using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Reflection;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Threading;
using NetTool.Client.Models;
using NetTool.Client.Services;

namespace NetTool.Client;

public partial class MainWindow : Window
{
    private readonly NetworkAdapterService _networkAdapterService = new();
    private readonly PasswordStoreService _passwordStoreService = new();
    private readonly DiscoveryService _discoveryService = new();
    private readonly ServerApiService _serverApiService = new();
    private IReadOnlyList<AdapterInfo> _allAdapters = [];
    private IReadOnlyList<AdapterInfo> _adapters = [];
    private readonly ObservableCollection<DiscoveredDevice> _discoveredDevices = [];
    private bool _isBusy;
    private bool _isSearchingDevices;
    private CancellationTokenSource? _deviceSearchCts;
    private CancellationTokenSource? _statusMessageCts;

    public MainWindow()
    {
        InitializeComponent();
        Title = $"NetTool {GetClientVersion()}";
        Loaded += MainWindow_OnLoaded;
    }

    private static string GetClientVersion()
    {
        return Assembly.GetExecutingAssembly()
            .GetCustomAttribute<AssemblyInformationalVersionAttribute>()?
            .InformationalVersion.Split('+')[0] ?? "unknown";
    }

    private void MainWindow_OnLoaded(object sender, RoutedEventArgs e)
    {
        LoadInitialState();
    }

    private void LoadInitialState()
    {
        _allAdapters = _networkAdapterService.GetAdapters();
        ApplyAdapterFilter();
        UpdateButtonStates();
    }

    private void ApplyAdapterFilter(string? selectedAdapterId = null)
    {
        _adapters = _allAdapters
            .Where(adapter => ShowUsableAdaptersOnlyCheckBox.IsChecked != true || IsUsableAdapter(adapter))
            .OrderByDescending(adapter => adapter.RecommendationScore)
            .ThenBy(adapter => adapter.Name)
            .ToList();
        AdapterComboBox.ItemsSource = _adapters;

        var selected = selectedAdapterId is null
            ? null
            : _adapters.FirstOrDefault(adapter => adapter.Id == selectedAdapterId);

        if (selected is not null)
        {
            AdapterComboBox.SelectedItem = selected;
        }
        else
        {
            AdapterComboBox.SelectedIndex = -1;
        }

        UpdateAdapterPlaceholder();
    }

    private static bool IsUsableAdapter(AdapterInfo adapter)
    {
        return adapter.HasLink && !string.IsNullOrWhiteSpace(adapter.IPv4Address);
    }

    private void AdapterComboBox_OnSelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        if (AdapterComboBox.SelectedItem is not AdapterInfo adapter)
        {
            CancelDeviceSearch();
            ClearDiscoveredDevices();
            UpdateAdapterPlaceholder();
            SetStatus("请选择一块网卡。", StatusMessageType.Warning, false);
            UpdateButtonStates();
            return;
        }

        UpdateAdapterPlaceholder();
        if (!adapter.HasLink)
        {
            CancelDeviceSearch();
            ClearDiscoveredDevices();
            SetStatus("当前网卡未检测到链路，请检查网线连接。", StatusMessageType.Warning, true);
            UpdateButtonStates();
            return;
        }

        UpdateButtonStates();
        _ = SearchDevicesAsync(adapter);
    }

    private void UpdateAdapterPlaceholder()
    {
        AdapterPlaceholderTextBlock.Visibility = AdapterComboBox.SelectedItem is null ? Visibility.Visible : Visibility.Collapsed;
    }

    private async void RefreshAdaptersButton_OnClick(object sender, RoutedEventArgs e)
    {
        SetBusyState(true, "正在刷新本机网卡...");
        try
        {
            var selectedAdapterId = (AdapterComboBox.SelectedItem as AdapterInfo)?.Id;
            RefreshAdapters(selectedAdapterId);
            SetStatus("已刷新本机网卡。", StatusMessageType.Success, true);
        }
        catch (Exception ex)
        {
            SetStatus($"刷新本机网卡失败：{ex.Message}", StatusMessageType.Error, true);
            MessageBox.Show(this, ex.Message, "刷新失败", MessageBoxButton.OK, MessageBoxImage.Error);
        }
        finally
        {
            SetBusyState(false);
        }

        if (AdapterComboBox.SelectedItem is AdapterInfo adapter)
        {
            await SearchDevicesAsync(adapter);
        }
    }

