From c16d632b318e65a4355bbe2e064fbb825a7e8055 Mon Sep 17 00:00:00 2001
From: LuanRT <luan.lrt4@gmail.com>
Date: Thu, 28 Jul 2022 05:11:10 -0300
Subject: [PATCH] =?UTF-8?q?fix:=20race=20condition=20causing=20=E2=80=9Cup?=
 =?UTF-8?q?date-credentials=E2=80=9D=20to=20fire=20multiple=20times?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/core/OAuth.ts       | 45 ++++++++++++++++++-----------------------
 src/core/Player.ts      |  6 +++---
 src/core/Session.ts     |  2 +-
 src/utils/HTTPClient.ts |  3 +--
 4 files changed, 25 insertions(+), 31 deletions(-)

diff --git a/src/core/OAuth.ts b/src/core/OAuth.ts
index c3595264..365a74cc 100644
--- a/src/core/OAuth.ts
+++ b/src/core/OAuth.ts
@@ -43,20 +43,21 @@ class OAuth {
    */
   async init(credentials?: Credentials) {
     this.#credentials = credentials;
+
     if (this.validateCredentials()) {
-      this.#session.emit('auth', {
-        credentials: this.#credentials,
-        status: 'SUCCESS'
-      });
+      if (!this.has_access_token_expired)
+        this.#session.emit('auth', {
+          credentials: this.#credentials,
+          status: 'SUCCESS'
+        });
     } else if (!(await this.#loadCachedCredentials())) {
       await this.#getUserCode();
     }
   }
 
   async cacheCredentials() {
-    const str = JSON.stringify(this.#credentials);
     const encoder = new TextEncoder();
-    const data = encoder.encode(str);
+    const data = encoder.encode(JSON.stringify(this.#credentials));
     await this.#session.cache?.set('youtubei_oauth_credentials', data.buffer);
   }
 
@@ -67,18 +68,21 @@ class OAuth {
   async #loadCachedCredentials() {
     const data = await this.#session.cache?.get('youtubei_oauth_credentials');
     if (!data) return false;
+
     const decoder = new TextDecoder();
-    const str = decoder.decode(data);
-    const credentials = JSON.parse(str);
+    const credentials = JSON.parse(decoder.decode(data));
+
     this.#credentials = {
       access_token: credentials.access_token,
       refresh_token: credentials.refresh_token,
       expires: new Date(credentials.expires)
     };
+
     this.#session.emit('auth', {
       credentials: this.#credentials,
       status: 'SUCCESS'
     });
+
     return true;
   }
 
@@ -170,21 +174,16 @@ class OAuth {
   }
 
   /**
-   * Refreshes the access token if necessary.
+   * Refresh access token if the same has expired.
    */
-  async checkAccessTokenValidity() {
-    const timestamp = this.#credentials ? new Date(this.#credentials.expires).getTime() : -Infinity;
-    if (new Date().getTime() > timestamp) {
+  async refreshIfRequired() {
+    if (this.has_access_token_expired) {
       await this.#refreshAccessToken();
     }
   }
 
-  /**
-   * Retrieves a new access token using the refresh token.
-   */
   async #refreshAccessToken() {
     if (!this.#credentials) return;
-
     this.#identity = await this.#getClientIdentity();
 
     const data = {
@@ -201,12 +200,6 @@ class OAuth {
       }
     });
 
-    if (response instanceof Error) {
-      const error = new OAuthError('Could not refresh access token.', { status: 'FAILED' });
-      this.#session.emit('update-credentials', error);
-      throw error;
-    }
-
     const response_data = await response.json();
     const expiration_date = new Date(new Date().getTime() + response_data.expires_in * 1000);
 
@@ -222,9 +215,6 @@ class OAuth {
     });
   }
 
-  /**
-   * Revokes credentials.
-   */
   async revokeCredentials() {
     if (!this.#credentials) return;
     await this.removeCache();
@@ -264,6 +254,11 @@ class OAuth {
     return this.#credentials;
   }
 
+  get has_access_token_expired(): boolean {
+    const timestamp = this.#credentials ? new Date(this.#credentials.expires).getTime() : -Infinity;
+    return new Date().getTime() > timestamp;
+  }
+
   validateCredentials(): this is this & { credentials: Credentials } {
     return this.#credentials &&
       Reflect.has(this.#credentials, 'access_token') &&
diff --git a/src/core/Player.ts b/src/core/Player.ts
index af55f5d6..a38ff58c 100644
--- a/src/core/Player.ts
+++ b/src/core/Player.ts
@@ -115,9 +115,9 @@ export default class Player {
 
     // We have the playerID now we can check if we have a cached player
     if (cache) {
-      const cachedPlayer = await Player.fromCache(cache, player_id);
-      if (cachedPlayer)
-        return cachedPlayer;
+      const cached_player = await Player.fromCache(cache, player_id);
+      if (cached_player)
+        return cached_player;
     }
 
     const player_url = new URL(`/s/player/${player_id}/player_ias.vflset/en_US/base.js`, Constants.URLS.YT_BASE);
diff --git a/src/core/Session.ts b/src/core/Session.ts
index 901f2d11..22b55c54 100644
--- a/src/core/Session.ts
+++ b/src/core/Session.ts
@@ -119,7 +119,7 @@ export default class Session extends EventEmitterLike {
         await this.oauth.init(credentials);
 
         if (this.oauth.validateCredentials()) {
-          await this.oauth.checkAccessTokenValidity();
+          await this.oauth.refreshIfRequired();
           this.logged_in = true;
           resolve();
         }
diff --git a/src/utils/HTTPClient.ts b/src/utils/HTTPClient.ts
index e63b4733..17e33126 100644
--- a/src/utils/HTTPClient.ts
+++ b/src/utils/HTTPClient.ts
@@ -92,8 +92,7 @@ export default class HTTPClient {
       const oauth = this.#session.oauth;
 
       if (oauth.validateCredentials()) {
-        // Check if the access token is valid to avoid authorization errors.
-        await oauth.checkAccessTokenValidity();
+        await oauth.refreshIfRequired();
 
         request_headers.set('authorization', `Bearer ${oauth.credentials.access_token}`);