieve and provide peer exchange peers from discv5":
    ## Setup (copied from test_waku_discv5.nim)
    let
      bindIp = ValidIpAddress.init("0.0.0.0")
      extIp = ValidIpAddress.init("127.0.0.1")

      nodeKey1 = crypto.PrivateKey.random(Secp256k1, rng[])[]
      nodeTcpPort1 = Port(64010)
      nodeUdpPort1 = Port(9000)
      node1 = WakuNode.new(nodeKey1, bindIp, nodeTcpPort1)

      nodeKey2 = crypto.PrivateKey.random(Secp256k1, rng[])[]
      nodeTcpPort2 = Port(64012)
      nodeUdpPort2 = Port(9002)
      node2 = WakuNode.new(nodeKey2, bindIp, nodeTcpPort2)

      nodeKey3 = crypto.PrivateKey.random(Secp256k1, rng[])[]
      nodeTcpPort3 = Port(64014)
      nodeUdpPort3 = Port(9004)
      node3 = WakuNode.new(nodeKey3, bindIp, nodeTcpPort3)

      # todo: px flag
      flags = initWakuFlags(lightpush = false,
                            filter = false,
                            store = false,
                            relay = true)

    # Mount discv5
    node1.wakuDiscv5 = WakuDiscoveryV5.new(
        some(extIp), some(nodeTcpPort1), some(nodeUdpPort1),
        bindIp,
        nodeUdpPort1,
        newSeq[string](),
        false,
        keys.PrivateKey(nodeKey1.skkey),
        flags,
        newSeq[MultiAddress](), # Empty multiaddr fields, for now
        node1.rng
      )

    node2.wakuDiscv5 = WakuDiscoveryV5.new(
        some(extIp), some(nodeTcpPort2), some(nodeUdpPort2),
        bindIp,
        nodeUdpPort2,
        @[node1.wakuDiscv5.protocol.localNode.record.toURI()], # Bootstrap with node1
        false,
        keys.PrivateKey(nodeKey2.skkey),
        flags,
        newSeq[MultiAddress](), # Empty multiaddr fields, for now
        node2.rng
      )

    ## Given
    await allFutures([node1.start(), node2.start(), node3.start()])
    await allFutures([node1.startDiscv5(), node2.startDiscv5()])

    # Mount peer exchange
    await node1.mountPeerExchange()
    await node3.mountPeerExchange()

    # Give the algorithm some time to work its magic
    await sleepAsync(3000.millis)

    asyncSpawn node1.wakuPeerExchange.runPeerExchangeDiscv5Loop()

    let connOpt = await node3.peerManager.dialPeer(node1.switch.peerInfo.toRemotePeerInfo(), WakuPeerExchangeCodec)
    check:
      connOpt.isSome

    # Give the algorithm some time to work its magic
    await sleepAsync(2000.millis)

    ## When
    let response = await node3.wakuPeerExchange.request(1, connOpt.get())

    ## Then
    check:
      response.isOk
      response.get().peerInfos.len == 1
      node1.wakuDiscv5.protocol.nodesDiscovered > 0

    await allFutures([node1.stop(), node2.stop(), node3.stop()])

  asyncTest "peer exchange request functions returns some discovered peers":
    let
      node1 = WakuNode.new(generateKey(), ValidIpAddress.init("0.0.0.0"), Port(0))
      node2 = WakuNode.new(generateKey(), ValidIpAddress.init("0.0.0.0"), Port(0))

    # Start and mount peer exchange
    await allFutures([node1.start(), node2.start()])
    await allFutures([node1.mountPeerExchange(), node2.mountPeerExchange()])

    # Create connection
    let connOpt = await node2.peerManager.dialPeer(node1.switch.peerInfo.toRemotePeerInfo(), WakuPeerExchangeCodec)
    require:
      connOpt.isSome

    # Create some enr and add to peer exchange (sumilating disv5)
    var enr1, enr2 = enr.Record()
    check enr1.fromUri("enr:-Iu4QGNuTvNRulF3A4Kb9YHiIXLr0z_CpvWkWjWKU-o95zUPR_In02AWek4nsSk7G_-YDcaT4bDRPzt5JIWvFqkXSNcBgmlkgnY0gmlwhE0WsGeJc2VjcDI1NmsxoQKp9VzU2FAh7fwOwSpg1M_Ekz4zzl0Fpbg6po2ZwgVwQYN0Y3CC6mCFd2FrdTIB")
    check enr2.fromUri("enr:-Iu4QGJllOWlviPIh_SGR-VVm55nhnBIU5L-s3ran7ARz_4oDdtJPtUs3Bc5aqZHCiPQX6qzNYF2ARHER0JPX97TFbEBgmlkgnY0gmlwhE0WsGeJc2VjcDI1NmsxoQP3ULycvday4EkvtVu0VqbBdmOkbfVLJx8fPe0lE_dRkIN0Y3CC6mCFd2FrdTIB")

