function for clear cookie in the user

cookies.go

@@ -172,6 +172,42 @@ func SetCookieWithMaxAge(w http.ResponseWriter, email string, token string, maxA
 	return nil
 }
 
+// ClearCookie instructs the browser to delete the "goffee" session cookie.
+// It writes an empty cookie with a MaxAge of -1 (immediate deletion) and an
+// expiration in the past, using the same attributes as when the cookie was set
+// (Path, HttpOnly, SameSite and Secure) so the browser reliably removes it.
+//
+// This complements a server-side signout: deleting the cached token prevents any
+// further authenticated use of the session, while clearing the cookie removes the
+// now-useless cookie from the client.
+func ClearCookie(w http.ResponseWriter) error {
+	// Determine if the cookie should have the Secure flag, mirroring SetCookieWithMaxAge.
+	// Set COOKIE_SECURE=false (or "0", "f") in your .env for local development over HTTP.
+	// Defaults to true for production safety.
+	cookieSecureStr := os.Getenv("COOKIE_SECURE")
+	if cookieSecureStr == "" {
+		cookieSecureStr = "true"
+	}
+	cookieSecure, _ := strconv.ParseBool(cookieSecureStr)
+
+	cookie := http.Cookie{
+		Name:     "goffee",
+		Value:    "",
+		Path:     "/",
+		MaxAge:   -1,
+		Expires:  time.Unix(0, 0),
+		HttpOnly: true,
+		SameSite: http.SameSiteLaxMode,
+		Secure:   cookieSecure,
+	}
+
+	// The value is empty, so there is nothing to encrypt. Write the deletion
+	// cookie directly so the browser removes the existing session cookie.
+	http.SetCookie(w, &cookie)
+
+	return nil
+}
+
 // CookieWrite writes a secure HTTP cookie to the response writer after base64 encoding its value.
 // Returns ErrValueTooLong if the cookie string exceeds the 4096-byte size limit.
 func CookieWrite(w http.ResponseWriter, cookie http.Cookie) error {