status-desktop/ui/app/AppLayouts/Wallet/services/dapps/DAppsRequestHandler.qml

import QtQuick 2.15

import AppLayouts.Wallet.services.dapps 1.0
import AppLayouts.Wallet.services.dapps.types 1.0
import AppLayouts.Wallet.stores 1.0 as WalletStore

import StatusQ.Core.Utils 0.1 as SQUtils

import shared.stores 1.0
import utils 1.0

import "types"

SQUtils.QObject {
    id: root

    required property WalletConnectSDKBase sdk
    required property DAppsStore store
    required property var accountsModel
    required property var networksModel
    required property CurrenciesStore currenciesStore
    required property WalletStore.WalletAssetsStore assetsStore

    property alias requestsModel: requests

    function rejectSessionRequest(topic, id, hasError) {
        sdk.rejectSessionRequest(topic, id, hasError)
    }

    /// Beware, it will fail if called multiple times before getting an answer
    function authenticate(topic, id, address, payload) {
        return store.authenticateUser(topic, id, address, payload)
    }

    signal sessionRequest(string id)
    /*type - maps to Constants.ephemeralNotificationType*/
    signal displayToastMessage(string message, int type)

    Connections {
        target: sdk

        function onSessionRequestEvent(event) {
            const res = d.resolveAsync(event)
            if (res.code == d.resolveAsyncResult.error) {
                let error = true
                sdk.rejectSessionRequest(event.topic, event.id, error)
                return
            }
            if (res.code == d.resolveAsyncResult.ignored) {
                return
            }
            if (!res.obj) {
                console.error("Unexpected res.obj value!")
                return
            }
            requests.enqueue(res.obj)
        }

        function onSessionRequestUserAnswerResult(topic, id, accept, error) {
            let request = requests.findRequest(topic, id)
            if (request === null) {
                console.error("Error finding event for topic", topic, "id", id)
                return
            }

            let methodStr = SessionRequest.methodToUserString(request.method)
            if (!methodStr) {
                console.error("Error finding user string for method", request.method)
                return
            }

            const appUrl = request.dappUrl
            const appDomain = SQUtils.StringUtils.extractDomainFromLink(appUrl)
            const requestExpired = request.isExpired()

            requests.removeRequest(topic, id)

            if (error) {
                root.displayToastMessage(qsTr("Fail to %1 from %2").arg(methodStr).arg(appDomain), Constants.ephemeralNotificationType.danger)
                root.rejectSessionRequest(topic, id, true /*hasError*/)
                console.error(`Error accepting session request for topic: ${topic}, id: ${id}, accept: ${accept}, error: ${error}`)
                return
            }

            if (!requestExpired) {
                let actionStr = accept ? qsTr("accepted") : qsTr("rejected")
                root.displayToastMessage("%1 %2 %3".arg(appDomain).arg(methodStr).arg(actionStr), Constants.ephemeralNotificationType.success)
                return
            }

            root.displayToastMessage("%1 sign request timed out".arg(appDomain), Constants.ephemeralNotificationType.normal)
        }

        function onSessionRequestExpired(sessionId) {
            // Expired event coming from WC
            // Handling as a failsafe in case the event is not processed by the SDK
            let request = requests.findById(sessionId)
            if (request === null) {
                console.error("Error finding event for session id", sessionId)
                return
            }

            if (request.isExpired()) {
                return //nothing to do. The request is already expired
            }

            request.setExpired()
        }
    }

    Connections {
        target: root.store

        function onUserAuthenticated(topic, id, password, pin, payload) {
            var request = requests.findRequest(topic, id)
            if (request === null) {
                console.error("Error finding event for topic", topic, "id", id)
                return
            }
            if (request.isExpired()) {
                console.warn("Error: request expired")
                root.rejectSessionRequest(topic, id, true /*hasError*/)
                return
            }

            d.executeSessionRequest(request, password, pin, payload)
        }

        function onUserAuthenticationFailed(topic, id) {
            let request = requests.findRequest(topic, id)
            let methodStr = SessionRequest.methodToUserString(request.method)
            if (request === null || !methodStr) {
                return
            }

            if (request.isExpired()) {
                console.warn("Error: request expired")
                root.rejectSessionRequest(topic, id, true /*hasError*/)
                return
            }

