Implement core Virtual FileSystem functionality

Co-authored-by: KSemenenko <4385716+KSemenenko@users.noreply.github.com>

Author: Copilot

ManagedCode.Storage.VirtualFileSystem/Core/IVfsEntry.cs

@@ -0,0 +1,137 @@
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using ManagedCode.Storage.VirtualFileSystem.Core;
+
+namespace ManagedCode.Storage.VirtualFileSystem.Core;
+
+/// <summary>
+/// Base interface for virtual file system entries
+/// </summary>
+public interface IVfsEntry
+{
+    /// <summary>
+    /// Gets the path of this entry
+    /// </summary>
+    VfsPath Path { get; }
+
+    /// <summary>
+    /// Gets the name of this entry
+    /// </summary>
+    string Name { get; }
+
+    /// <summary>
+    /// Gets the type of this entry
+    /// </summary>
+    VfsEntryType Type { get; }
+
+    /// <summary>
+    /// Gets when this entry was created
+    /// </summary>
+    DateTimeOffset CreatedOn { get; }
+
+    /// <summary>
+    /// Gets when this entry was last modified
+    /// </summary>
+    DateTimeOffset LastModified { get; }
+
+    /// <summary>
+    /// Checks if this entry exists
+    /// </summary>
+    /// <param name="cancellationToken">Cancellation token</param>
+    /// <returns>True if the entry exists</returns>
+    ValueTask<bool> ExistsAsync(CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Refreshes the entry information from storage
+    /// </summary>
+    /// <param name="cancellationToken">Cancellation token</param>
+    /// <returns>Task representing the async operation</returns>
+    Task RefreshAsync(CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Gets the parent directory of this entry
+    /// </summary>
+    /// <param name="cancellationToken">Cancellation token</param>
+    /// <returns>The parent directory</returns>
+    ValueTask<IVirtualDirectory> GetParentAsync(CancellationToken cancellationToken = default);
+}
+
+/// <summary>
+/// Type of virtual file system entry
+/// </summary>
+public enum VfsEntryType
+{
+    /// <summary>
+    /// A file entry
+    /// </summary>
+    File,
+
+    /// <summary>
+    /// A directory entry
+    /// </summary>
+    Directory
+}
+
+/// <summary>
+/// Progress information for copy operations
+/// </summary>
+public class CopyProgress
+{
+    /// <summary>
+    /// Total number of bytes to copy
+    /// </summary>
+    public long TotalBytes { get; set; }
+
+    /// <summary>
+    /// Number of bytes copied so far
+    /// </summary>
+    public long CopiedBytes { get; set; }
+
+    /// <summary>
+    /// Total number of files to copy
+    /// </summary>
+    public int TotalFiles { get; set; }
+
+    /// <summary>
+    /// Number of files copied so far
+    /// </summary>
+    public int CopiedFiles { get; set; }
+
+    /// <summary>
+    /// Current file being copied
+    /// </summary>
+    public string? CurrentFile { get; set; }
+
+    /// <summary>
+    /// Percentage completed (0-100)
+    /// </summary>
+    public double PercentageComplete => TotalBytes > 0 ? (double)CopiedBytes / TotalBytes * 100 : 0;
+}
+
+/// <summary>
+/// Result of a delete directory operation
+/// </summary>
+public class DeleteDirectoryResult
+{
+    /// <summary>
+    /// Whether the operation was successful
+    /// </summary>
+    public bool Success { get; set; }
+
+    /// <summary>
+    /// Number of files deleted
+    /// </summary>
+    public int FilesDeleted { get; set; }
+
+    /// <summary>
+    /// Number of directories deleted
+    /// </summary>
+    public int DirectoriesDeleted { get; set; }
+
+    /// <summary>
+    /// List of errors encountered during deletion
+    /// </summary>
+    public List<string> Errors { get; set; } = new();
+}