    private async void SearchDevicesButton_OnClick(object sender, RoutedEventArgs e)
    {
        if (AdapterComboBox.SelectedItem is AdapterInfo adapter)
        {
            await SearchDevicesAsync(adapter);
        }
        else
        {
            SetStatus("请先选择一块网卡。", StatusMessageType.Warning, true);
        }
    }

    private void ShowUsableAdaptersOnlyCheckBox_OnChanged(object sender, RoutedEventArgs e)
    {
        if (AdapterComboBox is null || ShowUsableAdaptersOnlyCheckBox is null)
        {
            return;
        }

        var selectedAdapterId = (AdapterComboBox.SelectedItem as AdapterInfo)?.Id;
        ApplyAdapterFilter(selectedAdapterId);
        UpdateButtonStates();
    }

    private async Task SearchDevicesAsync(AdapterInfo adapter)
    {
        if (_isBusy)
        {
            return;
        }

        if (string.IsNullOrWhiteSpace(adapter.IPv4Address))
        {
            CancelDeviceSearch();
            ClearDiscoveredDevices();
            SetStatus("当前网卡没有可用 IPv4，无法搜索设备。", StatusMessageType.Error, true);
            return;
        }

        if (!adapter.HasLink)
        {
            CancelDeviceSearch();
            ClearDiscoveredDevices();
            SetStatus("当前网卡未检测到链路，请检查网线连接。", StatusMessageType.Warning, true);
            return;
        }

        _deviceSearchCts?.Cancel();
        var searchCts = new CancellationTokenSource();
        _deviceSearchCts = searchCts;
        SetDeviceSearchState(true);
        ClearDiscoveredDevices();
        await Dispatcher.InvokeAsync(() => { }, System.Windows.Threading.DispatcherPriority.Render);

        try
        {
            await _discoveryService.DiscoverManyAsync(
                adapter.IPv4Address,
                device => Dispatcher.Invoke(() => UpsertDiscoveredDevice(device)),
                searchCts.Token);
            if (_discoveredDevices.Count == 0)
            {
                SetStatus("未发现 169.254 开头的设备 IP，请确认网卡、网线、远端服务和维护网段配置。", StatusMessageType.Warning, true);
                return;
            }

            SetStatus($"已发现 {_discoveredDevices.Count} 台设备，请点击右侧连接。", StatusMessageType.Success, true);
        }
        catch (OperationCanceledException)
        {
        }
        catch (Exception ex)
        {
            SetStatus($"搜索设备失败：{ex.Message}", StatusMessageType.Error, true);
            MessageBox.Show(this, ex.Message, "搜索设备失败", MessageBoxButton.OK, MessageBoxImage.Error);
        }
        finally
        {
            if (ReferenceEquals(_deviceSearchCts, searchCts))
            {
                SetDeviceSearchState(false);
            }
        }
    }

    private void SavePasswordForDevice(DiscoveredDevice device, string password)
    {
        var deviceKey = GetDevicePasswordKey(device);
        if (!string.IsNullOrWhiteSpace(deviceKey) && !string.IsNullOrWhiteSpace(password))
        {
            _passwordStoreService.SavePassword(deviceKey, password);
        }
    }

    private void UpdateButtonStates()
    {
        var adapter = AdapterComboBox.SelectedItem as AdapterInfo;
        var hasAdapter = adapter is not null;
        RefreshAdaptersButton.IsEnabled = !_isBusy;
        SearchDevicesButton.IsEnabled = !_isBusy && !_isSearchingDevices && hasAdapter && adapter!.HasLink;
    }

    private void RefreshAdapters(string? selectedAdapterId = null)
    {
        _allAdapters = _networkAdapterService.GetAdapters();
        ApplyAdapterFilter(selectedAdapterId);
    }

    private void ClearDiscoveredDevices()
    {
        _discoveredDevices.Clear();
        DiscoveredDevicesListView.ItemsSource = _discoveredDevices;
    }

    private void UpsertDiscoveredDevice(DiscoveredDevice device)
    {
        var existing = _discoveredDevices.FirstOrDefault(value => string.Equals(value.Lan2Ip, device.Lan2Ip, StringComparison.OrdinalIgnoreCase));
        if (existing is not null)
        {
            var index = _discoveredDevices.IndexOf(existing);
            _discoveredDevices[index] = device;
            return;
        }

        var insertIndex = 0;
        while (insertIndex < _discoveredDevices.Count && string.Compare(_discoveredDevices[insertIndex].Lan2Ip, device.Lan2Ip, StringComparison.OrdinalIgnoreCase) < 0)
        {
            insertIndex++;
        }

