refactor(ui): extract duplicated quota helpers to shared utils

Address PR review feedback:
- Add type guards (isAgyQuotaResult, isCodexQuotaResult, isGeminiQuotaResult)
- Add unified getProviderMinQuota() and getProviderResetTime() helpers
- Export QUOTA_SUPPORTED_PROVIDERS constant from hooks
- Update account-item.tsx and account-card.tsx to use shared functions
- Eliminate code duplication across provider-specific quota handling

Closes #400 review feedback

ui/src/components/account/flow-viz/account-card.tsx

@@ -5,20 +5,19 @@
 import {
   cn,
   formatResetTime,
-  getClaudeResetTime,
-  getMinClaudeQuota,
   getModelsWithTiers,
   groupModelsByTier,
-  getMinCodexQuota,
-  getMinGeminiQuota,
-  getCodexResetTime,
-  getGeminiResetTime,
+  getProviderMinQuota,
+  getProviderResetTime,
+  isAgyQuotaResult,
+  isCodexQuotaResult,
+  isGeminiQuotaResult,
   type ModelTier,
 } from '@/lib/utils';
 import { PRIVACY_BLUR_CLASS } from '@/contexts/privacy-context';
 import { GripVertical, Loader2, Clock, Pause, Play } from 'lucide-react';
-import { useAccountQuota } from '@/hooks/use-cliproxy-stats';
-import type { CodexQuotaResult, GeminiCliQuotaResult, QuotaResult } from '@/lib/api-client';
+import { useAccountQuota, QUOTA_SUPPORTED_PROVIDERS } from '@/hooks/use-cliproxy-stats';
+import type { QuotaSupportedProvider } from '@/hooks/use-cliproxy-stats';
 import { Tooltip, TooltipContent, TooltipProvider, TooltipTrigger } from '@/components/ui/tooltip';
 import { Button } from '@/components/ui/button';
 
@@ -95,28 +94,17 @@ export function AccountCard({
   const connectorPosition = CONNECTOR_POSITION_MAP[zone];
 
   // Quota for CLIProxy accounts (agy, codex, gemini)
-  const isCliproxyProvider = ['agy', 'codex', 'gemini'].includes(account.provider);
+  const isCliproxyProvider = QUOTA_SUPPORTED_PROVIDERS.includes(
+    account.provider as QuotaSupportedProvider
+  );
   const { data: quota, isLoading: quotaLoading } = useAccountQuota(
     account.provider,
     account.id,
     isCliproxyProvider
   );
 
-  // Get provider-specific minimum quota
-  const getProviderMinQuota = () => {
-    if (!quota?.success) return null;
-    switch (account.provider) {
-      case 'agy':
-        return getMinClaudeQuota((quota as QuotaResult).models);
-      case 'codex':
-        return getMinCodexQuota((quota as CodexQuotaResult).windows);
-      case 'gemini':
-        return getMinGeminiQuota((quota as GeminiCliQuotaResult).buckets);
-      default:
-        return null;
-    }
-  };
-  const minQuota = getProviderMinQuota();
+  // Use shared helper for provider-specific minimum quota
+  const minQuota = getProviderMinQuota(account.provider, quota);
 
