feature: show pools apr

app/javascript/src/utils/apr.ts

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+import BigNumber from "bignumber.js";
+
+import { BLOCKS_PER_YEAR } from "../constants";
+
+export const getApr = (
+  stakingTokenPrice: number,
+  rewardTokenPrice: number,
+  totalStaked: number,
+  tokenPerBlock: number
+) => {
+  const totalRewardPricePerYear = new BigNumber(rewardTokenPrice)
+    .times(tokenPerBlock)
+    .times(BLOCKS_PER_YEAR);
+
+  const totalStakingTokenInPool = new BigNumber(stakingTokenPrice).times(
+    totalStaked
+  );
+
+  const apr = totalRewardPricePerYear.div(totalStakingTokenInPool).times(100);
+
+  return apr.isNaN() || !apr.isFinite() ? null : apr.toNumber();
+};

app/javascript/src/utils/getPrice.ts

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+import { ethers } from "ethers";
+
+import { tokens } from "../constants/pancake/Tokens";
+import type { Token } from "../constants/pancake/Tokens";
+import type { BscContext } from "../contexts/BscProvider";
+
+// 1 Wei = 1*10^18 Ether
+const ONE_BUSD_IN_WEI = ethers.utils.parseUnits("1", 18);
+
+export const getPriceInBusd = async (router: any, token: Token) => {
+  try {
+    const result = await router.getAmountsOut(ONE_BUSD_IN_WEI, [
+      token.address["56"],
+      tokens.busd.address["56"],
+    ]);
+
+    return result[1].toString() / 1e18;
+  } catch {
+    return 0;
+  }
+};

app/javascript/src/utils/getTotalStaked.ts

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+import { ethers } from "ethers";
+import BigNumber from "bignumber.js";
+
+import erc20 from "../abi/erc20.json";
+import { Token } from "../constants/pancake/Tokens";
+import type { PoolConfig } from "../types";
+
+export const getTotalStaked = async (
+  provider: ethers.providers.Provider,
+  pool: PoolConfig
+) => {
+  if (pool.stakingToken.symbol === "BNB") {
+    // TODO: BNB
+    return 0;
+  }
+
+  const contract = new ethers.Contract(
+    pool.stakingToken.address["56"],
+    erc20,
+    provider
+  );
+
+  try {
+    const result = await contract.balanceOf(pool.contractAddress["56"]);
+
+    return new BigNumber(result.toJSON().hex).toNumber();
+  } catch {
+    return 0;
+  }
+};