feat: rate limiting, keyboard navigation, and accessibility

src-tauri/Cargo.toml

@@ -29,6 +29,7 @@ env_logger = "0.11"
 dirs = "5.0"
 sha2 = "0.10"
 hex = "0.4"
+rand = "0.8"
 
 [dev-dependencies]
 # Use same dependencies for tests

src-tauri/src/gmail.rs

@@ -1,9 +1,11 @@
 use crate::keychain::KeychainManager;
 use chrono::Utc;
-use reqwest::Client;
+use reqwest::{Client, StatusCode};
 use serde::Deserialize;
 use sha2::{Digest, Sha256};
 
+pub const RATE_LIMIT_ERROR: &str = "RATE_LIMIT_ERROR";
+
 const GMAIL_SCOPES: &[&str] = &["https://www.googleapis.com/auth/gmail.readonly"];
 const OAUTH_REDIRECT_URI: &str = "http://localhost:8234/callback";
 
@@ -238,13 +240,20 @@ impl GmailClient {
 
         let list_url = "https://gmail.googleapis.com/gmail/v1/users/me/messages?q=is%3Aunread%20newer_than:1d&maxResults=25".to_string();
 
-        let list_resp: MessageListResponse = self
+        let response = self
             .http_client
             .get(&list_url)
             .header("Authorization", format!("Bearer {}", access_token))
             .send()
             .await
-            .map_err(|e| format!("Gmail API request failed: {}", e))?
+            .map_err(|e| format!("Gmail API request failed: {}", e))?;
+
+        // Check for rate limit error (HTTP 429)
+        if response.status() == StatusCode::TOO_MANY_REQUESTS {
+            return Err(RATE_LIMIT_ERROR.to_string());
+        }
+
+        let list_resp: MessageListResponse = response
             .json()
             .await
             .map_err(|e| format!("Failed to parse message list: {}", e))?;

src-tauri/src/main.rs

@@ -29,6 +29,8 @@ use types::{AppState, ClipboardConfig, CodeEntry, PrivacyPreferences};
 const DEFAULT_POLL_INTERVAL_MS: u64 = 8000;
 const NOTIFICATION_COOLDOWN_MS: u64 = 3000;
 const DEFAULT_CLIPBOARD_TIMEOUT_SECONDS: u64 = 30;
+const BASE_BACKOFF_MS: u64 = 60_000; // 1 minute base backoff
+const MAX_BACKOFF_MS: u64 = 300_000; // 5 minutes max backoff
 
 fn get_poll_interval() -> u64 {
     std::env::var("OTPBAR_POLL_INTERVAL_MS")
@@ -93,6 +95,8 @@ fn main() {
                 timeout_seconds: clipboard_timeout,
             }),
             privacy_preferences: tokio::sync::Mutex::new(loaded_prefs),
+            backoff_until: tokio::sync::Mutex::new(None),
+            backoff_logged: tokio::sync::Mutex::new(false),
         })
         .setup(|app| {
             setup_menubar(app)?;
@@ -227,15 +231,35 @@ async fn start_polling(handle: &tauri::AppHandle) {
 
     let handle_clone = handle.clone();
     tauri::async_runtime::spawn(async move {
+        let mut retry_count = 0u32;
+
         loop {
             tokio::time::sleep(tokio::time::Duration::from_millis(poll_interval)).await;
 
             let state: State<AppState> = handle_clone.state();
+
+            // Check if we're in backoff period
+            let now = chrono::Utc::now().timestamp_millis();
+            let backoff_until = *state.backoff_until.lock().await;
+            if let Some(until) = backoff_until {
+                if now < until {
+                    // Still in backoff period, skip this poll
+                    continue;
+                }
+                // Backoff period expired, clear it
+                *state.backoff_until.lock().await = None;
+                *state.backoff_logged.lock().await = false;
+                log::info!("Rate limit backoff expired, resuming normal polling");
+            }
+
             let mut client_guard = state.gmail_client.lock().await;
 
