FileDatabase engine port from snailbird-content TS/Node program

DeepDrftContent/FileDatabase/Utils/FileUtils.cs

@@ -0,0 +1,118 @@
+using System.Text.Json;
+using DeepDrftContent.FileDatabase.Models;
+
+namespace DeepDrftContent.FileDatabase.Utils;
+
+/// <summary>
+/// Utility class for file I/O operations, matching the TypeScript file utilities
+/// </summary>
+public static class FileUtils
+{
+    /// <summary>
+    /// Reads a file and returns it as a FileBinary object
+    /// </summary>
+    /// <param name="mediaPath">Path to the media file</param>
+    /// <returns>FileBinary containing the file data</returns>
+    public static async Task<FileBinary> FetchFileAsync(string mediaPath)
+    {
+        using var fileStream = new FileStream(mediaPath, FileMode.Open, FileAccess.Read, FileShare.Read, bufferSize: 64 * 1024);
+        
+        var buffer = new byte[fileStream.Length];
+        var totalBytesRead = 0;
+        
+        while (totalBytesRead < fileStream.Length)
+        {
+            var bytesRead = await fileStream.ReadAsync(buffer.AsMemory(totalBytesRead));
+            if (bytesRead == 0)
+                throw new EndOfStreamException($"Unexpected end of stream while reading {mediaPath}");
+            
+            totalBytesRead += bytesRead;
+        }
+
+        return new FileBinary(new FileBinaryParams(buffer, buffer.Length));
+    }
+
+    /// <summary>
+    /// Writes binary data to a file
+    /// </summary>
+    /// <param name="mediaPath">Path where to write the file</param>
+    /// <param name="buffer">Binary data to write</param>
+    public static async Task PutFileAsync(string mediaPath, byte[] buffer)
+    {
+        const int chunkSize = 64 * 1024;
+        
+        using var fileStream = new FileStream(mediaPath, FileMode.Create, FileAccess.Write, FileShare.None, bufferSize: chunkSize);
+        
+        for (int offset = 0; offset < buffer.Length; offset += chunkSize)
+        {
+            var length = Math.Min(chunkSize, buffer.Length - offset);
+            await fileStream.WriteAsync(buffer.AsMemory(offset, length));
+        }
+        
+        await fileStream.FlushAsync();
+    }
+
+    /// <summary>
+    /// Serializes an object to a file using JSON
+    /// </summary>
+    /// <param name="filePath">Path to the file</param>
+    /// <param name="obj">Object to serialize</param>
+    public static async Task PutObjectAsync<T>(string filePath, T obj)
+    {
+        var options = new JsonSerializerOptions
+        {
+            WriteIndented = true,
+            PropertyNamingPolicy = JsonNamingPolicy.CamelCase
+        };
+
+        var json = JsonSerializer.Serialize(obj, options);
+        await File.WriteAllTextAsync(filePath, json);
+    }
+
+    /// <summary>
+    /// Deserializes an object from a JSON file
+    /// </summary>
+    /// <param name="filePath">Path to the file</param>
+    /// <returns>Deserialized object</returns>
+    public static async Task<T> FetchObjectAsync<T>(string filePath)
+    {
+        var json = await File.ReadAllTextAsync(filePath);
+        var options = new JsonSerializerOptions
+        {
+            PropertyNamingPolicy = JsonNamingPolicy.CamelCase
+        };
+
+        var result = JsonSerializer.Deserialize<T>(json, options);
+        return result ?? throw new InvalidOperationException($"Failed to deserialize object from {filePath}");
+    }
+
+    /// <summary>
+    /// Creates a directory if it doesn't exist
+    /// </summary>
+    /// <param name="directoryPath">Path to the directory</param>
+    public static Task MakeVaultDirectoryAsync(string directoryPath)
+    {
+        Directory.CreateDirectory(directoryPath);
+        return Task.CompletedTask;
+    }
+
+    /// <summary>
+    /// Checks if a file exists
+    /// </summary>
+    /// <param name="filePath">Path to check</param>
+    /// <returns>True if file exists</returns>
+    public static bool FileExists(string filePath)
+    {
+        return File.Exists(filePath);
+    }
+
+    /// <summary>
+    /// Checks if a directory exists
+    /// </summary>
+    /// <param name="directoryPath">Path to check</param>
+    /// <returns>True if directory exists</returns>
+    public static bool DirectoryExists(string directoryPath)
+    {
+        return Directory.Exists(directoryPath);
+    }
+}