// Generate a random UUID v4 for each request
const requestId = crypto.randomUUID();

// Example of proactive token refresh
class TokenManager {
  constructor() {
    this.userSessionToken = null;
    this.refreshToken = null;
    this.tokenExpiry = 0;
    this.refreshThreshold = 300; // Refresh 5 minutes before expiration
    this.refreshInProgress = false;
    this.refreshInterval = null;
  }
  
  setTokens(userSessionToken, refreshToken, expiresIn) {
    this.userSessionToken = userSessionToken;
    this.refreshToken = refreshToken;
    this.tokenExpiry = Date.now() + (expiresIn * 1000);
    
    // Set up automatic refresh
    this.setupRefreshInterval();
  }
  
  setupRefreshInterval() {
    // Clear any existing interval
    if (this.refreshInterval) {
      clearInterval(this.refreshInterval);
    }
    
    // Calculate time until refresh (expiry minus threshold)
    const timeUntilRefresh = Math.max(0, (this.tokenExpiry - Date.now()) - (this.refreshThreshold * 1000));
    
    // Set timeout to refresh the token
    setTimeout(() => this.refreshTokenIfNeeded(), timeUntilRefresh);
  }
  
  async refreshTokenIfNeeded() {
    // Check if token needs refresh and not already in progress
    if (this.shouldRefreshToken() && !this.refreshInProgress) {
      try {
        this.refreshInProgress = true;
        await this.performTokenRefresh();
      } catch (error) {
        console.error('Token refresh failed:', error);
        // Implement retry logic or redirect to login
      } finally {
        this.refreshInProgress = false;
      }
    }
  }
  
  shouldRefreshToken() {
    // Check if token will expire within the threshold
    return this.tokenExpiry - Date.now() < (this.refreshThreshold * 1000);
  }
  
  async performTokenRefresh() {
    const tenantId = localStorage.getItem('tenantId');
    const requestId = crypto.randomUUID();
    
    const response = await fetch('https://api.finhub.cloud/api/v2.1/auth/token/refresh', {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        'X-Tenant-ID': tenantId,
        'X-Request-ID': requestId
      },
      body: JSON.stringify({
        refreshToken: this.refreshToken,
        customerId: 'OQ1GG9iFxVcgzforkJR8CImHiuwa',
        customerSecret: 'lPGwgaAENdwLxtfuqQu5R606jswa'
      })
    });
    
    if (!response.ok) {
      throw new Error(`Token refresh failed: ${response.status}`);
    }
    
    const refreshData = await response.json();
    
    // Update stored tokens
    this.setTokens(
      refreshData.userSessionToken,
      refreshData.refreshToken,
      refreshData.expires_in
    );
    
    // Update secure storage
    localStorage.setItem('userSessionToken', refreshData.userSessionToken);
    localStorage.setItem('refreshToken', refreshData.refreshToken);
    localStorage.setItem('tokenExpiry', this.tokenExpiry);
    
    return refreshData.userSessionToken;
  }
  
  getValidToken() {
    // Check if token needs immediate refresh
    if (this.shouldRefreshToken()) {
      this.refreshTokenIfNeeded();
    }
    return this.userSessionToken;
  }
}

// Usage
const tokenManager = new TokenManager();

// After authentication
tokenManager.setTokens(
  authData.userSessionToken,
  authData.refreshToken,
  authData.expires_in
);

// When making API requests
const token = tokenManager.getValidToken();

async function logout() {
  const userSessionToken = localStorage.getItem('userSessionToken');
  const tenantId = localStorage.getItem('tenantId');
  const activityId = localStorage.getItem('activityId');
  const requestId = crypto.randomUUID();
  
  try {
    // Call logout endpoint
    const response = await fetch('https://api.finhub.cloud/api/v2.1/auth/logout', {
      method: 'POST',
      headers: {
        'Authorization': `Bearer ${userSessionToken}`,
        'Content-Type': 'application/json',
        'X-Tenant-ID': tenantId,
        'X-Activity-ID': activityId,
        'X-Request-ID': requestId
      }
    });
    
    // Log logout result
    if (response.ok) {
      console.log('Logout successful');
    } else {
      console.error('Logout failed:', response.status);
    }
  } catch (error) {
    console.error('Logout error:', error);
  } finally {
    // Clear all session data regardless of logout API success
    secureSessionStorage.clear();
    
    // Redirect to login page
    window.location.href = '/login';
  }
}