        _discoveredDevices.Insert(insertIndex, device);
        SetStatus($"已发现 {_discoveredDevices.Count} 台设备，搜索仍在继续。", StatusMessageType.Success, true);
    }

    private async void ConnectDeviceButton_OnClick(object sender, RoutedEventArgs e)
    {
        if (!_isBusy && sender is Button { DataContext: DiscoveredDevice device })
        {
            await ConnectToDeviceAsync(device);
        }
    }

    private void DiscoveredDevicesListView_OnSizeChanged(object sender, SizeChangedEventArgs e)
    {
        var availableWidth = DiscoveredDevicesListView.ActualWidth - 36;
        if (availableWidth <= 0)
        {
            return;
        }

        DeviceActionColumn.Width = 88;
        var contentWidth = Math.Max(0, availableWidth - DeviceActionColumn.Width);
        DeviceIpColumn.Width = Math.Max(130, contentWidth * 0.26);
        DeviceHostnameColumn.Width = Math.Max(150, contentWidth * 0.30);
        DeviceMacColumn.Width = Math.Max(180, contentWidth - DeviceIpColumn.Width - DeviceHostnameColumn.Width);
    }

    private void DiscoveredDevicesListView_OnLostKeyboardFocus(object sender, KeyboardFocusChangedEventArgs e)
    {
        if (sender is not ListView listView)
        {
            return;
        }

        Dispatcher.BeginInvoke(() =>
        {
            if (!listView.IsKeyboardFocusWithin)
            {
                listView.SelectedItem = null;
            }
        }, DispatcherPriority.Input);
    }

    private async Task ConnectToDeviceAsync(DiscoveredDevice device)
    {
        var deviceKey = GetDevicePasswordKey(device);
        var savedPassword = _passwordStoreService.LoadPassword(deviceKey);
        var passwordConfirmed = TryPromptForPassword(device, savedPassword, out var password, out var clearSavedPasswordRequested);

        if (clearSavedPasswordRequested)
        {
            _passwordStoreService.ClearPassword(deviceKey);
        }

        if (!passwordConfirmed)
        {
            return;
        }

        if (string.IsNullOrWhiteSpace(password))
        {
            SetStatus("请输入管理密码。", StatusMessageType.Warning, true);
            return;
        }

        var selectedAdapter = AdapterComboBox.SelectedItem as AdapterInfo;
        var httpPort = device.HttpPort > 0 ? device.HttpPort : 48888;
        var baseAddress = $"http://{device.Lan2Ip}:{httpPort}";

        while (true)
        {
            SetBusyState(true, $"正在连接 {device.Lan2Ip}...");

            try
            {
                var result = await _serverApiService.CheckHealthAsync(baseAddress, password, selectedAdapter?.IPv4Address ?? string.Empty);
                if (result.Success)
                {
                    if (!clearSavedPasswordRequested)
                    {
                        SavePasswordForDevice(device, password);
                    }

                    SetStatus("连接成功。", StatusMessageType.Success, true);
                    OpenDeviceDetailsWindow(baseAddress, selectedAdapter?.IPv4Address ?? string.Empty, password);
                    return;
                }

                if (result.StatusCode == 401)
                {
                    _passwordStoreService.ClearPassword(deviceKey);
                    SetStatus("管理密码错误，请重新输入。", StatusMessageType.Error, true);
                    SetBusyState(false);
                    MessageBox.Show(this, "管理密码校验失败，请重新输入管理密码。", "密码错误", MessageBoxButton.OK, MessageBoxImage.Warning);
                    if (!TryPromptForPassword(device, string.Empty, out password, out _))
                    {
                        return;
                    }

                    continue;
                }

                SetStatus($"设备已发现，但 HTTP 验证失败：{result.Message}", StatusMessageType.Error, true);
                return;
            }
            catch (Exception ex)
            {
                SetStatus($"连接失败：{ex.Message}", StatusMessageType.Error, true);
                MessageBox.Show(this, ex.Message, "连接失败", MessageBoxButton.OK, MessageBoxImage.Error);
                return;
            }
            finally
            {
                SetBusyState(false);
            }
        }
    }

    private void OpenDeviceDetailsWindow(string baseAddress, string localIPv4, string password)
    {
        var window = new DeviceDetailsWindow(baseAddress, localIPv4, password)
        {
            Owner = this,
        };
        window.ShowDialog();
    }

