using System.Collections.ObjectModel;
using System.Windows.Input;
using UIShare.PubEvent;
using UIShare.UIViewModel;
using UIShare.ViewModelBase;


namespace SettingModule.ViewModels.Dialogs
{
    /// <summary>
    /// VISA 连接配置对话框 VM。
    /// 通过 DialogParameters 接收宿主 DeviceInfoVM；保存时把副本写回宿主。
    /// </summary>
    public class VisaConfigViewModel : DialogViewModelBase
    {
        #region 属性

        private string _title = "VISA 连接配置";
        public string Title
        {
            get => _title;
            set => SetProperty(ref _title, value);
        }

        /// <summary>编辑用的副本，取消时不会污染宿主对象。</summary>
        private VisaConfigVM _config = new();
        public VisaConfigVM Config
        {
            get => _config;
            set => SetProperty(ref _config, value);
        }

        /// <summary>常用超时（毫秒）。</summary>
        public ObservableCollection<int> CommonTimeouts { get; } = new()
        {
            500, 1000, 2000, 3000, 5000, 10000
        };

        /// <summary>常见 VISA 资源字符串模板，便于快速填写（可直接编辑）。</summary>
        public ObservableCollection<string> ResourceTemplates { get; } = new()
        {
            "TCPIP0::192.168.20.125::inst0::INSTR",
            "TCPIP0::192.168.20.125::5025::SOCKET",
            "USB0::0x0699::0x0408::C012345::INSTR",
            "GPIB0::7::INSTR",
            "ASRL1::INSTR"
        };

        private string _errorMessage = string.Empty;
        public string ErrorMessage
        {
            get => _errorMessage;
            set => SetProperty(ref _errorMessage, value);
        }

        #endregion

        #region 命令
        public ICommand SaveCommand { get; }
        public ICommand CancelCommand { get; }
        #endregion

        // 用于保存时把副本回写到原对象
        private DeviceInfoVM? _hostDevice;

        public VisaConfigViewModel(IContainerProvider containerProvider) : base(containerProvider)
        {
            SaveCommand = new DelegateCommand(OnSave);
            CancelCommand = new DelegateCommand(OnCancel);
        }

        private bool Validate(out string error)
        {
            error = string.Empty;
            if (string.IsNullOrWhiteSpace(Config.ResourceName))
            {
                error = "VISA 资源字符串不能为空";
                return false;
            }
            if (!Config.ResourceName.Contains("::"))
            {
                error = "资源字符串格式不正确，应形如 TCPIP0::192.168.0.10::inst0::INSTR";
                return false;
            }
            if (Config.OpenTimeout < 0 || Config.IOTimeout < 0)
            {
                error = "超时时间不能为负数";
                return false;
            }
            return true;
        }

        private void OnSave()
        {
            if (!Validate(out var error))
            {
                ErrorMessage = error;
                return;
            }
            ErrorMessage = string.Empty;

            // 把副本写回宿主
            if (_hostDevice != null)
            {
                _hostDevice.VisaConfig ??= new VisaConfigVM();
                Config.CopyTo(_hostDevice.VisaConfig);
                _hostDevice.ConnectionType = "Visa";
            }

            RequestClose.Invoke(ButtonResult.OK);
        }

        private void OnCancel() => RequestClose.Invoke(ButtonResult.Cancel);

        #region Prism Dialog 规范
        public override void OnDialogOpened(IDialogParameters parameters)
        {
            _eventAggregator.GetEvent<OverlayEvent>().Publish(true);

            if (parameters.ContainsKey("Device"))
            {
                _hostDevice = parameters.GetValue<DeviceInfoVM>("Device");
                Title = $"VISA 连接配置 - {_hostDevice?.DeviceName}";
                Config = new VisaConfigVM(_hostDevice?.VisaConfig);
            }
            else if (parameters.ContainsKey("Config"))
            {
                Config = new VisaConfigVM(parameters.GetValue<VisaConfigVM>("Config"));
            }
        }

        public override void OnDialogClosed()
        {
            _eventAggregator.GetEvent<OverlayEvent>().Publish(false);
        }
        #endregion
    }
}