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

namespace NetworkTool.Client;

public partial class DeviceDetailsWindow : Window
{
    private const int ApplyConfirmationTimeoutSeconds = 20;
    private readonly ServerApiService _serverApiService = new();
    private readonly string _baseAddress;
    private readonly string _localIPv4;
    private readonly string _password;
    private bool _configValidated;
    private bool _isBusy;
    private bool _suppressConfigChangeHandling;
    private CancellationTokenSource? _statusMessageCts;

    public DeviceDetailsWindow(string baseAddress, string localIPv4, string password)
    {
        InitializeComponent();
        _baseAddress = baseAddress;
        _localIPv4 = localIPv4;
        _password = password;
        Loaded += DeviceDetailsWindow_OnLoaded;
    }

    private async void DeviceDetailsWindow_OnLoaded(object sender, RoutedEventArgs e)
    {
        try
        {
            await LoadRemoteDetailsAsync();
            UpdateButtonStates();
        }
        catch (Exception ex)
        {
            ShowStatusMessage($"读取设备信息失败：{ex.Message}");
            SetBusyState(false);
        }
    }

    private async Task LoadRemoteDetailsAsync()
    {
        ClearDetails();
        var device = await _serverApiService.GetDeviceInfoAsync(_baseAddress, _password, _localIPv4);
        if (device is not null)
        {
            RemoteDeviceIdTextBlock.Text = device.DeviceId;
            RemoteHostnameTextBlock.Text = device.Hostname;
            RemoteOsVersionTextBlock.Text = device.OSVersion;
            RemoteServerVersionTextBlock.Text = device.ServerVersion;
        }

        var interfaces = await _serverApiService.GetInterfacesAsync(_baseAddress, _password, _localIPv4);
        if (interfaces is null)
        {
            ShowStatusMessage("设备已连接，但暂时无法读取 Linux 接口列表。");
            return;
        }

        ShowStatusMessage($"当前管理接口：{interfaces.ManagementInterface}；建议目标接口：{interfaces.SuggestedTargetInterface}；{(interfaces.RequiresTargetSelection ? "需要手动选择目标接口。" : "已自动识别建议目标接口。")}");
        var suggested = interfaces.Interfaces.FirstOrDefault(item => item.SystemName == interfaces.SuggestedTargetInterface)
            ?? interfaces.Interfaces.FirstOrDefault(item => item.IsSuggestedTarget)
            ?? interfaces.Interfaces.FirstOrDefault(item => !item.IsManagementInterface);
        RemoteTargetInterfaceComboBox.ItemsSource = interfaces.Interfaces;
        if (suggested is not null)
        {
            RemoteTargetInterfaceComboBox.SelectedItem = suggested;
            await LoadRemoteInterfaceConfigAsync(suggested.SystemName);
        }
    }

    private void ClearDetails()
    {
        RemoteDeviceIdTextBlock.Text = "-";
        RemoteHostnameTextBlock.Text = "-";
        RemoteOsVersionTextBlock.Text = "-";
        RemoteServerVersionTextBlock.Text = "-";
        RemoteTargetInterfaceComboBox.ItemsSource = null;
        RemoteConfigInterfaceTextBlock.Text = "-";
        RemoteConfigIpTextBlock.Text = "-";
        RemoteConfigGatewayTextBlock.Text = "-";
        RemoteConfigDnsTextBlock.Text = "-";
        NewIpTextBox.Text = string.Empty;
        NewMaskTextBox.Text = string.Empty;
        NewGatewayTextBox.Text = string.Empty;
        NewDnsTextBox.Text = string.Empty;
        _configValidated = false;
    }

    private async void RemoteTargetInterfaceComboBox_OnSelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        try
        {
            if (RemoteTargetInterfaceComboBox.SelectedItem is not RemoteInterfaceInfo selected)
            {
                UpdateButtonStates();
                return;
            }

            await LoadRemoteInterfaceConfigAsync(selected.SystemName, useBusyState: true);
        }
        catch (Exception ex)
        {
            ShowStatusMessage($"读取目标接口配置失败：{ex.Message}");
            SetBusyState(false);
        }
    }

    private async Task LoadRemoteInterfaceConfigAsync(string interfaceName, bool useBusyState = false)
    {
        if (useBusyState)
        {
            SetBusyState(true, "正在读取 Linux 端 IP 配置...");
        }

