using System.Collections;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Runtime.CompilerServices;
using System.Windows;
using EmbyToolbox.Models;
using EmbyToolbox.Services;

namespace EmbyToolbox.ViewModels;

public sealed class BulkFileConversionSettingsViewModel : INotifyPropertyChanged, ITrackPlanPreviewHost
{
    private readonly ConversionQueueItem _representative;
    private readonly ConversionTaskOverride _draft;
    private readonly Action<IReadOnlyList<TrackOverrideEntry>> _onApply;
    private readonly Action _onClose;

    public BulkFileConversionSettingsViewModel(
        ConversionQueueItem representative,
        IReadOnlyList<ConversionQueueItem> targets,
        ConversionFormOptions formOptions,
        Action<IReadOnlyList<TrackOverrideEntry>> onApply,
        Action onClose)
    {
        _representative = representative;
        _draft = representative.TaskOverride.Clone();
        _onApply = onApply;
        _onClose = onClose;
        FormOptions = formOptions;

        TargetRowNumbersText = string.Join(", ", targets.OrderBy(i => i.OrderNumber).Select(i => i.OrderNumber));
        FilesCount = targets.Count;

        BuildRows();
        ValidateDefaultConflicts();

        SaveCommand = new RelayCommand(ExecuteSave);
        CancelCommand = new RelayCommand(() => _onClose());
        OnSelectionChangedCommand = new RelayCommand(OnSelectionChanged);
        SetSelectedTracksRemoveCommand = new RelayCommand(SetSelectedTracksRemove, CanSetSelectedTracksRemove);
    }

    public ConversionFormOptions FormOptions { get; }
    public ObservableCollection<TrackSettingsRowViewModel> TrackRows { get; } = new();
    public ObservableCollection<TrackSettingsRowViewModel> SelectedTracks { get; } = new();
    public RelayCommand SaveCommand { get; }
    public RelayCommand CancelCommand { get; }
    public RelayCommand OnSelectionChangedCommand { get; }
    public RelayCommand SetSelectedTracksRemoveCommand { get; }
    public int FilesCount { get; }
    public string TargetRowNumbersText { get; }

    public event PropertyChangedEventHandler? PropertyChanged;

    public void RecalculatePlanPreview()
    {
        // No per-file plan preview in bulk dialog.
    }

    public void OnTrackDefaultEnabled(TrackSettingsRowViewModel row)
    {
        if (row.DataModel.StreamKind is not (MediaStreamKind.Audio or MediaStreamKind.Subtitle))
        {
            return;
        }

        foreach (var r in TrackRows)
        {
            if (ReferenceEquals(r, row))
            {
                continue;
            }

            if (r.DataModel.StreamKind == row.DataModel.StreamKind)
            {
                r.Default = false;
            }
        }
    }

    public void ValidateDefaultConflicts()
    {
        var audioDefaults = TrackRows
            .Where(r => r.DataModel.StreamKind == MediaStreamKind.Audio && r.Action != TrackActionKind.Remove && r.Default is true)
            .ToList();
        var subDefaults = TrackRows
            .Where(r => r.DataModel.StreamKind == MediaStreamKind.Subtitle && r.Action != TrackActionKind.Remove && r.Default is true)
            .ToList();

        foreach (var r in TrackRows)
        {
            r.HasDefaultConflict = false;
        }

        if (audioDefaults.Count > 1)
        {
            foreach (var r in audioDefaults)
            {
                r.HasDefaultConflict = true;
            }
        }

        if (subDefaults.Count > 1)
        {
            foreach (var r in subDefaults)
            {
                r.HasDefaultConflict = true;
            }
        }
    }

    private void OnSelectionChanged(object? parameter)
    {
        SelectedTracks.Clear();
        if (parameter is IList list)
        {
            foreach (var r in list.OfType<TrackSettingsRowViewModel>())
            {
                SelectedTracks.Add(r);
            }
        }

        SetSelectedTracksRemoveCommand.RaiseCanExecuteChanged();
    }

    private bool CanSetSelectedTracksRemove(object? parameter)
    {
        if (parameter is not IList list || list.Count == 0)
        {
            return false;
        }

        return list.OfType<TrackSettingsRowViewModel>().Any(r => r.ValidActions.Contains(TrackActionKind.Remove));
    }

    private void SetSelectedTracksRemove(object? parameter)
    {
        if (parameter is not IList list || list.Count == 0)
        {
            return;
        }

        var rows = list.OfType<TrackSettingsRowViewModel>().ToList();
        var changed = false;
        foreach (var row in rows)
        {
            if (!row.ValidActions.Contains(TrackActionKind.Remove))
            {
                continue;
            }

            row.Action = TrackActionKind.Remove;
            changed = true;
        }

        if (changed)
        {
            ValidateDefaultConflicts();
            SetSelectedTracksRemoveCommand.RaiseCanExecuteChanged();
        }
    }

    private void ExecuteSave()
    {
        ValidateDefaultConflicts();
        var hasAudioConflict = TrackRows.Any(r => r.HasDefaultConflict && r.DataModel.StreamKind == MediaStreamKind.Audio);
        var hasSubConflict = TrackRows.Any(r => r.HasDefaultConflict && r.DataModel.StreamKind == MediaStreamKind.Subtitle);
        if (hasAudioConflict || hasSubConflict)
        {
            MessageBox.Show(
                "Ошибка: для Audio и Subtitle может быть только одна дорожка Default (исключая Remove).",
                "Валидация",
                MessageBoxButton.OK,
                MessageBoxImage.Warning);
            return;
        }

        _onApply(_draft.TrackOverrides.Select(t => t.Clone()).ToList());
        _onClose();
    }

    private void BuildRows()
    {
        TrackRows.Clear();
        var media = _representative.MediaAnalysis;
        var idx = 1;
        foreach (var t in _draft.TrackOverrides)
        {
            MediaStreamInfo? em = t.Source == SourceKind.Embedded && media is not null
                ? media.AllStreams.FirstOrDefault(s => s.Index == t.StreamIndex)
                : null;
            TrackRows.Add(new TrackSettingsRowViewModel(this, t, idx, em, _draft.TargetContainer));
            idx++;
        }
    }

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