feat: add leetcode.cn support to TUI login flow

src/__tests__/tui/auth-effects.test.ts

@@ -41,11 +41,20 @@
     getPath: vi.fn(() => '/tmp/.leetcode/credentials.v2.enc.json'),
   },
   mockLeetCodeClient: {
+    setSite: vi.fn(),
     setCredentials: vi.fn(),
     checkAuth: vi.fn(),
   },
 }));
 
+const { mockConfig } = vi.hoisted(() => ({
+  mockConfig: {
+    setSite: vi.fn(),
+    getSite: vi.fn(() => 'leetcode.com'),
+    getConfig: vi.fn(() => ({ site: 'leetcode.com' })),
+  },
+}));
+
 vi.mock('../../storage/credentials.js', () => ({
   credentials: mockCredentials,
   describeCredentialStatus: vi.fn((status: { reason: string | null }) => {
@@ -60,6 +69,10 @@
   leetcodeClient: mockLeetCodeClient,
 }));
 
+vi.mock('../../storage/config.js', () => ({
+  config: mockConfig,
+}));
+
 import { executeCommand } from '../../tui/commands/effects.js';
 
 async function flushAsync(): Promise<void> {
@@ -80,11 +93,11 @@
       readOnly: true,
       reason: null,
       path: null,
     } as any);
 
     const dispatched: AppMsg[] = [];
     executeCommand(
-      { type: 'CMD_LOGIN', session: 'session-token', csrf: 'csrf-token' },
+      { type: 'CMD_LOGIN', session: 'session-token', csrf: 'csrf-token', site: 'leetcode.com' },
       (msg) => dispatched.push(msg)
     );
 
@@ -105,11 +118,11 @@
       readOnly: false,
       reason: 'KEYCHAIN_UNAVAILABLE',
       path: null,
     } as any);
 
     const dispatched: AppMsg[] = [];
     executeCommand(
-      { type: 'CMD_LOGIN', session: 'session-token', csrf: 'csrf-token' },
+      { type: 'CMD_LOGIN', session: 'session-token', csrf: 'csrf-token', site: 'leetcode.com' },
       (msg) => dispatched.push(msg)
     );
 
@@ -132,7 +145,7 @@
       source: null,
       path: null,
       message: 'Unset LEETCODE_SESSION and LEETCODE_CSRF_TOKEN to log out.',
     } as any);
 
     const dispatched: AppMsg[] = [];
     executeCommand({ type: 'CMD_LOGOUT' }, (msg) => dispatched.push(msg));
@@ -155,7 +168,7 @@
       readOnly: false,
       reason: 'KEYCHAIN_UNAVAILABLE',
       path: null,
     } as any);
 
     const dispatched: AppMsg[] = [];
     executeCommand({ type: 'CMD_CHECK_AUTH' }, (msg) => dispatched.push(msg));
@@ -165,4 +178,32 @@
     expect(dispatched).toContainEqual({ type: 'GLOBAL_ERROR', error: 'System keychain is unavailable.' });
     expect(dispatched).toContainEqual({ type: 'AUTH_CHECK_COMPLETE', user: null });
   });
+
+  it('should persist selected site before verifying login credentials', async () => {
+    mockCredentials.status.mockResolvedValueOnce({
+      mode: 'keychain',
+      backend: 'keychain',
+      source: null,
+      hasCredentials: false,
+      readOnly: false,
+      reason: null,
+      path: null,
+    } as any);
+    mockLeetCodeClient.checkAuth.mockResolvedValueOnce({
+      isSignedIn: true,
+      username: 'dong',
+    });
+
+    const dispatched: AppMsg[] = [];
+    executeCommand(
+      { type: 'CMD_LOGIN', session: 'session-token', csrf: 'csrf-token', site: 'leetcode.cn' },
+      (msg) => dispatched.push(msg)
+    );
+
+    await flushAsync();
+
+    expect(mockConfig.setSite).toHaveBeenCalledWith('leetcode.cn');
+    expect(mockLeetCodeClient.setSite).toHaveBeenCalledWith('leetcode.cn');
+    expect(dispatched).toContainEqual({ type: 'LOGIN_SUCCESS', username: 'dong' });
+  });
 });

