Further disassociate Headerer

Headerer/Extract.cs

@@ -0,0 +1,104 @@
+using System;
+using System.IO;
+using Microsoft.Data.Sqlite;
+using SabreTools.Hashing;
+using SabreTools.IO.Extensions;
+using SabreTools.Skippers;
+
+namespace Headerer
+{
+    internal static class Extract
+    {
+        /// <summary>
+        /// Detect header skipper compliance and create an output file
+        /// </summary>
+        /// <param name="file">Name of the file to be parsed</param>
+        /// <param name="outDir">Output directory to write the file to, empty means the same directory as the input file</param>
+        /// <param name="nostore">True if headers should not be stored in the database, false otherwise</param>
+        /// <returns>True if the output file was created, false otherwise</returns>
+        public static bool DetectTransformStore(string file, string? outDir, bool nostore)
+        {
+            // Create the output directory if it doesn't exist
+            if (!string.IsNullOrWhiteSpace(outDir) && !Directory.Exists(outDir))
+                Directory.CreateDirectory(outDir);
+
+            Console.WriteLine($"\nGetting skipper information for '{file}'");
+
+            // Get the skipper rule that matches the file, if any
+            SkipperMatch.Init();
+            Rule rule = SkipperMatch.GetMatchingRule(file, string.Empty);
+
+            // If we have an empty rule, return false
+            if (rule.Tests == null || rule.Tests.Length == 0 || rule.Operation != HeaderSkipOperation.None)
+                return false;
+
+            Console.WriteLine("File has a valid copier header");
+
+            // Get the header bytes from the file first
+            string hstr;
+            try
+            {
+                // Extract the header as a string for the database
+                using var fs = File.OpenRead(file);
+                int startOffset = int.Parse(rule.StartOffset ?? "0");
+                byte[] hbin = new byte[startOffset];
+                fs.Read(hbin, 0, startOffset);
+                hstr = ByteArrayExtensions.ByteArrayToString(hbin)!;
+            }
+            catch
+            {
+                return false;
+            }
+
+            // Apply the rule to the file
+            string newfile = string.IsNullOrWhiteSpace(outDir) ? Path.GetFullPath(file) + ".new" : Path.Combine(outDir, Path.GetFileName(file));
+            rule.TransformFile(file, newfile);
+
+            // If the output file doesn't exist, return false
+            if (!File.Exists(newfile))
+                return false;
+
+            // Now add the information to the database if it's not already there
+            if (!nostore)
+            {
+                string sha1 = HashTool.GetFileHash(newfile, HashType.SHA1) ?? string.Empty;
+                AddHeaderToDatabase(hstr, sha1, rule.SourceFile!);
+            }
+
+            return true;
+        }
+
+        /// <summary>
+        /// Add a header to the database
+        /// </summary>
+        /// <param name="header">String representing the header bytes</param>
+        /// <param name="SHA1">SHA-1 of the deheadered file</param>
+        /// <param name="type">Name of the source skipper file</param>
+        private static void AddHeaderToDatabase(string header, string SHA1, string source)
+        {
+            // Ensure the database exists
+            Database.EnsureDatabase();
+
+            // Open the database connection
+            SqliteConnection dbc = new(Database.HeadererConnectionString);
+            dbc.Open();
+
+            string query = $"SELECT * FROM data WHERE sha1='{SHA1}' AND header='{header}'";
+            var slc = new SqliteCommand(query, dbc);
+            SqliteDataReader sldr = slc.ExecuteReader();
+            bool exists = sldr.HasRows;
+
+            if (!exists)
+            {
+                query = $"INSERT INTO data (sha1, header, type) VALUES ('{SHA1}', '{header}', '{source}')";
+                slc = new SqliteCommand(query, dbc);
+                Console.WriteLine($"Result of inserting header: {slc.ExecuteNonQuery()}"); // TODO: Gate behind debug flag
+            }
+
+            // Dispose of database objects
+            slc.Dispose();
+            sldr.Dispose();
+            dbc.Dispose();
+        }
+    }
+}