token refresh mechanism

internal/reddit/client.go

@@ -115,8 +115,10 @@ type AuthenticatedClient struct {
 	client *Client
 
 	redditId       string
-	refreshToken string
+	tokenRefreshed bool
-	accessToken  string
+
+	RefreshToken string
+	AccessToken  string
 }
 
 func (rc *Client) NewAuthenticatedClient(redditId, refreshToken, accessToken string) *AuthenticatedClient {
@@ -132,7 +134,7 @@ func (rc *Client) NewAuthenticatedClient(redditId, refreshToken, accessToken str
 		panic("requires a refresh token")
 	}
 
-	return &AuthenticatedClient{rc, redditId, refreshToken, accessToken}
+	return &AuthenticatedClient{rc, redditId, false, refreshToken, accessToken}
 }
 
 func (rc *Client) doRequest(ctx context.Context, r *Request) ([]byte, *RateLimitingInfo, error) {
@@ -199,6 +201,16 @@ func (rac *AuthenticatedClient) request(ctx context.Context, r *Request, rh Resp
 
 	bb, rli, err := rac.client.doRequest(ctx, r)
 
+	if err == ErrInvalidBasicAuth {
+		tokens, err := rac.RefreshTokens(ctx)
+		if err != nil {
+			return nil, ErrInvalidBasicAuth
+		}
+
+		rac.RefreshToken = tokens.RefreshToken
+		rac.AccessToken = tokens.AccessToken
+	}
+
 	if err != nil && err != ErrOauthRevoked && r.retry {
 		for _, backoff := range backoffSchedule {
 			done := make(chan struct{})
@@ -297,13 +309,19 @@ func (rac *AuthenticatedClient) markRateLimited(rli *RateLimitingInfo) error {
 }
 
 func (rac *AuthenticatedClient) RefreshTokens(ctx context.Context, opts ...RequestOption) (*RefreshTokenResponse, error) {
+	if rac.tokenRefreshed {
+		return nil, ErrTokenAlreadyRefreshed
+	}
+
+	rac.tokenRefreshed = true
+
 	opts = append(rac.client.defaultOpts, opts...)
 	opts = append(opts, []RequestOption{
 		WithTags([]string{"url:/api/v1/access_token"}),
 		WithMethod("POST"),
 		WithURL("https://www.reddit.com/api/v1/access_token"),
 		WithBody("grant_type", "refresh_token"),
-		WithBody("refresh_token", rac.refreshToken),
+		WithBody("refresh_token", rac.RefreshToken),
 		WithBasicAuth(rac.client.id, rac.client.secret),
 	}...)
 	req := NewRequest(opts...)
@@ -315,7 +333,7 @@ func (rac *AuthenticatedClient) RefreshTokens(ctx context.Context, opts ...Reque
 
 	ret := rtr.(*RefreshTokenResponse)
 	if ret.RefreshToken == "" {
-		ret.RefreshToken = rac.refreshToken
+		ret.RefreshToken = rac.RefreshToken
 	}
 