   // Tier badge (AGY only) - show P for Pro, U for Ultra
   const showTierBadge =
@@ -266,11 +254,11 @@ export function AccountCard({
                   </div>
                 </TooltipTrigger>
                 <TooltipContent side="top" className="max-w-xs">
-                  {account.provider === 'agy' ? (
+                  {quota && isAgyQuotaResult(quota) ? (
                     <div className="text-xs space-y-1">
                       <p className="font-medium">Model Quotas:</p>
                       {(() => {
-                        const tiered = getModelsWithTiers((quota as QuotaResult)?.models || []);
+                        const tiered = getModelsWithTiers(quota.models || []);
                         const groups = groupModelsByTier(tiered);
                         const tierOrder: ModelTier[] = ['primary', 'gemini-3', 'gemini-2', 'other'];
                         return tierOrder.map((tier, idx) => {
@@ -297,7 +285,7 @@ export function AccountCard({
                         });
                       })()}
                       {(() => {
-                        const resetTime = getClaudeResetTime((quota as QuotaResult)?.models || []);
+                        const resetTime = getProviderResetTime('agy', quota);
                         return resetTime ? (
                           <div className="flex items-center gap-1.5 pt-1 border-t border-border/50">
                             <Clock className="w-3 h-3 text-blue-400" />
@@ -308,10 +296,10 @@ export function AccountCard({
                         ) : null;
                       })()}
                     </div>
-                  ) : account.provider === 'codex' ? (
+                  ) : quota && isCodexQuotaResult(quota) ? (
                     <div className="text-xs space-y-1">
                       <p className="font-medium">Rate Limits:</p>
-                      {(quota as CodexQuotaResult)?.windows?.map((w) => (
+                      {quota.windows?.map((w) => (
                         <div key={w.label} className="flex justify-between gap-4">
                           <span className={cn(w.remainingPercent < 20 && 'text-red-500')}>
                             {w.label}
@@ -320,9 +308,7 @@ export function AccountCard({
                         </div>
                       ))}
                       {(() => {
-                        const resetTime = getCodexResetTime(
-                          (quota as CodexQuotaResult)?.windows || []
-                        );
+                        const resetTime = getProviderResetTime('codex', quota);
                         return resetTime ? (
                           <div className="flex items-center gap-1.5 pt-1 border-t border-border/50">
                             <Clock className="w-3 h-3 text-blue-400" />
@@ -333,10 +319,10 @@ export function AccountCard({
                         ) : null;
                       })()}
                     </div>
-                  ) : account.provider === 'gemini' ? (
+                  ) : quota && isGeminiQuotaResult(quota) ? (
                     <div className="text-xs space-y-1">
                       <p className="font-medium">Buckets:</p>
-                      {(quota as GeminiCliQuotaResult)?.buckets?.map((b) => (
+                      {quota.buckets?.map((b) => (
                         <div key={b.id} className="flex justify-between gap-4">
                           <span className={cn(b.remainingPercent < 20 && 'text-red-500')}>
                             {b.label}
@@ -345,9 +331,7 @@ export function AccountCard({
                         </div>
                       ))}
                       {(() => {
-                        const resetTime = getGeminiResetTime(
-                          (quota as GeminiCliQuotaResult)?.buckets || []
-                        );
+                        const resetTime = getProviderResetTime('gemini', quota);
                         return resetTime ? (
                           <div className="flex items-center gap-1.5 pt-1 border-t border-border/50">
                             <Clock className="w-3 h-3 text-blue-400" />

ui/src/components/cliproxy/provider-editor/account-item.tsx

@@ -32,24 +32,17 @@ import {
 import {
   cn,
   formatResetTime,
-  getClaudeResetTime,
-  getMinClaudeQuota,
   getModelsWithTiers,
   groupModelsByTier,
-  getMinCodexQuota,
-  getMinGeminiQuota,
-  getCodexResetTime,
-  getGeminiResetTime,
+  getProviderMinQuota,
+  getProviderResetTime,
+  isAgyQuotaResult,
+  isCodexQuotaResult,
+  isGeminiQuotaResult,
   type ModelTier,
 } from '@/lib/utils';
 import { PRIVACY_BLUR_CLASS } from '@/contexts/privacy-context';
-import {
-  useAccountQuota,
-  useCliproxyStats,
-  type QuotaResult,
-  type CodexQuotaResult,
-  type GeminiCliQuotaResult,
-} from '@/hooks/use-cliproxy-stats';
+import { useAccountQuota, useCliproxyStats } from '@/hooks/use-cliproxy-stats';
 import type { AccountItemProps } from './types';
 
 /**
@@ -128,151 +121,99 @@ export function AccountItem({
   const runtimeLastUsed = stats?.accountStats?.[account.email || account.id]?.lastUsedAt;
   const wasRecentlyUsed = isRecentlyUsed(runtimeLastUsed);
 
-  // Compute min quota based on provider
-  const getProviderMinQuota = (): number | null => {
-    if (!quota?.success) return null;
-    switch (account.provider) {
-      case 'agy':
-        return getMinClaudeQuota((quota as QuotaResult).models);
-      case 'codex':
-        return getMinCodexQuota((quota as CodexQuotaResult).windows);
-      case 'gemini':
-        return getMinGeminiQuota((quota as GeminiCliQuotaResult).buckets);
-      default:
-        return null;
-    }
-  };
-  const minQuota = getProviderMinQuota();
+  // Use shared utility functions for provider-specific quota handling
+  const minQuota = getProviderMinQuota(account.provider, quota);
+  const nextReset = getProviderResetTime(account.provider, quota);
 
