From 537a236b4238df460cd1b52b81902c7b581217ac Mon Sep 17 00:00:00 2001
From: Tee <teedia31@gmail.com>
Date: Sat, 27 Feb 2021 23:06:15 -0500
Subject: [PATCH] Create private singleton class for Client

---
 src/client.ts | 39 +++++++++++++++++++++++++++++----------
 1 file changed, 29 insertions(+), 10 deletions(-)

diff --git a/src/client.ts b/src/client.ts
index 5f71332..bb79a43 100644
--- a/src/client.ts
+++ b/src/client.ts
@@ -2,29 +2,48 @@ import * as axios from 'axios';
 import { Query } from './interfaces/query';
 
 export class Client {
-  private static readonly API_BASE_URL: string = 'https://api.pokemontcg.io';
-  private static readonly API_VERSION: string = '2';
-  private static readonly API_URL: string = `${Client.API_BASE_URL}/v${Client.API_VERSION}`;
+  private readonly POKEMONTCG_API_BASE_URL: string = 'https://api.pokemontcg.io';
+  private readonly POKEMONTCG_API_VERSION: string = '2';
+  private readonly POKEMONTCG_API_URL: string = `${this.POKEMONTCG_API_BASE_URL}/v${this.POKEMONTCG_API_VERSION}`;
+  private readonly POKEMONTCG_API_KEY?: string = process.env.POKEMONTCG_API_KEY;
 
-  static async get(resource: string, params?: Query[] | string): Promise<any> {
-    let url: string = `${this.API_URL}/${resource}`;
-    const config: axios.AxiosRequestConfig = {
-      headers: {
-        'Content-Type': 'application/json'
+  private static instance: Client;
+
+  private constructor() {}
+
+  public static getInstance() {
+      if (!Client.instance) {
+          Client.instance = new Client();
       }
+
+      return Client.instance;
+  }
+
+  async get<T>(resource: string, params?: Query[] | string): Promise<T> {
+    let url: string = `${this.POKEMONTCG_API_URL}/${resource}`;
+    let headers = {
+        'Content-Type': 'application/json'
+    }
+
+    if (this.POKEMONTCG_API_KEY) {
+        headers['X-Api-Key'] = this.POKEMONTCG_API_KEY;
+    }
+
+    const config: axios.AxiosRequestConfig = {
+      headers
     };
 
     if(typeof params === 'string') url += `/${params}`;
     else url += `?${this.paramsToQuery(params)}`;
 
-    return axios.default.get<any>(url, config)
+    return axios.default.get<T>(url, config)
       .then(response => {
         return response.data[Object.keys(response.data)[0]];
       })
       .catch(error => Promise.reject(error));
   }
 
-  private static paramsToQuery(params?: Query[]): string {
+  private paramsToQuery(params?: Query[]): string {
     let query: string = '';
 
     if (params) {