using System;
using System.Collections.ObjectModel;
using System.Linq;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using Elfisa.Core;

namespace Elfisa.Avalonia.ViewModels;

public class NavItem
{
    public string Title { get; }
    public string Icon { get; }
    public Func<ViewModelBase> Factory { get; }
    public NavItem(string title, string icon, Func<ViewModelBase> factory)
    {
        Title = title; Icon = icon; Factory = factory;
    }
}

public partial class ShellViewModel : ViewModelBase
{
    private readonly Action _logout;

    public ObservableCollection<NavItem> NavItems { get; }

    [ObservableProperty] private NavItem? _selectedNav;
    [ObservableProperty] private ViewModelBase? _currentPage;

    public string UserName => Session.Current.Username ?? "";
    public string RoleLabel => Session.Current.Role switch
    {
        "buyer" => "Покупатель",
        "supplier" => "Поставщик",
        "manager" => "Менеджер",
        "admin" => "Администратор",
        _ => Session.Current.Role ?? ""
    };

    public ShellViewModel(Action logout)
    {
        _logout = logout;
        NavItems = new ObservableCollection<NavItem>
        {
            new("Прайс-лист", "🧾", () => new PriceListViewModel()),
            new("Заказы",     "🛒", () => new OrdersViewModel()),
            new("Накладные",  "📄", () => new InvoicesViewModel()),
            new("Отчёты",     "📊", () => new ReportsViewModel()),
            new("Отправить",  "📤", () => new SendOrderViewModel()),
            new("Отказы",     "⛔", () => new PlaceholderPageViewModel("Отказы",
                "Отказные позиции по заказам. Нужен серверный эндпоинт: данные (RefuseItemsCount) сейчас есть только в локальной БД WinForms-клиента.")),
            new("Справочник", "📖", () => new DirectoryViewModel()),
        };
        SelectedNav = NavItems.First(n => n.Title == "Отчёты");
    }

    partial void OnSelectedNavChanged(NavItem? value) => CurrentPage = value?.Factory();

    [RelayCommand] private void Logout() => _logout();
}