{.push raises: [].}

import
  std/[tables, strutils, terminal, typetraits],
  chronicles, chronos, confutils, presto,
  chronicles/helpers as chroniclesHelpers, chronicles/topics_registry,
  stew/io2,
  ./spec/keystore,
  ./spec/datatypes/base,
  "."/[beacon_clock, conf]

export
  confutils, beacon_clock, conf

type
  SlotStartProc*[T] = proc(node: T, wallTime: BeaconTime,
                           lastSlot: Slot): Future[bool] {.gcsafe,
  raises: [].}

# silly chronicles, colors is a compile-time property
when defaultChroniclesStream.outputs.type.arity == 2:
  func stripAnsi(v: string): string =
    var
      res = newStringOfCap(v.len)
      i: int

    while i < v.len:
      let c = v[i]
      if c == '\x1b':
        var
          x = i + 1
          found = false

        while x < v.len: # look for [..m
          let c2 = v[x]
          if x == i + 1:
            if c2 != '[':
              break
          else:
            if c2 in {'0'..'9'} + {';'}:
              discard # keep looking
            elif c2 == 'm':
              i = x + 1
              found = true
              break
            else:
              break
          inc x

        if found: # skip adding c
          continue
      res.add c
      inc i

    res

proc updateLogLevel*(logLevel: string) {.raises: [ValueError].} =
  # Updates log levels (without clearing old ones)
  let directives = logLevel.split(";")
  try:
    setLogLevel(parseEnum[LogLevel](directives[0].capitalizeAscii()))
  except ValueError:
    raise (ref ValueError)(msg: "Please specify one of TRACE, DEBUG, INFO, NOTICE, WARN, ERROR or FATAL")

  if directives.len > 1:
    for topicName, settings in parseTopicDirectives(directives[1..^1]):
      if not setTopicState(topicName, settings.state, settings.logLevel):
        warn "Unrecognized logging topic", topic = topicName

proc detectTTY*(stdoutKind: StdoutLogKind): StdoutLogKind =
  if stdoutKind == StdoutLogKind.Auto:
    if isatty(stdout):
      # On a TTY, let's be fancy
      StdoutLogKind.Colors
    else:
      # When there's no TTY, we output no colors because this matches what
      # released binaries were doing before auto-detection was around and
      # looks decent in systemd-captured journals.
      StdoutLogKind.NoColors
  else:
    stdoutKind

when defaultChroniclesStream.outputs.type.arity == 2:
  from std/os import splitFile
  from "."/filepath import secureCreatePath

proc setupFileLimits*() =
  when not defined(windows):
    # In addition to databases and sockets, we need a file descriptor for every
    # validator - setting it to 16k should provide sufficient margin
    let
      limit = getMaxOpenFiles2().valueOr(16384)

    if limit < 16384:
      setMaxOpenFiles2(16384).isOkOr:
        warn "Cannot increase open file limit", err = osErrorMsg(error)

proc setupLogging*(
    logLevel: string, stdoutKind: StdoutLogKind, logFile: Option[OutFile]) =
  # In the cfg file for nimbus, we create two formats: textlines and json.
  # Here, we either write those logs to an output, or not, depending on the
  # given configuration.
  # Arguably, if we don't use a format, chronicles should not create it.

  when defaultChroniclesStream.outputs.type.arity != 2:
    warn "Logging configuration options not enabled in the current build"
  else:
    # Naive approach where chronicles will form a string and we will discard
    # it, even if it could have skipped the formatting phase

    proc noOutput(logLevel: LogLevel, msg: LogOutputStr) = discard
    proc writeAndFlush(f: File, msg: LogOutputStr) =
      try:
        f.write(msg)
        f.flushFile()
      except IOError as err:
        logLoggingFailure(cstring(msg), err)

    proc stdoutFlush(logLevel: LogLevel, msg: LogOutputStr) =
      writeAndFlush(stdout, msg)

    proc noColorsFlush(logLevel: LogLevel, msg: LogOutputStr) =
      writeAndFlush(stdout, stripAnsi(msg))

    let fileWriter =
      if logFile.isSome():
        let
          logFile = logFile.get.string
          logFileDir = splitFile(logFile).dir
          lres = secureCreatePath(logFileDir)
        if lres.isOk():
          try:
            let
              f = open(logFile, fmAppend)
              x = proc(logLevel: LogLevel, msg: LogOutputStr) =
                writeAndFlush(f, msg) # will close when program terminates
            x
          except CatchableError as exc:
            error "Failed to create log file", logFile, msg = exc.msg
            noOutput
        else:
          error "Failed to create directory for log file",
                path = logFileDir, err = ioErrorMsg(lres.error)
          noOutput
    else:
      noOutput