            const appDomain = SQUtils.StringUtils.extractDomainFromLink(request.dappUrl)
            root.displayToastMessage(qsTr("Failed to authenticate %1 from %2").arg(methodStr).arg(appDomain), Constants.ephemeralNotificationType.danger)
            root.rejectSessionRequest(topic, id, true /*hasError*/)
        }

        function onSigningResult(topic, id, data) {
            let hasErrors = (data == "")
            if (!hasErrors) {
                // acceptSessionRequest will trigger an sdk.sessionRequestUserAnswerResult signal
                sdk.acceptSessionRequest(topic, id, data)
            } else {
                root.rejectSessionRequest(topic, id, hasErrors)
            }
        }
    }

    SQUtils.QObject {
        id: d

        readonly property QtObject resolveAsyncResult: QtObject {
            readonly property int error: 0
            readonly property int ok: 1
            readonly property int ignored: 2
        }

        // returns {
        //   obj: obj or nil
        //   code: resolveAsyncResult codes
        // }
        function resolveAsync(event) {
            const method = event.params.request.method
            const { accountAddress, success } = lookupAccountFromEvent(event, method)
            if(!success) {
                console.info("Error finding accountAddress for event", JSON.stringify(event))
                return { obj: null, code: resolveAsyncResult.error }
            }

            if (!accountAddress) {
                console.info("Account not found for event", JSON.stringify(event))
                return { obj: null, code: resolveAsyncResult.ignored }
            }

            let chainId = lookupNetworkFromEvent(event, method)
            if(!chainId) {
                console.error("Error finding chainId for event", JSON.stringify(event))
                return { obj: null, code: resolveAsyncResult.error }
            }

            const data = extractMethodData(event, method)
            if(!data) {
                console.error("Error in event data lookup", JSON.stringify(event))
                return { obj: null, code: resolveAsyncResult.error }
            }

            const interpreted = d.prepareData(method, data)

            const enoughFunds = !d.isTransactionMethod(method)
            const requestExpiry = event.params.request.expiryTimestamp

            let obj = sessionRequestComponent.createObject(null, {
                event,
                topic: event.topic,
                id: event.id,
                method,
                accountAddress,
                chainId,
                data,
                preparedData: interpreted.preparedData,
                maxFeesText: "?",
                maxFeesEthText: "?",
                enoughFunds: enoughFunds,
                expirationTimestamp: requestExpiry
            })
            if (obj === null) {
                console.error("Error creating SessionRequestResolved for event")
                return { obj: null, code: resolveAsyncResult.error }
            }

            // Check later to have a valid request object
            if (!SessionRequest.getSupportedMethods().includes(method)) {
                console.error("Unsupported method", method)
                return { obj: null, code: resolveAsyncResult.error }
            }

            d.lookupSession(obj.topic, function(session) {
                if (session === null) {
                    console.error("DAppsRequestHandler.lookupSession: error finding session for topic", obj.topic)
                    return
                }

                obj.resolveDappInfoFromSession(session)
                root.sessionRequest(obj.id)

                if (!d.isTransactionMethod(method)) {
                    return
                }

                obj.estimatedTimeCategory = getEstimatedTimeInterval(data, method, obj.chainId)

                const mainNet = lookupMainnetNetwork()
                let mainChainId = obj.chainId
                if (!!mainNet) {
                    mainChainId = mainNet.chainId
                } else {
                    console.error("Error finding mainnet network")
                }

                let st = getEstimatedFeesStatus(data, method, obj.chainId, mainChainId)
                let fundsStatus = checkFundsStatus(st.feesInfo.maxFees, st.feesInfo.l1GasFee, obj.accountAddress, obj.chainId, mainNet.chainId, interpreted.value)
                obj.fiatMaxFees = st.fiatMaxFees
                obj.ethMaxFees = st.maxFeesEth
                obj.haveEnoughFunds = fundsStatus.haveEnoughFunds
                obj.haveEnoughFees = fundsStatus.haveEnoughForFees
                obj.feesInfo = st.feesInfo
            })

            return {
                obj: obj,
                code: resolveAsyncResult.ok
            }
        }

