'use client';

import { useState, useEffect } from 'react';
import Link from 'next/link';
import Image from 'next/image';
import { useRouter, useSearchParams } from 'next/navigation';
import DeleteButton from './DeleteButton';
import Pagination from '@/lib/components/Pagination';

interface User {
  id: string;
  username: string;
  avatar: string | null;
  createdAt: string;
  modifiedAt: string;
}

interface PaginationInfo {
  page: number;
  pageSize: number;
  totalCount: number;
  totalPages: number;
}

interface UsersResponse {
  data: User[];
  pagination: PaginationInfo;
}

export default function AdminUsers() {
  const router = useRouter();
  const searchParams = useSearchParams();

  // Get pagination values from URL params
  const initialPage = parseInt(searchParams.get('page') || '1');
  const initialPageSize = parseInt(searchParams.get('pageSize') || '10');

  // State for pagination
  const [page, setPage] = useState(initialPage);
  const [pageSize, setPageSize] = useState(initialPageSize);

  // State for data
  const [users, setUsers] = useState<User[]>([]);
  const [pagination, setPagination] = useState<PaginationInfo>({
    page: initialPage,
    pageSize: initialPageSize,
    totalCount: 0,
    totalPages: 0
  });
  const [isLoading, setIsLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);

  // Fetch users with pagination
  useEffect(() => {
    const fetchUsers = async () => {
      setIsLoading(true);
      setError(null);

      try {
        // Build query string with pagination
        const params = new URLSearchParams();
        params.append('page', initialPage.toString());
        params.append('pageSize', initialPageSize.toString());

        const response = await fetch(`/api/users?${params.toString()}`);

        if (!response.ok) {
          throw new Error('Failed to fetch users');
        }

        const responseData: UsersResponse = await response.json();
        setUsers(responseData.data);
        setPagination(responseData.pagination);
      } catch (err) {
        console.error('Error fetching users:', err);
        setError(err instanceof Error ? err.message : 'An error occurred');
      } finally {
        setIsLoading(false);
      }
    };

    fetchUsers();
  }, [initialPage, initialPageSize]);

  // Handle page change
  const handlePageChange = (newPage: number) => {
    setPage(newPage);

    // Build query string with new page
    const params = new URLSearchParams(searchParams.toString());
    params.set('page', newPage.toString());

    // Update URL with new page
    router.push(`/admin/users?${params.toString()}`);
  };

  return (
    <div>
      <div className="flex justify-between items-center">
        <h1 className="text-2xl font-semibold text-gray-900 dark:text-gray-100">Users</h1>
        <Link
          href="/admin/users/new"
          className="inline-flex items-center px-4 py-2 border border-transparent text-sm font-medium rounded-md shadow-sm text-white bg-indigo-600 hover:bg-indigo-700 focus:outline-none focus:ring-2 focus:ring-offset-2 focus:ring-indigo-500"
        >
          Add New User
        </Link>
      </div>

      {/* Error Message */}
      {error && (
        <div className="bg-red-50 border-l-4 border-red-400 p-4 my-4 dark:bg-red-900/20 dark:border-red-500">
          <div className="flex">
            <div className="flex-shrink-0">
              <svg className="h-5 w-5 text-red-400 dark:text-red-300" viewBox="0 0 20 20" fill="currentColor">
                <path fillRule="evenodd" d="M10 18a8 8 0 100-16 8 8 0 000 16zM8.707 7.293a1 1 0 00-1.414 1.414L8.586 10l-1.293 1.293a1 1 0 101.414 1.414L10 11.414l1.293 1.293a1 1 0 001.414-1.414L11.414 10l1.293-1.293a1 1 0 00-1.414-1.414L10 8.586 8.707 7.293z" clipRule="evenodd" />
              </svg>
            </div>
            <div className="ml-3">
              <p className="text-sm text-red-700 dark:text-red-300">{error}</p>
            </div>
          </div>
        </div>
      )}

