## Nim-Codex
## Copyright (c) 2021 Status Research & Development GmbH
## Licensed under either of
##  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
##  * MIT license ([LICENSE-MIT](LICENSE-MIT))
## at your option.
## This file may not be copied, modified, or distributed except according to
## those terms.

import std/sequtils
import std/strutils
import std/os
import std/tables
import std/cpuinfo

import pkg/chronos
import pkg/presto
import pkg/libp2p
import pkg/libp2p/protocols/connectivity/autonat/client
import pkg/libp2p/protocols/connectivity/autonat/service
import pkg/libp2p/protocols/connectivity/relay/client
import pkg/libp2p/services/[autorelayservice, hpservice]
import pkg/confutils
import pkg/confutils/defs
import pkg/nitro
import pkg/stew/io2
import pkg/stew/shims/net as stewnet
import pkg/datastore
import pkg/ethers except Rng
import pkg/stew/io2
import pkg/taskpools

import ./node
import ./conf
import ./rng
import ./rest/api
import ./stores
import ./slots
import ./blockexchange
import ./utils/fileutils
import ./erasure
import ./discovery
import ./contracts
import ./systemclock
import ./contracts/clock
import ./contracts/deployment
import ./utils/addrutils
import ./namespaces
import ./codextypes
import ./logutils

logScope:
  topics = "codex node"

type
  CodexServer* = ref object
    config: CodexConf
    restServer: RestServerRef
    codexNode: CodexNodeRef
    repoStore: RepoStore
    maintenance: BlockMaintainer
    taskpool: Taskpool

  CodexPrivateKey* = libp2p.PrivateKey # alias
  EthWallet = ethers.Wallet

proc waitForSync(provider: Provider): Future[void] {.async.} =
  var sleepTime = 1
  trace "Checking sync state of Ethereum provider..."
  while await provider.isSyncing:
    notice "Waiting for Ethereum provider to sync..."
    await sleepAsync(sleepTime.seconds)
    if sleepTime < 10:
      inc sleepTime
  trace "Ethereum provider is synced."

proc bootstrapInteractions(
  s: CodexServer): Future[void] {.async.} =
  ## bootstrap interactions and return contracts
  ## using clients, hosts, validators pairings
  ##
  let
    config = s.config
    repo = s.repoStore

  if config.persistence:
    if not config.ethAccount.isSome and not config.ethPrivateKey.isSome:
      error "Persistence enabled, but no Ethereum account was set"
      quit QuitFailure

    let provider = JsonRpcProvider.new(config.ethProvider)
    await waitForSync(provider)
    var signer: Signer
    if account =? config.ethAccount:
      signer = provider.getSigner(account)
    elif keyFile =? config.ethPrivateKey:
      without isSecure =? checkSecureFile(keyFile):
        error "Could not check file permissions: does Ethereum private key file exist?"
        quit QuitFailure
      if not isSecure:
        error "Ethereum private key file does not have safe file permissions"
        quit QuitFailure
      without key =? keyFile.readAllChars():
        error "Unable to read Ethereum private key file"
        quit QuitFailure
      without wallet =? EthWallet.new(key.strip(), provider):
        error "Invalid Ethereum private key in file"
        quit QuitFailure
      signer = wallet

    let deploy = Deployment.new(provider, config)
    without marketplaceAddress =? await deploy.address(Marketplace):
      error "No Marketplace address was specified or there is no known address for the current network"
      quit QuitFailure

    let marketplace = Marketplace.new(marketplaceAddress, signer)
    let market = OnChainMarket.new(marketplace)
    let clock = OnChainClock.new(provider)

    var client: ?ClientInteractions
    var host: ?HostInteractions
    var validator: ?ValidatorInteractions

    if config.validator or config.persistence:
      s.codexNode.clock = clock
    else:
      s.codexNode.clock = SystemClock()

    if config.persistence:
      # This is used for simulation purposes. Normal nodes won't be compiled with this flag
      # and hence the proof failure will always be 0.
      when codex_enable_proof_failures:
        let proofFailures = config.simulateProofFailures
        if proofFailures > 0:
          warn "Enabling proof failure simulation!"
      else:
        let proofFailures = 0
        if config.simulateProofFailures > 0:
          warn "Proof failure simulation is not enabled for this build! Configuration ignored"

