using System.Globalization;
using System.Windows;
using System.Windows.Controls;
using QuickIP.Client.Models;
using QuickIP.Client.Services;

namespace QuickIP.Client;

public partial class DeviceDetailsWindow : Window
{
    private readonly AgentApiService _agentApiService = new();
    private readonly string _baseAddress;
    private readonly string _localIPv4;
    private readonly string _password;
    private bool _configValidated;
    private bool _suppressConfigChangeHandling;

    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)
    {
        await LoadRemoteDetailsAsync();
        UpdateButtonStates();
    }

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

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

        RemoteSummaryTextBlock.Text = $"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 = "-";
        RemoteAgentVersionTextBlock.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;
        ConfigValidationTextBlock.Text = "点击 1/2/3 按顺序操作：先读取当前配置，再校验，最后应用。";
        _configValidated = false;
    }

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

        await LoadRemoteInterfaceConfigAsync(selected.SystemName);
    }

    private async Task LoadRemoteInterfaceConfigAsync(string interfaceName)
    {
        var result = await _agentApiService.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";
            ConfigValidationTextBlock.Text = $"读取目标接口 {interfaceName} 配置失败：{result.Message}";
            return;
        }

        var config = result.Data;
        RemoteConfigInterfaceTextBlock.Text = config.Interface;
        RemoteConfigIpTextBlock.Text = string.IsNullOrWhiteSpace(config.IP) ? "无" : $"{config.IP}/{config.Prefix}";
        RemoteConfigGatewayTextBlock.Text = string.IsNullOrWhiteSpace(config.Gateway) ? "无" : config.Gateway;
        RemoteConfigDnsTextBlock.Text = config.DnsSummary;
        _suppressConfigChangeHandling = true;
        NewIpTextBox.Text = config.IP;
        NewMaskTextBox.Text = PrefixToMask(config.Prefix);
        NewGatewayTextBox.Text = config.Gateway;
        NewDnsTextBox.Text = config.Dns.FirstOrDefault() ?? string.Empty;
        _suppressConfigChangeHandling = false;
        _configValidated = false;
        ConfigValidationTextBlock.Text = "已回填目标接口当前配置，可直接修改后校验。";
        UpdateButtonStates();
    }

    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;
        }

        var result = await _agentApiService.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;
            ConfigValidationTextBlock.Text = result.Success ? $"校验通过。{warnings}" : $"校验失败。{errors}{warnings}";
        }
        else
        {
            ConfigValidationTextBlock.Text = $"校验失败：{result.Message}";
        }

        ConfigValidationTextBlock.Text = _configValidated ? "配置已通过校验，可提交应用。" : "当前配置尚未通过校验。";
        UpdateButtonStates();
    }

    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" +
                             $"IP：{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;
        }

        var applyResult = await _agentApiService.ApplyInterfaceConfigAsync(_baseAddress, _password, _localIPv4, request);
        if (!applyResult.Success || applyResult.Data is null)
        {
            ConfigValidationTextBlock.Text = $"提交配置任务失败：{applyResult.Message}";
            return;
        }

        ConfigValidationTextBlock.Text = $"配置任务已提交：{applyResult.Data.TaskId}，正在轮询状态。";
        await PollTaskAsync(applyResult.Data.TaskId);
    }

    private async Task PollTaskAsync(string taskId)
    {
        var transientFailureCount = 0;
        for (var i = 0; i < 20; i++)
        {
            await Task.Delay(1000);
            var result = await _agentApiService.GetTaskAsync(_baseAddress, _password, _localIPv4, taskId);
            if (!result.Success || result.Data is null)
            {
                if (result.StatusCode is null)
                {
                    transientFailureCount++;
                    ConfigValidationTextBlock.Text = $"任务 {taskId} 轮询中，检测到短暂断连，正在重试（{transientFailureCount}）。";
                    continue;
                }

                ConfigValidationTextBlock.Text = $"读取任务状态失败：{result.Message}";
                return;
            }

            transientFailureCount = 0;
            var task = result.Data;
            ConfigValidationTextBlock.Text = $"任务 {task.TaskId} / {task.Status} / {task.Step} / {task.Detail}";
            if (task.Status is "success" or "failed" or "rolled_back")
            {
                if (RemoteTargetInterfaceComboBox.SelectedItem is RemoteInterfaceInfo selected)
                {
                    await LoadRemoteInterfaceConfigAsync(selected.SystemName);
                }

                return;
            }
        }

        ConfigValidationTextBlock.Text = $"任务 {taskId} 轮询超时，请稍后手动刷新。";
    }

    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？",
            () => _agentApiService.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？",
            () => _agentApiService.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)
        {
            ConfigValidationTextBlock.Text = $"{title}失败：{result.Message}";
            return;
        }

        ConfigValidationTextBlock.Text = $"{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)
    {
        if (string.IsNullOrWhiteSpace(NewIpTextBox.Text))
        {
            ConfigValidationTextBlock.Text = "IP 地址不能为空。";
            return null;
        }

        if (!TryMaskToPrefix(NewMaskTextBox.Text, out var prefix))
        {
            ConfigValidationTextBlock.Text = "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,
            IP = NewIpTextBox.Text.Trim(),
            Prefix = prefix,
            Gateway = NewGatewayTextBox.Text.Trim(),
            Dns = dns,
        };
    }

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

    private void UpdateButtonStates()
    {
        ReloadInterfaceConfigButton.IsEnabled = RemoteTargetInterfaceComboBox.SelectedItem is RemoteInterfaceInfo;
        ValidateConfigButton.IsEnabled = RemoteTargetInterfaceComboBox.SelectedItem is RemoteInterfaceInfo;
        ApplyConfigButton.IsEnabled = _configValidated && RemoteTargetInterfaceComboBox.SelectedItem is RemoteInterfaceInfo;
    }
}