      {/* Loading State */}
      {isLoading ? (
        <div className="text-center py-8">
          <p className="text-gray-500 dark:text-gray-400">Loading users...</p>
        </div>
      ) : (
        <div className="mt-8 flex flex-col">
          <div className="-my-2 -mx-4 overflow-x-auto sm:-mx-6 lg:-mx-8">
            <div className="inline-block min-w-full py-2 align-middle md:px-6 lg:px-8">
              <div className="overflow-hidden shadow ring-1 ring-black ring-opacity-5 md:rounded-lg">
                <table className="min-w-full divide-y divide-gray-300 dark:divide-gray-700">
                  <thead className="bg-gray-50 dark:bg-gray-700">
                    <tr>
                      <th
                        scope="col"
                        className="py-3.5 pl-4 pr-3 text-left text-sm font-semibold text-gray-900 dark:text-gray-200 sm:pl-6"
                      >
                        Username
                      </th>
                      <th
                        scope="col"
                        className="px-3 py-3.5 text-left text-sm font-semibold text-gray-900 dark:text-gray-200"
                      >
                        Avatar
                      </th>
                      <th
                        scope="col"
                        className="px-3 py-3.5 text-left text-sm font-semibold text-gray-900 dark:text-gray-200"
                      >
                        Created
                      </th>
                      <th
                        scope="col"
                        className="px-3 py-3.5 text-left text-sm font-semibold text-gray-900 dark:text-gray-200"
                      >
                        Modified
                      </th>
                      <th scope="col" className="relative py-3.5 pl-3 pr-4 sm:pr-6">
                        <span className="sr-only">Actions</span>
                      </th>
                    </tr>
                  </thead>
                  <tbody className="divide-y divide-gray-200 bg-white dark:bg-gray-800 dark:divide-gray-700">
                    {users.length > 0 ? (
                      users.map((user) => (
                        <tr key={user.id}>
                          <td className="whitespace-nowrap py-4 pl-4 pr-3 text-sm font-medium text-gray-900 dark:text-gray-200 sm:pl-6">
                            {user.username}
                          </td>
                          <td className="whitespace-nowrap px-3 py-4 text-sm text-gray-500 dark:text-gray-400">
                            {user.avatar ? (
                              <Image
                                src={user.avatar}
                                alt={user.username}
                                width={40}
                                height={40}
                                className="rounded-full"
                              />
                            ) : (
                              <div className="h-10 w-10 rounded-full bg-gray-200 dark:bg-gray-600 flex items-center justify-center text-gray-500 dark:text-gray-300">
                                {user.username.charAt(0).toUpperCase()}
                              </div>
                            )}
                          </td>
                          <td className="whitespace-nowrap px-3 py-4 text-sm text-gray-500 dark:text-gray-400">
                            {new Date(user.createdAt).toLocaleDateString()}
                          </td>
                          <td className="whitespace-nowrap px-3 py-4 text-sm text-gray-500 dark:text-gray-400">
                            {new Date(user.modifiedAt).toLocaleDateString()}
                          </td>
                          <td className="relative whitespace-nowrap py-4 pl-3 pr-4 text-right text-sm font-medium sm:pr-6">
                            <Link
                              href={`/admin/users/edit/${user.id}`}
                              className="text-indigo-600 hover:text-indigo-900 dark:text-indigo-400 dark:hover:text-indigo-300 mr-4"
                            >
                              Edit
                            </Link>
                            <DeleteButton userId={user.id} username={user.username} />
                          </td>
                        </tr>
                      ))
                    ) : (
                      <tr>
                        <td colSpan={5} className="py-4 pl-4 pr-3 text-sm text-gray-500 dark:text-gray-400 text-center">
                          No users found. Create your first user!
                        </td>
                      </tr>
                    )}
                  </tbody>
                </table>

                {/* Pagination */}
                <Pagination
                  currentPage={pagination.page}
                  totalPages={pagination.totalPages}
                  totalItems={pagination.totalCount}
                  pageSize={pagination.pageSize}
                  onPageChange={handlePageChange}
                />
              </div>
            </div>
          </div>
        </div>
      )}
    </div>
  );
}