using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Diagnostics;
using System.IO;
using System.Runtime.CompilerServices;
using EmbyToolbox.Services;

namespace EmbyToolbox.ViewModels;

/// <summary>UI вкладки «Логи». Поток записей — <see cref="UiEntries"/> (тот же <see cref="LoggingService.UiEntries"/>, без дублирования).</summary>
public sealed class LogsViewModel : INotifyPropertyChanged
{
    private readonly LoggingService _logging;
    private int _scrollPulse;

    public LogsViewModel(LoggingService logging)
    {
        _logging = logging;
        RefreshLogViewCommand = new RelayCommand(ExecuteRefreshScroll);
        OpenLogsFolderCommand = new RelayCommand(ExecuteOpenLogsFolder);
        ClearUiLogCommand = new RelayCommand(ExecuteClearUiLog, () => UiEntries.Count > 0);
    }

    /// <summary>Инкремент для умного принудительного скролла вниз (кнопка «Обновить»).</summary>
    public int ScrollPulse
    {
        get => _scrollPulse;
        private set
        {
            if (_scrollPulse == value)
            {
                return;
            }

            _scrollPulse = value;
            OnPropertyChanged();
        }
    }

    /// <summary>Тот же <see cref="LoggingService.UiEntries"/>, что и у главного окна.</summary>
    public ObservableCollection<LogEntryViewModel> UiEntries => _logging.UiEntries;

    public RelayCommand RefreshLogViewCommand { get; }

    public RelayCommand OpenLogsFolderCommand { get; }

    public RelayCommand ClearUiLogCommand { get; }

    public event PropertyChangedEventHandler? PropertyChanged;

    private void ExecuteRefreshScroll() => ScrollPulse++;

    private void ExecuteOpenLogsFolder()
    {
        Directory.CreateDirectory(_logging.LogsDirectory);
        Process.Start(new ProcessStartInfo
        {
            FileName = "explorer.exe",
            Arguments = _logging.LogsDirectory,
            UseShellExecute = true
        });
        _logging.Info("открыта папка логов", "ui.log");
    }

    private void ExecuteClearUiLog()
    {
        _logging.ClearUi();
        _logging.Info("UI-лог очищен", "ui.log");
    }

    public void RaiseClearCommandState() =>
        ClearUiLogCommand.RaiseCanExecuteChanged();

    private void OnPropertyChanged([CallerMemberName] string? propertyName = null) =>
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}