-  // Compute reset time based on provider
-  const getProviderResetTime = (): string | null => {
-    if (!quota?.success) return null;
-    switch (account.provider) {
-      case 'agy':
-        return getClaudeResetTime((quota as QuotaResult).models);
-      case 'codex':
-        return getCodexResetTime((quota as CodexQuotaResult).windows);
-      case 'gemini':
-        return getGeminiResetTime((quota as GeminiCliQuotaResult).buckets);
-      default:
-        return null;
-    }
-  };
-  const nextReset = getProviderResetTime();
-
-  // Render Antigravity (agy) provider tooltip
-  const renderAgyTooltip = () => {
-    const tiered = getModelsWithTiers((quota as QuotaResult).models || []);
-    const groups = groupModelsByTier(tiered);
-    const tierOrder: ModelTier[] = ['primary', 'gemini-3', 'gemini-2', 'other'];
-    return tierOrder.map((tier, idx) => {
-      const models = groups.get(tier);
-      if (!models || models.length === 0) return null;
-      const isFirst = tierOrder.slice(0, idx).every((t) => !groups.get(t)?.length);
-      return (
-        <div key={tier}>
-          {!isFirst && <div className="border-t border-border/40 my-1" />}
-          {models.map((m) => (
-            <div key={m.name} className="flex justify-between gap-4">
-              <span className={cn('truncate', m.exhausted && 'text-red-500')}>{m.displayName}</span>
-              <span className={cn('font-mono', m.exhausted && 'text-red-500')}>
-                {m.percentage}%
-              </span>
-            </div>
-          ))}
-        </div>
-      );
-    });
-  };
-
-  // Render Codex provider tooltip
-  const renderCodexTooltip = () => {
-    const windows = (quota as CodexQuotaResult).windows;
-    const planType = (quota as CodexQuotaResult).planType;
-    return (
-      <>
-        {planType && <p className="text-muted-foreground">Plan: {planType}</p>}
-        {windows.map((w) => (
-          <div key={w.label} className="flex justify-between gap-4">
-            <span>{w.label}</span>
-            <span className="font-mono">{w.remainingPercent}%</span>
-          </div>
-        ))}
-      </>
-    );
-  };
-
-  // Render Gemini provider tooltip
-  const renderGeminiTooltip = () => {
-    const buckets = (quota as GeminiCliQuotaResult).buckets;
-    return (
-      <>
-        {buckets.map((b) => (
-          <div key={b.id} className="flex justify-between gap-4">
-            <span>
-              {b.label}
-              {b.tokenType ? ` (${b.tokenType})` : ''}
-            </span>
-            <span className="font-mono">{b.remainingPercent}%</span>
-          </div>
-        ))}
-      </>
-    );
-  };
-
-  // Provider-specific tooltip content renderer
+  // Provider-specific tooltip content renderer using type guards
   const renderQuotaTooltip = () => {
     if (!quota?.success) return null;
 
