import { assert } from "chai"
import { EventHandler } from "../../src/keeper/EventHandler"
import { ContractEventSubscription } from "../../src/keeper/ContractEvent"
import { Ocean } from "../../src/ocean/Ocean"
import config from "../config"
import TestContractHandler from "./TestContractHandler"

describe("ContractEvent", () => {

    let ocean: Ocean
    let account: string
    let eventHandler: EventHandler
    let executeTransaction: () => Promise<any>

    beforeEach(async () => {
        await TestContractHandler.prepareContracts()
        ocean = await Ocean.getInstance(config)
        eventHandler = new EventHandler((<any>ocean).instanceConfig)
        account = (await ocean.accounts.list())[0].getId()

        executeTransaction = () => ocean.keeper.dispenser.requestTokens(10, account)
    })

    describe("#subscribe()", () => {
        it("should listen the events", async () => {
            const event = eventHandler.getEvent(ocean.keeper.token, "Transfer", {to: account})
            let validResolve = false
            let subscription: ContractEventSubscription

            const waitUntilEvent = new Promise(resolve => {
                subscription = event.subscribe(events => {
                    assert.isDefined(events)
                    assert.lengthOf(events, 2)
                    if (validResolve) {
                        resolve()
                    }
                })
            })

            await Promise.all([
                executeTransaction(),
                executeTransaction(),
            ])

            await new Promise(_ => setTimeout(_, 2000))
            validResolve = true

            await Promise.all([
                executeTransaction(),
                executeTransaction(),
            ])

            await waitUntilEvent

            subscription.unsubscribe()
        })
    })

    describe("#once()", () => {
        it("should listen only once", async () => {
            const to = account
            const event = eventHandler.getEvent(ocean.keeper.token, "Transfer", {to})
            let canBeRejected = false

            const waitUntilEvent = new Promise((resolve, reject) => {
                event.once(events => {
                    if (canBeRejected) {
                        reject()
                    }
                    setTimeout(resolve, 600)
                })
            })

            await executeTransaction()

            await new Promise(_ => setTimeout(_, 2000))
            canBeRejected = true

            await executeTransaction()

            await waitUntilEvent
        })

        it("should get the event like a promise", async () => {
            const to = account
            const event = eventHandler.getEvent(ocean.keeper.token, "Transfer", {to})

            const waitUntilEvent = event.once()

            await new Promise(_ => setTimeout(_, 400))

            await executeTransaction()

            await waitUntilEvent
        })
    })
})