    # Mock that we have discovered these enrs
    node1.wakuPeerExchange.enrCache.add(enr1)
    node1.wakuPeerExchange.enrCache.add(enr2)

    # Request 2 peer from px. Test all request variants
    let response1 = await node2.wakuPeerExchange.request(2)
    let response2 = await node2.wakuPeerExchange.request(2, node1.peerInfo.toRemotePeerInfo())
    let response3 = await node2.wakuPeerExchange.request(2, connOpt.get())

    # Check the response or dont even continue
    require:
      response1.isOk
      response2.isOk
      response3.isOk

    check:
      response1.get().peerInfos.len == 2
      response2.get().peerInfos.len == 2
      response3.get().peerInfos.len == 2

      # Since it can return duplicates test that at least one of the enrs is in the response
      response1.get().peerInfos.anyIt(it.enr == enr1.raw) or response1.get().peerInfos.anyIt(it.enr == enr2.raw)
      response2.get().peerInfos.anyIt(it.enr == enr1.raw) or response2.get().peerInfos.anyIt(it.enr == enr2.raw)
      response3.get().peerInfos.anyIt(it.enr == enr1.raw) or response3.get().peerInfos.anyIt(it.enr == enr2.raw)

  asyncTest "peer exchange handler works as expected":
    let
      node1 = WakuNode.new(generateKey(), ValidIpAddress.init("0.0.0.0"), Port(0))
      node2 = WakuNode.new(generateKey(), ValidIpAddress.init("0.0.0.0"), Port(0))

    # Start and mount peer exchange
    await allFutures([node1.start(), node2.start()])
    await allFutures([node1.mountPeerExchange(), node2.mountPeerExchange()])

    # Mock that we have discovered these enrs
    var enr1 = enr.Record()
    check enr1.fromUri("enr:-Iu4QGNuTvNRulF3A4Kb9YHiIXLr0z_CpvWkWjWKU-o95zUPR_In02AWek4nsSk7G_-YDcaT4bDRPzt5JIWvFqkXSNcBgmlkgnY0gmlwhE0WsGeJc2VjcDI1NmsxoQKp9VzU2FAh7fwOwSpg1M_Ekz4zzl0Fpbg6po2ZwgVwQYN0Y3CC6mCFd2FrdTIB")
    node1.wakuPeerExchange.enrCache.add(enr1)

    # Create connection
    let connOpt = await node2.peerManager.dialPeer(node1.switch.peerInfo.toRemotePeerInfo(), WakuPeerExchangeCodec)
    require connOpt.isSome
    let conn = connOpt.get()

    # Send bytes so that they directly hit the handler
    let rpc = PeerExchangeRpc(
      request: PeerExchangeRequest(numPeers: 1))

    var buffer: seq[byte]
    await conn.writeLP(rpc.encode().buffer)
    buffer = await conn.readLp(MaxRpcSize.int)

    # Decode the response
    let decodedBuff = PeerExchangeRpc.decode(buffer)
    require decodedBuff.isOk

    # Check we got back the enr we mocked
    check:
      decodedBuff.get().response.peerInfos.len == 1
      decodedBuff.get().response.peerInfos[0].enr == enr1.raw

  asyncTest "peer exchange request fails gracefully":
    let
      node1 = WakuNode.new(generateKey(), ValidIpAddress.init("0.0.0.0"), Port(0))
      node2 = WakuNode.new(generateKey(), ValidIpAddress.init("0.0.0.0"), Port(0))

    # Start and mount peer exchange
    await allFutures([node1.start(), node2.start()])
    await allFutures([node1.mountPeerExchange(), node2.mountPeerExchange()])

    # Create connection
    let connOpt = await node2.peerManager.dialPeer(node1.switch.peerInfo.toRemotePeerInfo(), WakuPeerExchangeCodec)
    require connOpt.isSome

    # Force closing the connection to simulate a failed peer
    await connOpt.get().close()

    # Request 2 peer from px
    let response = await node1.wakuPeerExchange.request(2, connOpt.get())

    # Check that it failed gracefully
    check: response.isErr