using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Runtime.CompilerServices;
using VideoDownloader.Core.Detection;
using VideoDownloader.Core.Social;

namespace VideoDownloader.App.ViewModels;

public class DownloadItemViewModel : INotifyPropertyChanged
{
    private string _status = "대기";
    private int _progress;
    private bool _isIndeterminate;
    private string _segments = "";
    private string? _outputPath;
    private string? _error;
    private FormatOption? _selectedFormat;
    private bool _isFetchingFormats;

    private string _title;
    public string Title { get => _title; set => SetField(ref _title, value); }
    public string FormatTag { get; init; } = "FILE";

    // 다운로드 실행에 필요한 컨텍스트 (감지 시 고정)
    public MediaKind Kind { get; init; }
    public Uri MediaUrl { get; init; } = null!;
    public string OutputBase { get; set; } = "";
    public string? PageUrl { get; init; }
    public string? ContentType { get; init; }

    // 소셜(YouTube/Instagram/X) 카드: 화질/형식 선택
    public bool IsSocial => Kind == MediaKind.Social;
    public ObservableCollection<FormatOption> Formats { get; } = new();
    public FormatOption? SelectedFormat { get => _selectedFormat; set => SetField(ref _selectedFormat, value); }
    public bool IsFetchingFormats { get => _isFetchingFormats; set => SetField(ref _isFetchingFormats, value); }

    public CancellationTokenSource? Cts { get; set; }
    public bool Started { get; set; }

    public string Status { get => _status; set => SetField(ref _status, value); }
    public int Progress { get => _progress; set => SetField(ref _progress, value); }
    // #9 직링크 길이 미상 시 진행률 바를 부정확(애니메이션) 모드로
    public bool IsIndeterminate { get => _isIndeterminate; set => SetField(ref _isIndeterminate, value); }
    public string Segments { get => _segments; set => SetField(ref _segments, value); }
    public string? OutputPath { get => _outputPath; set => SetField(ref _outputPath, value); }
    public string? Error { get => _error; set => SetField(ref _error, value); }

    public DownloadItemViewModel(string title) { _title = title; }

    public event PropertyChangedEventHandler? PropertyChanged;

    private void SetField<T>(ref T field, T value, [CallerMemberName] string? name = null)
    {
        if (Equals(field, value)) return;
        field = value;
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));
    }
}