using System;
using System.Collections.Generic;
using System.Text;
using System.Threading.Tasks;
using Vinno.IUS.Common.Log;
using Vinno.IUS.Common.Utilities;

namespace vCloud.GeneratePackages.Tool.ViewModels
{
    public class ModalActionViewModel : ViewModel
    {
        IDescriptionUpdater _descriptionUpdater;
        private bool _isBusy;
        private string _title;
        private readonly Action _action;
        /// <summary>
        /// The event page closed
        /// </summary>
        public event EventHandler ClosedRequest;

        /// <summary>
        /// view model is busy
        /// </summary>
        public bool IsBusy
        {
            get { return _isBusy; }
            set
            {
                if (_isBusy != value)
                {
                    _isBusy = value;
                    OnPropertyChanged(() => IsBusy);
                }
            }
        }

        /// <summary>
        /// Title of this window
        /// </summary>
        public string Title
        {
            get { return _title; }
            set
            {
                if (_title != value)
                {
                    _title = value;
                    OnPropertyChanged(() => Title);
                }
            }
        }


        public ModalActionViewModel(Action action, IDescriptionUpdater descriptionUpdater, string descpription = null, string titile = null)
        {
            Title = titile;
            _descriptionUpdater = descriptionUpdater;
            if (_descriptionUpdater != null)
            _descriptionUpdater.DescriptionUpdated += OnDescriptionUpdated;
            _action = action;
            if (!string.IsNullOrEmpty(descpription))
            {
                Description = TranslateHelper.Translate(descpription);
            }
            OnLoadedAsync();
        }

        /// <summary>
        /// 更新描述信息
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void OnDescriptionUpdated(object sender, string e)
        {
            AppManager.MainDispatcher.Invoke(() => { Description = e; });
        }

        /// <summary>
        /// 加载ftp编译包信息
        /// </summary>
        private async void OnLoadedAsync()
        {
            try
            {
                await DoActionAsync();
            }           
            catch(Exception e)
            {
                Logger.WriteLineError($"Action {Title} ex:{e}");
                OnClosedRequest();
            }
        }

        /// <summary>
        /// 阻碍UI直至信息加载完成
        /// </summary>
        /// <returns></returns>
        async Task DoActionAsync()
        {
            IsBusy = true;
            await Task.Run(() =>
            {
                _action.Invoke();
            });
            IsBusy = false;

            OnClosedRequest();
        }

        /// <summary>
        /// 关闭时反注册事件
        /// </summary>
        protected virtual void OnClosedRequest()
        {
            if (_descriptionUpdater != null)
                _descriptionUpdater.DescriptionUpdated -= OnDescriptionUpdated;
            ClosedRequest?.Invoke(this, EventArgs.Empty);
        }
    }
}