api: refactor the market data api (#1569)

* api: refactor the market data api

* api: refactor the market data api

* api: refactor the market data api

api/market_data.js

@@ -0,0 +1,103 @@
+// Dia to Coingecko names
+const tickers = {
+  "Tether USD": "tether",
+  "Acala USD": "acala-dollar",
+  "BNB": "binancecoin",
+  "Wrapped BTC": "wrapped-bitcoin",
+  "Dai Stablecoin": "dai",
+  "Ether": "ethereum",
+  "USD Coin": "usd-coin",
+  "tBTC v2": "tbtc"
+}
+
+// Coingecko to Dia asset ids
+const dia_assets = {
+  "bitcoin": "/Bitcoin/0x0000000000000000000000000000000000000000",
+  "ethereum": "/Ethereum/0x0000000000000000000000000000000000000000",
+  "interlay": "/Interlay/0x0000000000000000000000000000000000000000",
+  "polkadot": "/Polkadot/0x0000000000000000000000000000000000000000",
+  "kusama": "/Kusama/0x0000000000000000000000000000000000000000",
+  "kintsugi": "/Kintsugi/Token:KINT",
+  "acala-dollar": "/Acala/Token:AUSD",
+  "karura": "/Bifrost/518",
+  "tether": "/Ethereum/0xdAC17F958D2ee523a2206206994597C13D831ec7",
+  "voucher-dot": "/Bifrost-polkadot/2304",
+  "binancecoin": "/Ethereum/0xB8c77482e45F1F44dE1745F52C74426C631bDD52",
+  "bnb": "/Ethereum/0xB8c77482e45F1F44dE1745F52C74426C631bDD52",
+  "tbtc": "/Ethereum/0x18084fbA666a33d37592fA2633fD49a74DD93a88",
+  "dai": "/Ethereum/0x6B175474E89094C44Da98b954EedeAC495271d0F",
+  "moonbeam": "/Moonbeam/0x0000000000000000000000000000000000000000",
+  "usd-coin": "/Ethereum/0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
+  "wrapped-bitcoin": "/Ethereum/0x2260FAC5E5542a773Aa44fBCfeDf7C193bc2C599"
+}
+
+const fetchDiaAsset = async (asset) => {
+  try {
+    if (!dia_assets[asset]) {
+      console.log('Missing DIA asset: ', asset)
+      return coingecko({ ids: [asset], vs_currencies: ["usd"] })
+    }
+    const url = 'https://api.diadata.org/v1/assetQuotation' + dia_assets[asset]
+    const response = await fetch(url, { headers: { "accept": "application/json" } })
+    if (!response.ok) {
+      throw new Error(response.status)
+    }
+    const json = await response.json()
+
+    // optionally rename the ticker
+    const name = (tickers[json.Name] ?? json.Name).toLowerCase()
+    return {
+      [name]: {
+        'usd': json.Price
+      }
+    }
+  } catch (error) {
+    console.log(error)
+  }
+}
+
+const dia = async (args) => {
+  const assets = args.ids.split(',')
+
+  return Promise
+    .all(assets.map(x => fetchDiaAsset(x)))
+    .then(x => x.reduce((map, obj) => {
+      // we need to convert the list to an object
+      const k = Object.keys(obj)[0]
+      map[k] = obj[k]
+      return map
+    }, {}))
+}
+
+const coingecko = async (args) => {
+  const url = 'https://api.coingecko.com/api/v3/simple/price?' + new URLSearchParams(args)
+  const response = await fetch(url, { headers: { "accept": "application/json" } })
+  return await response.json()
+}
+
+const fetchPrices = (priceSource, args) => {
+  if (priceSource === 'coingecko') {
+    return coingecko(args)
+  } else if (priceSource === 'dia') {
+    return dia(args)
+  } else {
+    try {
+      return dia(args)
+    } catch (error) {
+      console.log(error)
+      return coingecko(args)
+    }
+  }
+}
+
+export default async function (request, response) {
+  const args = request.query
+  const priceSource = args['price-source']
+
+  const resp = await fetchPrices(priceSource, args)
+  return response
+    .status(200)
+    .setHeader("content-type", "application/json")
+    .setHeader("cache-control", "public, maxage=0, s-maxage=300")
+    .json(resp)
+}

vercel.json

@@ -7,6 +7,10 @@
     "api/terms.js": {
       "memory": 256,
       "maxDuration": 10
+    },
+    "api/market_data.js": {
+      "memory": 128,
+      "maxDuration": 5
     }
   },
   "rewrites": [
@@ -20,7 +24,7 @@
     },
     {
       "source": "/marketdata/(.*)",
-      "destination": "/api/market_data.py"
+      "destination": "/api/market_data.js"
     },
     {
       "source": "/terms/(.*)",