        /// returns {
        ///   accountAddress
        ///   success
        /// }
        /// if account is null and success is true it means that the account was not found
        function lookupAccountFromEvent(event, method) {
            let address = ""
            if (method === SessionRequest.methods.personalSign.name) {
                if (event.params.request.params.length < 2) {
                    return { accountAddress: "", success: false }
                }
                address = event.params.request.params[1]
            } else if (method === SessionRequest.methods.sign.name) {
                if (event.params.request.params.length === 1) {
                    return { accountAddress: "", success: false }
                }
                address = event.params.request.params[0]
            } else if(method === SessionRequest.methods.signTypedData_v4.name ||
                      method === SessionRequest.methods.signTypedData.name)
            {
                if (event.params.request.params.length < 2) {
                    return { accountAddress: "", success: false }
                }
                address = event.params.request.params[0]
            } else if (d.isTransactionMethod(method)) {
                if (event.params.request.params.length == 0) {
                    return { accountAddress: "", success: false }
                }
                address = event.params.request.params[0].from
            } else {
                console.error("Unsupported method to lookup account: ", method)
                return { accountAddress: "", success: false }
            }
            const account = SQUtils.ModelUtils.getFirstModelEntryIf(root.accountsModel, (account) => {
                return account.address.toLowerCase() === address.toLowerCase();
            })

            if (!account) {
                return { accountAddress: "", success: true }
            }

            return { accountAddress: account.address, success: true }
        }

        /// Returns null if the network is not found
        function lookupNetworkFromEvent(event, method) {
            if (SessionRequest.getSupportedMethods().includes(method) === false) {
                return null
            }
            const chainId = DAppsHelpers.chainIdFromEip155(event.params.chainId)
            const network = SQUtils.ModelUtils.getByKey(root.networksModel, "chainId", chainId)

            if (!network) {
                return null
            }

            return network.chainId
        }

        /// Returns null if the network is not found
        function lookupMainnetNetwork() {
            return SQUtils.ModelUtils.getByKey(root.networksModel, "layer", 1)
        }

        function extractMethodData(event, method) {
            if (method === SessionRequest.methods.personalSign.name ||
                method === SessionRequest.methods.sign.name)
            {
                if (event.params.request.params.length < 1) {
                    return null
                }
                let message = ""
                const messageIndex = (method === SessionRequest.methods.personalSign.name ? 0 : 1)
                const messageParam = event.params.request.params[messageIndex]
                // There is no standard on how data is encoded. Therefore we support hex or utf8
                if (DAppsHelpers.isHex(messageParam)) {
                    message = DAppsHelpers.hexToString(messageParam)
                } else {
                    message = messageParam
                }
                return SessionRequest.methods.personalSign.buildDataObject(message)
            } else if (method === SessionRequest.methods.signTypedData_v4.name ||
                       method === SessionRequest.methods.signTypedData.name)
            {
                if (event.params.request.params.length < 2) {
                    return null
                }
                const jsonMessage = event.params.request.params[1]
                const methodObj = method === SessionRequest.methods.signTypedData_v4.name
                      ? SessionRequest.methods.signTypedData_v4
                      : SessionRequest.methods.signTypedData
                return methodObj.buildDataObject(jsonMessage)
            } else if (method === SessionRequest.methods.signTransaction.name) {
                if (event.params.request.params.length == 0) {
                    return null
                }
                const tx = event.params.request.params[0]
                return SessionRequest.methods.signTransaction.buildDataObject(tx)
            } else if (method === SessionRequest.methods.sendTransaction.name) {
                if (event.params.request.params.length == 0) {
                    return null
                }
                const tx = event.params.request.params[0]
                return SessionRequest.methods.sendTransaction.buildDataObject(tx)
            } else {
                return null
            }
        }

        function lookupSession(topicToLookup, callback) {
            sdk.getActiveSessions((res) => {
                Object.keys(res).forEach((topic) => {
                    if (topic === topicToLookup) {
                        let session = res[topic]
                        callback(session)
                    }
                })
            })
        }

        function executeSessionRequest(request, password, pin, payload) {
            if (!SessionRequest.getSupportedMethods().includes(request.method)) {
                console.error("Unsupported method to execute: ", request.method)
                return
            }

            if (password === "") {
                console.error("No password provided to sign message")
                return
            }

