add initial file scan and rescanning algorithms to hash all penumbra files

MareSynchronos/Factories/FileCacheFactory.cs

@@ -0,0 +1,41 @@
+using System;
+using System.IO;
+using MareSynchronos.FileCacheDB;
+using System.Security.Cryptography;
+
+
+namespace MareSynchronos.Factories
+{
+    public class FileCacheFactory
+    {
+        public FileCacheFactory()
+        {
+
+        }
+
+        public FileCache Create(string file)
+        {
+            FileInfo fileInfo = new(file);
+            string sha1Hash = GetHash(fileInfo.FullName);
+            return new FileCache()
+            {
+                Filepath = fileInfo.FullName,
+                Hash = sha1Hash,
+                LastModifiedDate = fileInfo.LastWriteTimeUtc.Ticks.ToString(),
+            };
+        }
+
+        public void UpdateFileCache(FileCache cache)
+        {
+            FileInfo fileInfo = new(cache.Filepath);
+            cache.Hash = GetHash(cache.Filepath);
+            cache.LastModifiedDate = fileInfo.LastWriteTimeUtc.Ticks.ToString();
+        }
+
+        private string GetHash(string filePath)
+        {
+            using SHA1CryptoServiceProvider cryptoProvider = new();
+            return BitConverter.ToString(cryptoProvider.ComputeHash(File.ReadAllBytes(filePath)));
+        }
+    }
+}