        try
        {
            var result = await _serverApiService.GetInterfaceConfigAsync(_baseAddress, _password, _localIPv4, interfaceName);
            if (!result.Success || result.Data is null)
            {
                RemoteConfigInterfaceTextBlock.Text = interfaceName;
                RemoteConfigIpTextBlock.Text = "读取失败";
                RemoteConfigGatewayTextBlock.Text = "读取失败";
                RemoteConfigDnsTextBlock.Text = "读取失败";
                ShowStatusMessage($"读取目标接口 {interfaceName} 配置失败：{result.Message}");
                return;
            }

            var config = result.Data;
            RemoteConfigInterfaceTextBlock.Text = config.Interface;
            RemoteConfigIpTextBlock.Text = FormatCurrentIp(config);
            RemoteConfigGatewayTextBlock.Text = string.IsNullOrWhiteSpace(config.Gateway) ? "无" : config.Gateway;
            RemoteConfigDnsTextBlock.Text = config.DnsSummary;
            _suppressConfigChangeHandling = true;
            Dhcp4CheckBox.IsChecked = false;
            NewIpTextBox.Text = config.IP;
            NewMaskTextBox.Text = PrefixToMask(config.Prefix);
            NewGatewayTextBox.Text = config.Gateway;
            NewDnsTextBox.Text = config.Dns?.FirstOrDefault() ?? string.Empty;
            _suppressConfigChangeHandling = false;
            _configValidated = false;
            ShowStatusMessage("已读取Linux端IP配置。");
            UpdateButtonStates();
        }
        finally
        {
            if (useBusyState)
            {
                SetBusyState(false);
            }
        }
    }

    private async void ReloadInterfaceConfigButton_OnClick(object sender, RoutedEventArgs e)
    {
        if (RemoteTargetInterfaceComboBox.SelectedItem is RemoteInterfaceInfo selected)
        {
            await LoadRemoteInterfaceConfigAsync(selected.SystemName);
        }
    }

    private async void ValidateConfigButton_OnClick(object sender, RoutedEventArgs e)
    {
        if (RemoteTargetInterfaceComboBox.SelectedItem is not RemoteInterfaceInfo selected)
        {
            return;
        }

        var request = BuildConfigRequest(selected.SystemName);
        if (request is null)
        {
            return;
        }

        SetBusyState(true, "正在校验配置，请稍候...");
        try
        {
            var result = await _serverApiService.ValidateInterfaceConfigAsync(_baseAddress, _password, _localIPv4, request);
            _configValidated = result.Success && result.Data?.Valid == true;
            if (result.Data is not null)
            {
                var warnings = result.Data.Warnings.Count > 0 ? $" 警告：{string.Join("；", result.Data.Warnings)}" : string.Empty;
                var errors = result.Data.Errors.Count > 0 ? $" 错误：{string.Join("；", result.Data.Errors)}" : string.Empty;
                ShowStatusMessage(_configValidated ? $"校验通过，可应用配置。{warnings}" : $"校验失败。{errors}{warnings}");
            }
            else
            {
                ShowStatusMessage($"校验失败：{result.Message}");
            }

            UpdateButtonStates();
        }
        finally
        {
            SetBusyState(false);
        }
    }

    private async void ApplyConfigButton_OnClick(object sender, RoutedEventArgs e)
    {
        if (RemoteTargetInterfaceComboBox.SelectedItem is not RemoteInterfaceInfo selected)
        {
            return;
        }

        var request = BuildConfigRequest(selected.SystemName);
        if (request is null)
        {
            return;
        }

        var confirmMessage = $"将要把以下配置应用到接口 {selected.SystemName}：\n\n" +
                             $"模式：{(request.Dhcp4 ? "DHCP 自动获取" : "静态 IPv4")}\n" +
                             $"IP：{(request.Dhcp4 ? "自动获取" : $"{request.IP}/{request.Prefix}")}\n" +
                             $"网关：{(string.IsNullOrWhiteSpace(request.Gateway) ? "无" : request.Gateway)}\n" +
                             $"DNS：{(request.Dns.Count == 0 ? "无" : string.Join(", ", request.Dns))}\n\n" +
                             "请确认是否继续。";
        if (MessageBox.Show(this, confirmMessage, "确认应用配置", MessageBoxButton.OKCancel, MessageBoxImage.Question) != MessageBoxResult.OK)
        {
            return;
        }