    private bool TryPromptForPassword(DiscoveredDevice device, string savedPassword, out string password, out bool clearSavedPasswordRequested)
    {
        var label = string.IsNullOrWhiteSpace(device.Mac) ? device.Lan2Ip : device.Mac;
        var window = new PasswordPromptWindow(label, savedPassword)
        {
            Owner = this,
        };

        var dialogResult = window.ShowDialog();
        clearSavedPasswordRequested = window.ClearSavedPasswordRequested;
        if (dialogResult == true)
        {
            password = window.Password;
            return true;
        }

        password = string.Empty;
        return false;
    }

    private static string GetDevicePasswordKey(DiscoveredDevice device)
    {
        if (!string.IsNullOrWhiteSpace(device.Mac))
        {
            return device.Mac;
        }

        return device.DeviceId;
    }

    private void SetStatus(string message, StatusMessageType type, bool addLog)
    {
        ApplyStatusMessageStyle(type);
        StatusTextBlock.Text = message;
        StatusMessageBorder.Opacity = 0;
        StatusMessageBorder.Visibility = Visibility.Visible;
        StatusMessageBorder.BeginAnimation(OpacityProperty, new DoubleAnimation(1, TimeSpan.FromMilliseconds(160)));
        _statusMessageCts?.Cancel();
        _statusMessageCts = new CancellationTokenSource();
        _ = HideStatusMessageAsync(_statusMessageCts.Token);
        _ = addLog;
    }

    private async Task HideStatusMessageAsync(CancellationToken cancellationToken)
    {
        try
        {
            await Task.Delay(3000, cancellationToken);
            await Dispatcher.InvokeAsync(() =>
            {
                var animation = new DoubleAnimation(0, TimeSpan.FromMilliseconds(200));
                animation.Completed += (_, _) =>
                {
                    if (!cancellationToken.IsCancellationRequested)
                    {
                        StatusMessageBorder.Visibility = Visibility.Collapsed;
                    }
                };
                StatusMessageBorder.BeginAnimation(OpacityProperty, animation);
            });
        }
        catch (TaskCanceledException)
        {
        }
    }

    private void ApplyStatusMessageStyle(StatusMessageType type)
    {
        var (background, icon) = GetStatusMessageVisuals(type);
        StatusIconBorder.Background = background;
        StatusIconTextBlock.Text = icon;
        StatusTextBlock.Foreground = new SolidColorBrush((Color)ColorConverter.ConvertFromString("#1F2937"));
    }

    private static (Brush Background, string Icon) GetStatusMessageVisuals(StatusMessageType type)
    {
        return type switch
        {
            StatusMessageType.Success => (new SolidColorBrush((Color)ColorConverter.ConvertFromString("#27C346")), "✓"),
            StatusMessageType.Error => (new SolidColorBrush((Color)ColorConverter.ConvertFromString("#F76965")), "×"),
            StatusMessageType.Warning => (new SolidColorBrush((Color)ColorConverter.ConvertFromString("#FF9626")), "!"),
            _ => (new SolidColorBrush((Color)ColorConverter.ConvertFromString("#508DF8")), "i"),
        };
    }

    private void SetBusyState(bool isBusy, string? message = null)
    {
        _isBusy = isBusy;
        BusyOverlay.Visibility = isBusy ? Visibility.Visible : Visibility.Collapsed;
        BusyMessageTextBlock.Text = string.IsNullOrWhiteSpace(message) ? "正在处理，请稍候..." : message;
        AdapterComboBox.IsEnabled = !isBusy;
        RefreshAdaptersButton.IsEnabled = !isBusy;
        SearchDevicesButton.IsEnabled = !isBusy && !_isSearchingDevices && AdapterComboBox.SelectedItem is AdapterInfo adapter && adapter.HasLink;
    }

    private void SetDeviceSearchState(bool isSearching)
    {
        _isSearchingDevices = isSearching;
        SearchProgressBar.Visibility = isSearching ? Visibility.Visible : Visibility.Collapsed;
        SearchProgressTextBlock.Visibility = isSearching ? Visibility.Visible : Visibility.Collapsed;
        SearchDevicesButton.Content = isSearching ? "搜索中..." : "重新搜索设备";
        UpdateButtonStates();
    }

    private void CancelDeviceSearch()
    {
        _deviceSearchCts?.Cancel();
        SetDeviceSearchState(false);
    }
}