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

namespace ShrlAlgo.Addin.Test
{
    // 用于给外界调用的报告器
    public class ProgressReporter
    {
        private readonly ProgressViewModel _viewModel;
        private DateTime _lastUpdate = DateTime.MinValue;

        public ProgressReporter(ProgressViewModel viewModel)
        {
            _viewModel = viewModel;
        }

        /// <summary>
        /// 更新进度 (自带节流控制，防止频繁更新导致UI卡顿)
        /// </summary>
        public void Report(int current, int total, string message = null)
        {
            // 限制 UI 刷新频率（每 50 毫秒最多刷新一次）
            if ((DateTime.Now - _lastUpdate).TotalMilliseconds < 50 && current != total)
                return;

            _lastUpdate = DateTime.Now;
            _viewModel.Update(current, total, message);
        }

        public void ReportMessage(string message) => _viewModel.UpdateMessage(message);
    }

    // WPF 的 ViewModel
    public class ProgressViewModel : INotifyPropertyChanged
    {
        private readonly CancellationTokenSource _cts;
        public Dispatcher UIDispatcher { get; set; }
        public Action CloseAction { get; set; }

        public ProgressViewModel(string title, CancellationTokenSource cts)
        {
            Title = title;
            _cts = cts;
        }

        private string _title;
        public string Title { get => _title; set => SetProperty(ref _title, value); }

        private string _message = "正在准备...";
        public string Message { get => _message; set => SetProperty(ref _message, value); }

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

        private double _maximum = 100;
        public double Maximum { get => _maximum; set => SetProperty(ref _maximum, value); }

        public void Cancel()
        {
            if (!_cts.IsCancellationRequested)
            {
                Message = "正在取消任务，请稍候...";
                _cts.Cancel();
            }
        }

        // 跨线程更新 UI
        public void Update(int current, int total, string message)
        {
            UIDispatcher?.InvokeAsync(() =>
            {
                ProgressValue = current;
                Maximum = total;
                if (!string.IsNullOrEmpty(message)) Message = message;
            });
        }

        public void UpdateMessage(string message)
        {
            UIDispatcher?.InvokeAsync(() => Message = message);
        }

        public event PropertyChangedEventHandler PropertyChanged;
        protected void SetProperty<T>(ref T field, T value, [CallerMemberName] string propertyName = null)
        {
            field = value;
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}