/**
 * ZCLAW SaaS Client
 *
 * Typed HTTP client for the ZCLAW SaaS backend API (v1).
 * Handles authentication, model listing, chat relay, and config management.
 *
 * API base path: /api/v1/...
 * Auth: HttpOnly cookie (primary) + Bearer token fallback
 *
 * Security: Tokens are NO LONGER persisted to localStorage.
 * The backend sets HttpOnly cookies on login/register/refresh.
 * On page reload, cookie-based auth is verified via GET /api/v1/auth/me.
 *
 * Architecture: This file is the main entry point and thin shell.
 * Types, errors, session helpers, and API methods are in sub-modules:
 *   - saas-types.ts       — all type/interface definitions
 *   - saas-errors.ts      — SaaSApiError class
 *   - saas-session.ts     — session persistence (load/save/clear)
 *   - saas-auth.ts        — login/register/TOTP methods (mixin)
 *   - saas-relay.ts       — relay tasks, chat completion, usage (mixin)
 *   - saas-prompt.ts      — prompt OTA methods (mixin)
 *   - saas-telemetry.ts   — telemetry reporting methods (mixin)
 */

// === Re-export everything from sub-modules ===
export type {
  SaaSAccountInfo,
  SaaSModelInfo,
  SaaSConfigItem,
  SaaSErrorResponse,
  SaaSLoginResponse,
  SaaSRefreshResponse,
  TotpSetupResponse,
  TotpResultResponse,
  DeviceInfo,
  RelayTaskInfo,
  SyncConfigRequest,
  ConfigDiffItem,
  ConfigDiffResponse,
  ConfigSyncResult,
  PaginatedResponse,
  PromptTemplateInfo,
  PromptVersionInfo,
  PromptVariable,
  PromptCheckResult,
  PromptUpdatePayload,
  ProviderInfo,
  CreateProviderRequest,
  UpdateProviderRequest,
  ModelInfo,
  CreateModelRequest,
  UpdateModelRequest,
  AccountApiKeyInfo,
  CreateApiKeyRequest,
  UsageStats,
  AccountPublic,
  UpdateAccountRequest,
  TokenInfo,
  CreateTokenRequest,
  OperationLogInfo,
  DashboardStats,
  RoleInfo,
  CreateRoleRequest,
  UpdateRoleRequest,
  PermissionTemplate,
  CreateTemplateRequest,
  AgentTemplateAvailable,
  AgentTemplateFull,
  AgentConfigFromTemplate,
} from './saas-types';

export { SaaSApiError } from './saas-errors';

export type { SaaSSession } from './saas-session';
export {
  loadSaaSSession,
  loadSaaSSessionSync,
  saveSaaSSession,
  clearSaaSSession,
  saveConnectionMode,
  loadConnectionMode,
} from './saas-session';

// === Imports for the class implementation ===
import type {
  SaaSAccountInfo,
  SaaSLoginResponse,
  TotpSetupResponse,
  TotpResultResponse,
  SaaSModelInfo,
  SaaSConfigItem,
  DeviceInfo,
  SyncConfigRequest,
  ConfigDiffResponse,
  ConfigSyncResult,
  SaaSErrorResponse,
  RelayTaskInfo,
  UsageStats,
  PromptCheckResult,
  PromptTemplateInfo,
  PromptVersionInfo,
  PaginatedResponse,
  AgentTemplateAvailable,
  AgentTemplateFull,
  AgentConfigFromTemplate,
} from './saas-types';
import { SaaSApiError } from './saas-errors';
import { clearSaaSSession } from './saas-session';
import { createLogger } from './logger';

const saasLog = createLogger('saas-client');
import { installAuthMethods } from './saas-auth';

import { installRelayMethods } from './saas-relay';
import { installPromptMethods } from './saas-prompt';
import { installTelemetryMethods } from './saas-telemetry';
import { installBillingMethods } from './saas-billing';

// === Client Implementation ===

export class SaaSClient {
  private baseUrl: string;
  private token: string | null = null;

  /**
   * Refresh mutex: shared Promise to prevent concurrent token refresh.
   * When multiple requests hit 401 simultaneously, they all await the same
   * refresh Promise instead of triggering N parallel refresh calls.
   */
  private _refreshPromise: Promise<string> | null = null;

