using System.Collections.Generic;
using System.Globalization;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Threading;
using NetworkTool.Client.Models;
using NetworkTool.Client.Services;

namespace NetworkTool.Client;

public partial class MainWindow : Window
{
    private readonly NetworkAdapterService _networkAdapterService = new();
    private readonly PasswordStoreService _passwordStoreService = new();
    private readonly NetworkConfigurationService _networkConfigurationService = new();
    private readonly DiscoveryService _discoveryService = new();
    private readonly ServerApiService _serverApiService = new();
    private readonly AdminPrivilegeService _adminPrivilegeService = new();
    private IReadOnlyList<AdapterInfo> _adapters = [];
    private bool _isShowingPassword;
    private bool _isBusy;
    private bool _suppressPasswordSync;
    private CancellationTokenSource? _statusMessageCts;

    public MainWindow()
    {
        InitializeComponent();
        Loaded += MainWindow_OnLoaded;
    }

    private async void MainWindow_OnLoaded(object sender, RoutedEventArgs e)
    {
        await LoadInitialStateAsync();
    }

    private async Task LoadInitialStateAsync()
    {
        AdminStateTextBlock.Text = _adminPrivilegeService.IsAdministrator()
            ? "管理员状态：当前已以管理员身份运行，可执行本机网卡切换。"
            : "管理员状态：当前不是管理员运行，切换到维护网络会失败。";

        _adapters = _networkAdapterService.GetEthernetAdapters();
        await _networkAdapterService.ProbeMaintenanceReachabilityAsync(_adapters);
        _adapters = _adapters
            .OrderByDescending(adapter => adapter.RecommendationScore)
            .ThenBy(adapter => adapter.Name)
            .ToList();
        AdapterComboBox.ItemsSource = _adapters;

        var recommendedAdapter = _networkAdapterService.GetRecommendedAdapter(_adapters);

        var savedPassword = _passwordStoreService.LoadPassword();
        if (!string.IsNullOrWhiteSpace(savedPassword))
        {
            PasswordBox.Password = savedPassword;
            PasswordTextBox.Text = savedPassword;
        }

        if (recommendedAdapter is not null)
        {
            AdapterComboBox.SelectedItem = recommendedAdapter;
            UpdateAdapterDetails(recommendedAdapter);
        }
        else if (_adapters.Count > 0)
        {
            AdapterComboBox.SelectedIndex = 0;
            UpdateAdapterDetails(_adapters[0]);
        }

        AppendLog("客户端已加载连接页。", true);
        UpdateButtonStates();
    }

    private void AdapterComboBox_OnSelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        if (AdapterComboBox.SelectedItem is not AdapterInfo adapter)
        {
            UpdateAdapterDetails(null);
            SetStatus("请选择一块有线网卡。", false);
            UpdateButtonStates();
            return;
        }

        UpdateAdapterDetails(adapter);
        SetStatus(adapter.HasLink
            ? $"已选择 {adapter.RecommendationLabel} 网卡，可切换到维护网络。{adapter.RecommendationReason}"
            : "当前网卡未检测到链路，请检查网线连接。", true);

        UpdateButtonStates();
    }

    private async void SwitchMaintenanceButton_OnClick(object sender, RoutedEventArgs e)
    {
        if (!_adminPrivilegeService.IsAdministrator())
        {
            SetStatus("当前程序未以管理员身份运行，无法修改本机网卡。", true);
            MessageBox.Show(this, "请以管理员身份运行客户端后再切换到维护网络。", "需要管理员权限", MessageBoxButton.OK, MessageBoxImage.Warning);
            return;
        }

        if (AdapterComboBox.SelectedItem is not AdapterInfo adapter)
        {
            SetStatus("请先选择一块网卡。", true);
            return;
        }

        PersistPasswordIfNeeded();

        if (adapter.IsReachableToMaintenance)
        {
            SetStatus("当前网卡已经可以直接访问 169.254.100.2，无需切换到维护网络。", true);
            return;
        }

        SetBusyState(true);
        SetStatus("正在切换到维护网络，请稍候。", true);
        await Dispatcher.InvokeAsync(() => { }, System.Windows.Threading.DispatcherPriority.Render);

        try
        {
            await _networkConfigurationService.ConfigureMaintenanceNetworkAsync(adapter);
            SetStatus("已切换到维护网络。", true);
            await RefreshAdaptersAsync(adapter.Id);
        }
        catch (Exception ex)
        {
            SetStatus($"切换维护网络失败：{ex.Message}", true);
            MessageBox.Show(this, ex.Message, "切换维护网络失败", MessageBoxButton.OK, MessageBoxImage.Error);
        }
        finally
        {
            SetBusyState(false);
        }
    }

