feat: add get latest prices

src/alexSDK.ts

@@ -9,6 +9,7 @@ import {
   defaultReadonlyCallExecutor,
   ReadonlyCallExecutor,
 } from './utils/readonlyCallExecutor';
+import { fetchLatestPrices } from './utils/currencyPrice';
 
 export class AlexSDK {
   constructor(
@@ -64,4 +65,12 @@ export class AlexSDK {
   getCurrencyFrom(address: string): Currency | undefined {
     return findCurrencyByNativeAddress(address);
   }
+
+  getLatestPrices(): Promise<
+    Partial<{
+      [currency in Currency]: number;
+    }>
+  > {
+    return fetchLatestPrices();
+  }
 }

src/utils/currencyPrice.ts

@@ -0,0 +1,37 @@
+import { Currency } from '../currency';
+
+export async function fetchLatestPrices(): Promise<
+  Partial<{
+    [currency in Currency]: number;
+  }>
+> {
+  const res = await fetch('https://gql.alexlab.co/v1/graphql', {
+    body: JSON.stringify({
+      query: `
+        query FetchLatestPrices {
+          laplace_current_token_price {
+            avg_price_usd
+            token
+          }
+        }
+      `,
+    }),
+  }).then((a) => a.json());
+  const result: Partial<{ [currency in Currency]: number }> = {};
+  for (const value of Object.values(Currency)) {
+    const external = res.data.laplace_current_token_price.find(
+      (a: any) => a.token === value + '-external' && a.avg_price_usd != null
+    );
+    if (external) {
+      result[value] = external.avg_price_usd!;
+    } else {
+      const nonExternal = res.data.laplace_current_token_price.find(
+        (a: any) => a.token === value && a.avg_price_usd != null
+      );
+      if (nonExternal) {
+        result[value] = nonExternal.avg_price_usd!;
+      }
+    }
+  }
+  return result;
+}