            if (request.method === SessionRequest.methods.sign.name) {
                store.signMessageUnsafe(request.topic,
                                        request.id,
                                        request.accountAddress,
                                        SessionRequest.methods.personalSign.getMessageFromData(request.data),
                                        password,
                                        pin)
            } else if (request.method === SessionRequest.methods.personalSign.name) {
                store.signMessage(request.topic,
                                  request.id,
                                  request.accountAddress,
                                  SessionRequest.methods.personalSign.getMessageFromData(request.data),
                                  password,
                                  pin)
            } else if (request.method === SessionRequest.methods.signTypedData_v4.name ||
                       request.method === SessionRequest.methods.signTypedData.name)
            {
                let legacy = request.method === SessionRequest.methods.signTypedData.name
                store.safeSignTypedData(request.topic,
                                        request.id,
                                        request.accountAddress,
                                        SessionRequest.methods.signTypedData.getMessageFromData(request.data),
                                        request.chainId,
                                        legacy,
                                        password,
                                        pin)
            } else if (d.isTransactionMethod(request.method)) {
                let txObj = d.getTxObject(request.method, request.data)
                if (!!payload) {
                    let feesInfoJson = payload
                    let hexFeesJson = root.store.convertFeesInfoToHex(feesInfoJson)
                    if (!!hexFeesJson) {
                        let feesInfo = JSON.parse(hexFeesJson)
                        if (feesInfo.maxFeePerGas) {
                            txObj.maxFeePerGas = feesInfo.maxFeePerGas
                        }
                        if (feesInfo.maxPriorityFeePerGas) {
                            txObj.maxPriorityFeePerGas = feesInfo.maxPriorityFeePerGas
                        }
                    }
                    delete txObj.gasLimit
                    delete txObj.gasPrice
                }
                // Remove nonce from txObj to be auto-filled by the wallet
                delete txObj.nonce

                if (request.method === SessionRequest.methods.signTransaction.name) {
                    store.signTransaction(request.topic,
                                          request.id,
                                          request.accountAddress,
                                          request.chainId,
                                          txObj,
                                          password,
                                          pin)
                } else if (request.method === SessionRequest.methods.sendTransaction.name) {
                    store.sendTransaction(
                                request.topic,
                                request.id,
                                request.accountAddress,
                                request.chainId,
                                txObj,
                                password,
                                pin)
                }
            }
        }

        // Returns Constants.TransactionEstimatedTime
        function getEstimatedTimeInterval(data, method, chainId) {
            let tx = {}
            let maxFeePerGas = ""
            if (d.isTransactionMethod(method)) {
                tx = d.getTxObject(method, data)
                // Empty string instructs getEstimatedTime to fetch the blockchain value
                if (!!tx.maxFeePerGas) {
                    maxFeePerGas = tx.maxFeePerGas
                } else if (!!tx.gasPrice) {
                    maxFeePerGas = tx.gasPrice
                }
            }

            return root.store.getEstimatedTime(chainId, maxFeePerGas)
        }

        // Returns {
        //      maxFees -> Big number in Gwei
        //      maxFeePerGas
        //      maxPriorityFeePerGas
        //      gasPrice
        // }
        function getEstimatedMaxFees(data, method, chainId, mainNetChainId) {
            let tx = {}
            if (d.isTransactionMethod(method)) {
                tx = d.getTxObject(method, data)
            }

            let BigOps = SQUtils.AmountsArithmetic
            let gasLimit = BigOps.fromString("21000")
            let gasPrice, maxFeePerGas, maxPriorityFeePerGas
            let l1GasFee = BigOps.fromNumber(0)

            // Beware, the tx values are standard blockchain hex big number values; the fees values are nim's float64 values, hence the complex conversions
            if (!!tx.maxFeePerGas && !!tx.maxPriorityFeePerGas) {
                maxFeePerGas = hexToGwei(tx.maxFeePerGas)
                maxPriorityFeePerGas = hexToGwei(tx.maxPriorityFeePerGas)

