using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace BaiduSearchApp
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {
        private int _currentPage = 1;
        private int _pageSize = 10; // 每页显示10条结果
        private int _totalItems = 0;
        private int _totalPages = 1;
        private string _currentQuery = string.Empty;
        private BaiduSearchApi _searchApi;
        private List<Reference> _allSearchResults = new List<Reference>(); // 存储所有搜索结果

        public MainWindow()
        {
            InitializeComponent();
            // 初始化占位符可见性
            txtApiKeyPlaceholder.Visibility = Visibility.Visible;
            txtSearchQueryPlaceholder.Visibility = Visibility.Visible;
            // 初始化 WebView2
            InitializeWebView();
        }
        
        private void TxtApiKey_TextChanged(object sender, TextChangedEventArgs e)
        {
            txtApiKeyPlaceholder.Visibility = string.IsNullOrEmpty(txtApiKey.Text) ? Visibility.Visible : Visibility.Collapsed;
        }
        
        private void TxtSearchQuery_TextChanged(object sender, TextChangedEventArgs e)
        {
            txtSearchQueryPlaceholder.Visibility = string.IsNullOrEmpty(txtSearchQuery.Text) ? Visibility.Visible : Visibility.Collapsed;
        }

        private async void BtnSearch_Click(object sender, RoutedEventArgs e)
        {
            await PerformSearchAsync();
        }

        private async void TxtSearchQuery_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.Key == Key.Enter)
            {
                await PerformSearchAsync();
            }
        }

        private async Task PerformSearchAsync()
        {
            string apiKey = txtApiKey.Text.Trim();
            string query = txtSearchQuery.Text.Trim();

            if (string.IsNullOrEmpty(apiKey))
            {
                ShowErrorMessage("请先输入百度千帆API Key");
                return;
            }

            if (string.IsNullOrEmpty(query))
            {
                ShowErrorMessage("请输入搜索内容");
                return;
            }

            try
            {
                txtStatus.Text = "正在搜索中...";
                btnSearch.IsEnabled = false;
                btnPrevPage.IsEnabled = false;
                btnNextPage.IsEnabled = false;
                lvSearchResults.Items.Clear();

                _searchApi = new BaiduSearchApi(apiKey);
                _currentQuery = query;
                _currentPage = 1; // 重置为第一页
                
                // 一次获取最多50条结果
                SearchResponse response = await _searchApi.SearchAsync(query, 50);

                if (response.References != null && response.References.Count > 0)
                {
                    // 保存所有搜索结果
                    _allSearchResults = response.References;
                    _totalItems = _allSearchResults.Count;
                    
                    // 计算总页数
                    _totalPages = (int)Math.Ceiling((double)_totalItems / _pageSize);
                    
                    txtStatus.Text = $"找到 {_totalItems} 条结果";
                    
                    // 显示当前页结果
                    ShowCurrentPageResults();
                    
                    // 更新分页信息
                    UpdatePaginationInfo();
                }
                else
                {
                    txtStatus.Text = "未找到相关结果";
                    _allSearchResults.Clear();
                    _totalItems = 0;
                    _totalPages = 1;
                    _currentPage = 1;
                    UpdatePaginationInfo();
                }
            }
            catch (HttpRequestException ex)
            {
                ShowErrorMessage($"网络错误: {ex.Message}");
            }
            catch (Exception ex)
            {
                ShowErrorMessage($"搜索失败: {ex.Message}");
            }
            finally
            {
                btnSearch.IsEnabled = true;
            }
        }

        private void ShowErrorMessage(string message)
        {
            txtStatus.Text = message;
            MessageBox.Show(message, "错误", MessageBoxButton.OK, MessageBoxImage.Error);
        }
        
        #region 分页相关方法
        
        /// <summary>
        /// 显示当前页的搜索结果
        /// </summary>
        private void ShowCurrentPageResults()
        {
            lvSearchResults.Items.Clear();
            
            // 计算当前页的起始和结束索引
            int startIndex = (_currentPage - 1) * _pageSize;
            int endIndex = Math.Min(startIndex + _pageSize, _totalItems);
            
            // 添加当前页的结果
            for (int i = startIndex; i < endIndex; i++)
            {
                lvSearchResults.Items.Add(_allSearchResults[i]);
            }
        }
        
        private void UpdatePaginationInfo()
        {
            // 更新分页信息
            txtPageInfo.Text = $"第 {_currentPage} 页，共 {_totalPages} 页";
            
            // 启用/禁用分页按钮
            btnPrevPage.IsEnabled = _currentPage > 1;
            btnNextPage.IsEnabled = _currentPage < _totalPages;
        }
        
        private void BtnPrevPage_Click(object sender, RoutedEventArgs e)
        {
            if (_currentPage > 1)
            {
                _currentPage--;
                ShowCurrentPageResults();
                UpdatePaginationInfo();
            }
        }
        
        private void BtnNextPage_Click(object sender, RoutedEventArgs e)
        {
            if (_currentPage < _totalPages)
            {
                _currentPage++;
                ShowCurrentPageResults();
                UpdatePaginationInfo();
            }
        }
        
        #endregion
        
        #region WebView2 相关方法
        
        private async void InitializeWebView()
        {
            // 初始化 WebView2
            await webView.EnsureCoreWebView2Async();
            
            // 设置 WebView2 事件
            webView.CoreWebView2.NavigationCompleted += CoreWebView2_NavigationCompleted;
            webView.CoreWebView2.HistoryChanged += CoreWebView2_HistoryChanged;
        }
        
        private void CoreWebView2_NavigationCompleted(object sender, Microsoft.Web.WebView2.Core.CoreWebView2NavigationCompletedEventArgs e)
        {
            // 更新地址栏
            txtBrowserUrl.Text = webView.Source.ToString();
        }
        
        private void CoreWebView2_HistoryChanged(object sender, object e)
        {
            // 更新前进后退按钮状态
            btnBack.IsEnabled = webView.CanGoBack;
            btnForward.IsEnabled = webView.CanGoForward;
        }
        
        private void LvSearchResults_MouseDoubleClick(object sender, MouseButtonEventArgs e)
        {
            // 双击搜索结果项打开链接
            if (lvSearchResults.SelectedItem is Reference selectedReference)
            {
                OpenUrlInBrowser(selectedReference.Url);
            }
        }
        
        private void OpenUrlInBrowser(string url)
        {
            if (!string.IsNullOrEmpty(url) && webView.CoreWebView2 != null)
            {
                webView.CoreWebView2.Navigate(url);
            }
        }
        
        private void BtnBack_Click(object sender, RoutedEventArgs e)
        {
            if (webView.CanGoBack)
            {
                webView.GoBack();
            }
        }
        
        private void BtnForward_Click(object sender, RoutedEventArgs e)
        {
            if (webView.CanGoForward)
            {
                webView.GoForward();
            }
        }
        
        private void BtnRefresh_Click(object sender, RoutedEventArgs e)
        {
            webView.Reload();
        }
        
        private void BtnGo_Click(object sender, RoutedEventArgs e)
        {
            if (!string.IsNullOrEmpty(txtBrowserUrl.Text) && webView.CoreWebView2 != null)
            {
                webView.CoreWebView2.Navigate(txtBrowserUrl.Text);
            }
        }
        
        private void BtnCloseBrowser_Click(object sender, RoutedEventArgs e)
        {
            if (webView.CoreWebView2 != null)
            {
                webView.CoreWebView2.NavigateToString("<html><body><h3>浏览器已关闭</h3><p>双击搜索结果项打开链接</p></body></html>");
            }
        }
        
        #endregion
    }
}