import { computed } from "vue";
import { useUserStore } from "@/stores/user";

// ============================================================================
// TYPES
// ============================================================================

export interface MenuItem {
  id?: string;
  title?: string;
  icon?: string;
  to?: string;
  divider?: boolean;
  chip?: string;
  chipColor?: string;
  chipVariant?: string;
  chipIcon?: string;
  children?: MenuItem[];
  disabled?: boolean;
  type?: string;
  subCaption?: string;
  permissions?: string[];
  permissionLogic?: "AND" | "OR";
  roles?: string[];
  roleLogic?: "AND" | "OR";
}

// ============================================================================
// MENU CONFIGURATION
// ============================================================================

const rawSidebarItems: MenuItem[] = [
  {
    title: "Dashboard",
    icon: "custom-home-trend",
    to: "/dashboard",
  },

  // ========================================================================
  // SHAREHOLDER MANAGEMENT
  // ========================================================================
  {
    title: "Shareholders",
    icon: "custom-users",
    to: "/shareholders",
    permissions: ["view shareholders", "manage shareholders"],
    permissionLogic: "OR",
    roles: ["Admin", "Finance", "SystemOwner"],
    roleLogic: "OR",
  },
  {
    title: "Add Shareholder",
    icon: "custom-user-add",
    to: "/shareholders/create",
    permissions: ["manage shareholders"],
    roles: ["Admin", "SystemOwner"],
    roleLogic: "OR",
  },

  // ========================================================================
  // PAYMENTS
  // ========================================================================
  {
    title: "Payments",
    icon: "custom-wallet",
    to: "/payments",
    permissions: ["view payments", "manage payments", "view own data"],
    permissionLogic: "OR",
    roles: ["Admin", "Finance", "SystemOwner", "Shareholder"],
    roleLogic: "OR",
  },
  {
    title: "Record Payment",
    icon: "custom-shopping-bag",
    to: "/payments/create",
    permissions: ["manage payments"],
    roles: ["Admin", "Finance", "SystemOwner"],
    roleLogic: "OR",
  },

  // ========================================================================
  // INVOICES
  // ========================================================================
  {
    title: "Invoices",
    icon: "custom-invoice",
    to: "/invoices",
    permissions: ["view invoices", "manage invoices", "view own data"],
    permissionLogic: "OR",
    roles: ["Admin", "Finance", "SystemOwner", "Shareholder"],
    roleLogic: "OR",
  },
  {
    title: "Create Invoice",
    icon: "custom-table",
    to: "/invoices/create",
    permissions: ["manage invoices"],
    roles: ["Admin", "Finance", "SystemOwner"],
    roleLogic: "OR",
  },

  // ========================================================================
  // DIVIDENDS
  // ========================================================================
  {
    title: "Financial Years",
    icon: "custom-dollar-fill",
    to: "/financial-years",
    permissions: ["view invoices", "manage invoices"],
    permissionLogic: "OR",
    roles: ["Admin", "Finance", "SystemOwner"],
    roleLogic: "OR",
  },
  // ========================================================================
  // REPORTS
  // ========================================================================
  {
    title: "Reports",
    icon: "custom-graph",
    to: "/reports",
    permissions: ["view reports"],
    roles: ["Admin", "Finance", "SystemOwner"],
    roleLogic: "OR",
    children: [
      {
        title: "Shareholder Summary",
        to: "/reports/shareholder-summary",
        permissions: ["view reports"],
      },
      {
        title: "Payment History",
        to: "/reports/payment-history",
        permissions: ["view reports"],
      },
      {
        title: "Arrears Report",
        to: "/reports/arrears",
        permissions: ["view reports"],
      },
      {
        title: "Monthly Contributions",
        to: "/reports/monthly-contributions",
        permissions: ["view reports"],
      },
    ],
  },
  {
    title: "My Statement",
    icon: "custom-document-text",
    to: "/statement",
    permissions: ["view own data"],
    roles: ["Shareholder"],
  },

  // ========================================================================
  // USER MANAGEMENT
  // ========================================================================
  {
    title: "User Management",
    icon: "custom-setting-fill",
    to: "/users",
    permissions: ["manage users"],
    roles: ["Admin", "SystemOwner"],
    roleLogic: "OR",
    children: [
      {
        title: "All Users",
        to: "/users",
        permissions: ["manage users"],
      },
      {
        title: "Create User",
        to: "/users/create",
        permissions: ["manage users"],
      },
      {
        title: "Roles & Permissions",
        to: "/users/roles",
        permissions: ["manage roles"],
      },
    ],
  },

  // ========================================================================
  // PROFILE
  // ========================================================================
  {
    title: "My Profile",
    icon: "custom-user",
    to: "/profile",
  },

  // ========================================================================
  // AUDIT TRAIL
  // ========================================================================
  {
    title: "Audit Trail",
    icon: "custom-history",
    to: "/audit-logs",
    permissions: ["view audit logs"],
    roles: ["SystemOwner"],
  },
];

// ============================================================================
// UTILITY FUNCTIONS
// ============================================================================

