nim-codex/dagger/sales.nim

151 lines
4.4 KiB
Nim

import std/times
import std/sequtils
import pkg/questionable
import pkg/upraises
import pkg/stint
import pkg/nimcrypto
import ./market
export stint
const DefaultOfferExpiryInterval = (10 * 60).u256
type
Sales* = ref object
market: Market
subscription: ?Subscription
available*: seq[Availability]
offerExpiryInterval*: UInt256
onSale: ?OnSale
Availability* = object
id*: array[32, byte]
size*: uint64
duration*: uint64
minPrice*: UInt256
Negotiation = ref object
sales: Sales
requestId: array[32, byte]
ask: StorageAsk
availability: Availability
offer: ?StorageOffer
subscription: ?Subscription
waiting: ?Future[void]
finished: bool
OnSale = proc(offer: StorageOffer) {.gcsafe, upraises: [].}
func new*(_: type Sales, market: Market): Sales =
Sales(market: market, offerExpiryInterval: DefaultOfferExpiryInterval)
proc init*(_: type Availability,
size: uint64,
duration: uint64,
minPrice: UInt256): Availability =
var id: array[32, byte]
doAssert randomBytes(id) == 32
Availability(id: id, size: size, duration: duration, minPrice: minPrice)
proc `onSale=`*(sales: Sales, callback: OnSale) =
sales.onSale = some callback
func add*(sales: Sales, availability: Availability) =
sales.available.add(availability)
func remove*(sales: Sales, availability: Availability) =
sales.available.keepItIf(it != availability)
func findAvailability(sales: Sales, ask: StorageAsk): ?Availability =
for availability in sales.available:
if ask.size <= availability.size.u256 and
ask.duration <= availability.duration.u256 and
ask.maxPrice >= availability.minPrice:
return some availability
proc createOffer(negotiation: Negotiation): StorageOffer =
StorageOffer(
requestId: negotiation.requestId,
price: negotiation.ask.maxPrice,
expiry: getTime().toUnix().u256 + negotiation.sales.offerExpiryInterval
)
proc sendOffer(negotiation: Negotiation) {.async.} =
let offer = negotiation.createOffer()
negotiation.offer = some await negotiation.sales.market.offerStorage(offer)
proc finish(negotiation: Negotiation, success: bool) =
if negotiation.finished:
return
negotiation.finished = true
if subscription =? negotiation.subscription:
asyncSpawn subscription.unsubscribe()
if waiting =? negotiation.waiting:
waiting.cancel()
if success and offer =? negotiation.offer:
if onSale =? negotiation.sales.onSale:
onSale(offer)
else:
negotiation.sales.add(negotiation.availability)
proc onSelect(negotiation: Negotiation, offerId: array[32, byte]) =
if offer =? negotiation.offer and offer.id == offerId:
negotiation.finish(success = true)
else:
negotiation.finish(success = false)
proc subscribeSelect(negotiation: Negotiation) {.async.} =
without offer =? negotiation.offer:
return
proc onSelect(offerId: array[32, byte]) {.gcsafe, upraises:[].} =
negotiation.onSelect(offerId)
let market = negotiation.sales.market
let subscription = await market.subscribeSelection(offer.requestId, onSelect)
negotiation.subscription = some subscription
proc waitForExpiry(negotiation: Negotiation) {.async.} =
without offer =? negotiation.offer:
return
await negotiation.sales.market.waitUntil(offer.expiry)
negotiation.finish(success = false)
proc start(negotiation: Negotiation) {.async.} =
let sales = negotiation.sales
let availability = negotiation.availability
sales.remove(availability)
await negotiation.sendOffer()
await negotiation.subscribeSelect()
negotiation.waiting = some negotiation.waitForExpiry()
proc handleRequest(sales: Sales,
requestId: array[32, byte],
ask: StorageAsk) {.async.} =
without availability =? sales.findAvailability(ask):
return
let negotiation = Negotiation(
sales: sales,
requestId: requestId,
ask: ask,
availability: availability
)
asyncSpawn negotiation.start()
proc start*(sales: Sales) =
doAssert sales.subscription.isNone, "Sales already started"
proc onRequest(requestId: array[32, byte], ask: StorageAsk) {.gcsafe, upraises:[].} =
asyncSpawn sales.handleRequest(requestId, ask)
proc subscribe {.async.} =
sales.subscription = some await sales.market.subscribeRequests(onRequest)
asyncSpawn subscribe()
proc stop*(sales: Sales) =
if subscription =? sales.subscription:
asyncSpawn subscription.unsubscribe()
sales.subscription = Subscription.none