src/__tests__/tui/login-screen.test.ts

@@ -0,0 +1,44 @@
+import { describe, expect, it, vi } from 'vitest';
+
+const { mockConfig } = vi.hoisted(() => ({
+  mockConfig: {
+    getSite: vi.fn(() => 'leetcode.com'),
+    getConfig: vi.fn(() => ({ site: 'leetcode.com' })),
+  },
+}));
+
+vi.mock('../../storage/config.js', () => ({
+  config: mockConfig,
+}));
+
+import { init, update } from '../../tui/screens/login/index.js';
+
+describe('TUI login screen', () => {
+  it('should move from instructions to site selection before credential entry', () => {
+    const [initialModel] = init();
+
+    const [siteModel] = update({ type: 'LOGIN_SUBMIT' }, initialModel);
+    const [inputModel] = update({ type: 'LOGIN_SUBMIT' }, siteModel);
+
+    expect(siteModel.step).toBe('site');
+    expect(inputModel.step).toBe('input');
+    expect(inputModel.site).toBe('leetcode.com');
+  });
+
+  it('should include selected site in the login command payload', () => {
+    const [initialModel] = init();
+    const [siteModel] = update({ type: 'LOGIN_SUBMIT' }, initialModel);
+    const [cnModel] = update({ type: 'LOGIN_SWITCH_SITE' }, siteModel);
+    const [inputModel] = update({ type: 'LOGIN_SUBMIT' }, cnModel);
+    const [sessionModel] = update({ type: 'LOGIN_SESSION_INPUT', value: 'session-token' }, inputModel);
+    const [readyModel] = update({ type: 'LOGIN_CSRF_INPUT', value: 'csrf-token' }, sessionModel);
+    const [, cmd] = update({ type: 'LOGIN_SUBMIT' }, readyModel);
+
+    expect(cmd).toEqual({
+      type: 'CMD_LOGIN',
+      session: 'session-token',
+      csrf: 'csrf-token',
+      site: 'leetcode.cn',
+    });
+  });
+});

src/tui/commands/effects.ts

@@ -123,7 +123,7 @@
       return;
 
     case 'CMD_LOGIN':
-      login(cmd.session, cmd.csrf, dispatch);
+      login(cmd.session, cmd.csrf, cmd.site, dispatch);
       return;
 
     default:
@@ -244,7 +244,7 @@
 function saveConfig(key: string, value: string): void {
   switch (key) {
     case 'language':
       config.setLanguage(value as any);
       break;
     case 'site': {
       const site = normalizeLeetCodeSiteInput(value);
@@ -287,7 +287,7 @@
   try {
     const code = await fs.readFile(filePath, 'utf-8');
     return { code, lang: leetcodeLang, questionId: problem.questionId };
   } catch (e) {
     const rootPath = path.join(workDir, fileName);
     try {
       const code = await fs.readFile(rootPath, 'utf-8');
@@ -340,7 +340,7 @@
 
     try {
       await fs.mkdir(targetDir, { recursive: true });
     } catch (e) {}
 
     const fileName = getSolutionFileName(problem.questionFrontendId, problem.titleSlug, language);
     const filePath = path.join(targetDir, fileName);
@@ -554,7 +554,12 @@
   dispatch({ type: 'AUTH_CHECK_COMPLETE', user: null });
 }
 
-async function login(session: string, csrf: string, dispatch: Dispatch): Promise<void> {
+async function login(
+  session: string,
+  csrf: string,
+  site: import('../../types.js').LeetCodeSite,
+  dispatch: Dispatch
+): Promise<void> {
   const credentialStatus = await credentials.status();
   if (credentialStatus.mode === 'env-readonly') {
     dispatch({
@@ -573,6 +578,9 @@
     return;
   }
 
+  config.setSite(site);
+  configureLeetCodeClientSite(site);
+
   const creds = { session, csrfToken: csrf };
   leetcodeClient.setCredentials(creds);
 

src/tui/screens/login/index.ts

@@ -1,12 +1,17 @@
-import { AppModel, Cmd, Command, LoginScreenModel, LoginMsg } from '../../types.js';
-import { leetcodeClient } from '../../../api/client.js';
-import { credentials } from '../../../storage/credentials.js';
+import { Cmd, Command, LoginScreenModel, LoginMsg } from '../../types.js';
+import { config } from '../../../storage/config.js';
+import { DEFAULT_LEETCODE_SITE, normalizeLeetCodeSiteInput } from '../../../utils/site.js';
 
 export { view } from './view.js';
 