    private async void RefreshAdaptersButton_OnClick(object sender, RoutedEventArgs e)
    {
        SetBusyState(true);
        try
        {
            await RefreshAdaptersAsync();
            SetStatus("已刷新本机网卡和管理口探测结果。", true);
        }
        catch (Exception ex)
        {
            SetStatus($"刷新本机网卡失败：{ex.Message}", true);
            MessageBox.Show(this, ex.Message, "刷新失败", MessageBoxButton.OK, MessageBoxImage.Error);
        }
        finally
        {
            SetBusyState(false);
        }
    }

    private async void DiscoverConnectButton_OnClick(object sender, RoutedEventArgs e)
    {
        if (string.IsNullOrWhiteSpace(GetCurrentPassword()))
        {
            SetStatus("请输入管理密码。", true);
            MessageBox.Show(this, "请先在右侧“管理密码（必填）”区域输入密码。", "缺少管理密码", MessageBoxButton.OK, MessageBoxImage.Information);
            return;
        }

        PersistPasswordIfNeeded();
        SetBusyState(true);
        SetStatus("正在检查当前网卡是否可直接访问管理口。", true);
        await Dispatcher.InvokeAsync(() => { }, System.Windows.Threading.DispatcherPriority.Render);

        try
        {
            if (AdapterComboBox.SelectedItem is AdapterInfo adapter && adapter.IsReachableToMaintenance)
            {
                var directResult = await _serverApiService.CheckHealthAsync("http://169.254.100.2:48888", GetCurrentPassword(), adapter.IPv4Address);
                if (directResult.Success)
                {
                    SetStatus("连接成功，无需切换本机网卡。", true);
                    OpenDeviceDetailsWindow("http://169.254.100.2:48888", adapter.IPv4Address);
                    return;
                }

                if (directResult.StatusCode == 401)
                {
                    SetStatus("该网卡可以直连管理口，但管理密码错误。", true);
                    MessageBox.Show(this, "当前网卡已经可以直连 Server，但密码校验失败，请确认密码是否正确。", "密码错误", MessageBoxButton.OK, MessageBoxImage.Warning);
                    return;
                }

                if (directResult.StatusCode == 403)
                {
                    SetStatus("该网卡可以直连管理口，但 Server 拒绝访问，请确认远端是否还是旧版本。", true);
                    MessageBox.Show(this, "当前网卡已经可以直连 Server，但请求被拒绝。请确认 Linux 端是否运行的是最新版本 Server。", "访问被拒绝", MessageBoxButton.OK, MessageBoxImage.Warning);
                    return;
                }

                SetStatus($"该网卡虽可建立连接，但直连 HTTP 校验失败：{directResult.Message}。正在尝试设备发现。", true);
            }

            SetStatus("当前网卡无法完成直连校验，正在发现设备，请稍候。", true);
            var selectedAdapter = AdapterComboBox.SelectedItem as AdapterInfo;
            var device = await _discoveryService.DiscoverAsync(selectedAdapter?.IPv4Address ?? string.Empty);
            if (device is null)
            {
                SetStatus("未发现设备。如果当前网卡不可达，请先切换到维护网络。", true);
                return;
            }

            SetStatus("已发现设备，正在验证连接。", true);

            var discoveredResult = await _serverApiService.CheckHealthAsync($"http://{device.Lan2Ip}:48888", GetCurrentPassword(), selectedAdapter?.IPv4Address ?? string.Empty);
            if (discoveredResult.Success)
            {
                SetStatus("连接成功。", true);
                OpenDeviceDetailsWindow($"http://{device.Lan2Ip}:48888", selectedAdapter?.IPv4Address ?? string.Empty);
            }
            else
            {
                SetStatus($"设备已发现，但 HTTP 验证失败：{discoveredResult.Message}", true);
            }
        }
        catch (Exception ex)
        {
            SetStatus($"连接失败：{ex.Message}", true);
            MessageBox.Show(this, ex.Message, "连接失败", MessageBoxButton.OK, MessageBoxImage.Error);
        }
        finally
        {
            SetBusyState(false);
        }
    }

    private void PersistPasswordIfNeeded()
    {
        var password = GetCurrentPassword();
        if (!string.IsNullOrWhiteSpace(password))
        {
            _passwordStoreService.SavePassword(password);
            return;
        }
    }

    private string GetCurrentPassword()
    {
        return _isShowingPassword ? PasswordTextBox.Text : PasswordBox.Password;
    }

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

    private async Task RefreshAdaptersAsync(string? selectedAdapterId = null)
    {
        _adapters = _networkAdapterService.GetEthernetAdapters();
        await _networkAdapterService.ProbeMaintenanceReachabilityAsync(_adapters);
        _adapters = _adapters
            .OrderByDescending(adapter => adapter.RecommendationScore)
            .ThenBy(adapter => adapter.Name)
            .ToList();
        AdapterComboBox.ItemsSource = _adapters;