        SetBusyState(true, "正在提交并应用配置，请稍候...");
        try
        {
            var applyResult = await _serverApiService.ApplyInterfaceConfigAsync(_baseAddress, _password, _localIPv4, request);
            if (!applyResult.Success || applyResult.Data is null)
            {
                ShowStatusMessage($"提交配置任务失败：{applyResult.Message}");
                return;
            }

            ShowStatusMessage("配置任务已提交，正在应用并等待连通确认...");
            await PollTaskAsync(applyResult.Data.TaskId);
        }
        finally
        {
            SetBusyState(false);
        }
    }

    private async Task PollTaskAsync(string taskId)
    {
        var transientFailureCount = 0;
        var confirmationRequested = false;
        for (var i = 0; i < 20; i++)
        {
            await Task.Delay(1000);
            var result = await _serverApiService.GetTaskAsync(_baseAddress, _password, _localIPv4, taskId);
            if (!result.Success || result.Data is null)
            {
                if (result.StatusCode is null)
                {
                    transientFailureCount++;
                    ShowStatusMessage($"设备连接短暂中断，正在重试（{transientFailureCount}）。");
                    continue;
                }

                ShowStatusMessage($"读取任务状态失败：{result.Message}");
                return;
            }

            transientFailureCount = 0;
            var task = result.Data;
            ShowStatusMessage(FormatTaskStatusMessage(task));
            if (task.Status == "running" && task.Step == "confirming" && !confirmationRequested)
            {
                confirmationRequested = true;
                var confirm = ShowApplyConfirmationDialog(ApplyConfirmationTimeoutSeconds);
                if (confirm)
                {
                    var confirmResult = await _serverApiService.ConfirmApplyTaskAsync(_baseAddress, _password, _localIPv4, taskId);
                    ShowStatusMessage(confirmResult.Success ? "已发送保留配置确认。" : $"发送确认失败：{confirmResult.Message}");
                }
                else
                {
                    var cancelResult = await _serverApiService.CancelApplyTaskAsync(_baseAddress, _password, _localIPv4, taskId);
                    ShowStatusMessage(cancelResult.Success ? "已取消保留配置，正在回滚。" : $"发送取消失败：{cancelResult.Message}");
                }
            }

            if (task.Status is "success" or "failed" or "rolled_back")
            {
                ShowTaskCompletionDialog(task);
                if (RemoteTargetInterfaceComboBox.SelectedItem is RemoteInterfaceInfo selected)
                {
                    await LoadRemoteInterfaceConfigAsync(selected.SystemName);
                }

                return;
            }
        }

        ShowStatusMessage($"任务 {taskId} 轮询超时，请稍后手动刷新。");
    }

    private bool ShowApplyConfirmationDialog(int timeoutSeconds)
    {
        var remaining = timeoutSeconds;
        var result = false;
        var messageTextBlock = new TextBlock
        {
            Width = 420,
            TextWrapping = TextWrapping.Wrap,
            FontSize = 13,
            Foreground = Brushes.Black,
        };
        var confirmButton = new Button
        {
            MinWidth = 88,
            MinHeight = 32,
            Margin = new Thickness(0, 0, 10, 0),
            Content = "确认保留",
            IsDefault = true,
        };
        var cancelButton = new Button
        {
            MinWidth = 88,
            MinHeight = 32,
            Content = "取消回滚",
            IsCancel = true,
        };
        var dialog = new Window
        {
            Title = "确认保留网络配置",
            Owner = this,
            WindowStartupLocation = WindowStartupLocation.CenterOwner,
            ResizeMode = ResizeMode.NoResize,
            SizeToContent = SizeToContent.WidthAndHeight,
            Content = new StackPanel
            {
                Margin = new Thickness(18),
                Children =
                {
                    messageTextBlock,
                    new StackPanel
                    {
                        Margin = new Thickness(0, 18, 0, 0),
                        HorizontalAlignment = HorizontalAlignment.Right,
                        Orientation = Orientation.Horizontal,
                        Children = { confirmButton, cancelButton },
                    },
                },
            },
        };

