Loan due date using current block height

bobtimus/src/lib.rs

@@ -265,6 +265,8 @@ where
     /// We return the range of possible loan terms to the borrower.
     /// The borrower can then request a loan using parameters that are within our terms.
     pub async fn handle_loan_offer_request(&mut self) -> Result<LoanOffer> {
+        let current_height = self.elementsd.get_blockcount().await?;
+
         Ok(LoanOffer {
             rate: self.rate_service.latest_rate(),
             // TODO: Dynamic fee estimation
@@ -277,8 +279,9 @@ where
             max_ltv: dec!(0.8),
             // TODO: Dynamic interest based on current market values
             interest: vec![Interest {
+                // Absolute timelock calculated from current block height
                 // Assuming 1 min block interval, 43200 mins = 30 days
-                timelock: 43200,
+                timelock: current_height + 43200,
                 interest_rate: dec!(0.15),
             }],
         })

bobtimus/src/loan.rs

@@ -46,7 +46,7 @@ pub struct LoanOffer {
 #[derive(Debug, Clone, serde::Serialize)]
 pub struct Interest {
     /// Timelock in blocks
-    pub timelock: u64,
+    pub timelock: u32,
     /// Interest rate in percent
     pub interest_rate: Decimal,
 }

extension/src/background-proxy.ts

@@ -82,3 +82,8 @@ export async function getPastTransactions(): Promise<Txid[]> {
     // @ts-ignore
     return proxy.getPastTransactions();
 }
+
+export async function getBlockHeight(): Promise<number> {
+    // @ts-ignore
+    return proxy.getBlockHeight();
+}

extension/src/background/index.ts

@@ -9,6 +9,7 @@ import {
     extractTrade,
     getAddress,
     getBalances,
+    getBlockHeight,
     getOpenLoans,
     getPastTransactions,
     makeBuyCreateSwapPayload,
@@ -214,6 +215,11 @@ window.createWalletFromBip39 = async (seed_words: string, password: string) => {
     return createNewBip39Wallet(walletName, seed_words, password);
 };
 
+// @ts-ignore
+window.getBlockHeight = async () => {
+    return getBlockHeight();
+};
+
 function updateBadge() {
     let count = 0;
     if (loanToSign) count++;

extension/src/components/ConfirmLoan.tsx

@@ -1,11 +1,15 @@
-import { Box, Button, Flex, Heading, Image, Spacer, Text } from "@chakra-ui/react";
+import { Box, Button, Flex, Heading, Image, Spacer, Text, useInterval } from "@chakra-ui/react";
+import Debug from "debug";
+import moment from "moment";
 import React from "react";
 import { useAsync } from "react-async";
-import { signLoan } from "../background-proxy";
+import { getBlockHeight, signLoan } from "../background-proxy";
 import { LoanToSign, USDT_TICKER } from "../models";
 import YouSwapItem from "./SwapItem";
 import Usdt from "./tether.svg";
 
+const debug = Debug("confirmloan:error");
+
 interface ConfirmLoanProps {
     onCancel: (tabId: number) => void;
     onSuccess: () => void;
@@ -24,6 +28,22 @@ export default function ConfirmLoan(
 
     let { details: { collateral, principal, principalRepayment, term } } = loanToSign;
 
+    const blockHeightHook = useAsync({
+        promiseFn: getBlockHeight,
+        onReject: (e) => debug("Failed to fetch block height %s", e),
+    });
+    let { data: blockHeight, reload: reloadBlockHeight } = blockHeightHook;
+
+    useInterval(() => {
+        reloadBlockHeight();
+    }, 6000); // 1 min
+
+    // format the time nicely into something like : `in 13 hours` or `in 1 month`.
+    // block-height and loan-term are in "blocktime" ^= minutes
+    const deadline = blockHeight && term
+        ? moment().add(Math.abs(blockHeight - term), "minutes").fromNow()
+        : null;
+
     return (<Box>
         <form
             onSubmit={async e => {
@@ -64,7 +84,7 @@ export default function ConfirmLoan(
             <Box w="100%">
                 <Flex>
                     <Box h="40px" p="1">
-                        <Text>Loan term: {term}</Text>
+                        <Text>Loan term: {term} block-height {deadline ? "(due " + deadline + ")" : ""}</Text>
                     </Box>
                 </Flex>
             </Box>

extension/src/components/OpenLoans.tsx

@@ -1,10 +1,21 @@
-import { Box, Button, FormControl, FormErrorMessage, HStack, Image, VStack } from "@chakra-ui/react";
+import {
+    Box,
+    Button,
+    FormControl,
+    FormErrorMessage,
+    HStack,
+    Image,
+    SkeletonText,
+    useInterval,
+    VStack,
+} from "@chakra-ui/react";
 import { Accordion, AccordionButton, AccordionIcon, AccordionItem, AccordionPanel } from "@chakra-ui/react";
 import Debug from "debug";
 import moment from "moment";
 import * as React from "react";
 import { useAsync } from "react-async";
 import { repayLoan } from "../background-proxy";
+import { getBlockHeight } from "../background-proxy";
 import { LoanDetails } from "../models";
 import Btc from "./bitcoin.svg";
 import Usdt from "./tether.svg";
@@ -45,10 +56,21 @@ function OpenLoan({ loanDetails, onRepayed, index }: OpenLoanProps) {
         onReject: (e) => error("Failed to repay loan %s: %s", loanDetails.txid, e),
     });
 
