import { useState, useEffect, useCallback } from 'react';
import { useAuth } from '../contexts/AuthContext';

/**
 * 前端权限 hook
 * 获取当前用户在活动租户下的权限集，提供便捷的检查方法
 *
 * @example
 * ```tsx
 * const { hasPermission, hasAnyPermission, isLoading } = usePermissions();
 *
 * if (hasPermission('user:create')) {
 *   // 渲染创建用户按钮
 * }
 *
 * {hasAnyPermission('user:edit', 'user:delete') && <AdminActions />}
 * ```
 */
export function usePermissions() {
  const { apiKey, activeTenant } = useAuth();
  const [permissions, setPermissions] = useState<string[]>([]);
  const [isLoading, setIsLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);

  const fetchPermissions = useCallback(async () => {
    if (!apiKey || !activeTenant) {
      setPermissions([]);
      setIsLoading(false);
      return;
    }

    try {
      setIsLoading(true);
      const res = await fetch('/api/permissions/mine', {
        headers: {
          'x-api-key': apiKey,
          'x-tenant-id': activeTenant.tenantId,
        },
      });

      if (res.ok) {
        const data = await res.json();
        setPermissions(data.permissions || []);
        setError(null);
      } else {
        setPermissions([]);
      }
    } catch (err: any) {
      console.error('Failed to fetch permissions:', err);
      setError(err.message);
      setPermissions([]);
    } finally {
      setIsLoading(false);
    }
  }, [apiKey, activeTenant?.tenantId]);

  // 获取权限
  useEffect(() => {
    fetchPermissions();
  }, [fetchPermissions]);

  const hasPermission = useCallback(
    (key: string) => permissions.includes(key),
    [permissions],
  );

  const hasAnyPermission = useCallback(
    (...keys: string[]) => keys.some(k => permissions.includes(k)),
    [permissions],
  );

  const hasAllPermissions = useCallback(
    (...keys: string[]) => keys.every(k => permissions.includes(k)),
    [permissions],
  );

  return {
    permissions,
    isLoading,
    error,
    hasPermission,
    hasAnyPermission,
    hasAllPermissions,
    refresh: fetchPermissions,
  };
}