import std/sequtils
import std/strutils
import std/sugar
import pkg/ethers
import pkg/upraises
import pkg/questionable
import ../utils/exceptions
import ../logutils
import ../market
import ./marketplace
import ./proofs

export market

logScope:
  topics = "marketplace onchain market"

type
  OnChainMarket* = ref object of Market
    contract: Marketplace
    signer: Signer
  MarketSubscription = market.Subscription
  EventSubscription = ethers.Subscription
  OnChainMarketSubscription = ref object of MarketSubscription
    eventSubscription: EventSubscription

func new*(_: type OnChainMarket, contract: Marketplace): OnChainMarket =
  without signer =? contract.signer:
    raiseAssert("Marketplace contract should have a signer")
  OnChainMarket(
    contract: contract,
    signer: signer,
  )

proc raiseMarketError(message: string) {.raises: [MarketError].} =
  raise newException(MarketError, message)

template convertEthersError(body) =
  try:
    body
  except EthersError as error:
    raiseMarketError(error.msgDetail)

proc approveFunds(market: OnChainMarket, amount: UInt256) {.async.} =
  debug "Approving tokens", amount
  convertEthersError:
    let tokenAddress = await market.contract.token()
    let token = Erc20Token.new(tokenAddress, market.signer)
    discard await token.increaseAllowance(market.contract.address(), amount).confirm(0)

method getZkeyHash*(market: OnChainMarket): Future[?string] {.async.} =
  let config = await market.contract.config()
  return some config.proofs.zkeyHash

method getSigner*(market: OnChainMarket): Future[Address] {.async.} =
  convertEthersError:
    return await market.signer.getAddress()

method periodicity*(market: OnChainMarket): Future[Periodicity] {.async.} =
  convertEthersError:
    let config = await market.contract.config()
    let period = config.proofs.period
    return Periodicity(seconds: period)

method proofTimeout*(market: OnChainMarket): Future[UInt256] {.async.} =
  convertEthersError:
    let config = await market.contract.config()
    return config.proofs.timeout

method proofDowntime*(market: OnChainMarket): Future[uint8] {.async.} =
  convertEthersError:
    let config = await market.contract.config()
    return config.proofs.downtime

method getPointer*(market: OnChainMarket, slotId: SlotId): Future[uint8] {.async.} =
  convertEthersError:
    let overrides = CallOverrides(blockTag: some BlockTag.pending)
    return await market.contract.getPointer(slotId, overrides)

method myRequests*(market: OnChainMarket): Future[seq[RequestId]] {.async.} =
  convertEthersError:
    return await market.contract.myRequests

method mySlots*(market: OnChainMarket): Future[seq[SlotId]] {.async.} =
  convertEthersError:
    let slots = await market.contract.mySlots()
    debug "Fetched my slots", numSlots=len(slots)

    return slots

method requestStorage(market: OnChainMarket, request: StorageRequest){.async.} =
  convertEthersError:
    debug "Requesting storage"
    await market.approveFunds(request.price())
    discard await market.contract.requestStorage(request).confirm(0)

method getRequest(market: OnChainMarket,
                  id: RequestId): Future[?StorageRequest] {.async.} =
  convertEthersError:
    try:
      return some await market.contract.getRequest(id)
    except ProviderError as e:
      if e.msgDetail.contains("Unknown request"):
        return none StorageRequest
      raise e

method requestState*(market: OnChainMarket,
                     requestId: RequestId): Future[?RequestState] {.async.} =
  convertEthersError:
    try:
      let overrides = CallOverrides(blockTag: some BlockTag.pending)
      return some await market.contract.requestState(requestId, overrides)
    except ProviderError as e:
      if e.msgDetail.contains("Unknown request"):
        return none RequestState
      raise e

method slotState*(market: OnChainMarket,
                  slotId: SlotId): Future[SlotState] {.async.} =
  convertEthersError:
    let overrides = CallOverrides(blockTag: some BlockTag.pending)
    return await market.contract.slotState(slotId, overrides)

method getRequestEnd*(market: OnChainMarket,
                      id: RequestId): Future[SecondsSince1970] {.async.} =
  convertEthersError:
    return await market.contract.requestEnd(id)

method requestExpiresAt*(market: OnChainMarket,
                      id: RequestId): Future[SecondsSince1970] {.async.} =
  convertEthersError:
    return await market.contract.requestExpiry(id)

