From 2f4f25e1161a2c0152731ca935922f8e15680817 Mon Sep 17 00:00:00 2001
From: Brendon Votteler <bvotteler@users.noreply.github.com>
Date: Wed, 22 Nov 2023 10:51:31 +0200
Subject: [PATCH] chore: add monetary dependency, add usd conversions for dex
 tvl

---
 api/currency-utils.js | 13 ++++++++++---
 api/package-lock.json |  1 +
 api/tvl_dex.js        | 40 +++++++++++++++++++++++++++++++++-------
 3 files changed, 44 insertions(+), 10 deletions(-)

diff --git a/api/currency-utils.js b/api/currency-utils.js
index 776a294d0..58e9f86f3 100644
--- a/api/currency-utils.js
+++ b/api/currency-utils.js
@@ -6,8 +6,10 @@ import {
     Kintsugi, // On Kusama
     Kusama, // on Kusama
     Polkadot // on Polkadot
-  } from '@interlay/monetary-js';
-  
+} from '@interlay/monetary-js';
+import { isForeignAsset } from "@interlay/interbtc-api";
+
+
 const COINGECKO_ID_BY_CURRENCY_TICKER = {
     [Bitcoin.ticker]: 'bitcoin',
     [Kintsugi.ticker]: 'kintsugi',
@@ -33,4 +35,9 @@ const getCoingeckoId = (currency) => {
     return COINGECKO_ID_BY_CURRENCY_TICKER[currency.ticker];
 };
 
-export { getCoingeckoId };
\ No newline at end of file
+const getCoingeckoQueryUrl = (vsId, coingeckoIds) => {
+    const idsString = coingeckoIds.join(",");
+    return `https://api.coingecko.com/api/v3/simple/price?vs_currencies=${vsId}&ids=${idsString}`;
+};
+
+export { getCoingeckoId, getCoingeckoQueryUrl };
\ No newline at end of file
diff --git a/api/package-lock.json b/api/package-lock.json
index f0d3d3f52..124d156d0 100644
--- a/api/package-lock.json
+++ b/api/package-lock.json
@@ -10,6 +10,7 @@
       "license": "ISC",
       "dependencies": {
         "@interlay/interbtc-api": "2.6.0-rc.0",
+        "@interlay/monetary-js": "0.7.3",
         "@polkadot/util-crypto": "12.6.1",
         "pg": "^8.10.0"
       },
diff --git a/api/tvl_dex.js b/api/tvl_dex.js
index 28b94162b..46289d3c3 100644
--- a/api/tvl_dex.js
+++ b/api/tvl_dex.js
@@ -1,5 +1,5 @@
 import { createInterBtcApi, isForeignAsset } from "@interlay/interbtc-api";
-import { getCoingeckoId } from "./currency-utils";
+import { getCoingeckoId, getCoingeckoQueryUrl } from "./currency-utils";
 
 const tvlDex = async (request, response) => {
     if (request.method === 'GET') {
@@ -11,13 +11,39 @@ const tvlDex = async (request, response) => {
         );
 
         const pools = await interbtcApi.amm.getLiquidityPools();
+        // dedupe ids
+        const coingeckoIds = new Set(
+            pools.flatMap((pool) => pool.pooledCurrencies)
+            .map((monetaryAmount) => getCoingeckoId(monetaryAmount))
+        );
+        // base: usd, get price for all coingeckoIds
+        const queryUrl = getCoingeckoQueryUrl("usd", Array.from(coingeckoIds));
+        // return format: [ { <conigeckoId> : { <vs_id>: <price_as_number> } }, ... ]
+        const response = await fetch(queryUrl, { headers: { "accept": "application/json" } });
+        const cgData = await response.json();
+        
         const amounts = pools.flatMap((pool) => pool.pooledCurrencies)
-            .map((monetaryAmount) => ({
-                currency: monetaryAmount.currency,
-                coingeckoId: getCoingeckoId(monetaryAmount.currency),
-                atomicAmount: monetaryAmount.toString(true),
-                amount: monetaryAmount.toHuman()
-            }));
+            .map((monetaryAmount) => {
+                const atomicAmount = monetaryAmount.toString(true);
+                const amount = monetaryAmount.toString();
+
+                const cgId = getCoingeckoId(monetaryAmount.currency);
+                const usdPrice = (cgData[cgId] != undefined && cgData[cgId]["usd"] != undefined) 
+                    ? cgData[cgId]["usd"]
+                    : undefined;
+                
+                const monetaryAmountUsd = usdPrice ? monetaryAmount.mul(usdPrice) : undefined;
+                const amountUsd = monetaryAmountUsd?.toString(true);
+                const atomicAmountUsd = monetaryAmountUsd?.toString();
+                return {
+                    currency: monetaryAmount.currency,
+                    coingeckoId: getCoingeckoId(monetaryAmount.currency),
+                    atomicAmount,
+                    amount,
+                    atomicAmountUsd,
+                    amountUsd
+                }
+            });
 
         return response.status(200)
             .setHeader("content-type", "application/json")