      let purchasing = Purchasing.new(market, clock)
      let sales = Sales.new(market, clock, repo, proofFailures)
      client = some ClientInteractions.new(clock, purchasing)
      host = some HostInteractions.new(clock, sales)

    if config.validator:
      let validation = Validation.new(clock, market, config.validatorMaxSlots)
      validator = some ValidatorInteractions.new(clock, validation)

    s.codexNode.contracts = (client, host, validator)

proc start*(s: CodexServer) {.async.} =
  trace "Starting codex node", config = $s.config

  await s.repoStore.start()
  s.maintenance.start()

  await s.codexNode.switch.start()

  let
    # TODO: Can't define these as constants, pity
    natIpPart = MultiAddress.init("/ip4/" & $s.config.nat & "/")
      .expect("Should create multiaddress")
    anyAddrIp = MultiAddress.init("/ip4/0.0.0.0/")
      .expect("Should create multiaddress")
    loopBackAddrIp = MultiAddress.init("/ip4/127.0.0.1/")
      .expect("Should create multiaddress")

    # announce addresses should be set to bound addresses,
    # but the IP should be mapped to the provided nat ip
    announceAddrs = s.codexNode.switch.peerInfo.addrs.mapIt:
      block:
        let
          listenIPPart = it[multiCodec("ip4")].expect("Should get IP")

        if listenIPPart == anyAddrIp or
          (listenIPPart == loopBackAddrIp and natIpPart != loopBackAddrIp):
          it.remapAddr(s.config.nat.some)
        else:
          it

  s.codexNode.discovery.updateAnnounceRecord(announceAddrs)
  s.codexNode.discovery.updateDhtRecord(s.config.nat, s.config.discoveryPort)

  await s.bootstrapInteractions()
  await s.codexNode.start()
  s.restServer.start()

proc stop*(s: CodexServer) {.async.} =
  notice "Stopping codex node"


  s.taskpool.syncAll()
  s.taskpool.shutdown()

  await allFuturesThrowing(
    s.restServer.stop(),
    s.codexNode.switch.stop(),
    s.codexNode.stop(),
    s.repoStore.stop(),
    s.maintenance.stop())

proc getAutonatService*(rng: ref HmacDrbgContext): AutonatService =
  ## AutonatService request other peers to dial us back
  ## flagging us as Reachable or NotReachable.
  ## minConfidence is used as threshold to determine the state.
  ## If maxQueueSize > numPeersToAsk past samples are considered
  ## in the calculation.
  ##

  let
    autonatService = AutonatService.new(
      autonatClient = AutonatClient.new(),
      rng = rng,
      scheduleInterval = Opt.some(chronos.seconds(120)),
      askNewConnectedPeers = false,
      numPeersToAsk = 3,
      maxQueueSize = 3,
      minConfidence = 0.7)

  proc statusAndConfidenceHandler(
    networkReachability: NetworkReachability,
    confidence: Opt[float]): Future[void] {.gcsafe, async.} =
    if confidence.isSome():
      info "Peer reachability status",
        networkReachability = networkReachability, confidence = confidence.get()

  autonatService.statusAndConfidenceHandler(statusAndConfidenceHandler)

  return autonatService

proc new*(
  T: type CodexServer,
  config: CodexConf,
  privateKey: CodexPrivateKey): CodexServer =
  ## create CodexServer including setting up datastore, repostore, etc
  ##

  var
    builder = SwitchBuilder.new()
      .withPrivateKey(privateKey)
      .withAddresses(config.listenAddrs)
      .withRng(Rng.instance())
      .withNoise()
      .withYamux()
      .withMplex(5.minutes, 5.minutes)
      .withMaxConnections(config.maxPeers)
      .withAgentVersion(config.agentString)
      .withSignedPeerRecord(true)
      .withTcpTransport({ServerFlags.ReuseAddr})
      .withAutonat()
      .withRendezVous()
      # .withObservedAddrManager()

  builder = if config.lpRelay:
      builder.withCircuitRelay()
    else:
      let
        relayClient = RelayClient.new()
        autoRelayService = AutoRelayService.new(1, relayClient, nil, Rng.instance())
        autonatService = getAutonatService(Rng.instance())
        hpservice = HPService.new(autonatService, autoRelayService)

      builder
        .withCircuitRelay(relayClient)
        .withServices(@[Service(hpservice)])

  let
    switch = builder.build

  var
    cache: CacheStore = nil

  if config.cacheSize > 0'nb:
    cache = CacheStore.new(cacheSize = config.cacheSize)
    ## Is unused?