                // TODO: check why we need to set gasPrice here and why if it's not checked we cannot send the tx and fees are unknown????
                gasPrice = hexToGwei(tx.maxFeePerGas)
            } else {
                let fees = root.store.getSuggestedFees(chainId)
                maxPriorityFeePerGas = fees.maxPriorityFeePerGas
                if (fees.eip1559Enabled) {
                    if (!!fees.maxFeePerGasM) {
                        gasPrice = BigOps.fromNumber(fees.maxFeePerGasM)
                        maxFeePerGas = fees.maxFeePerGasM
                    } else if(!!tx.maxFeePerGas) {
                        let maxFeePerGasDec = root.store.hexToDec(tx.maxFeePerGas)
                        gasPrice = BigOps.fromString(maxFeePerGasDec)
                        maxFeePerGas = maxFeePerGasDec
                    } else {
                        console.error("Error fetching maxFeePerGas from fees or tx objects")
                        return
                    }
                } else {
                    if (!!fees.gasPrice) {
                        gasPrice = BigOps.fromNumber(fees.gasPrice)
                    } else {
                        console.error("Error fetching suggested fees")
                        return
                    }
                }
                l1GasFee = BigOps.fromNumber(fees.l1GasFee)
            }

            let maxFees = BigOps.times(gasLimit, gasPrice)
            return {maxFees, maxFeePerGas, maxPriorityFeePerGas, gasPrice, l1GasFee}
        }

        // Returned values are Big numbers
        function getEstimatedFeesStatus(data, method, chainId, mainNetChainId) {
            let BigOps = SQUtils.AmountsArithmetic

            let feesInfo = getEstimatedMaxFees(data, method, chainId, mainNetChainId)

            let totalMaxFees = BigOps.sum(feesInfo.maxFees, feesInfo.l1GasFee)
            let maxFeesEth = BigOps.div(totalMaxFees, BigOps.fromNumber(1, 9))

            let maxFeesEthStr = maxFeesEth.toString()
            let fiatMaxFeesStr = root.currenciesStore.getFiatValue(maxFeesEthStr, Constants.ethToken)
            let fiatMaxFees = BigOps.fromString(fiatMaxFeesStr)
            let symbol = root.currenciesStore.currentCurrency

            return {fiatMaxFees, maxFeesEth, symbol, feesInfo}
        }

        function getBalanceInEth(balances, address, chainId) {
            const BigOps = SQUtils.AmountsArithmetic
            let accEth = SQUtils.ModelUtils.getFirstModelEntryIf(balances, (balance) => {
                return balance.account.toLowerCase() === address.toLowerCase() && balance.chainId == chainId
            })
            if (!accEth) {
                console.error("Error balance lookup for account ", address, " on chain ", chainId)
                return null
            }
            let accountFundsWei = BigOps.fromString(accEth.balance)
            return BigOps.div(accountFundsWei, BigOps.fromNumber(1, 18))
        }

        // Returns {haveEnoughForFees, haveEnoughFunds} and true in case of error not to block request
        function checkFundsStatus(maxFees, l1GasFee, address, chainId, mainNetChainId, valueEth) {
            let BigOps = SQUtils.AmountsArithmetic

            let haveEnoughForFees = true
            let haveEnoughFunds = true

            let token = SQUtils.ModelUtils.getByKey(root.assetsStore.groupedAccountAssetsModel, "tokensKey", Constants.ethToken)
            if (!token || !token.balances) {
                console.error("Error token balances lookup for ETH")
                return {haveEnoughForFees, haveEnoughFunds}
            }

            let chainBalance = getBalanceInEth(token.balances, address, chainId)
            if (!chainBalance) {
                console.error("Error fetching chain balance")
                return {haveEnoughForFees, haveEnoughFunds}
            }
            haveEnoughFunds = BigOps.cmp(chainBalance, valueEth) >= 0
            if (haveEnoughFunds) {
                chainBalance = BigOps.sub(chainBalance, valueEth)

                if (chainId == mainNetChainId) {
                    const finalFees = BigOps.sum(maxFees, l1GasFee)
                    let feesEth = BigOps.div(finalFees, BigOps.fromNumber(1, 9))
                    haveEnoughForFees = BigOps.cmp(chainBalance, feesEth) >= 0
                } else {
                    const feesChain = BigOps.div(maxFees, BigOps.fromNumber(1, 9))
                    const haveEnoughOnChain = BigOps.cmp(chainBalance, feesChain) >= 0

                    const mainBalance = getBalanceInEth(token.balances, address, mainNetChainId)
                    if (!mainBalance) {
                        console.error("Error fetching mainnet balance")
                        return {haveEnoughForFees, haveEnoughFunds}
                    }
                    const feesMain = BigOps.div(l1GasFee, BigOps.fromNumber(1, 9))
                    const haveEnoughOnMain = BigOps.cmp(mainBalance, feesMain) >= 0