ManagedCode.Storage.VirtualFileSystem/Core/IVirtualDirectory.cs

@@ -0,0 +1,138 @@
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using ManagedCode.Storage.VirtualFileSystem.Options;
+
+namespace ManagedCode.Storage.VirtualFileSystem.Core;
+
+/// <summary>
+/// Represents a directory in the virtual filesystem
+/// </summary>
+public interface IVirtualDirectory : IVfsEntry
+{
+    /// <summary>
+    /// Lists files in this directory with pagination and pattern matching
+    /// </summary>
+    /// <param name="pattern">Search pattern for filtering</param>
+    /// <param name="recursive">Whether to search recursively</param>
+    /// <param name="pageSize">Page size for pagination</param>
+    /// <param name="cancellationToken">Cancellation token</param>
+    /// <returns>Async enumerable of files</returns>
+    IAsyncEnumerable<IVirtualFile> GetFilesAsync(
+        SearchPattern? pattern = null,
+        bool recursive = false,
+        int pageSize = 100,
+        CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Lists subdirectories with pagination
+    /// </summary>
+    /// <param name="pattern">Search pattern for filtering</param>
+    /// <param name="recursive">Whether to search recursively</param>
+    /// <param name="pageSize">Page size for pagination</param>
+    /// <param name="cancellationToken">Cancellation token</param>
+    /// <returns>Async enumerable of directories</returns>
+    IAsyncEnumerable<IVirtualDirectory> GetDirectoriesAsync(
+        SearchPattern? pattern = null,
+        bool recursive = false,
+        int pageSize = 100,
+        CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Lists all entries (files and directories) in this directory
+    /// </summary>
+    /// <param name="pattern">Search pattern for filtering</param>
+    /// <param name="recursive">Whether to search recursively</param>
+    /// <param name="pageSize">Page size for pagination</param>
+    /// <param name="cancellationToken">Cancellation token</param>
+    /// <returns>Async enumerable of entries</returns>
+    IAsyncEnumerable<IVfsEntry> GetEntriesAsync(
+        SearchPattern? pattern = null,
+        bool recursive = false,
+        int pageSize = 100,
+        CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Creates a file in this directory
+    /// </summary>
+    /// <param name="name">File name</param>
+    /// <param name="options">File creation options</param>
+    /// <param name="cancellationToken">Cancellation token</param>
+    /// <returns>The created file</returns>
+    ValueTask<IVirtualFile> CreateFileAsync(
+        string name,
+        CreateFileOptions? options = null,
+        CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Creates a subdirectory
+    /// </summary>
+    /// <param name="name">Directory name</param>
+    /// <param name="cancellationToken">Cancellation token</param>
+    /// <returns>The created directory</returns>
+    ValueTask<IVirtualDirectory> CreateDirectoryAsync(
+        string name,
+        CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Gets statistics for this directory
+    /// </summary>
+    /// <param name="recursive">Whether to calculate recursively</param>
+    /// <param name="cancellationToken">Cancellation token</param>
+    /// <returns>Directory statistics</returns>
+    Task<DirectoryStats> GetStatsAsync(
+        bool recursive = true,
+        CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Deletes this directory
+    /// </summary>
+    /// <param name="recursive">Whether to delete recursively</param>
+    /// <param name="cancellationToken">Cancellation token</param>
+    /// <returns>Delete operation result</returns>
+    Task<DeleteDirectoryResult> DeleteAsync(
+        bool recursive = false,
+        CancellationToken cancellationToken = default);
+}
+
+/// <summary>
+/// Statistics for a directory
+/// </summary>
+public class DirectoryStats
+{
+    /// <summary>
+    /// Number of files in the directory
+    /// </summary>
+    public int FileCount { get; init; }
+
+    /// <summary>
+    /// Number of subdirectories
+    /// </summary>
+    public int DirectoryCount { get; init; }
+
+    /// <summary>
+    /// Total size of all files in bytes
+    /// </summary>
+    public long TotalSize { get; init; }
+
+    /// <summary>
+    /// File count by extension
+    /// </summary>
+    public Dictionary<string, int> FilesByExtension { get; init; } = new();
+
+    /// <summary>
+    /// The largest file in the directory
+    /// </summary>
+    public IVirtualFile? LargestFile { get; init; }
+
+    /// <summary>
+    /// Oldest modification date
+    /// </summary>
+    public DateTimeOffset? OldestModified { get; init; }
+
+    /// <summary>
+    /// Newest modification date
+    /// </summary>
+    public DateTimeOffset? NewestModified { get; init; }
+}