-    // TODO: get current block height from explorer
-    const currentHeight = 10;
-    // this will format the time nicely into something like : `in 13 hours` or `in 1 month`.
-    const deadline = moment().add((currentHeight - loanDetails.term) * 60, "hours").fromNow();
+    const blockHeightHook = useAsync({
+        promiseFn: getBlockHeight,
+        onReject: (e) => error("Failed to fetch block height %s", e),
+    });
+    let { data: blockHeight, reload: reloadBlockHeight } = blockHeightHook;
+
+    useInterval(() => {
+        reloadBlockHeight();
+    }, 6000); // 1 min
+
+    // format the time nicely into something like : `in 13 hours` or `in 1 month`.
+    // block-height and loan-term are in "blocktime" ^= minutes
+    const deadline = blockHeight
+        ? moment().add(Math.abs(blockHeight - loanDetails.term), "minutes").fromNow()
+        : null;
 
     return <AccordionItem>
         <h2>
@@ -66,7 +88,9 @@ function OpenLoan({ loanDetails, onRepayed, index }: OpenLoanProps) {
                     <Box w="32px" h="32px">
                         <Image src={Usdt} h="32px" />
                     </Box>
-                    <Box>are due {deadline}</Box>
+                    {deadline
+                        ? <Box>are due {deadline}</Box>
+                        : <Box><SkeletonText noOfLines={2} spacing="4" /></Box>}
                 </HStack>
                 <AccordionIcon />
             </AccordionButton>
@@ -104,7 +128,7 @@ function OpenLoan({ loanDetails, onRepayed, index }: OpenLoanProps) {
                         </Box>
                     </HStack>
                     <Box>
-                        Loan term: {loanDetails.term}
+                        Loan term: {loanDetails.term} (due block-height)
                     </Box>
                     <FormControl id="repayment" isInvalid={repayFailed}>
                         <Box>

extension/src/wasmProxy.ts

@@ -140,3 +140,10 @@ export async function createNewBip39Wallet(name: string, seedWords: string, pass
     debug("create_new_bip39_wallet");
     return create_new_bip39_wallet(name, seedWords, password);
 }
+
+export async function getBlockHeight(): Promise<string> {
+    const { get_block_height } = await import("./wallet");
+
+    debug("getBlockHeight");
+    return get_block_height();
+}

extension/wallet/src/esplora.rs

@@ -149,6 +149,23 @@ pub async fn get_fee_estimates() -> Result<FeeEstimatesResponse> {
     Ok(fee_estimates)
 }
 
+pub async fn get_block_height() -> Result<u32> {
+    let esplora_url = {
+        let guard = ESPLORA_API_URL.lock().expect_throw("can get lock");
+        guard.clone()
+    };
+    let esplora_url = esplora_url.join("/blocks/tip/height")?;
+
+    let latest_block_height = reqwest::get(esplora_url.clone())
+        .await
+        .with_context(|| format!("failed to GET {}", esplora_url))?
+        .json()
+        .await
+        .context("failed to deserialize latest block height")?;
+
+    Ok(latest_block_height)
+}
+
 /// The response object for the `/fee-estimates` endpoint.
 ///
 /// The key is the confirmation target (in number of blocks) and the value is the estimated feerate (in sat/vB).

extension/wallet/src/lib.rs

@@ -143,6 +143,15 @@ pub async fn wallet_status(name: String) -> Result<JsValue, JsValue> {
     Ok(status)
 }
 
+/// Retrieve the latest block height from Esplora
+#[wasm_bindgen]
+pub async fn get_block_height() -> Result<JsValue, JsValue> {
+    let latest_block_height = map_err_from_anyhow!(esplora::get_block_height().await)?;
+    let latest_block_height = map_err_from_anyhow!(JsValue::from_serde(&latest_block_height))?;
+
+    Ok(latest_block_height)
+}
+
 /// Get an address for the wallet with the given name.
 ///
 /// Fails if the wallet is currently not loaded.

waves/src/Borrow.tsx

@@ -75,6 +75,8 @@ function Borrow({ dispatch, state, rate, wavesProvider, walletStatusAsyncState }
                 // Liquid has 1 minute blocktime
                 const loanTermInBlocks = state.loanTermInDays * 24 * 60;
 
+                debug("loan term in blocks: " + loanTermInBlocks);
+
                 let loanRequest = await wavesProvider.makeLoanRequestPayload(
                     collateralAmount.toString(),
                     feeRate.toString(),