feat: add library scanning mechanic

Tools/MetadataExtractor.cs

@@ -0,0 +1,67 @@
+using SharpExifTool;
+using System.Security.Cryptography;
+namespace Shadow.Tools;
+
+public static class MetadataExtractor
+{
+	private readonly static ExifTool exifTool = new();
+	private readonly static GeneralUseHelpers guhf = new();
+	public async static Task<Dictionary<string, string>> ExtractAsync(string fullPath)
+	{
+		// Get all relevant metadata
+		Dictionary<string, string> fileMetadata = new(await
+			exifTool.ExtractAllMetadataAsync(fullPath));
+
+		// Add in a MD5 hint
+		string md5sum = await GetFileMD5Async(fullPath);
+		fileMetadata?.Add("_shadow:fileHash", md5sum);
+
+		return fileMetadata ?? [];
+	}
+
+	/// <summary>
+	/// Compute MD5 checksum of a file
+	/// </summary>
+	/// <param name="fullPath">Input file absolute path</param>
+	/// <returns>MD5 hexstring</returns>
+	public static async Task<string> GetFileMD5Async(string fullPath)
+	{
+		string fallbackValue = String.Empty;
+		
+		try
+		{
+			if (File.Exists(fullPath))
+				using (MD5 md5 = MD5.Create())
+				{
+					using (FileStream stream = File.OpenRead(fullPath))
+					{
+						byte[] hashBytes = await md5.ComputeHashAsync(stream);
+						string hashString = Convert.ToHexStringLower(hashBytes);
+						return hashString;
+					}
+				}
+			else return fallbackValue;
+		}
+		catch
+		{
+			return fallbackValue;
+		}
+	}
+
+	/// <summary>
+	/// Compute MD5 checksum of a string
+	/// </summary>
+	/// <param name="input">Input string for the MD5 hash</param>
+	/// <returns>MD5 hexstring</returns>
+	public static string GetStringMD5(string input)
+	{
+		// https://stackoverflow.com/a/24031467
+		byte[] inputBytes = System.Text.Encoding.ASCII.GetBytes(input);
+		byte[] hashBytes = MD5.HashData(inputBytes);
+		string hashString = Convert.ToHexStringLower(hashBytes);
+
+		return hashString;
+	}
+
+
+}