    defaultChroniclesStream.outputs[1].writer = fileWriter

    let tmp = detectTTY(stdoutKind)

    case tmp
    of StdoutLogKind.Auto: raiseAssert "checked above"
    of StdoutLogKind.Colors:
      defaultChroniclesStream.outputs[0].writer = stdoutFlush
    of StdoutLogKind.NoColors:
      defaultChroniclesStream.outputs[0].writer = noColorsFlush
    of StdoutLogKind.Json:
      defaultChroniclesStream.outputs[0].writer = noOutput

      let prevWriter = defaultChroniclesStream.outputs[1].writer
      defaultChroniclesStream.outputs[1].writer =
        proc(logLevel: LogLevel, msg: LogOutputStr) =
          stdoutFlush(logLevel, msg)
          prevWriter(logLevel, msg)
    of StdoutLogKind.None:
     defaultChroniclesStream.outputs[0].writer = noOutput

    if logFile.isSome():
      warn "The --log-file option is deprecated. Consider redirecting the standard output to a file instead"
  try:
    updateLogLevel(logLevel)
  except ValueError as err:
    try:
      stderr.write "Invalid value for --log-level. " & err.msg
    except IOError:
      echo "Invalid value for --log-level. " & err.msg
    quit 1

template makeBannerAndConfig*(clientId: string, ConfType: type): untyped =
  let
    version = clientId & "\p" & copyrights & "\p\p" &
      "eth2 specification v" & SPEC_VERSION & "\p\p" &
      nimBanner

  # TODO for some reason, copyrights are printed when doing `--help`
  {.push warning[ProveInit]: off.}
  let config = try:
    ConfType.load(
      version = version, # but a short version string makes more sense...
      copyrightBanner = clientId,
      secondarySources = proc (
          config: ConfType, sources: ref SecondarySources
      ) {.raises: [ConfigurationError].} =
        if config.configFile.isSome:
          sources.addConfigFile(Toml, config.configFile.get)
    )
  except CatchableError as err:
    # We need to log to stderr here, because logging hasn't been configured yet
    try:
      stderr.write "Failure while loading the configuration:\n"
      stderr.write err.msg
      stderr.write "\n"

      if err[] of ConfigurationError and
        err.parent != nil and
        err.parent[] of TomlFieldReadingError:
        let fieldName = ((ref TomlFieldReadingError)(err.parent)).field
        if fieldName in ["web3-url", "bootstrap-node",
                        "direct-peer", "validator-monitor-pubkey"]:
          stderr.write "Since the '" & fieldName & "' option is allowed to " &
                       "have more than one value, please make sure to supply " &
                       "a properly formatted TOML array\n"
    except IOError:
      discard
    quit 1
  {.pop.}
  config

proc sleepAsync*(t: TimeDiff): Future[void] =
  sleepAsync(nanoseconds(
    if t.nanoseconds < 0: 0'i64 else: t.nanoseconds))

proc runSlotLoop*[T](node: T, startTime: BeaconTime,
                     slotProc: SlotStartProc[T]) {.async.} =
  var
    curSlot = startTime.slotOrZero()
    nextSlot = curSlot + 1 # No earlier than GENESIS_SLOT + 1
    timeToNextSlot = nextSlot.start_beacon_time() - startTime

  while true:
    # Start by waiting for the time when the slot starts. Sleeping relinquishes
    # control to other tasks which may or may not finish within the alotted
    # time, so below, we need to be wary that the ship might have sailed
    # already.
    await sleepAsync(timeToNextSlot)

    let
      wallTime = node.beaconClock.now()
      wallSlot = wallTime.slotOrZero() # Always > GENESIS!

    if wallSlot < nextSlot:
      # While we were sleeping, the system clock changed and time moved
      # backwards!
      if wallSlot + 1 < nextSlot:
        return

      # cur & next slot remain the same
      timeToNextSlot = nextSlot.start_beacon_time() - wallTime
      continue

    if wallSlot > nextSlot + SLOTS_PER_EPOCH:
      curSlot = wallSlot - SLOTS_PER_EPOCH

    let breakLoop = await slotProc(node, wallTime, curSlot)
    if breakLoop:
      break

    curSlot = wallSlot
    nextSlot = wallSlot + 1
    timeToNextSlot = nextSlot.start_beacon_time() - node.beaconClock.now()