 	return ret, nil
@@ -325,7 +343,7 @@ func (rac *AuthenticatedClient) AboutInfo(ctx context.Context, fullname string,
 	opts = append(rac.client.defaultOpts, opts...)
 	opts = append(opts, []RequestOption{
 		WithMethod("GET"),
-		WithToken(rac.accessToken),
+		WithToken(rac.AccessToken),
 		WithURL("https://oauth.reddit.com/api/info"),
 		WithQuery("id", fullname),
 	}...)
@@ -344,7 +362,7 @@ func (rac *AuthenticatedClient) UserPosts(ctx context.Context, user string, opts
 	opts = append(rac.client.defaultOpts, opts...)
 	opts = append(opts, []RequestOption{
 		WithMethod("GET"),
-		WithToken(rac.accessToken),
+		WithToken(rac.AccessToken),
 		WithURL(url),
 	}...)
 	req := NewRequest(opts...)
@@ -362,7 +380,7 @@ func (rac *AuthenticatedClient) UserAbout(ctx context.Context, user string, opts
 	opts = append(rac.client.defaultOpts, opts...)
 	opts = append(opts, []RequestOption{
 		WithMethod("GET"),
-		WithToken(rac.accessToken),
+		WithToken(rac.AccessToken),
 		WithURL(url),
 	}...)
 	req := NewRequest(opts...)
@@ -381,7 +399,7 @@ func (rac *AuthenticatedClient) SubredditAbout(ctx context.Context, subreddit st
 	opts = append(rac.client.defaultOpts, opts...)
 	opts = append(opts, []RequestOption{
 		WithMethod("GET"),
-		WithToken(rac.accessToken),
+		WithToken(rac.AccessToken),
 		WithURL(url),
 	}...)
 	req := NewRequest(opts...)
@@ -399,7 +417,7 @@ func (rac *AuthenticatedClient) subredditPosts(ctx context.Context, subreddit st
 	opts = append(rac.client.defaultOpts, opts...)
 	opts = append(opts, []RequestOption{
 		WithMethod("GET"),
-		WithToken(rac.accessToken),
+		WithToken(rac.AccessToken),
 		WithURL(url),
 	}...)
 	req := NewRequest(opts...)
@@ -429,7 +447,7 @@ func (rac *AuthenticatedClient) MessageInbox(ctx context.Context, opts ...Reques
 	opts = append(opts, []RequestOption{
 		WithTags([]string{"url:/api/v1/message/inbox"}),
 		WithMethod("GET"),
-		WithToken(rac.accessToken),
+		WithToken(rac.AccessToken),
 		WithURL("https://oauth.reddit.com/message/inbox"),
 		WithEmptyResponseBytes(122),
 	}...)
@@ -447,7 +465,7 @@ func (rac *AuthenticatedClient) MessageUnread(ctx context.Context, opts ...Reque
 	opts = append(opts, []RequestOption{
 		WithTags([]string{"url:/api/v1/message/unread"}),
 		WithMethod("GET"),
-		WithToken(rac.accessToken),
+		WithToken(rac.AccessToken),
 		WithURL("https://oauth.reddit.com/message/unread"),
 		WithEmptyResponseBytes(122),
 	}...)
@@ -466,7 +484,7 @@ func (rac *AuthenticatedClient) Me(ctx context.Context, opts ...RequestOption) (
 	opts = append(opts, []RequestOption{
 		WithTags([]string{"url:/api/v1/me"}),
 		WithMethod("GET"),
-		WithToken(rac.accessToken),
+		WithToken(rac.AccessToken),
 		WithURL("https://oauth.reddit.com/api/v1/me"),
 	}...)
 

internal/reddit/errors.go

@@ -25,4 +25,6 @@ var (
 	ErrRequiresRedditId = errors.New("requires reddit id")
 	// ErrInvalidBasicAuth .
 	ErrInvalidBasicAuth = errors.New("invalid basic auth")
+	// ErrTokenAlreadyRefreshed .
+	ErrTokenAlreadyRefreshed = errors.New("token already refreshed")
 )

internal/worker/notifications.go

@@ -167,7 +167,12 @@ func (nc *notificationsConsumer) Consume(delivery rmq.Delivery) {
 
 	account.CheckCount++
 
-	defer func(acc *domain.Account) {
+	rac := nc.reddit.NewAuthenticatedClient(account.AccountID, account.RefreshToken, account.AccessToken)
+
+	defer func(acc *domain.Account, rac *reddit.AuthenticatedClient) {
+		account.AccessToken = rac.AccessToken
+		account.RefreshToken = rac.RefreshToken
+
 		if err = nc.accountRepo.Update(nc, acc); err != nil {
 			nc.logger.Error("failed to update account",
 				zap.Error(err),
@@ -175,46 +180,7 @@ func (nc *notificationsConsumer) Consume(delivery rmq.Delivery) {
 				zap.String("account#username", account.NormalizedUsername()),
 			)
 		}
-	}(&account)
+	}(&account, rac)
-
-	rac := nc.reddit.NewAuthenticatedClient(account.AccountID, account.RefreshToken, account.AccessToken)
-	if account.TokenExpiresAt.Before(now.Add(5 * time.Minute)) {
-		nc.logger.Debug("refreshing reddit token",
-			zap.Int64("account#id", id),
-			zap.String("account#username", account.NormalizedUsername()),
-		)
-
-		tokens, err := rac.RefreshTokens(nc)
-		if err != nil {
-			if err != reddit.ErrOauthRevoked {
-				nc.logger.Error("failed to refresh reddit tokens",
-					zap.Error(err),
-					zap.Int64("account#id", id),
-					zap.String("account#username", account.NormalizedUsername()),
-				)
-				return
-			}
-
-			err = nc.deleteAccount(account)
-			if err != nil {
-				nc.logger.Error("failed to remove revoked account",
-					zap.Error(err),
-					zap.Int64("account#id", id),
-					zap.String("account#username", account.NormalizedUsername()),
-				)
-			}
-
-			return
-		}
-
-		// Update account
-		account.AccessToken = tokens.AccessToken
-		account.RefreshToken = tokens.RefreshToken
-		account.TokenExpiresAt = now.Add(tokens.Expiry)
-
-		// Refresh client
-		rac = nc.reddit.NewAuthenticatedClient(account.AccountID, tokens.RefreshToken, tokens.AccessToken)
-	}
 
 	// Only update delay on accounts we can actually check, otherwise it skews
 	// the numbers too much.