using Prism.Commands;
using Prism.Mvvm;
using System;
using System.Collections.ObjectModel;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using TeamAAS_VP.Interfaces;
using TeamAAS_VP.Models;

namespace TeamAAS_VP.ViewModels.Statistics
{
    public class HeadChangeRecordQueryViewModel : BindableBase
    {
        private readonly ISystemDatabaseService _systemDatabaseService;
        public HeadChangeRecordQueryViewModel(ISystemDatabaseService systemDatabaseService)
        {
            _systemDatabaseService = systemDatabaseService;
            PageSize = 20; PageIndex = 1;
            StartDate = DateTime.Now.Date; EndDate = DateTime.Now.Date.AddDays(1);
            SearchCommand = new DelegateCommand(async () => await ExecuteSearchCommand());
            PrevPageCommand = new DelegateCommand(async () => { if (PageIndex > 1) { PageIndex--; await ExecuteSearchCommand(); } });
            NextPageCommand = new DelegateCommand(async () => { if (PageIndex * PageSize < TotalCount) { PageIndex++; await ExecuteSearchCommand(); } });
            ExportCommand = new DelegateCommand(async () => await ExecuteExportCommand());
        }

        private DateTime? _StartDate;
        public DateTime? StartDate
        {
            get { return _StartDate; }
            set { SetProperty(ref _StartDate, value); }
        }
        private DateTime? _EndDate;
        public DateTime? EndDate
        {
            get { return _EndDate; }
            set { SetProperty(ref _EndDate, value); }
        }
        private string _HeadBatchNumber;
        public string HeadBatchNumber
        {
            get { return _HeadBatchNumber; }
            set { SetProperty(ref _HeadBatchNumber, value); }
        }
        private ObservableCollection<HeadChangeRecord> _Results;
        public ObservableCollection<HeadChangeRecord> Results
        {
            get { return _Results; }
            set { SetProperty(ref _Results, value); }
        }
        private int _PageIndex;
        public int PageIndex
        {
            get { return _PageIndex; }
            set { SetProperty(ref _PageIndex, value); }
        }
        private int _PageSize;
        public int PageSize
        {
            get { return _PageSize; }
            set { SetProperty(ref _PageSize, value); }
        }
        private int _TotalCount;
        public int TotalCount
        {
            get { return _TotalCount; }
            set { SetProperty(ref _TotalCount, value); }
        }

        public DelegateCommand SearchCommand { get; private set; }
        public DelegateCommand PrevPageCommand { get; private set; }
        public DelegateCommand NextPageCommand { get; private set; }
        public DelegateCommand ExportCommand { get; private set; }

        private async Task ExecuteSearchCommand()
        {
            try
            {
                var start = StartDate.HasValue ? StartDate.Value : (DateTime?)null;
                var end = EndDate.HasValue ? EndDate.Value : (DateTime?)null;
                var res = await _systemDatabaseService.QueryHeadChangeRecordsPagedAsync(start, end, HeadBatchNumber, PageIndex, PageSize);
                Results = new ObservableCollection<HeadChangeRecord>(res.Items);
                TotalCount = res.TotalCount;
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "错误", MessageBoxButton.OK, MessageBoxImage.Error);
            }
        }

        private async Task ExecuteExportCommand()
        {
            try
            {
                var start = StartDate.HasValue ? StartDate.Value : (DateTime?)null;
                var end = EndDate.HasValue ? EndDate.Value : (DateTime?)null;
                var all = await _systemDatabaseService.QueryHeadChangeRecordsAsync(start, end, HeadBatchNumber);
                if (all == null || !all.Any()) { MessageBox.Show("没有找到符合条件的记录", "提示", MessageBoxButton.OK, MessageBoxImage.Information); return; }
                var dlg = new Microsoft.Win32.SaveFileDialog { FileName = $"HeadChange_{DateTime.Now:yyyyMMddHHmmss}.csv", DefaultExt = ".csv", Filter = "CSV Files (*.csv)|*.csv" };
                if (dlg.ShowDialog() != true) return;
                var path = dlg.FileName;
                using (var sw = new StreamWriter(path, false, Encoding.UTF8))
                {
                    sw.WriteLine("ChangeTime,HeadBatchNumber,CurrentLockCount,OperatorName");
                    foreach (var r in all)
                    {
                        sw.WriteLine($"{r.ChangeTime:yyyy-MM-dd HH:mm:ss},{r.HeadBatchNumber},{r.CurrentLockCount},{r.OperatorName}");
                    }
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "错误", MessageBoxButton.OK, MessageBoxImage.Error);
            }
        }
    }
}