+function getConfiguredSite() {
+  return normalizeLeetCodeSiteInput(config.getSite?.() ?? config.getConfig?.().site ?? '') ?? DEFAULT_LEETCODE_SITE;
+}
+
 export function init(): [LoginScreenModel, Command] {
   const model: LoginScreenModel = {
     step: 'instructions',
+    site: getConfiguredSite(),
     sessionToken: '',
     csrfToken: '',
     focusedField: 'session',
@@ -17,6 +22,16 @@ export function init(): [LoginScreenModel, Command] {
 
 export function update(msg: LoginMsg, model: LoginScreenModel): [LoginScreenModel, Command] {
   switch (msg.type) {
+    case 'LOGIN_SWITCH_SITE':
+      return [
+        {
+          ...model,
+          site: model.site === 'leetcode.cn' ? 'leetcode.com' : 'leetcode.cn',
+          error: null,
+        },
+        Cmd.none(),
+      ];
+
     case 'LOGIN_SESSION_INPUT':
       return [{ ...model, sessionToken: msg.value }, Cmd.none()];
 
@@ -33,18 +48,24 @@ export function update(msg: LoginMsg, model: LoginScreenModel): [LoginScreenMode
       return [{ ...model, focusedField: msg.field }, Cmd.none()];
 
     case 'LOGIN_BACK':
+      if (model.step === 'input' || model.step === 'error' || model.step === 'verifying') {
+        return [{ ...model, step: 'site', focusedField: 'session', error: null }, Cmd.none()];
+      }
       return [{ ...model, step: 'instructions', focusedField: 'session', error: null }, Cmd.none()];
 
     case 'LOGIN_SUBMIT':
       if (model.step === 'instructions') {
-        return [{ ...model, step: 'input', focusedField: 'session' }, Cmd.none()];
+        return [{ ...model, step: 'site', focusedField: 'session', error: null }, Cmd.none()];
+      }
+      if (model.step === 'site') {
+        return [{ ...model, step: 'input', focusedField: 'session', error: null }, Cmd.none()];
       }
       if (!model.sessionToken || !model.csrfToken) {
         return [{ ...model, error: 'Both fields are required' }, Cmd.none()];
       }
       return [
         { ...model, step: 'verifying', error: null },
-        Cmd.login(model.sessionToken, model.csrfToken),
+        Cmd.login(model.sessionToken, model.csrfToken, model.site),
       ];
 
     case 'LOGIN_SUCCESS':

src/tui/screens/login/view.ts

@@ -32,13 +32,9 @@ export function view(model: LoginScreenModel, width: number, height: number): st
     const instructions = [
       chalk.hex(colors.warning).bold('How to Login:'),
       '',
-      '1. Open https://leetcode.com in your browser',
-      '2. Login to your account',
-      '3. Open DevTools (F12) → Application → Cookies → leetcode.com',
-      '4. Copy the values of ' +
-        chalk.bold.cyan('LEETCODE_SESSION') +
-        ' and ' +
-        chalk.bold.cyan('csrftoken'),
+      '1. Continue to choose your LeetCode site',
+      '2. We will show the correct cookie domain on the next screen',
+      '3. Copy the values of ' + chalk.bold.cyan('LEETCODE_SESSION') + ' and ' + chalk.bold.cyan('csrftoken'),
       '',
       'Default storage: system keychain.',
       'Use LEETCODECLI_CREDENTIAL_BACKEND=file + LEETCODECLI_MASTER_KEY for encrypted file mode.',
@@ -54,10 +50,34 @@ export function view(model: LoginScreenModel, width: number, height: number): st
 
     boxed.forEach((l) => contentLines.push(center(l, width)));
     contentLines.push(''); // Spacing
-    contentLines.push(center(keyHint('Enter', 'Continue to Login'), width));
+    contentLines.push(center(keyHint('Enter', 'Choose Site'), width));
+  } else if (model.step === 'site') {
+    const contentWidth = Math.max(28, Math.min(100, width - 4));
+    const options = [
+      model.site === 'leetcode.com'
+        ? chalk.hex(colors.primary)('> leetcode.com (Global)')
+        : '  leetcode.com (Global)',
+      model.site === 'leetcode.cn'
+        ? chalk.hex(colors.primary)('> leetcode.cn (China)')
+        : '  leetcode.cn (China)',
+      '',
+      chalk.gray('Use Up/Down/Tab to switch sites.'),
+    ];
+
+    const boxed = box(options, contentWidth, {
+      title: 'Choose Site',
+      borderColor: colors.primary,
+      padding: 1,
+      borderStyle: 'round',
+    });
+
+    boxed.forEach((l) => contentLines.push(center(l, width)));
+    contentLines.push('');
+    contentLines.push(center(keyHint('Enter', 'Continue') + '  ' + keyHint('Esc', 'Back'), width));
   } else if (model.step === 'input' || model.step === 'verifying' || model.step === 'error') {
     const contentWidth = Math.max(28, Math.min(100, width - 4));
     const boxLines = [];
+    const domain = model.site === 'leetcode.cn' ? 'leetcode.cn' : 'leetcode.com';
 
     const isSessionFocused = model.focusedField === 'session';
     const isCsrfFocused = model.focusedField === 'csrf';
@@ -95,6 +115,8 @@ export function view(model: LoginScreenModel, width: number, height: number): st
         : '  ' + csrfVal + (model.csrfToken ? chalk.green(' ✔') : '')
     );
 
