BathhouseManagment/ViewModels/UserControlViewModels/PositionViewModel.cs

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using BathHouseManagmet.Database;
using BathHouseManagmet.Models;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using Microsoft.Extensions.DependencyInjection;

namespace BathHouseManagmet.ViewModels;

public partial class PositionViewModel : ViewModelBase
{
    private readonly IServiceProvider _serviceProvider;
    
    [ObservableProperty] ObservableCollection<Position> _positions;
    [ObservableProperty] int _currentPageSize;
    [ObservableProperty] List<int> _pageSizes;
    [ObservableProperty] string pageInfo;

    private int currentPage = 0;
    private int totalPages;

    public PositionViewModel(IServiceProvider serviceProvider)
    {
        _serviceProvider = serviceProvider;

        using (var rep = _serviceProvider.GetRequiredService<PositionRepository>())
            Positions = new ObservableCollection<Position>(rep.GetPage());
        
        PageSizes = new List<int>([5, 10, 15]);
        CurrentPageSize = PageSizes.First();
    }
    
    partial void OnCurrentPageSizeChanged(int value)
    {
        CalculatePage();
    }

    void CalculatePage()
    {
        using var db = new DiscountRepository();
        var rowsCount = db.GetRowsCount();
        totalPages = (int)Math.Ceiling(((double)rowsCount / CurrentPageSize));
        ShowFirstPage();
    }

    void ShowPage(int pageIndex)
    {
        currentPage = pageIndex;
        using var db = new PositionRepository();
        Positions.Clear();
        using (var rep = _serviceProvider.GetRequiredService<PositionRepository>())
        {
            var rows = db.GetPage(pageIndex, CurrentPageSize);
            rows.ForEach(p => Positions.Add(p));
        }
        PageInfo = $"Страница {currentPage + 1} из {totalPages}";
    }

    [RelayCommand]
    private void ShowFirstPage()
    {
        ShowPage(0);
    }

    [RelayCommand]
    private void ShowLastPage()
    {
        ShowPage(totalPages - 1);
    }

    [RelayCommand]
    private void ShowNextPage()
    {
        if (currentPage < totalPages - 1)
            ShowPage(currentPage + 1);
    }

    [RelayCommand]
    private void ShowPreviousPage()
    {
        if (currentPage > 0)
            ShowPage(currentPage - 1);
    }
}