             if let Some(client) = client_guard.as_mut() {
                 match client.get_recent_unread().await {
                     Ok(messages) => {
+                        // Reset retry count on success
+                        retry_count = 0;
+
                         for msg in messages {
                             let text = format!("{} {} {}", msg.subject, msg.snippet, msg.body);
                             if let Some(otp_code) = otp::extract_otp(&text) {
@@ -315,6 +339,30 @@ async fn start_polling(handle: &tauri::AppHandle) {
                             }
                         }
                     }
+                    Err(e) if e == gmail::RATE_LIMIT_ERROR => {
+                        // Rate limit error - implement exponential backoff with jitter
+                        let backoff_ms = calculate_backoff(retry_count);
+                        retry_count = retry_count.saturating_add(1);
+
+                        // Add jitter: +/- 25% of backoff time
+                        let jitter_ms = (backoff_ms as f64 * 0.25 * rand::random::<f64>()) as i64
+                            - (backoff_ms as i64 / 4);
+                        let backoff_until = now + backoff_ms as i64 + jitter_ms;
+
+                        *state.backoff_until.lock().await = Some(backoff_until);
+
+                        // Only log once per backoff period
+                        let mut logged = state.backoff_logged.lock().await;
+                        if !*logged {
+                            let backoff_seconds = (backoff_until - now) / 1000;
+                            log::warn!(
+                                "Gmail API rate limit exceeded. Backing off for ~{} seconds. Retry count: {}",
+                                backoff_seconds,
+                                retry_count
+                            );
+                            *logged = true;
+                        }
+                    }
                     Err(e) => {
                         log::error!("Gmail polling failed: {}", e);
                     }
@@ -324,6 +372,12 @@ async fn start_polling(handle: &tauri::AppHandle) {
     });
 }
 
+/// Calculate exponential backoff with a maximum cap
+fn calculate_backoff(retry_count: u32) -> u64 {
+    let backoff = BASE_BACKOFF_MS * 2u64.pow(retry_count.min(6));
+    backoff.min(MAX_BACKOFF_MS)
+}
+
 fn extract_sender_name(from: &str) -> String {
     let re = regex::Regex::new(r"^([^<@]+)").expect("Sender name regex should be valid");
     if let Some(caps) = re.captures(from) {

src-tauri/src/types.rs

@@ -55,4 +55,6 @@ pub struct AppState {
     pub is_polling: tokio::sync::Mutex<bool>,
     pub clipboard_config: tokio::sync::Mutex<ClipboardConfig>,
     pub privacy_preferences: tokio::sync::Mutex<PrivacyPreferences>,
+    pub backoff_until: tokio::sync::Mutex<Option<i64>>,
+    pub backoff_logged: tokio::sync::Mutex<bool>,
 }

src/App.tsx

@@ -111,7 +111,7 @@ function App() {
           </div>
           <button
             onClick={handleRetry}
-            className="inline-flex items-center gap-2 px-4 py-2 bg-primary text-primary-foreground rounded-lg text-sm font-medium hover:bg-primary/90 transition-colors"
+            className="inline-flex items-center gap-2 px-4 py-2 bg-primary text-primary-foreground rounded-lg text-sm font-medium hover:bg-primary/90 transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 focus-visible:ring-offset-background"
           >
             <RefreshCw size={16} />
             Try Again
@@ -167,14 +167,16 @@ function App() {
               <>
                 <button
                   onClick={handleShowSettings}
-                  className="flex items-center gap-1.5 text-xs font-medium text-muted-foreground hover:text-foreground transition-colors group"
+                  aria-label="Open settings"
+                  className="flex items-center gap-1.5 text-xs font-medium text-muted-foreground hover:text-foreground transition-colors group focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 focus-visible:ring-offset-background rounded px-1.5 py-1"
                 >
                   <Settings size={12} className="opacity-60 group-hover:opacity-100 transition-opacity" />
                   <span>Settings</span>
                 </button>
                 <button
                   onClick={handleShowPrivacy}
-                  className="flex items-center gap-1.5 text-xs font-medium text-muted-foreground hover:text-foreground transition-colors group"
+                  aria-label="Open privacy dashboard"
+                  className="flex items-center gap-1.5 text-xs font-medium text-muted-foreground hover:text-foreground transition-colors group focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 focus-visible:ring-offset-background rounded px-1.5 py-1"
                 >
                   <Shield size={12} className="opacity-60 group-hover:opacity-100 transition-opacity" />
                   <span>Privacy</span>
@@ -184,7 +186,8 @@ function App() {
             {isAuthenticated && (
               <button
                 onClick={handleLogout}
-                className="flex items-center gap-1.5 text-xs font-medium text-muted-foreground hover:text-foreground transition-colors group"
+                aria-label="Logout from Gmail"
+                className="flex items-center gap-1.5 text-xs font-medium text-muted-foreground hover:text-foreground transition-colors group focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 focus-visible:ring-offset-background rounded px-1.5 py-1"
               >
                 <LogOut size={12} className="opacity-60 group-hover:opacity-100 transition-opacity" />
                 <span>Logout</span>
@@ -194,7 +197,8 @@ function App() {
 