+    boxLines.push('');
+    boxLines.push(chalk.gray(`Cookie source: https://${domain} → DevTools → Application → Cookies → ${domain}`));
     boxLines.push('');
     if (model.error) {
       boxLines.push(center(chalk.red(model.error), contentWidth - 4));

src/tui/types.ts

@@ -4,6 +4,7 @@ import type {
   ProblemListFilters as RootProblemListFilters,
   DailyChallenge,
 } from '../types.js';
+import type { LeetCodeSite } from '../types.js';
 
 export type Problem = RootProblem;
 export type ProblemDetail = RootProblemDetail;
@@ -133,7 +134,8 @@ export interface HelpScreenModel {
 }
 
 export interface LoginScreenModel {
-  readonly step: 'instructions' | 'input' | 'verifying' | 'success' | 'error';
+  readonly step: 'instructions' | 'site' | 'input' | 'verifying' | 'success' | 'error';
+  readonly site: LeetCodeSite;
   readonly sessionToken: string;
   readonly csrfToken: string;
   readonly focusedField: 'session' | 'csrf';
@@ -356,6 +358,7 @@ export type HelpMsg =
 export type LoginMsg =
   | { readonly type: 'LOGIN_SESSION_INPUT'; readonly value: string }
   | { readonly type: 'LOGIN_CSRF_INPUT'; readonly value: string }
+  | { readonly type: 'LOGIN_SWITCH_SITE' }
   | { readonly type: 'LOGIN_SUBMIT' }
   | { readonly type: 'LOGIN_BACK' }
   | { readonly type: 'LOGIN_SWITCH_FOCUS' }
@@ -438,7 +441,7 @@ export type Command =
   | { readonly type: 'CMD_SWITCH_WORKSPACE'; readonly name: string }
   | { readonly type: 'CMD_FETCH_CHANGELOG' }
   | { readonly type: 'CMD_LOGOUT' }
-  | { readonly type: 'CMD_LOGIN'; readonly session: string; readonly csrf: string };
+  | { readonly type: 'CMD_LOGIN'; readonly session: string; readonly csrf: string; readonly site: LeetCodeSite };
 
 export const Cmd = {
   none: (): Command => ({ type: 'CMD_NONE' }),
@@ -482,7 +485,12 @@ export const Cmd = {
   switchWorkspace: (name: string): Command => ({ type: 'CMD_SWITCH_WORKSPACE', name }),
   fetchChangelog: (): Command => ({ type: 'CMD_FETCH_CHANGELOG' }),
   logout: (): Command => ({ type: 'CMD_LOGOUT' }),
-  login: (session: string, csrf: string): Command => ({ type: 'CMD_LOGIN', session, csrf }),
+  login: (session: string, csrf: string, site: LeetCodeSite): Command => ({
+    type: 'CMD_LOGIN',
+    session,
+    csrf,
+    site,
+  }),
 };
 
 export function createInitialModel(username?: string): AppModel {

src/tui/update.ts

@@ -127,13 +127,7 @@ export function update(msg: AppMsg, model: AppModel): [AppModel, Command] {
           user: null,
           screenState: {
             screen: 'login',
-            model: {
-              step: 'instructions',
-              sessionToken: '',
-              csrfToken: '',
-              focusedField: 'session',
-              error: null,
-            },
+            model: LoginScreen.init()[0],
           },
           needsRender: true,
         },
@@ -973,6 +967,14 @@ function handleLoginKeyPress(model: AppModel, msg: AppMsg): [AppModel, Command]
     } else if (key.name === 'escape') {
       return [model, Cmd.exit()];
     }
+  } else if (loginModel.step === 'site') {
+    if (key.name === 'escape') {
+      return updateLogin(model, { type: 'LOGIN_BACK' });
+    } else if (key.name === 'tab' || key.name === 'down' || key.name === 'up' || key.name === 'left' || key.name === 'right') {
+      return updateLogin(model, { type: 'LOGIN_SWITCH_SITE' });
+    } else if (key.name === 'return' || key.name === 'enter') {
+      return updateLogin(model, { type: 'LOGIN_SUBMIT' });
+    }
   } else if (loginModel.step === 'input' || loginModel.step === 'error') {
     if (key.name === 'escape') {
       return updateLogin(model, { type: 'LOGIN_BACK' });