                    haveEnoughForFees = haveEnoughOnChain && haveEnoughOnMain
                }
            } else {
                haveEnoughForFees = false
            }

            return {haveEnoughForFees, haveEnoughFunds}
        }

        function isTransactionMethod(method) {
            return method === SessionRequest.methods.signTransaction.name
                || method === SessionRequest.methods.sendTransaction.name
        }

        function getTxObject(method, data) {
            let tx
            if (method === SessionRequest.methods.signTransaction.name) {
                tx = SessionRequest.methods.signTransaction.getTxObjFromData(data)
            } else if (method === SessionRequest.methods.sendTransaction.name) {
                tx = SessionRequest.methods.sendTransaction.getTxObjFromData(data)
            } else {
                console.error("Not a transaction method")
            }
            return tx
        }

        // returns {
        //   preparedData,
        //   value // null or ETH Big number
        // }
        function prepareData(method, data) {
            let payload = null
            switch(method) {
                case SessionRequest.methods.personalSign.name: {
                    payload = SessionRequest.methods.personalSign.getMessageFromData(data)
                    break
                }
                case SessionRequest.methods.sign.name: {
                    payload = SessionRequest.methods.sign.getMessageFromData(data)
                    break
                }
                case SessionRequest.methods.signTypedData_v4.name: {
                    const stringPayload = SessionRequest.methods.signTypedData_v4.getMessageFromData(data)
                    payload = JSON.stringify(JSON.parse(stringPayload), null, 2)
                    break
                }
                case SessionRequest.methods.signTypedData.name: {
                    const stringPayload = SessionRequest.methods.signTypedData.getMessageFromData(data)
                    payload = JSON.stringify(JSON.parse(stringPayload), null, 2)
                    break
                }
                case SessionRequest.methods.signTransaction.name:
                case SessionRequest.methods.sendTransaction.name:
                    // For transactions we process the data in a different way as follows
                    break
                default:
                    console.error("Unhandled method", method)
                    break;
            }

            let value = SQUtils.AmountsArithmetic.fromNumber(0)
            if (d.isTransactionMethod(method)) {
                let txObj = d.getTxObject(method, data)
                let tx = Object.assign({}, txObj)
                if (tx.value) {
                    value = hexToEth(tx.value)
                    tx.value = value.toString()
                }
                if (tx.maxFeePerGas) {
                    tx.maxFeePerGas = hexToGwei(tx.maxFeePerGas).toString()
                }
                if (tx.maxPriorityFeePerGas) {
                    tx.maxPriorityFeePerGas = hexToGwei(tx.maxPriorityFeePerGas).toString()
                }
                if (tx.gasPrice) {
                    tx.gasPrice = hexToGwei(tx.gasPrice)
                }
                if (tx.gasLimit) {
                    tx.gasLimit = parseInt(root.store.hexToDec(tx.gasLimit))
                }
                if (tx.nonce) {
                    tx.nonce = parseInt(root.store.hexToDec(tx.nonce))
                }

                payload = JSON.stringify(tx, null, 2)
            }
            return {
                    preparedData: payload,
                    value: value
                }
        }

        function hexToEth(value) {
            return hexToEthDenomination(value, "eth")
        }
        function hexToGwei(value) {
            return hexToEthDenomination(value, "gwei")
        }
        function hexToEthDenomination(value, ethUnit) {
            let unitMapping = {
                "gwei": 9,
                "eth": 18
            }
            let BigOps = SQUtils.AmountsArithmetic
            let decValue = root.store.hexToDec(value)
            if (!!decValue) {
                return BigOps.div(BigOps.fromNumber(decValue), BigOps.fromNumber(1, unitMapping[ethUnit]))
            }
            return BigOps.fromNumber(0)
        }
    }

    /// The queue is used to ensure that the events are processed in the order they are received but they could be
    /// processed handled randomly on user intervention through activity center
    SessionRequestsModel {
        id: requests
    }

    Component {
        id: sessionRequestComponent

        SessionRequestResolved {
            sourceId: Constants.DAppConnectors.WalletConnect
        }
    }
}