Add access control (#65)

manual-tests/cognito-client.ts

@@ -0,0 +1,65 @@
+import axios from 'axios';
+
+interface TokenResponse {
+  access_token: string;
+  expires_in: number;
+  token_type: string;
+}
+
+export default class CognitoClient {
+  tokenEndpont: string;
+  clientId: string;
+  clientSecret: string;
+  scope: string;
+  expiresAt: number;
+  accessToken: string;
+
+  constructor(
+    tokenEndpoint: string,
+    clientId: string,
+    clientSecret: string,
+    scope: string,
+  ) {
+    this.tokenEndpont = `${tokenEndpoint}/oauth2/token`;
+    this.clientId = clientId;
+    this.clientSecret = clientSecret;
+    this.scope = scope;
+    this.accessToken = '';
+    this.expiresAt = 0;
+  }
+
+  private getPostData(): URLSearchParams {
+    const params = new URLSearchParams();
+    params.append('grant_type', 'client_credentials');
+    params.append('client_id', this.clientId);
+    params.append('scope', this.scope);
+    return params;
+  }
+
+  public async getToken(): Promise<string> {
+    const now = Date.now();
+    if (this.expiresAt < now) {
+      await this.getNewToken();
+    }
+    console.log('Getting cached token');
+    return this.accessToken;
+  }
+
+  private async getNewToken(): Promise<void> {
+    console.log('Getting new token');
+    const authString =
+      'Basic ' +
+      Buffer.from(this.clientId + ':' + this.clientSecret).toString('base64');
+    const res: TokenResponse = await axios
+      .post(this.tokenEndpont, this.getPostData(), {
+        headers: {
+          'Content-Type': 'application/x-www-form-urlencoded',
+          Authorization: authString,
+        },
+      })
+      .then((r) => r.data);
+
+    this.accessToken = res.access_token;
+    this.expiresAt = Date.now() + res.expires_in * 1e3;
+  }
+}