using System.Collections.ObjectModel;
using System.Linq;
using CRAWLER.Infrastructure;
using CRAWLER.Models;

namespace CRAWLER.ViewModels;

internal sealed class EditInstrumentWindowViewModel : ObservableObject
{
    private readonly InstrumentRecord _draft;
    private PendingPdfFile _selectedPendingPdf;

    public EditInstrumentWindowViewModel(InstrumentRecord draft, bool isNewRecord)
    {
        _draft = draft ?? new InstrumentRecord();
        PendingPdfFiles = new ObservableCollection<PendingPdfFile>();
        ExistingAttachments = new ObservableCollection<PdfAttachment>(_draft.Attachments ?? Enumerable.Empty<PdfAttachment>());
        WindowTitle = isNewRecord ? "Новая запись" : $"Редактирование: {(_draft.RegistryNumber ?? _draft.Name)}";
    }

    public string WindowTitle { get; }

    public ObservableCollection<PendingPdfFile> PendingPdfFiles { get; }

    public ObservableCollection<PdfAttachment> ExistingAttachments { get; }

    public PendingPdfFile SelectedPendingPdf
    {
        get { return _selectedPendingPdf; }
        set { SetProperty(ref _selectedPendingPdf, value); }
    }

    public InstrumentRecord Draft
    {
        get { return _draft; }
    }

    public void AddPendingFiles(IReadOnlyList<string> paths)
    {
        foreach (var path in paths.Where(path => !string.IsNullOrWhiteSpace(path)))
        {
            if (PendingPdfFiles.Any(item => string.Equals(item.SourcePath, path, StringComparison.OrdinalIgnoreCase)))
            {
                continue;
            }

            PendingPdfFiles.Add(new PendingPdfFile
            {
                SourcePath = path,
                DisplayName = System.IO.Path.GetFileName(path)
            });
        }
    }

    public void RemovePendingSelected()
    {
        if (SelectedPendingPdf != null)
        {
            PendingPdfFiles.Remove(SelectedPendingPdf);
        }
    }

    public string[] GetPendingPaths()
    {
        return PendingPdfFiles.Select(item => item.SourcePath).ToArray();
    }

    public bool Validate(out string errorMessage)
    {
        if (string.IsNullOrWhiteSpace(Draft.Name))
        {
            errorMessage = "Укажите наименование средства измерения.";
            return false;
        }

        errorMessage = null;
        return true;
    }
}