# beacon_chain
# Copyright (c) 2022 Status Research & Development GmbH
# Licensed and distributed under either of
#   * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
#   * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
# at your option. This file may not be copied, modified, or distributed except according to those terms.

# https://notes.ethereum.org/@9AeMAlpyQYaAAyuj47BzRw/rkwW3ceVY
# Monitor traffic: socat -v TCP-LISTEN:9550,fork TCP-CONNECT:127.0.0.1:8550

import
  std/options,
  stew/results,
  chronos,
  ../beacon_chain/eth1/eth1_monitor

from nimcrypto/utils import fromHex
from web3/engine_api_types import PayloadExecutionStatus
from ../beacon_chain/networking/network_metadata import Eth1Network
from ../beacon_chain/spec/datatypes/base import ZERO_HASH
from ../beacon_chain/spec/presets import Eth1Address, defaultRuntimeConfig

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

# TODO hm, actually factor this out into a callable function
# and have a version with the result of the JWT secret slurp for testing purposes
proc readJwtSecret(jwtSecretFile: string): Result[seq[byte], cstring] =
  # https://github.com/ethereum/execution-apis/blob/v1.0.0-alpha.9/src/engine/authentication.md#key-distribution
  # If such a parameter is given, but the file cannot be read, or does not
  # contain a hex-encoded key of at least 256 bits, the client should treat
  # this as an error: either abort the startup, or show error and continue
  # without exposing the authenticated port.
  const MIN_SECRET_LEN = 32

  try:
    let lines = readLines(jwtSecretFile, 1)
    if lines.len > 0:
      # Secret JWT key is parsed in constant time using nimcrypto:
      # https://github.com/cheatfate/nimcrypto/pull/44
      let secret = utils.fromHex(lines[0])
      if secret.len >= MIN_SECRET_LEN:
        ok(secret)
      else:
        err("JWT secret not at least 256 bits")
    else:
      err("JWT secret file empty")
  except IOError as exc:
    err("JWT secret file could not be read from")

const
  feeRecipient =
    Eth1Address.fromHex("0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b")
  web3Url = "http://127.0.0.1:8551"

proc run() {.async.} =
  let
    jwtSecret = some readJwtSecret("jwt.hex").get
    eth1Monitor = Eth1Monitor.init(
      defaultRuntimeConfig, db = nil, nil, @[web3Url],
      none(DepositContractSnapshot), none(Eth1Network), false, jwtSecret)
    web3Provider = (await Web3DataProvider.new(
      default(Eth1Address), web3Url, jwtSecret)).get

  const feeRecipient =
    Eth1Address.fromHex("0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b")
  let
    existingBlock = await web3Provider.getBlockByNumber(0)
  await eth1Monitor.ensureDataProvider()
  let
    payloadId = await eth1Monitor.forkchoiceUpdated(
      existingBlock.hash.asEth2Digest,
      existingBlock.hash.asEth2Digest,
      existingBlock.timestamp.uint64 + 12,
      ZERO_HASH.data,  # Random
      feeRecipient)
    payload =         await eth1Monitor.getPayload(
      array[8, byte] (payloadId.payloadId.get))
    payloadStatus =   await eth1Monitor.newPayload(payload)
    fcupdatedStatus = await eth1Monitor.forkchoiceUpdated(
      payload.blockHash.asEth2Digest,
      payload.blockHash.asEth2Digest,
      existingBlock.timestamp.uint64 + 24,
      ZERO_HASH.data,  # Random
      feeRecipient)

    payload2 =         await eth1Monitor.getPayload(
      array[8, byte] (fcupdatedStatus.payloadId.get))
    payloadStatus2 =   await eth1Monitor.newPayload(payload2)
    fcupdatedStatus2 = await eth1Monitor.forkchoiceUpdated(
      payload2.blockHash.asEth2Digest,
      payload2.blockHash.asEth2Digest,
      existingBlock.timestamp.uint64 + 36,
      ZERO_HASH.data,  # Random
      feeRecipient)

  doAssert payloadStatus.status == PayloadExecutionStatus.valid
  doAssert fcupdatedStatus.payloadStatus.status == PayloadExecutionStatus.valid
  doAssert payloadStatus2.status == PayloadExecutionStatus.valid
  doAssert fcupdatedStatus2.payloadStatus.status == PayloadExecutionStatus.valid

waitFor run()