method getHost(market: OnChainMarket,
               requestId: RequestId,
               slotIndex: UInt256): Future[?Address] {.async.} =
  convertEthersError:
    let slotId = slotId(requestId, slotIndex)
    let address = await market.contract.getHost(slotId)
    if address != Address.default:
      return some address
    else:
      return none Address

method getActiveSlot*(market: OnChainMarket,
                      slotId: SlotId): Future[?Slot] {.async.} =
  convertEthersError:
    try:
      return some await market.contract.getActiveSlot(slotId)
    except ProviderError as e:
      if e.msgDetail.contains("Slot is free"):
        return none Slot
      raise e

method fillSlot(market: OnChainMarket,
                requestId: RequestId,
                slotIndex: UInt256,
                proof: Groth16Proof,
                collateral: UInt256) {.async.} =
  convertEthersError:
    await market.approveFunds(collateral)
    discard await market.contract.fillSlot(requestId, slotIndex, proof).confirm(0)

method freeSlot*(market: OnChainMarket, slotId: SlotId) {.async.} =
  convertEthersError:
    discard await market.contract.freeSlot(slotId).confirm(0)

method withdrawFunds(market: OnChainMarket,
                     requestId: RequestId) {.async.} =
  convertEthersError:
    discard await market.contract.withdrawFunds(requestId).confirm(0)

method isProofRequired*(market: OnChainMarket,
                        id: SlotId): Future[bool] {.async.} =
  convertEthersError:
    try:
      let overrides = CallOverrides(blockTag: some BlockTag.pending)
      return await market.contract.isProofRequired(id, overrides)
    except ProviderError as e:
      if e.msgDetail.contains("Slot is free"):
        return false
      raise e

method willProofBeRequired*(market: OnChainMarket,
                            id: SlotId): Future[bool] {.async.} =
  convertEthersError:
    try:
      let overrides = CallOverrides(blockTag: some BlockTag.pending)
      return await market.contract.willProofBeRequired(id, overrides)
    except ProviderError as e:
      if e.msgDetail.contains("Slot is free"):
        return false
      raise e

method getChallenge*(market: OnChainMarket, id: SlotId): Future[ProofChallenge] {.async.} =
  convertEthersError:
    let overrides = CallOverrides(blockTag: some BlockTag.pending)
    return await market.contract.getChallenge(id, overrides)

method submitProof*(market: OnChainMarket,
                    id: SlotId,
                    proof: Groth16Proof) {.async.} =
  convertEthersError:
    discard await market.contract.submitProof(id, proof).confirm(0)

method markProofAsMissing*(market: OnChainMarket,
                           id: SlotId,
                           period: Period) {.async.} =
  convertEthersError:
    discard await market.contract.markProofAsMissing(id, period).confirm(0)

method canProofBeMarkedAsMissing*(
    market: OnChainMarket,
    id: SlotId,
    period: Period
): Future[bool] {.async.} =
  let provider = market.contract.provider
  let contractWithoutSigner = market.contract.connect(provider)
  let overrides = CallOverrides(blockTag: some BlockTag.pending)
  try:
    discard await contractWithoutSigner.markProofAsMissing(id, period, overrides)
    return true
  except EthersError as e:
    trace "Proof cannot be marked as missing", msg = e.msg
    return false

method subscribeRequests*(market: OnChainMarket,
                         callback: OnRequest):
                        Future[MarketSubscription] {.async.} =
  proc onEvent(event: StorageRequested) {.upraises:[].} =
    callback(event.requestId,
             event.ask,
             event.expiry)

  convertEthersError:
    let subscription = await market.contract.subscribe(StorageRequested, onEvent)
    return OnChainMarketSubscription(eventSubscription: subscription)

method subscribeSlotFilled*(market: OnChainMarket,
                            callback: OnSlotFilled):
                           Future[MarketSubscription] {.async.} =
  proc onEvent(event: SlotFilled) {.upraises:[].} =
    callback(event.requestId, event.slotIndex)

  convertEthersError:
    let subscription = await market.contract.subscribe(SlotFilled, onEvent)
    return OnChainMarketSubscription(eventSubscription: subscription)

method subscribeSlotFilled*(market: OnChainMarket,
                            requestId: RequestId,
                            slotIndex: UInt256,
                            callback: OnSlotFilled):
                           Future[MarketSubscription] {.async.} =
  proc onSlotFilled(eventRequestId: RequestId, eventSlotIndex: UInt256) =
    if eventRequestId == requestId and eventSlotIndex == slotIndex:
      callback(requestId, slotIndex)

