From: Florian Forster <ff@octo.it>
Date: Thu, 11 Jan 2018 07:39:16 +0000 (+0100)
Subject: Package fitbit: Update RefreshToken in Datastore after refreshing OAuth token.
X-Git-Url: https://git.verplant.org/?a=commitdiff_plain;h=6e353fc58f08533be15182536e7b0c5099c098b8;p=kraftakt.git

Package fitbit: Update RefreshToken in Datastore after refreshing OAuth token.
---

diff --git a/fitbit/fitbit.go b/fitbit/fitbit.go
index 6f15027..bdfc3dd 100644
--- a/fitbit/fitbit.go
+++ b/fitbit/fitbit.go
@@ -123,19 +123,40 @@ type Client struct {
 }
 
 func NewClient(ctx context.Context, fitbitUserID string, u *app.User) (*Client, error) {
-	tok, err := u.Token(ctx, "Fitbit")
+	if fitbitUserID == "" {
+		fitbitUserID = "-"
+	}
+
+	storedToken, err := u.Token(ctx, "Fitbit")
 	if err != nil {
 		return nil, err
 	}
 
-	if fitbitUserID == "" {
-		fitbitUserID = "-"
+	// The oauth2 package will refresh the token when it is valid for less
+	// than 10 seconds. To avoid a race with later calls (which would
+	// refresh the token but the new RefreshToken wouldn't make it back
+	// into datastore), we refresh earlier than that. The Fitbit tokens are
+	// quite long-lived (six hours?); the additional load this puts on the
+	// backends is negligible.
+	if storedToken.Expiry.Round(0).Add(-5 * time.Minute).Before(time.Now()) {
+		storedToken.Expiry = time.Now()
+	}
+
+	refreshedToken, err := oauth2Config.TokenSource(ctx, storedToken).Token()
+	if err != nil {
+		return nil, err
+	}
+
+	if refreshedToken.RefreshToken != storedToken.RefreshToken {
+		if err := u.SetToken(ctx, "Fitbit", refreshedToken); err != nil {
+			return nil, err
+		}
 	}
 
 	return &Client{
 		fitbitUserID: fitbitUserID,
 		appUser:      u,
-		client:       oauth2Config.Client(ctx, tok),
+		client:       oauth2Config.Client(ctx, refreshedToken),
 	}, nil
 }