           <button
             onClick={handleQuit}
-            className="flex items-center gap-1.5 text-xs font-medium text-muted-foreground hover:text-foreground transition-colors group ml-auto"
+            aria-label="Quit application"
+            className="flex items-center gap-1.5 text-xs font-medium text-muted-foreground hover:text-foreground transition-colors group ml-auto focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 focus-visible:ring-offset-background rounded px-1.5 py-1"
           >
             <Power size={12} className="opacity-60 group-hover:opacity-100 transition-opacity" />
             <span>Quit</span>

src/components/Auth.tsx

@@ -48,6 +48,7 @@ export const Auth: React.FC<AuthProps> = ({ onAuthSuccess }) => {
         <button
           onClick={handleLogin}
           disabled={loading}
+          aria-label="Sign in with Google to connect your account"
           className={cn(
             "group relative w-full flex items-center justify-center gap-2 px-4 py-2.5",
             "bg-foreground/90 text-background text-sm font-medium rounded-lg",

src/components/CodeCard.tsx

@@ -100,12 +100,22 @@ export const CodeCard: React.FC<CodeCardProps> = ({ entry }) => {
   return (
     <div
       onClick={handleCopy}
+      role="button"
+      tabIndex={0}
+      aria-label={`Copy OTP code from ${entry.provider || entry.sender}`}
+      onKeyDown={(e) => {
+        if (e.key === 'Enter' || e.key === ' ') {
+          e.preventDefault();
+          handleCopy();
+        }
+      }}
       className={cn(
         "group relative flex items-center justify-between p-3 rounded-lg",
         "bg-card/60 border border-border/30",
         "cursor-pointer transition-all duration-200",
         "hover:bg-card hover:border-border/50",
         "shadow-inner-glow",
+        "focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 focus-visible:ring-offset-background",
         copied && "bg-status-active/10 border-status-active/30"
       )}
     >

src/components/PrivacyDashboard.tsx

@@ -1,6 +1,5 @@
 import { useEffect, useRef, useState } from 'react';
 import {
-  Shield,
   FolderOpen,
   Key,
   Clock,
@@ -11,28 +10,8 @@ import {
   AlertCircle
 } from 'lucide-react';
 import { cn } from '../lib/utils';
-
-interface PrivacyData {
-  dataLocations: {
-    configPath: string;
-    historyPath: string;
-    keychainItems: string[];
-  };
-  permissions: {
-    scopes: string[];
-    hasAccessToken: boolean;
-    hasRefreshToken: boolean;
-  };
-  activity: {
-    totalCodes: number;
-    lastActivity: number | null;
-    historyRetention: number;
-  };
-  retention: {
-    maxHistorySize: number;
-    currentSize: number;
-  };
-}
+import { tauriApi } from '../lib/tauri';
+import type { PrivacyData } from '../types/tauri';
 
 export const PrivacyDashboard: React.FC<{
   onBack: () => void;
@@ -56,7 +35,7 @@ export const PrivacyDashboard: React.FC<{
     try {
       setLoading(true);
       setError(null);
-      const data = await window.__OTPBAR__.getPrivacyData();
+      const data = await tauriApi.getPrivacyData();
       setPrivacyData(data);
     } catch (err) {
       setError(err instanceof Error ? err.message : 'Failed to load privacy data');
@@ -71,10 +50,10 @@ export const PrivacyDashboard: React.FC<{
       setError(null);
       setSuccessMessage(null);
 
-      await window.__OTPBAR__.clearHistory();
+      await tauriApi.clearHistory();
 
       // Refresh privacy data after clearing
-      const updatedData = await window.__OTPBAR__.getPrivacyData();
+      const updatedData = await tauriApi.getPrivacyData();
       setPrivacyData(updatedData);
 
       // Show success message
@@ -158,21 +137,15 @@ export const PrivacyDashboard: React.FC<{
   return (
     <div className="flex flex-col h-full w-full overflow-hidden">
       {/* Header */}
-      <div className="flex items-center gap-3 px-4 py-3 border-b border-border/40 shrink-0">
+      <div className="flex items-center gap-3 px-4 py-3 glass-panel border-b border-border/40 shrink-0">
         <button
           onClick={onBack}
-          className="flex items-center gap-1.5 text-xs font-medium text-muted-foreground hover:text-foreground transition-colors"
+          aria-label="Back to main view"
+          className="flex items-center justify-center w-8 h-8 rounded-lg hover:bg-secondary/80 transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 focus-visible:ring-offset-background"
         >
-          <ArrowLeft size={14} />
-          <span>Back</span>
+          <ArrowLeft size={16} className="text-foreground/80" />
         </button>
-        <div className="flex-1" />
-        <div className="flex items-center gap-2">
-          <div className="w-7 h-7 rounded-lg bg-secondary/80 flex items-center justify-center border border-border/50">
-            <Shield size={14} className="text-muted-foreground" strokeWidth={2} />
-          </div>
-          <h1 className="text-sm font-semibold text-foreground/90">Privacy Dashboard</h1>
-        </div>
+        <h1 className="font-semibold text-sm text-foreground/90">Privacy Dashboard</h1>
       </div>
 
       {/* Content */}