  convertEthersError:
    return await market.subscribeSlotFilled(onSlotFilled)

method subscribeSlotFreed*(market: OnChainMarket,
                           callback: OnSlotFreed):
                          Future[MarketSubscription] {.async.} =
  proc onEvent(event: SlotFreed) {.upraises:[].} =
    callback(event.requestId, event.slotIndex)

  convertEthersError:
    let subscription = await market.contract.subscribe(SlotFreed, onEvent)
    return OnChainMarketSubscription(eventSubscription: subscription)

method subscribeFulfillment(market: OnChainMarket,
                            callback: OnFulfillment):
                           Future[MarketSubscription] {.async.} =
  proc onEvent(event: RequestFulfilled) {.upraises:[].} =
    callback(event.requestId)

  convertEthersError:
    let subscription = await market.contract.subscribe(RequestFulfilled, onEvent)
    return OnChainMarketSubscription(eventSubscription: subscription)

method subscribeFulfillment(market: OnChainMarket,
                            requestId: RequestId,
                            callback: OnFulfillment):
                           Future[MarketSubscription] {.async.} =
  proc onEvent(event: RequestFulfilled) {.upraises:[].} =
    if event.requestId == requestId:
      callback(event.requestId)

  convertEthersError:
    let subscription = await market.contract.subscribe(RequestFulfilled, onEvent)
    return OnChainMarketSubscription(eventSubscription: subscription)

method subscribeRequestCancelled*(market: OnChainMarket,
                                  callback: OnRequestCancelled):
                                Future[MarketSubscription] {.async.} =
  proc onEvent(event: RequestCancelled) {.upraises:[].} =
    callback(event.requestId)

  convertEthersError:
    let subscription = await market.contract.subscribe(RequestCancelled, onEvent)
    return OnChainMarketSubscription(eventSubscription: subscription)

method subscribeRequestCancelled*(market: OnChainMarket,
                                  requestId: RequestId,
                                  callback: OnRequestCancelled):
                                Future[MarketSubscription] {.async.} =
  proc onEvent(event: RequestCancelled) {.upraises:[].} =
    if event.requestId == requestId:
      callback(event.requestId)

  convertEthersError:
    let subscription = await market.contract.subscribe(RequestCancelled, onEvent)
    return OnChainMarketSubscription(eventSubscription: subscription)

method subscribeRequestFailed*(market: OnChainMarket,
                              callback: OnRequestFailed):
                            Future[MarketSubscription] {.async.} =
  proc onEvent(event: RequestFailed) {.upraises:[]} =
    callback(event.requestId)

  convertEthersError:
    let subscription = await market.contract.subscribe(RequestFailed, onEvent)
    return OnChainMarketSubscription(eventSubscription: subscription)

method subscribeRequestFailed*(market: OnChainMarket,
                              requestId: RequestId,
                              callback: OnRequestFailed):
                            Future[MarketSubscription] {.async.} =
  proc onEvent(event: RequestFailed) {.upraises:[]} =
    if event.requestId == requestId:
      callback(event.requestId)

  convertEthersError:
    let subscription = await market.contract.subscribe(RequestFailed, onEvent)
    return OnChainMarketSubscription(eventSubscription: subscription)

method subscribeProofSubmission*(market: OnChainMarket,
                                 callback: OnProofSubmitted):
                                Future[MarketSubscription] {.async.} =
  proc onEvent(event: ProofSubmitted) {.upraises: [].} =
    callback(event.id)

  convertEthersError:
    let subscription = await market.contract.subscribe(ProofSubmitted, onEvent)
    return OnChainMarketSubscription(eventSubscription: subscription)

method unsubscribe*(subscription: OnChainMarketSubscription) {.async.} =
  await subscription.eventSubscription.unsubscribe()

method queryPastStorageRequests*(market: OnChainMarket,
                                 blocksAgo: int):
                                Future[seq[PastStorageRequest]] {.async.} =
  convertEthersError:
    let contract = market.contract
    let provider = contract.provider

    let head = await provider.getBlockNumber()
    let fromBlock = BlockTag.init(head - blocksAgo.abs.u256)

    let events = await contract.queryFilter(StorageRequested,
                                            fromBlock,
                                            BlockTag.latest)
    return events.map(event =>
      PastStorageRequest(
        requestId: event.requestId,
        ask: event.ask,
        expiry: event.expiry
      )
    )