/**
 * Extract permission names from user permissions array
 */
function extractPermissionNames(permissions: any[]): string[] {
  if (!Array.isArray(permissions)) return [];
  return permissions.map((p) => (typeof p === "string" ? p : p.name));
}

/**
 * Extract role names from user roles array
 */
function extractRoleNames(roles: any[]): string[] {
  if (!Array.isArray(roles)) return [];
  return roles.map((r) => (typeof r === "string" ? r : r.name));
}

/**
 * Check if conditions match using AND/OR logic
 */
function checkConditions(
  requiredItems: string[],
  availableItems: string[],
  logic: "AND" | "OR" = "AND",
): boolean {
  if (requiredItems.length === 0) return true;

  return logic === "OR"
    ? requiredItems.some((item) => availableItems.includes(item))
    : requiredItems.every((item) => availableItems.includes(item));
}

// ============================================================================
// PERMISSION & ROLE CHECKING
// ============================================================================

/**
 * Check if user has required permissions
 */
function hasRequiredPermissions(
  item: MenuItem,
  userPermissions: string[],
): boolean {
  if (!item.permissions?.length) return true;

  const logic = item.permissionLogic || "AND";
  return checkConditions(item.permissions, userPermissions, logic);
}

/**
 * Check if user has required roles
 */
function hasRequiredRoles(item: MenuItem, userRoles: string[]): boolean {
  if (!item.roles?.length) return true;

  const logic = item.roleLogic || "AND";
  return checkConditions(item.roles, userRoles, logic);
}

// ============================================================================
// MENU FILTERING
// ============================================================================

/**
 * Filter menu items recursively based on permissions and roles
 */
function filterMenuItems(
  items: MenuItem[],
  userPermissions: string[],
  userRoles: string[],
): MenuItem[] {
  return items
    .filter((item) => {
      // Check permissions
      if (!hasRequiredPermissions(item, userPermissions)) {
        return false;
      }

      // Check roles
      if (!hasRequiredRoles(item, userRoles)) {
        return false;
      }

      return true;
    })
    .map((item) => {
      if (!item.children?.length) return item;

      // Recursively filter children
      const filteredChildren = filterMenuItems(
        item.children,
        userPermissions,
        userRoles,
      );

      // If parent has no valid children, hide it
      if (filteredChildren.length === 0) {
        return null;
      }

      return { ...item, children: filteredChildren };
    })
    .filter(Boolean) as MenuItem[];
}

// ============================================================================
// REACTIVE SIDEBAR ITEMS
// ============================================================================

export const sidebarItems = computed(() => {
  const userStore = useUserStore();

  // 1. If we have a token but user not loaded → trigger fetch (non-blocking)
  if (userStore.token && !userStore.isLoaded && !userStore.isLoading) {
    userStore.fetchUser().catch(() => {
      // Silently fail — navigation guard will redirect anyway
    });
  }

  // 2. While loading or not ready → return empty menu (no flicker)
  if (!userStore.isLoaded || !userStore.user) {
    return [];
  }

  // 3. User is fully loaded → build menu
  // Use abilityRules directly (your Spatie permissions)
  const userPermissions = userStore.abilityRules || [];

  const userRole = userStore.user.user_role || "";

  // Optional: fallback for old role field (if you still have it)
  const userRoles = userStore.user.role ? [userStore.user.role] : [userRole];

  return filterMenuItems(rawSidebarItems, userPermissions, userRoles);
});

// ============================================================================
// COMPOSABLE API
// ============================================================================

export const useFilteredMenu = () => {
  const userStore = useUserStore();

  const refreshMenu = async () => {
    if (!userStore.isLoaded || !userStore.user) {
      await userStore.fetchUser();
    }
    return sidebarItems.value;
  };

  const getUserPermissions = (): string[] => {
    return extractPermissionNames(userStore.user?.permissions || []);
  };

  const getUserRoles = (): string[] => {
    return extractRoleNames(userStore.user?.roles || []);
  };

  const hasPermission = (permission: string): boolean => {
    const permissions = getUserPermissions();
    return permissions.includes(permission);
  };

  const hasAnyPermission = (permissions: string[]): boolean => {
    const userPermissions = getUserPermissions();
    return permissions.some((p) => userPermissions.includes(p));
  };

  const hasAllPermissions = (permissions: string[]): boolean => {
    const userPermissions = getUserPermissions();
    return permissions.every((p) => userPermissions.includes(p));
  };

  const hasRole = (role: string): boolean => {
    const roles = getUserRoles();
    return roles.includes(role);
  };

  const hasAnyRole = (roles: string[]): boolean => {
    const userRoles = getUserRoles();
    return roles.some((r) => userRoles.includes(r));
  };

  const hasAllRoles = (roles: string[]): boolean => {
    const userRoles = getUserRoles();
    return roles.every((r) => userRoles.includes(r));
  };

  return {
    sidebarItems,
    refreshMenu,
    getUserPermissions,
    getUserRoles,
    hasPermission,
    hasAnyPermission,
    hasAllPermissions,
    hasRole,
    hasAnyRole,
    hasAllRoles,
  };
};

export default sidebarItems;