/**
 * SaaS Session Persistence
 *
 * Handles loading/saving SaaS auth session data.
 * Token is stored in secure storage (OS keyring), not plain localStorage.
 * Auth state is carried by HttpOnly cookies when possible (same-origin).
 */

import type { SaaSAccountInfo } from './saas-types';
import { createLogger } from './logger';

const logger = createLogger('saas-session');

// === Storage Keys ===
const SAAS_TOKEN_SECURE_KEY = 'zclaw-saas-token'; // OS keyring key
const SAAS_REFRESH_TOKEN_KEY = 'zclaw-saas-refresh-token'; // OS keyring key for refresh token
const SAASTOKEN_KEY = 'zclaw-saas-token'; // legacy localStorage — only used for cleanup
const SAASURL_KEY = 'zclaw-saas-url';
const SAASACCOUNT_KEY = 'zclaw-saas-account';
const SAASMODE_KEY = 'zclaw-connection-mode';

// === Session Interface ===

export interface SaaSSession {
  token: string | null; // null when using cookie-based auth (page reload)
  refreshToken: string | null; // for token refresh on restore
  account: SaaSAccountInfo | null;
  saasUrl: string;
}

// === Session Functions ===

/**
 * Load a persisted SaaS session.
 * Token is stored in secure storage (OS keyring), not plain localStorage.
 * Returns null if no URL is stored (never logged in).
 *
 * NOTE: Token loading is async due to secure storage access.
 * For synchronous checks, use loadSaaSSessionSync() (URL + account only).
 */
export async function loadSaaSSession(): Promise<SaaSSession | null> {
  try {
    const saasUrl = localStorage.getItem(SAASURL_KEY);
    if (!saasUrl) {
      return null;
    }

    // Clean up any legacy plaintext token from localStorage
    const legacyToken = localStorage.getItem(SAASTOKEN_KEY);
    if (legacyToken) {
      localStorage.removeItem(SAASTOKEN_KEY);
    }

    // Load token from secure storage
    let token: string | null = null;
    let refreshToken: string | null = null;
    try {
      const { secureStorage } = await import('./secure-storage');
      token = await secureStorage.get(SAAS_TOKEN_SECURE_KEY);
      refreshToken = await secureStorage.get(SAAS_REFRESH_TOKEN_KEY);
    } catch (e) {
      logger.debug('Secure storage unavailable for token load', { error: e });
      // Secure storage unavailable — token stays null (cookie auth will be attempted)
    }

    const accountRaw = localStorage.getItem(SAASACCOUNT_KEY);
    const account: SaaSAccountInfo | null = accountRaw
      ? (JSON.parse(accountRaw) as SaaSAccountInfo)
      : null;

    return { token, refreshToken, account, saasUrl };
  } catch (e) {
    logger.debug('Corrupted session data, clearing', { error: e });
    // Corrupted data - clear all
    clearSaaSSession();
    return null;
  }
}

/**
 * Synchronous version — returns URL + account only (no token).
 * Used during store initialization where async is not available.
 */
export function loadSaaSSessionSync(): { saasUrl: string; account: SaaSAccountInfo | null } | null {
  try {
    const saasUrl = localStorage.getItem(SAASURL_KEY);
    if (!saasUrl) return null;

    // Clean up legacy plaintext token
    const legacyToken = localStorage.getItem(SAASTOKEN_KEY);
    if (legacyToken) {
      localStorage.removeItem(SAASTOKEN_KEY);
    }

    const accountRaw = localStorage.getItem(SAASACCOUNT_KEY);
    const account: SaaSAccountInfo | null = accountRaw
      ? (JSON.parse(accountRaw) as SaaSAccountInfo)
      : null;

    return { saasUrl, account };
  } catch (e) {
    logger.debug('Failed to load sync session', { error: e });
    return null;
  }
}

/**
 * Persist SaaS session.
 * Access token + refresh token go to secure storage (OS keyring), metadata to localStorage.
 */
export async function saveSaaSSession(session: SaaSSession): Promise<void> {
  // Store access token in secure storage (OS keyring)
  if (session.token) {
    try {
      const { secureStorage } = await import('./secure-storage');
      await secureStorage.set(SAAS_TOKEN_SECURE_KEY, session.token);
    } catch (e) {
      logger.debug('Secure storage unavailable for token save', { error: e });
    }
  }

  // Store refresh token in secure storage (OS keyring)
  if (session.refreshToken) {
    try {
      const { secureStorage } = await import('./secure-storage');
      await secureStorage.set(SAAS_REFRESH_TOKEN_KEY, session.refreshToken);
    } catch (e) {
      logger.debug('Secure storage unavailable for refresh token save', { error: e });
    }
  }

  localStorage.setItem(SAASURL_KEY, session.saasUrl);
  if (session.account) {
    localStorage.setItem(SAASACCOUNT_KEY, JSON.stringify(session.account));
  }
}

/**
 * Clear the persisted SaaS session from all storage.
 */
export async function clearSaaSSession(): Promise<void> {
  // Remove access token from secure storage
  try {
    const { secureStorage } = await import('./secure-storage');
    await secureStorage.set(SAAS_TOKEN_SECURE_KEY, '');
  } catch (e) { logger.debug('Failed to clear secure storage token', { error: e }); }

  // Remove refresh token from secure storage
  try {
    const { secureStorage } = await import('./secure-storage');
    await secureStorage.set(SAAS_REFRESH_TOKEN_KEY, '');
  } catch (e) { logger.debug('Failed to clear secure storage refresh token', { error: e }); }

  localStorage.removeItem(SAASTOKEN_KEY);
  localStorage.removeItem(SAASURL_KEY);
  localStorage.removeItem(SAASACCOUNT_KEY);
}

/**
 * Persist the connection mode to localStorage with timestamp.
 */
export function saveConnectionMode(mode: string): void {
  const data = JSON.stringify({ mode, timestamp: Date.now() });
  localStorage.setItem(SAASMODE_KEY, data);
}

/**
 * Load the connection mode from localStorage.
 * Handles both new JSON format and legacy plain string format.
 * Returns null if not set.
 */
export function loadConnectionMode(): string | null {
  const raw = localStorage.getItem(SAASMODE_KEY);
  if (!raw) return null;
  try {
    const parsed = JSON.parse(raw);
    if (typeof parsed === 'string') return parsed; // legacy format
    return parsed.mode ?? null;
  } catch {
    return raw; // legacy format (plain string)
  }
}