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

        if (selected is not null)
        {
            AdapterComboBox.SelectedItem = selected;
            UpdateAdapterDetails(selected);
        }
    }

    private void UpdateAdapterDetails(AdapterInfo? adapter)
    {
        if (adapter is null)
        {
            AdapterProbeTextBlock.Text = "-";
            return;
        }

        AdapterProbeTextBlock.Text = $"{adapter.ProbeStatus} / {adapter.ProbeReason}";
    }

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

    private void SetStatus(string message, bool addLog)
    {
        ApplyStatusMessageStyle(message);
        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);
        if (addLog)
        {
            AppendLog(message, false);
        }
    }

    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(string message)
    {
        var (background, foreground) = GetStatusMessageBrushes(message);
        StatusMessageBorder.Background = background;
        StatusTextBlock.Foreground = foreground;
    }

    private static (Brush Background, Brush Foreground) GetStatusMessageBrushes(string message)
    {
        if (ContainsAny(message, "失败", "错误", "拒绝", "超时", "不能为空", "不正确", "无法"))
        {
            return (new SolidColorBrush((Color)ColorConverter.ConvertFromString("#B91C1C")), Brushes.White);
        }

        if (ContainsAny(message, "未发现", "请", "重试", "警告", "需要"))
        {
            return (new SolidColorBrush((Color)ColorConverter.ConvertFromString("#C2410C")), Brushes.White);
        }

        if (ContainsAny(message, "成功", "已切换", "已刷新", "已读取", "已加载", "已发现", "已提交", "已回填"))
        {
            return (new SolidColorBrush((Color)ColorConverter.ConvertFromString("#047857")), Brushes.White);
        }

        return (new SolidColorBrush((Color)ColorConverter.ConvertFromString("#111827")), Brushes.White);
    }

    private static bool ContainsAny(string message, params string[] markers)
    {
        return markers.Any(marker => message.Contains(marker, StringComparison.Ordinal));
    }

    private void AppendLog(string message, bool isInitial)
    {
        var prefix = DateTime.Now.ToString("HH:mm:ss", CultureInfo.InvariantCulture);
        EventLogListBox.Items.Add($"[{prefix}] {message}");
        if (!isInitial)
        {
            EventLogListBox.ScrollIntoView(EventLogListBox.Items[^1]);
        }
    }

    private void SetBusyState(bool isBusy)
    {
        _isBusy = isBusy;
        AdapterComboBox.IsEnabled = !isBusy;
        RefreshAdaptersButton.IsEnabled = !isBusy;
        PasswordBox.IsEnabled = !isBusy;
        PasswordTextBox.IsEnabled = !isBusy;
        TogglePasswordVisibilityButton.IsEnabled = !isBusy;
        SwitchMaintenanceButton.IsEnabled = !isBusy && AdapterComboBox.SelectedItem is AdapterInfo;
        DiscoverConnectButton.IsEnabled = !isBusy && AdapterComboBox.SelectedItem is AdapterInfo adapter && adapter.HasLink;
    }

    private void TogglePasswordVisibilityButton_OnClick(object sender, RoutedEventArgs e)
    {
        _isShowingPassword = !_isShowingPassword;
        if (_isShowingPassword)
        {
            PasswordTextBox.Text = PasswordBox.Password;
            PasswordBox.Visibility = Visibility.Collapsed;
            PasswordTextBox.Visibility = Visibility.Visible;
            TogglePasswordVisibilityButton.Content = "🙈";
            PasswordTextBox.Focus();
            PasswordTextBox.CaretIndex = PasswordTextBox.Text.Length;
            return;
        }

        PasswordBox.Password = PasswordTextBox.Text;
        PasswordTextBox.Visibility = Visibility.Collapsed;
        PasswordBox.Visibility = Visibility.Visible;
        TogglePasswordVisibilityButton.Content = "👁";
        PasswordBox.Focus();
    }

    private void PasswordBox_OnPasswordChanged(object sender, RoutedEventArgs e)
    {
        if (_suppressPasswordSync)
        {
            return;
        }

        _suppressPasswordSync = true;
        PasswordTextBox.Text = PasswordBox.Password;
        _suppressPasswordSync = false;
    }

    private void PasswordTextBox_OnTextChanged(object sender, TextChangedEventArgs e)
    {
        if (_suppressPasswordSync)
        {
            return;
        }

        _suppressPasswordSync = true;
        PasswordBox.Password = PasswordTextBox.Text;
        _suppressPasswordSync = false;
    }
}