-    switch (account.provider) {
-      case 'agy':
-        return (
-          <div className="text-xs space-y-1">
-            <p className="font-medium">Model Quotas:</p>
-            {renderAgyTooltip()}
-            {nextReset && (
-              <div className="flex items-center gap-1.5 pt-1 border-t border-border/50">
-                <Clock className="w-3 h-3 text-blue-400" />
-                <span className="text-blue-400 font-medium">
-                  Resets {formatResetTime(nextReset)}
-                </span>
+    // Antigravity (agy) provider tooltip
+    if (isAgyQuotaResult(quota)) {
+      const tiered = getModelsWithTiers(quota.models || []);
+      const groups = groupModelsByTier(tiered);
+      const tierOrder: ModelTier[] = ['primary', 'gemini-3', 'gemini-2', 'other'];
+      return (
+        <div className="text-xs space-y-1">
+          <p className="font-medium">Model Quotas:</p>
+          {tierOrder.map((tier, idx) => {
+            const models = groups.get(tier);
+            if (!models || models.length === 0) return null;
+            const isFirst = tierOrder.slice(0, idx).every((t) => !groups.get(t)?.length);
+            return (
+              <div key={tier}>
+                {!isFirst && <div className="border-t border-border/40 my-1" />}
+                {models.map((m) => (
+                  <div key={m.name} className="flex justify-between gap-4">
+                    <span className={cn('truncate', m.exhausted && 'text-red-500')}>
+                      {m.displayName}
+                    </span>
+                    <span className={cn('font-mono', m.exhausted && 'text-red-500')}>
+                      {m.percentage}%
+                    </span>
+                  </div>
+                ))}
               </div>
-            )}
-          </div>
-        );
-      case 'codex':
-        return (
-          <div className="text-xs space-y-1">
-            <p className="font-medium">Rate Limit Windows:</p>
-            {renderCodexTooltip()}
-            {nextReset && (
-              <div className="flex items-center gap-1.5 pt-1 border-t border-border/50">
-                <Clock className="w-3 h-3 text-blue-400" />
-                <span className="text-blue-400 font-medium">
-                  Resets {formatResetTime(nextReset)}
-                </span>
-              </div>
-            )}
-          </div>
-        );
-      case 'gemini':
-        return (
-          <div className="text-xs space-y-1">
-            <p className="font-medium">Model Buckets:</p>
-            {renderGeminiTooltip()}
-            {nextReset && (
-              <div className="flex items-center gap-1.5 pt-1 border-t border-border/50">
-                <Clock className="w-3 h-3 text-blue-400" />
-                <span className="text-blue-400 font-medium">
-                  Resets {formatResetTime(nextReset)}
-                </span>
-              </div>
-            )}
-          </div>
-        );
-      default:
-        return null;
+            );
+          })}
+          {nextReset && (
+            <div className="flex items-center gap-1.5 pt-1 border-t border-border/50">
+              <Clock className="w-3 h-3 text-blue-400" />
+              <span className="text-blue-400 font-medium">Resets {formatResetTime(nextReset)}</span>
+            </div>
+          )}
+        </div>
+      );
     }
+
+    // Codex provider tooltip
+    if (isCodexQuotaResult(quota)) {
+      return (
+        <div className="text-xs space-y-1">
+          <p className="font-medium">Rate Limit Windows:</p>
+          {quota.planType && <p className="text-muted-foreground">Plan: {quota.planType}</p>}
+          {quota.windows.map((w) => (
+            <div key={w.label} className="flex justify-between gap-4">
+              <span>{w.label}</span>
+              <span className="font-mono">{w.remainingPercent}%</span>
+            </div>
+          ))}
+          {nextReset && (
+            <div className="flex items-center gap-1.5 pt-1 border-t border-border/50">
+              <Clock className="w-3 h-3 text-blue-400" />
+              <span className="text-blue-400 font-medium">Resets {formatResetTime(nextReset)}</span>
+            </div>
+          )}
+        </div>
+      );
+    }
+
+    // Gemini provider tooltip
+    if (isGeminiQuotaResult(quota)) {
+      return (
+        <div className="text-xs space-y-1">
+          <p className="font-medium">Model Buckets:</p>
+          {quota.buckets.map((b) => (
+            <div key={b.id} className="flex justify-between gap-4">
+              <span>
+                {b.label}
+                {b.tokenType ? ` (${b.tokenType})` : ''}
+              </span>
+              <span className="font-mono">{b.remainingPercent}%</span>
+            </div>
+          ))}
+          {nextReset && (
+            <div className="flex items-center gap-1.5 pt-1 border-t border-border/50">
+              <Clock className="w-3 h-3 text-blue-400" />
+              <span className="text-blue-400 font-medium">Resets {formatResetTime(nextReset)}</span>
+            </div>
+          )}
+        </div>
+      );
+    }
+
+    return null;
   };
 
   return (

ui/src/hooks/use-cliproxy-stats.ts

@@ -204,7 +204,8 @@ export function useCliproxyErrorLogContent(name: string | null) {
 export type { ModelQuota, QuotaResult, CodexQuotaResult, GeminiCliQuotaResult };
 
 /** Providers with quota API support */
-const SUPPORTED_PROVIDERS = ['agy', 'codex', 'gemini'] as const;
+export const QUOTA_SUPPORTED_PROVIDERS = ['agy', 'codex', 'gemini'] as const;
+export type QuotaSupportedProvider = (typeof QUOTA_SUPPORTED_PROVIDERS)[number];
 