  /**
   * Thread-safe token refresh — coalesces concurrent refresh attempts into one.
   * First caller triggers the actual refresh; subsequent callers await the same Promise.
   */
  async refreshMutex(): Promise<string> {
    if (this._refreshPromise) return this._refreshPromise;
    this._refreshPromise = this.refreshToken().finally(() => {
      this._refreshPromise = null;
    });
    return this._refreshPromise;
  }

  constructor(baseUrl: string) {
    this.baseUrl = baseUrl.replace(/\/+$/, '');
  }

  /** Update the base URL (e.g. when user changes server address) */
  setBaseUrl(url: string): void {
    this.baseUrl = url.replace(/\/+$/, '');
  }

  /** Get the current base URL */
  getBaseUrl(): string {
    return this.baseUrl;
  }

  /** Set or clear the auth token (in-memory only, never persisted) */
  setToken(token: string | null): void {
    this.token = token;
  }

  /** Check if the client is authenticated (token in memory or cookie-based) */
  isAuthenticated(): boolean {
    return !!this.token || this._cookieAuth;
  }

  /** Track cookie-based auth state (page reload) */
  private _cookieAuth: boolean = false;

  /**
   * Attempt to restore auth state from HttpOnly cookie.
   * Called on page reload when no token is in memory.
   * Returns account info if cookie is valid, null otherwise.
   */
  async restoreFromCookie(): Promise<SaaSAccountInfo | null> {
    try {
      const account = await this.me();
      this._cookieAuth = true;
      return account;
    } catch (e) {
      saasLog.debug('Cookie auth restore failed', { error: e });
      this._cookieAuth = false;
      return null;
    }
  }

  /** Check if a path is an auth endpoint (avoid infinite refresh loop) */
  private _isAuthEndpoint(path: string): boolean {
    return path.includes('/auth/login') || path.includes('/auth/register') || path.includes('/auth/refresh');
  }

  // --- Core HTTP ---

  /** Track whether the server appears reachable */
  private _serverReachable: boolean = true;

  /** Check if the SaaS server was last known to be reachable */
  isServerReachable(): boolean {
    return this._serverReachable;
  }

  /**
   * Make an authenticated request with automatic retry on transient failures.
   * Retries up to 2 times with exponential backoff (1s, 2s).
   * Throws SaaSApiError on non-ok responses.
   */
  public async request<T>(
    method: string,
    path: string,
    body?: unknown,
    timeoutMs = 15000,
    _isRefreshRetry = false,
  ): Promise<T> {
    const maxRetries = 2;
    const baseDelay = 1000;

    for (let attempt = 0; attempt <= maxRetries; attempt++) {
      const headers: Record<string, string> = {
        'Content-Type': 'application/json',
      };
      // Bearer token as fallback — primary auth is HttpOnly cookie
      if (this.token) {
        headers['Authorization'] = `Bearer ${this.token}`;
      }

      try {
        const response = await fetch(`${this.baseUrl}${path}`, {
          method,
          headers,
          credentials: 'include', // Send HttpOnly cookies
          body: body !== undefined ? JSON.stringify(body) : undefined,
          signal: AbortSignal.timeout(timeoutMs),
        });

        this._serverReachable = true;

        // 401: 尝试刷新 Token 后重试 (防止递归)
        if (response.status === 401 && !this._isAuthEndpoint(path) && !_isRefreshRetry) {
          try {
            const newToken = await this.refreshMutex();
            if (newToken) {
              return this.request<T>(method, path, body, timeoutMs, true);
            }
          } catch (refreshErr) {
            // Token refresh failed — clear session and trigger logout
            clearSaaSSession().catch(e => saasLog.debug('Failed to clear SaaS session on refresh failure', { error: e })); // async cleanup, fire-and-forget
            localStorage.removeItem('zclaw-connection-mode');
            throw new SaaSApiError(401, 'SESSION_EXPIRED', '会话已过期，请重新登录');
          }
          throw new SaaSApiError(401, 'UNAUTHORIZED', '认证已过期，请重新登录');
        }

        if (!response.ok) {
          const errorBody = (await response.json().catch(() => null)) as SaaSErrorResponse | null;
          throw new SaaSApiError(
            response.status,
            errorBody?.error || 'UNKNOWN',
            errorBody?.message || `请求失败 (${response.status})`,
          );
        }