        void UpdateMessage()
        {
            messageTextBlock.Text = $"当前客户端仍可连接到设备。是否确认保留这次网络配置？\n\n剩余 {remaining} 秒；超时或取消时，Linux 端会自动回滚。";
        }

        var timer = new System.Windows.Threading.DispatcherTimer { Interval = TimeSpan.FromSeconds(1) };
        timer.Tick += (_, _) =>
        {
            remaining--;
            if (remaining <= 0)
            {
                timer.Stop();
                dialog.DialogResult = false;
                dialog.Close();
                return;
            }
            UpdateMessage();
        };
        confirmButton.Click += (_, _) =>
        {
            result = true;
            dialog.DialogResult = true;
            dialog.Close();
        };
        cancelButton.Click += (_, _) =>
        {
            dialog.DialogResult = false;
            dialog.Close();
        };
        dialog.Closed += (_, _) => timer.Stop();

        UpdateMessage();
        timer.Start();
        dialog.ShowDialog();
        return result;
    }

    private async void RebootButton_OnClick(object sender, RoutedEventArgs e)
    {
        await ExecuteSystemActionAsync(
            "重启设备",
            "设备将立即重启，当前窗口和连接可能马上中断。是否继续？",
            () => _serverApiService.RebootAsync(_baseAddress, _password, _localIPv4));
    }

    private async void ShutdownButton_OnClick(object sender, RoutedEventArgs e)
    {
        await ExecuteSystemActionAsync(
            "关闭设备",
            "设备将立即关机，当前窗口和连接可能马上中断。是否继续？",
            () => _serverApiService.ShutdownAsync(_baseAddress, _password, _localIPv4));
    }

    private async Task ExecuteSystemActionAsync(string title, string confirmMessage, Func<Task<ApiCallResult<RemoteSystemActionResponse>>> action)
    {
        if (MessageBox.Show(this, confirmMessage, title, MessageBoxButton.OKCancel, MessageBoxImage.Warning) != MessageBoxResult.OK)
        {
            return;
        }

        var result = await action();
        if (!result.Success || result.Data is null)
        {
            ShowStatusMessage($"{title}失败：{result.Message}");
            return;
        }

        ShowStatusMessage($"{title}任务已提交：{result.Data.TaskId}。命令已发出，设备可能立即断开。");
    }

    private RemoteInterfaceConfig? BuildConfigRequest(string interfaceName)
    {
        var dhcp4 = Dhcp4CheckBox.IsChecked == true;
        var prefix = 0;
        if (!dhcp4 && string.IsNullOrWhiteSpace(NewIpTextBox.Text))
        {
            ShowStatusMessage("IP 地址不能为空。");
            return null;
        }

        if (!dhcp4 && !TryMaskToPrefix(NewMaskTextBox.Text, out prefix))
        {
            ShowStatusMessage("子网掩码格式不正确。");
            return null;
        }

        var dns = string.IsNullOrWhiteSpace(NewDnsTextBox.Text) ? Array.Empty<string>() : new[] { NewDnsTextBox.Text.Trim() };
        return new RemoteInterfaceConfig
        {
            Interface = interfaceName,
            Dhcp4 = dhcp4,
            IP = dhcp4 ? string.Empty : NewIpTextBox.Text.Trim(),
            Prefix = prefix,
            Gateway = dhcp4 ? string.Empty : NewGatewayTextBox.Text.Trim(),
            Dns = dhcp4 ? Array.Empty<string>() : dns,
        };
    }

    private static string FormatCurrentIp(RemoteInterfaceConfig config)
    {
        if (string.IsNullOrWhiteSpace(config.IP))
        {
            return config.Dhcp4 ? "DHCP 自动获取，暂无 IPv4" : "无";
        }

        var text = $"{config.IP}/{config.Prefix}";
        return config.Dhcp4 ? $"{text} (DHCP)" : text;
    }

    private static string PrefixToMask(int prefix)
    {
        if (prefix < 0 || prefix > 32)
        {
            return string.Empty;
        }

        var mask = prefix == 0 ? 0u : uint.MaxValue << (32 - prefix);
        return string.Join('.', new[] { (mask >> 24) & 255, (mask >> 16) & 255, (mask >> 8) & 255, mask & 255 });
    }

    private static bool TryMaskToPrefix(string maskText, out int prefix)
    {
        prefix = 0;
        if (string.IsNullOrWhiteSpace(maskText))
        {
            return false;
        }