 /**
  * Fetch account quota from API (Antigravity only)
@@ -290,7 +291,7 @@ export function useAccountQuota(provider: string, accountId: string, enabled = t
     queryFn: () => fetchQuotaByProvider(provider, accountId),
     enabled:
       enabled &&
-      SUPPORTED_PROVIDERS.includes(provider as (typeof SUPPORTED_PROVIDERS)[number]) &&
+      QUOTA_SUPPORTED_PROVIDERS.includes(provider as QuotaSupportedProvider) &&
       !!accountId,
     staleTime: 60000, // Match refetchInterval to prevent early refetching
     refetchInterval: 60000, // Refresh every 1 minute

ui/src/lib/utils.ts

@@ -1,6 +1,12 @@
 import { clsx, type ClassValue } from 'clsx';
 import { twMerge } from 'tailwind-merge';
-import type { CodexQuotaWindow, GeminiCliBucket } from './api-client';
+import type {
+  CodexQuotaWindow,
+  CodexQuotaResult,
+  GeminiCliBucket,
+  GeminiCliQuotaResult,
+  QuotaResult,
+} from './api-client';
 
 export function cn(...inputs: ClassValue[]) {
   return twMerge(clsx(inputs));
@@ -337,3 +343,87 @@ export function getGeminiResetTime(buckets: GeminiCliBucket[]): string | null {
   if (resets.length === 0) return null;
   return resets.sort()[0];
 }
+
+// ==================== Unified Quota Type Guards ====================
+
+/** Unified quota result type for provider-agnostic handling */
+export type UnifiedQuotaResult = QuotaResult | CodexQuotaResult | GeminiCliQuotaResult;
+
+/** Type guard: Check if quota result is from Antigravity (agy) provider */
+export function isAgyQuotaResult(quota: UnifiedQuotaResult): quota is QuotaResult {
+  return 'models' in quota && Array.isArray((quota as QuotaResult).models);
+}
+
+/** Type guard: Check if quota result is from Codex provider */
+export function isCodexQuotaResult(quota: UnifiedQuotaResult): quota is CodexQuotaResult {
+  return 'windows' in quota && Array.isArray((quota as CodexQuotaResult).windows);
+}
+
+/** Type guard: Check if quota result is from Gemini CLI provider */
+export function isGeminiQuotaResult(quota: UnifiedQuotaResult): quota is GeminiCliQuotaResult {
+  return 'buckets' in quota && Array.isArray((quota as GeminiCliQuotaResult).buckets);
+}
+
+// ==================== Unified Quota Helpers ====================
+
+/**
+ * Get minimum quota percentage for any provider
+ * Centralizes provider-specific logic to eliminate duplication
+ */
+export function getProviderMinQuota(
+  provider: string,
+  quota: UnifiedQuotaResult | null | undefined
+): number | null {
+  if (!quota?.success) return null;
+
+  switch (provider) {
+    case 'agy':
+      if (isAgyQuotaResult(quota)) {
+        return getMinClaudeQuota(quota.models);
+      }
+      return null;
+    case 'codex':
+      if (isCodexQuotaResult(quota)) {
+        return getMinCodexQuota(quota.windows);
+      }
+      return null;
+    case 'gemini':
+      if (isGeminiQuotaResult(quota)) {
+        return getMinGeminiQuota(quota.buckets);
+      }
+      return null;
+    default:
+      return null;
+  }
+}
+
+/**
+ * Get earliest reset time for any provider
+ * Centralizes provider-specific logic to eliminate duplication
+ */
+export function getProviderResetTime(
+  provider: string,
+  quota: UnifiedQuotaResult | null | undefined
+): string | null {
+  if (!quota?.success) return null;
+
+  switch (provider) {
+    case 'agy':
+      if (isAgyQuotaResult(quota)) {
+        return getClaudeResetTime(quota.models);
+      }
+      return null;
+    case 'codex':
+      if (isCodexQuotaResult(quota)) {
+        return getCodexResetTime(quota.windows);
+      }
+      return null;
+    case 'gemini':
+      if (isGeminiQuotaResult(quota)) {
+        return getGeminiResetTime(quota.buckets);
+      }
+      return null;
+    default:
+      return null;
+  }
+}