export interface UserWithGroups {
  id: string;
  email: string;
  username: string;
  name: string;
  authMethod: string;
  groups: string[];
}

export interface AuthState {
  user: UserWithGroups | null;
  authenticated: boolean;
  groups: string[];
}

/**
 * Authorization composable for role-based access control
 */
export const useAuthorization = () => {
  // Get the current user state from Nuxt
  const nuxtApp = useNuxtApp();
  
  // Create reactive auth state
  const authState = ref<AuthState>({
    user: null,
    authenticated: false,
    groups: []
  });

  // Create a loading state
  const isLoading = ref(true);

  // Function to sync auth state from nuxtApp payload
  const syncAuthState = () => {
    try {
      // Safely check if payload data exists
      if (nuxtApp.payload && nuxtApp.payload.data && nuxtApp.payload.data.authState) {
        const payloadAuthState = nuxtApp.payload.data.authState as AuthState;
        authState.value = payloadAuthState;
        isLoading.value = false;
        console.log('[useAuthorization] Auth state synced from payload:', {
          authenticated: payloadAuthState.authenticated,
          groups: payloadAuthState.groups,
          user: payloadAuthState.user?.email
        });
        return true;
      }
    } catch (error) {
      console.error('[useAuthorization] Error syncing auth state:', error);
    }
    return false;
  };

  // Try to get auth state from API if not in payload
  const loadAuthState = async () => {
    try {
      const sessionData = await $fetch('/api/auth/session') as AuthState;
      authState.value = sessionData;
      isLoading.value = false;
      console.log('[useAuthorization] Auth state loaded from API:', {
        authenticated: sessionData.authenticated,
        groups: sessionData.groups,
        user: sessionData.user?.email
      });
      
      // Update nuxtApp payload for future use
      updateAuthState(sessionData);
    } catch (error) {
      console.error('[useAuthorization] Failed to load auth state:', error);
      isLoading.value = false;
    }
  };

  // Initialize auth state immediately (not just onMounted)
  if (process.client) {
    // Try to sync from payload first
    const synced = syncAuthState();
    
    // If not synced from payload, load from API
    if (!synced) {
      loadAuthState();
    }
  } else {
    // On server, try to get from payload
    syncAuthState();
  }

  /**
   * Get current user groups from session
   */
  const getUserGroups = (): string[] => {
    try {
      return authState.value?.groups || [];
    } catch (error) {
      console.error('[useAuthorization] Error getting user groups:', error);
      return [];
    }
  };

  /**
   * Get current authenticated user
   */
  const getCurrentUser = (): UserWithGroups | null => {
    try {
      return authState.value?.user || null;
    } catch (error) {
      console.error('[useAuthorization] Error getting current user:', error);
      return null;
    }
  };

  /**
   * Check if user has specific role/group
   */
  const hasRole = (role: string): boolean => {
    const groups = getUserGroups();
    return groups.includes(role);
  };

  /**
   * Check if user has any of the specified roles
   */
  const hasAnyRole = (roles: string[]): boolean => {
    const groups = getUserGroups();
    return roles.some(role => groups.includes(role));
  };

  /**
   * Check if user has all of the specified roles
   */
  const hasAllRoles = (roles: string[]): boolean => {
    const groups = getUserGroups();
    return roles.every(role => groups.includes(role));
  };

  /**
   * Check if user can access a specific resource/feature
   */
  const canAccess = (resource: string): boolean => {
    const groups = getUserGroups();
    
    // Define access rules for different resources
    const accessRules: Record<string, string[]> = {
      'expenses': ['sales', 'admin'],
      'admin-console': ['admin'],
      'audit-logs': ['admin'],
      'system-logs': ['admin'],
      'duplicate-management': ['admin'],
      'user-management': ['admin'],
      'interests': ['user', 'sales', 'admin'],
      'berths': ['user', 'sales', 'admin'],
      'dashboard': ['user', 'sales', 'admin'],
    };

    const requiredRoles = accessRules[resource];
    if (!requiredRoles) {
      // If no specific rules defined, allow for authenticated users
      return groups.length > 0;
    }

    return hasAnyRole(requiredRoles);
  };

  /**
   * Convenience methods for common role checks
   */
  const isAdmin = (): boolean => hasRole('admin');
  const isSales = (): boolean => hasRole('sales');
  const isUser = (): boolean => hasRole('user');
  const isSalesOrAdmin = (): boolean => hasAnyRole(['sales', 'admin']);
  const isUserOrAbove = (): boolean => hasAnyRole(['user', 'sales', 'admin']);

  /**
   * Get user's highest role (for display purposes)
   */
  const getHighestRole = (): string => {
    const groups = getUserGroups();
    if (groups.includes('admin')) return 'admin';
    if (groups.includes('sales')) return 'sales';
    if (groups.includes('user')) return 'user';
    return 'none';
  };

  /**
   * Get role display name
   */
  const getRoleDisplayName = (role: string): string => {
    const roleNames: Record<string, string> = {
      'admin': 'Administrator',
      'sales': 'Sales Team',
      'user': 'User',
      'none': 'No Access'
    };
    return roleNames[role] || role;
  };

  /**
   * Get role color for UI display
   */
  const getRoleColor = (role: string): string => {
    const roleColors: Record<string, string> = {
      'admin': 'red',
      'sales': 'purple',
      'user': 'blue',
      'none': 'grey'
    };
    return roleColors[role] || 'grey';
  };

  /**
   * Check if current route requires specific roles
   */
  const checkRouteAccess = (route: any): boolean => {
    if (!route.meta?.roles) {
      // No role requirements, allow access
      return true;
    }

    const requiredRoles = Array.isArray(route.meta.roles) ? route.meta.roles : [route.meta.roles];
    return hasAnyRole(requiredRoles);
  };

  /**
   * Get navigation items filtered by user permissions
   */
  const getFilteredNavigation = (navigationItems: any[]): any[] => {
    return navigationItems.filter(item => {
      if (!item.roles) return true; // No role restrictions
      return hasAnyRole(item.roles);
    });
  };

  /**
   * Update auth state (called by middleware)
   */
  const updateAuthState = (authState: AuthState) => {
    if (!nuxtApp.payload.data) {
      nuxtApp.payload.data = {};
    }
    nuxtApp.payload.data.authState = authState;
  };

  return {
    // State getters
    getUserGroups,
    getCurrentUser,
    
    // Role checking
    hasRole,
    hasAnyRole,
    hasAllRoles,
    canAccess,
    
    // Convenience methods
    isAdmin,
    isSales,
    isUser,
    isSalesOrAdmin,
    isUserOrAbove,
    
    // Utility methods
    getHighestRole,
    getRoleDisplayName,
    getRoleColor,
    checkRouteAccess,
    getFilteredNavigation,
    
    // State management
    updateAuthState
  };
};