        var parts = maskText.Trim().Split('.');
        if (parts.Length != 4)
        {
            return false;
        }

        uint mask = 0;
        foreach (var part in parts)
        {
            if (!byte.TryParse(part, out var octet))
            {
                return false;
            }

            mask = (mask << 8) | octet;
        }

        var seenZero = false;
        for (var i = 31; i >= 0; i--)
        {
            var bit = (mask & (1u << i)) != 0;
            if (bit && seenZero)
            {
                return false;
            }

            if (bit)
            {
                prefix++;
            }
            else
            {
                seenZero = true;
            }
        }

        return true;
    }

    private void ConfigInputChanged_OnChanged(object sender, TextChangedEventArgs e)
    {
        if (_suppressConfigChangeHandling)
        {
            return;
        }

        _configValidated = false;
        ShowStatusMessage("配置内容已变更，请重新点击“2. 校验配置”。");
        UpdateButtonStates();
    }

    private void ConfigModeChanged_OnChanged(object sender, RoutedEventArgs e)
    {
        if (_suppressConfigChangeHandling)
        {
            UpdateButtonStates();
            return;
        }

        _configValidated = false;
        ShowStatusMessage("配置模式已变更，请重新点击“2. 校验配置”。");
        UpdateButtonStates();
    }

    private void ShowStatusMessage(string message)
    {
        ApplyStatusMessageStyle(message);
        StatusMessageTextBlock.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);
    }

    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;
        StatusMessageTextBlock.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 static string FormatTaskStatusMessage(RemoteTaskResult task)
    {
        return task.Status switch
        {
            "success" => string.IsNullOrWhiteSpace(task.Detail) ? "配置已成功应用。" : task.Detail,
            "failed" => string.IsNullOrWhiteSpace(task.Detail) ? "配置应用失败。" : task.Detail,
            "rolled_back" => string.IsNullOrWhiteSpace(task.Detail) ? "配置应用失败，已自动回滚。" : task.Detail,
            _ => task.Step switch
            {
                "validating" => "正在校验配置...",
                "writing_netplan" => "正在写入 Linux 网络配置...",
                "applying" => "正在应用 Linux 网络配置...",
                "confirming" => string.IsNullOrWhiteSpace(task.Detail) ? "等待确认保留配置..." : task.Detail,
                "rolling_back" => "配置应用失败，正在自动回滚...",
                _ => string.IsNullOrWhiteSpace(task.Detail) ? "正在处理，请稍候..." : task.Detail,
            }
        };
    }

    private void ShowTaskCompletionDialog(RemoteTaskResult task)
    {
        var message = FormatTaskStatusMessage(task);
        var title = task.Status == "success" ? "应用配置成功" : "应用配置失败";
        var image = task.Status == "success" ? MessageBoxImage.Information : MessageBoxImage.Warning;
        MessageBox.Show(this, message, title, MessageBoxButton.OK, image);
    }

    private void UpdateButtonStates()
    {
        var hasSelectedInterface = RemoteTargetInterfaceComboBox.SelectedItem is RemoteInterfaceInfo;
        var canEdit = !_isBusy && hasSelectedInterface;

        RemoteTargetInterfaceComboBox.IsEnabled = !_isBusy && RemoteTargetInterfaceComboBox.Items.Count > 0;
        ReloadInterfaceConfigButton.IsEnabled = canEdit;
        ValidateConfigButton.IsEnabled = canEdit;
        ApplyConfigButton.IsEnabled = !_isBusy && _configValidated && hasSelectedInterface;
        Dhcp4CheckBox.IsEnabled = canEdit;
        NewIpTextBox.IsEnabled = canEdit && Dhcp4CheckBox.IsChecked != true;
        NewMaskTextBox.IsEnabled = canEdit && Dhcp4CheckBox.IsChecked != true;
        NewGatewayTextBox.IsEnabled = canEdit && Dhcp4CheckBox.IsChecked != true;
        NewDnsTextBox.IsEnabled = canEdit && Dhcp4CheckBox.IsChecked != true;
        RebootButton.IsEnabled = !_isBusy;
        ShutdownButton.IsEnabled = !_isBusy;
    }

    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;
        UpdateButtonStates();
    }
}