        // 204 No Content
        if (response.status === 204) {
          return undefined as T;
        }

        return response.json() as Promise<T>;
      } catch (err: unknown) {
        const isNetworkError = err instanceof TypeError
          && (err.message.includes('Failed to fetch') || err.message.includes('NetworkError'));

        if (isNetworkError && attempt < maxRetries) {
          this._serverReachable = false;
          const delay = baseDelay * Math.pow(2, attempt);
          await new Promise((r) => setTimeout(r, delay));
          continue;
        }

        this._serverReachable = false;
        if (err instanceof SaaSApiError) throw err;
        throw new SaaSApiError(0, 'NETWORK_ERROR', `网络错误: ${err instanceof Error ? err.message : String(err)}`);
      }
    }

    // Unreachable, but TypeScript needs it
    throw new SaaSApiError(0, 'UNKNOWN', '请求失败');
  }

  // --- Health ---

  /**
   * Quick connectivity check against the SaaS backend.
   */
  async healthCheck(): Promise<boolean> {
    try {
      await this.request<unknown>('GET', '/api/health', undefined, 5000);
      return true;
    } catch (e) {
      saasLog.debug('Health check failed', { error: e });
      return false;
    }
  }

  // --- Device Endpoints ---

  /**
   * Register or update this device with the SaaS backend.
   * Uses UPSERT semantics — same (account, device_id) updates last_seen_at.
   */
  async registerDevice(params: {
    device_id: string;
    device_name?: string;
    platform?: string;
    app_version?: string;
  }): Promise<void> {
    await this.request<unknown>('POST', '/api/v1/devices/register', params);
  }

  /**
   * Send a heartbeat to indicate the device is still active.
   * Also sends platform and app_version so the backend can detect client upgrades.
   */
  async deviceHeartbeat(deviceId: string): Promise<void> {
    const appVersion = typeof __APP_VERSION__ !== 'undefined' ? __APP_VERSION__ : 'unknown';
    await this.request<unknown>('POST', '/api/v1/devices/heartbeat', {
      device_id: deviceId,
      platform: typeof navigator !== 'undefined' ? navigator.platform : undefined,
      app_version: appVersion,
    });
  }

  /**
   * List devices registered for the current account.
   */
  async listDevices(): Promise<DeviceInfo[]> {
    const res = await this.request<{ items: DeviceInfo[] }>('GET', '/api/v1/devices');
    return res.items;
  }

  // --- Model Endpoints ---

  /**
   * List available models for relay.
   * Only returns enabled models from enabled providers.
   */
  async listModels(): Promise<SaaSModelInfo[]> {
    return this.request<SaaSModelInfo[]>('GET', '/api/v1/relay/models');
  }

  // --- Config Endpoints ---

  /**
   * List config items, optionally filtered by category.
   */
  async listConfig(category?: string): Promise<SaaSConfigItem[]> {
    const qs = category ? `?category=${encodeURIComponent(category)}` : '';
    const res = await this.request<{ items: SaaSConfigItem[] }>('GET', `/api/v1/config/items${qs}`);
    return res.items;
  }

  /** Compute config diff between client and SaaS (read-only) */
  async computeConfigDiff(request: SyncConfigRequest): Promise<ConfigDiffResponse> {
    return this.request<ConfigDiffResponse>('POST', '/api/v1/config/diff', request);
  }

  /** Sync config from client to SaaS (push) or merge */
  async syncConfig(request: SyncConfigRequest): Promise<ConfigSyncResult> {
    return this.request<ConfigSyncResult>('POST', '/api/v1/config/sync', request);
  }

  /**
   * Pull all config items from SaaS (for startup auto-sync).
   * Returns configs updated since the given timestamp, or all if since is omitted.
   */
  async pullConfig(since?: string): Promise<{
    configs: Array<{
      key: string
      category: string
      value: string | null
      value_type: string
      default: string | null
      updated_at: string
    }>
    pulled_at: string
  }> {
    const qs = since ? `?since=${encodeURIComponent(since)}` : '';
    return this.request('GET', '/api/v1/config/pull' + qs);
  }

  // --- Agent Template Endpoints ---

  /**
   * List available agent templates (lightweight).
   * Used for template selection during onboarding.
   */
  async fetchAvailableTemplates(): Promise<AgentTemplateAvailable[]> {
    return this.request<AgentTemplateAvailable[]>('GET', '/api/v1/agent-templates/available');
  }

  /**
   * Get full template details by ID.
   * Returns all fields needed to create an agent from template.
   */
  async fetchTemplateFull(id: string): Promise<AgentTemplateFull> {
    return this.request<AgentTemplateFull>('GET', `/api/v1/agent-templates/${id}/full`);
  }