  let
    discoveryDir = config.dataDir / CodexDhtNamespace

  if io2.createPath(discoveryDir).isErr:
    trace "Unable to create discovery directory for block store", discoveryDir = discoveryDir
    raise (ref Defect)(
      msg: "Unable to create discovery directory for block store: " & discoveryDir)

  let
    discoveryStore = Datastore(
      SQLiteDatastore.new(config.dataDir / CodexDhtProvidersNamespace)
      .expect("Should create discovery datastore!"))

    discovery = Discovery.new(
      switch.peerInfo.privateKey,
      announceAddrs = config.listenAddrs,
      bindIp = config.discoveryIp,
      bindPort = config.discoveryPort,
      bootstrapNodes = config.bootstrapNodes,
      store = discoveryStore)

    wallet = WalletRef.new(EthPrivateKey.random())
    network = BlockExcNetwork.new(switch)

    repoData = case config.repoKind
                of repoFS: Datastore(FSDatastore.new($config.dataDir, depth = 5)
                  .expect("Should create repo file data store!"))
                of repoSQLite: Datastore(SQLiteDatastore.new($config.dataDir)
                  .expect("Should create repo SQLite data store!"))

    repoStore = RepoStore.new(
      repoDs = repoData,
      metaDs = SQLiteDatastore.new(config.dataDir / CodexMetaNamespace)
        .expect("Should create meta data store!"),
      quotaMaxBytes = config.storageQuota.uint,
      blockTtl = config.blockTtl)

    maintenance = BlockMaintainer.new(
      repoStore,
      interval = config.blockMaintenanceInterval,
      numberOfBlocksPerInterval = config.blockMaintenanceNumberOfBlocks)

    peerStore = PeerCtxStore.new()
    pendingBlocks = PendingBlocksManager.new()
    blockDiscovery = DiscoveryEngine.new(repoStore, peerStore, network, discovery, pendingBlocks)
    engine = BlockExcEngine.new(repoStore, wallet, network, blockDiscovery, peerStore, pendingBlocks)
    store = NetworkStore.new(engine, repoStore)
    prover = if config.prover:
      if not fileAccessible($config.circomR1cs, {AccessFlags.Read}) and
        endsWith($config.circomR1cs, ".r1cs"):
        error "Circom R1CS file not accessible"
        raise (ref Defect)(
          msg: "r1cs file not readable, doesn't exist or wrong extension (.r1cs)")

      if not fileAccessible($config.circomWasm, {AccessFlags.Read}) and
        endsWith($config.circomWasm, ".wasm"):
        error "Circom wasm file not accessible"
        raise (ref Defect)(
          msg: "wasm file not readable, doesn't exist or wrong extension (.wasm)")

      let zkey = if not config.circomNoZkey:
          if not fileAccessible($config.circomZkey, {AccessFlags.Read}) and
            endsWith($config.circomZkey, ".zkey"):
            error "Circom zkey file not accessible"
            raise (ref Defect)(
              msg: "zkey file not readable, doesn't exist or wrong extension (.zkey)")

          $config.circomZkey
        else: ""

      some Prover.new(
        store,
        CircomCompat.init($config.circomR1cs, $config.circomWasm, zkey),
        config.numProofSamples)
    else:
      none Prover

    taskpool = Taskpool.new(num_threads = countProcessors())

    codexNode = CodexNodeRef.new(
      switch = switch,
      networkStore = store,
      engine = engine,
      prover = prover,
      discovery = discovery,
      taskpool = taskpool)

    restServer = RestServerRef.new(
      codexNode.initRestApi(config, repoStore),
      initTAddress(config.apiBindAddress , config.apiPort),
      bufferSize = (1024 * 64),
      maxRequestBodySize = int.high)
      .expect("Should start rest server!")

  switch.mount(network)

  CodexServer(
    config: config,
    codexNode: codexNode,
    restServer: restServer,
    repoStore: repoStore,
    maintenance: maintenance,
    taskpool: taskpool)