Add networking layer and wire up v9 login flow with unit tests.

Introduce APIClient/AuthAPI, complete login with multi-account selection, and polish the login card UI with shadow and keyboard dismiss.

Co-authored-by: Cursor <cursoragent@cursor.com>

suixinkan/UI/Login/LoginViewModel.swift

@@ -12,13 +12,38 @@ final class LoginViewModel {
     private(set) var password = ""
     private(set) var isPrivacyChecked = false
     private(set) var enableRegister = false
+    private(set) var isLoading = false
+    private(set) var isSelectingAccount = false
+    private(set) var pendingAccountSelection: AccountSelectionPayload?
 
     var isLoginEnabled: Bool {
-        !account.isEmpty && !password.isEmpty
+        isValidPhone && !trimmedPassword.isEmpty
+    }
+
+    var trimmedPassword: String {
+        password.trimmingCharacters(in: .whitespacesAndNewlines)
+    }
+
+    var normalizedUsername: String {
+        normalizedPhoneNumber(account)
+    }
+
+    var isValidPhone: Bool {
+        normalizedUsername.count == 11 && normalizedUsername.first == "1"
     }
 
     var onStateChange: (() -> Void)?
 
+    /// 从本地存储恢复上次登录手机号与协议勾选状态。
+    func applyStoredPreferences() {
+        if account.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty,
+           let lastUsername = AppStore.shared.lastLoginUsername {
+            account = lastUsername
+        }
+        isPrivacyChecked = AppStore.shared.privacyAgreementAccepted
+        notifyStateChange()
+    }
+
     func updateAccount(_ value: String) {
         account = value
         notifyStateChange()
@@ -39,15 +64,101 @@ final class LoginViewModel {
         notifyStateChange()
     }
 
-    func login() {
+    /// 当输入包含 +86 前缀时，把手机号规范化为 11 位国内手机号。
+    func normalizeUsernameCountryCodeIfNeeded() {
+        let digits = account.filter(\.isNumber)
+        let normalizedPhone = normalizedPhoneNumber(account)
+        guard normalizedPhone != digits, normalizedPhone.count == 11 else { return }
+        account = normalizedPhone
+        notifyStateChange()
+    }
+
+    /// 校验登录表单，并返回第一个需要处理的错误。
+    func validateForLogin() -> LoginValidationError? {
+        guard isValidPhone else {
+            return .invalidPhone
+        }
+        guard !trimmedPassword.isEmpty else {
+            return .emptyPassword
+        }
         guard isPrivacyChecked else {
-            onShowMessage?("请先阅读并同意用户协议与隐私政策")
+            return .privacyUnchecked
+        }
+        return nil
+    }
+
+    func login() {
+        if let error = validateForLogin() {
+            onShowMessage?(error.message)
             return
         }
-        guard isLoginEnabled else { return }
         onLogin?()
     }
 
+    /// 加载 App 配置，控制验证码登录/注册入口显隐。
+    func loadAppConfig(authAPI: AuthAPI) async {
+        do {
+            let config = try await authAPI.getAppConfig()
+            updateEnableRegister(config.enableRegister)
+        } catch {
+            // 配置加载失败不影响密码登录，静默忽略。
+        }
+    }
+
+    /// 发起登录，并根据账号数量决定直接完成或进入账号选择。
+    func login(authAPI: AuthAPI) async throws -> LoginResolution {
+        guard !isLoading else {
+            throw CancellationError()
+        }
+
+        isLoading = true
+        notifyStateChange()
+        defer {
+            isLoading = false
+            notifyStateChange()
+        }
+
+        let response = try await authAPI.login(
+            username: normalizedUsername,
+            password: trimmedPassword
+        )
+        return try await resolveLoginResponse(response, authAPI: authAPI)
+    }
+
+    /// 选择一个账号并调用 set-user 换取正式 token。
+    func selectAccount(_ account: AccountSwitchAccount, authAPI: AuthAPI) async throws -> V9AuthResponse {
+        guard let payload = pendingAccountSelection, payload.hasTempToken else {
+            throw LoginFlowError.missingToken
+        }
+        guard account.businessUserId > 0 else {
+            throw LoginFlowError.invalidAccount
+        }
+        guard !isSelectingAccount else {
+            throw CancellationError()
+        }
+
+        isSelectingAccount = true
+        notifyStateChange()
+        defer {
+            isSelectingAccount = false
+            notifyStateChange()
+        }
+
+        let response = try await authAPI.setUser(account.toSetUserRequest(), tokenOverride: payload.tempToken)
+        guard !response.token.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty else {
+            throw LoginFlowError.missingToken
+        }
+        pendingAccountSelection = nil
+        notifyStateChange()
+        return response
+    }
+
+    /// 清空待选账号信息，通常在用户取消账号选择时调用。
+    func clearPendingAccountSelection() {
+        pendingAccountSelection = nil
+        notifyStateChange()
+    }
+
     var onShowMessage: ((String) -> Void)?
     var onLogin: (() -> Void)?
     var onLoginByCode: (() -> Void)?
@@ -55,6 +166,39 @@ final class LoginViewModel {
     var onUserAgreement: (() -> Void)?
     var onPrivacyPolicy: (() -> Void)?
 
+    private func resolveLoginResponse(_ response: V9AuthResponse, authAPI: AuthAPI) async throws -> LoginResolution {
+        let token = response.token.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !token.isEmpty else {
+            throw LoginFlowError.missingToken
+        }
+
+        let accounts = response.accounts.filter { $0.businessUserId > 0 }
+        guard !accounts.isEmpty else {
+            throw LoginFlowError.noAvailableAccount
+        }
+
+        if accounts.count == 1, let account = accounts.first {
+            let finalResponse = try await authAPI.setUser(account.toSetUserRequest(), tokenOverride: token)
+            guard !finalResponse.token.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty else {
+                throw LoginFlowError.missingToken
+            }
+            return .completed(finalResponse)
+        }
+
+        let payload = AccountSelectionPayload(tempToken: token, accounts: accounts)
+        pendingAccountSelection = payload
+        notifyStateChange()
+        return .needsAccountSelection(payload)
+    }
+
+    private func normalizedPhoneNumber(_ value: String) -> String {
+        var digits = value.filter(\.isNumber)
+        if digits.hasPrefix("86"), digits.count == 13 {
+            digits.removeFirst(2)
+        }
+        return digits
+    }
+
     private func notifyStateChange() {
         onStateChange?()
     }