using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;

namespace _29WxOrderWpf.Ctrls.OrderCtrls;

public partial class OrderListCtrl : INotifyPropertyChanged
{
	#region NotifayProperty
	/// <summary>
	/// Occurs when a property value changes.
	/// </summary>
	public event PropertyChangedEventHandler PropertyChanged;

	/// <summary>
	/// Checks if a property already matches a desired value. Sets the property and
	/// notifies listeners only when necessary.
	/// </summary>
	/// <typeparam name="T">Type of the property.</typeparam>
	/// <param name="storage">Reference to a property with both getter and setter.</param>
	/// <param name="value">Desired value for the property.</param>
	/// <param name="propertyName">Name of the property used to notify listeners. This
	/// value is optional and can be provided automatically when invoked from compilers that
	/// support CallerMemberName.</param>
	/// <returns>True if the value was changed, false if the existing value matched the
	/// desired value.</returns>
	protected virtual bool SetProperty<T>(ref T storage, T value, [CallerMemberName] string propertyName = null)
	{
		if (EqualityComparer<T>.Default.Equals(storage, value)) return false;

		storage = value;
		RaisePropertyChanged(propertyName);

		return true;
	}

	/// <summary>
	/// Checks if a property already matches a desired value. Sets the property and
	/// notifies listeners only when necessary.
	/// </summary>
	/// <typeparam name="T">Type of the property.</typeparam>
	/// <param name="storage">Reference to a property with both getter and setter.</param>
	/// <param name="value">Desired value for the property.</param>
	/// <param name="propertyName">Name of the property used to notify listeners. This
	/// value is optional and can be provided automatically when invoked from compilers that
	/// support CallerMemberName.</param>
	/// <param name="onChanged">Action that is called after the property value has been changed.</param>
	/// <returns>True if the value was changed, false if the existing value matched the
	/// desired value.</returns>
	protected virtual bool SetProperty<T>(ref T storage, T value, Action onChanged, [CallerMemberName] string propertyName = null)
	{
		if (EqualityComparer<T>.Default.Equals(storage, value)) return false;

		storage = value;
		onChanged?.Invoke();
		RaisePropertyChanged(propertyName);

		return true;
	}

	/// <summary>
	/// Raises this object's PropertyChanged event.
	/// </summary>
	/// <param name="propertyName">Name of the property used to notify listeners. This
	/// value is optional and can be provided automatically when invoked from compilers
	/// that support <see cref="CallerMemberNameAttribute"/>.</param>
	protected void RaisePropertyChanged([CallerMemberName] string propertyName = null)
	{
		OnPropertyChanged(new PropertyChangedEventArgs(propertyName));
	}

	/// <summary>
	/// Raises this object's PropertyChanged event.
	/// </summary>
	/// <param name="args">The PropertyChangedEventArgs</param>
	protected virtual void OnPropertyChanged(PropertyChangedEventArgs args)
	{
		PropertyChanged?.Invoke(this, args);
	}
	#endregion


	private string _bottomMsg = "";
	public string BottomMsg
	{
		get => _bottomMsg;
		set => SetProperty(ref _bottomMsg, value);
	}

	private double _progressValue;
	public double ProgressValue
	{
		get => _progressValue;
		set => SetProperty(ref _progressValue, value);
	}

	private double _progressMaximum = 100;
	public double ProgressMaximum
	{
		get => _progressMaximum;
		set => SetProperty(ref _progressMaximum, value);
	}
	public void SetProgress(int value, int maxValue)
	{
		StopUnknownTotalProgressTimer();
		ProgressValue = value;
		ProgressMaximum = maxValue;
	}

	#region 未知总数百分比模拟进度
	private System.Threading.Timer _unknownTotalProgressTimer;
	private DateTime _unknownTotalProgressStartTime;

	/// <summary>
	/// 开始未知总数的百分比模拟进度：80% 之前走得快，越到最后走得越慢，
	/// 理论上永远走不到 95% 以上，直到调用 <see cref="CompleteProgress"/> 才会变成 100%。
	/// </summary>
	public void StartProgress()
	{
		StopUnknownTotalProgressTimer();
		ProgressMaximum = 100;
		ProgressValue = 0;
		_unknownTotalProgressStartTime = DateTime.Now;
		_unknownTotalProgressTimer = new System.Threading.Timer(_ => UpdateUnknownTotalProgress(), null, 0, 200);
	}

	/// <summary>
	/// 结束进度：停止模拟，进度条立即变为 100%。
	/// </summary>
	public void CompleteProgress()
	{
		StopUnknownTotalProgressTimer();
		ProgressMaximum = 100;
		ProgressValue = 100;
	}

	private void UpdateUnknownTotalProgress()
	{
		try
		{
			Dispatcher.BeginInvoke(new Action(() =>
			{
				var elapsed = (DateTime.Now - _unknownTotalProgressStartTime).TotalSeconds;
				double progress;
				if (elapsed <= 10)
				{
					// 前 10 秒内快速推进到 80%
					progress = Math.Max(0, Math.Min(80, elapsed * 8));
				}
				else
				{
					// 超过 80% 后指数衰减越来越慢，渐近线为 95%，理论上永远走不到 95% 以上
					progress = 95.0 - 15.0 * Math.Exp(-(elapsed - 10.0) / 20.0);
				}
				if (progress > 95) progress = 95;
				ProgressValue = progress;
			}));
		}
		catch
		{
		}
	}

	private void StopUnknownTotalProgressTimer()
	{
		if (_unknownTotalProgressTimer == null) return;
		try
		{
			_unknownTotalProgressTimer.Dispose();
		}
		catch
		{
		}
		_unknownTotalProgressTimer = null;
	}
	#endregion
}