corp-app/CORP-MAUI/ViewModels/PostViewModel.cs

using System.ComponentModel;
using System.Diagnostics;
using System.Runtime.CompilerServices;
using CORP_MAUI.Models;

namespace CORP_MAUI.ViewModels;

public class PostViewModel : INotifyPropertyChanged
{
    public Post Post { get; }

    public PostViewModel(Post post)
    {
        Post = post;
        // Truncate content for preview
        if (!string.IsNullOrEmpty(Post.Content) && Post.Content.Length > 0)
        {
            if (Post.Content.Length > 100)
            {
                _previewContent = Post.Content.Substring(0, 100) + "...";
            }
            else
            {
                _previewContent = Post.Content;
            }
        }
        else
        {
            _previewContent = string.Empty; 
        }
    }

    private string? _localImagePath;
    public string? LocalImagePath
    {
        get => _localImagePath;
        set
        {
            _localImagePath = value;
            OnPropertyChanged();
            OnPropertyChanged(nameof(IsImageVisible));
            OnPropertyChanged(nameof(DisplayImageSource));
        }
    }

    private ImageSource? _imageSource;
    public ImageSource? AuthorizedImageSource
    {
        get => _imageSource;
        set
        {
            _imageSource = value;
            OnPropertyChanged();
            OnPropertyChanged(nameof(IsImageVisible));
            OnPropertyChanged(nameof(DisplayImageSource));
        }
    }

    public ImageSource? DisplayImageSource
    {
        get
        {
            if (_imageSource != null) return _imageSource;
            
            if (!string.IsNullOrEmpty(_localImagePath) && File.Exists(_localImagePath)) 
            {
                // Basic check for empty files
                try 
                {
                    if (new FileInfo(_localImagePath).Length == 0) return null;
                }
                catch { return null; }

                // Используем FromStream для надежности, чтобы не блокировать файл
                // и гарантировать чтение даже из системных папок
                return ImageSource.FromStream(() => 
                {
                    try
                    {
                        return new FileStream(_localImagePath, FileMode.Open, FileAccess.Read, FileShare.Read);
                    }
                    catch (Exception ex)
                    {
                        Trace.WriteLine($"[PostViewModel] Error reading image {_localImagePath}: {ex.Message}");
                        return null;
                    }
                });
            }
            return null;
        }
    }

    public bool IsImageVisible => DisplayImageSource != null;

    private string _previewContent;
    public string PreviewContent
    {
        get => _previewContent;
        set
        {
            _previewContent = value;
            OnPropertyChanged();
        }
    }
    
    // Proxy properties for cleaner XAML binding if needed, or bind to Post.Title directly
    public int Id => Post.Id;
    public string Title => Post.Title;
    public string? AuthorizedImageUrl => Post.DisplayImageUrl; 

    public event PropertyChangedEventHandler? PropertyChanged;

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