  // --- Template Assignment ---

  /**
   * Assign a template to the current account.
   * Records the user's industry choice for onboarding flow control.
   */
  async assignTemplate(templateId: string): Promise<AgentTemplateFull> {
    return this.request<AgentTemplateFull>('POST', '/api/v1/accounts/me/assign-template', {
      template_id: templateId,
    });
  }

  /**
   * Get the template currently assigned to the account.
   * Returns null if no template is assigned.
   */
  async getAssignedTemplate(): Promise<AgentTemplateFull | null> {
    return this.request<AgentTemplateFull | null>('GET', '/api/v1/accounts/me/assigned-template');
  }

  /**
   * Unassign the current template from the account.
   */
  async unassignTemplate(): Promise<void> {
    await this.request<unknown>('DELETE', '/api/v1/accounts/me/assigned-template');
  }

  /**
   * Create an agent configuration from a template.
   * Merges capabilities into tools, applies default model fallback.
   */
  async createAgentFromTemplate(templateId: string): Promise<AgentConfigFromTemplate> {
    return this.request<AgentConfigFromTemplate>('POST', `/api/v1/agent-templates/${templateId}/create-agent`);
  }
}

// === Install mixin methods ===
installAuthMethods(SaaSClient);
installRelayMethods(SaaSClient);
installPromptMethods(SaaSClient);
installTelemetryMethods(SaaSClient);
installBillingMethods(SaaSClient);

// === API Method Type Declarations ===
// These methods are installed at runtime by installXxxMethods() in saas-*.ts.
// We declare them here via interface merging so TypeScript knows they exist on SaaSClient.

export interface SaaSClient {
  // --- Auth (saas-auth.ts) ---
  login(username: string, password: string, totpCode?: string): Promise<SaaSLoginResponse>;
  register(data: { username: string; email: string; password: string; display_name?: string }): Promise<SaaSLoginResponse>;
  me(): Promise<SaaSAccountInfo>;
  refreshToken(): Promise<string>;
  changePassword(oldPassword: string, newPassword: string): Promise<void>;
  setupTotp(): Promise<TotpSetupResponse>;
  verifyTotp(code: string): Promise<TotpResultResponse>;
  disableTotp(password: string): Promise<TotpResultResponse>;

  // --- Relay (saas-relay.ts) ---
  listRelayTasks(query?: { status?: string; page?: number; page_size?: number }): Promise<RelayTaskInfo[]>;
  getRelayTask(taskId: string): Promise<RelayTaskInfo>;
  retryRelayTask(taskId: string): Promise<{ ok: boolean; task_id: string }>;
  chatCompletion(body: unknown, signal?: AbortSignal): Promise<Response>;
  getUsage(params?: { from?: string; to?: string; provider_id?: string; model_id?: string }): Promise<UsageStats>;

  // --- Prompt OTA (saas-prompt.ts) ---
  checkPromptUpdates(deviceId: string, currentVersions: Record<string, number>): Promise<PromptCheckResult>;
  listPrompts(params?: { category?: string; source?: string; status?: string; page?: number; page_size?: number }): Promise<PaginatedResponse<PromptTemplateInfo>>;
  getPrompt(name: string): Promise<PromptTemplateInfo>;
  listPromptVersions(name: string): Promise<PromptVersionInfo[]>;
  getPromptVersion(name: string, version: number): Promise<PromptVersionInfo>;

  // --- Telemetry (saas-telemetry.ts) ---
  reportTelemetry(data: {
    device_id: string;
    app_version: string;
    entries: Array<{
      model_id: string;
      input_tokens: number;
      output_tokens: number;
      latency_ms?: number;
      success: boolean;
      error_type?: string;
      timestamp: string;
      connection_mode: string;
    }>;
  }): Promise<{ accepted: number; rejected: number }>;
  reportAuditSummary(data: {
    device_id: string;
    entries: Array<{
      action: string;
      target: string;
      result: string;
      timestamp: string;
    }>;
  }): Promise<{ accepted: number; total: number }>;

  // --- Billing (saas-billing.ts) ---
  incrementUsageDimension(dimension: string, count?: number): Promise<import('./saas-billing').UsageIncrementResult>;
  reportUsageFireAndForget(dimension: string, count?: number): void;
}

// === Singleton ===

/**
 * Global SaaS client singleton.
 * Initialized with a default URL; the URL and token are updated on login.
 */
export const saasClient = new SaaSClient('https://saas.zclaw.com');