From dcf62122dede374d7547309d2deff37e8515d7a5 Mon Sep 17 00:00:00 2001
From: Danil Kovtonyuk <danx.kov@gmail.com>
Date: Fri, 22 Oct 2021 00:45:02 +1000
Subject: [PATCH] fix: provider

---
 src/config/configuration.ts      |  2 +-
 src/constants/variables.ts       |  4 ++++
 src/modules/api/api.service.ts   |  8 ++++----
 src/services/provider.service.ts | 20 ++++++++++++++------
 4 files changed, 23 insertions(+), 11 deletions(-)

diff --git a/src/config/configuration.ts b/src/config/configuration.ts
index 6b60f1b..123aec1 100644
--- a/src/config/configuration.ts
+++ b/src/config/configuration.ts
@@ -8,7 +8,7 @@ export const baseConfig = () => ({
   base: {
     version,
     port: process.env.PORT,
-    chainId: process.env.CHAIN_ID,
+    chainId: Number(process.env.CHAIN_ID),
     serviceFee: {
       transfer: toWei(process.env.TRANSFER_SERVICE_FEE).toString(),
       withdrawal: Number(process.env.WITHDRAWAL_SERVICE_FEE),
diff --git a/src/constants/variables.ts b/src/constants/variables.ts
index e28cb33..b7322f4 100644
--- a/src/constants/variables.ts
+++ b/src/constants/variables.ts
@@ -3,18 +3,22 @@ import { ChainId } from '@/types';
 
 const NETWORKS_INFO: { [chainId in ChainId] } = {
   [ChainId.MAINNET]: {
+    symbol: 'ETH',
     gasLimit: BigNumber.from(1500000),
     minimumBalance: '0.5',
   },
   [ChainId.GOERLI]: {
+    symbol: 'gETH',
     gasLimit: BigNumber.from(1500000),
     minimumBalance: '0.5',
   },
   [ChainId.OPTIMISM]: {
+    symbol: 'ETH',
     gasLimit: '',
     minimumBalance: '0.5',
   },
   [ChainId.XDAI]: {
+    symbol: 'xDAI',
     gasLimit: BigNumber.from(2000000),
     minimumBalance: '0.5',
   },
diff --git a/src/modules/api/api.service.ts b/src/modules/api/api.service.ts
index 14b5a7a..0848c11 100644
--- a/src/modules/api/api.service.ts
+++ b/src/modules/api/api.service.ts
@@ -3,9 +3,9 @@ import { v4 as uuid } from 'uuid';
 import { InjectQueue } from '@nestjs/bull';
 import { Injectable } from '@nestjs/common';
 
-import { jobStatus } from '@/constants';
 import { ProviderService } from '@/services';
 import { ConfigService } from '@nestjs/config';
+import { jobStatus, NETWORKS_INFO } from '@/constants';
 
 import { Transaction } from '@/types';
 
@@ -25,9 +25,9 @@ class ApiService {
     return {
       health,
       version,
+      chainId,
       serviceFee,
       rewardAddress,
-      chainId: Number(chainId),
     };
   }
 
@@ -59,11 +59,11 @@ class ApiService {
   private async healthCheck(): Promise<Health> {
     const status = await this.providerService.checkSenderBalance();
 
-    const minimumBalance = this.configService.get('base.minimumBalance');
+    const { chainId, minimumBalance } = this.configService.get('base');
 
     return {
       status,
-      error: status ? '' : `Not enough balance, less than ${minimumBalance} ETH`,
+      error: status ? '' : `Not enough balance, less than ${minimumBalance} ${NETWORKS_INFO[chainId].symbol}`,
     };
   }
 }
diff --git a/src/services/provider.service.ts b/src/services/provider.service.ts
index 315e211..acabb77 100644
--- a/src/services/provider.service.ts
+++ b/src/services/provider.service.ts
@@ -9,23 +9,31 @@ import { TornadoPool__factory as TornadoPool, OffchainOracle__factory as Offchai
 @Injectable()
 export class ProviderService {
   private readonly chainId: number;
-  public provider: ethers.providers.JsonRpcProvider;
+  private readonly providers: Map<ChainId, ethers.providers.StaticJsonRpcProvider> = new Map();
 
   constructor(private configService: ConfigService) {
     this.chainId = this.configService.get<number>('base.chainId');
-    this.provider = new ethers.providers.JsonRpcProvider(RPC_LIST[this.chainId]);
   }
 
-  getProviderWithSigner() {
-    return ethers.providers.getDefaultProvider(RPC_LIST[this.chainId]);
+  get provider() {
+    return this.getProvider(this.chainId);
+  }
+
+  getProvider(chainId: ChainId) {
+    if (!this.providers.has(chainId)) {
+      this.providers.set(chainId, new ethers.providers.StaticJsonRpcProvider(RPC_LIST[chainId], chainId));
+    }
+
+    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+    return this.providers.get(chainId)!;
   }
 
   getTornadoPool() {
-    return TornadoPool.connect(CONTRACT_NETWORKS[this.chainId], this.getProviderWithSigner());
+    return TornadoPool.connect(CONTRACT_NETWORKS[this.chainId], this.provider);
   }
 
   getOffChainOracle() {
-    const provider = ethers.providers.getDefaultProvider(RPC_LIST[ChainId.MAINNET]);
+    const provider = this.getProvider(ChainId.MAINNET);
     return OffchainOracle.connect(OFF_CHAIN_ORACLE, provider);
   }