Tests?

2024-09-25 20:01:32 -06:00
parent d39e73a6fa
commit 94ab274246
10 changed files with 146 additions and 59 deletions
@@ -0,0 +1,165 @@
+using System.Text;
+
+namespace fxl.codes.kisekae.data.Archives;
+
+internal class LhContainer
+{
+    public LhContainer(ref readonly Stream stream)
+    {
+        HeaderDataPosition = stream.Position;
+        var bytes = new byte[21];
+        stream.ReadExactly(bytes);
+
+        var span = bytes.AsSpan();
+        Level = span[20];
+        MethodId = Encoding.ASCII.GetString(span[2..7]);
+        CompressedSize = EndianUtility.ToLittleEndian(span[7..11]);
+        CompressedFile = new byte[CompressedSize];
+        UncompressedSize = EndianUtility.ToLittleEndian(span[11..15]);
+        Created = EndianUtility.ToDateTime(span[15..19]);
+        FileOrDirectory = span[19];
+
+        switch (Level)
+        {
+            case 0:
+                Level0(span, in stream);
+                break;
+            case 1:
+                Level1(span, in stream);
+                break;
+            case 2:
+                Level2(span, in stream);
+                break;
+            default: throw new Exception("Invalid LH Header");
+        }
+    }
+
+    public int HeaderSize { get; private set; }
+    public int HeaderCheckSum { get; private set; }
+    public string MethodId { get; private set; }
+    public int CompressedSize { get; }
+    public int UncompressedSize { get; private set; }
+    public DateTime Created { get; private set; }
+    public int FileOrDirectory { get; private set; }
+    public int Level { get; }
+    public short Crc16 { get; private set; }
+
+    public string? FileName { get; private set; }
+
+    public long HeaderDataPosition { get; }
+    public long FileDataPosition { get; private set; }
+    public byte[] CompressedFile { get; }
+
+    private void Level0(ReadOnlySpan<byte> span, ref readonly Stream stream)
+    {
+        HeaderSize = span[0];
+        HeaderCheckSum = span[1];
+        FileName = GetFilename(in stream);
+        Crc16 = (short)stream.ReadLittleEndian(2);
+
+        FileDataPosition = stream.Position;
+        stream.ReadExactly(CompressedFile);
+    }
+
+    private void Level1(ReadOnlySpan<byte> span, ref readonly Stream stream)
+    {
+        HeaderSize = span[0];
+        HeaderCheckSum = span[1];
+        FileName = GetFilename(in stream);
+        Crc16 = (short)stream.ReadLittleEndian(2);
+        OperatingSystem = (char)stream.ReadByte();
+
+        SetExtendedHeaders(in stream);
+
+        FileDataPosition = stream.Position;
+        stream.ReadExactly(CompressedFile);
+    }
+
+    private void Level2(ReadOnlySpan<byte> span, ref readonly Stream stream)
+    {
+        HeaderSize = span[..2].ToLittleEndian();
+        Crc16 = (short)stream.ReadLittleEndian(2);
+        OperatingSystem = (char)stream.ReadByte();
+
+        SetExtendedHeaders(in stream);
+
+        FileDataPosition = stream.Position;
+        stream.ReadExactly(CompressedFile);
+    }
+
+    private static string GetFilename(ref readonly Stream stream)
+    {
+        var length = stream.ReadByte();
+        var buffer = new byte[length];
+        stream.ReadExactly(buffer);
+        return Encoding.ASCII.GetString(buffer);
+    }
+
+    private void SetExtendedHeaders(ref readonly Stream stream)
+    {
+        var extendedHeaderSize = stream.ReadLittleEndian(2);
+        while (extendedHeaderSize != 0)
+        {
+            var type = stream.ReadByte();
+            var nextSize = stream.ReadLittleEndian(2);
+
+            switch (type)
+            {
+                case 0x00:
+                    Crc16 = (short)stream.ReadLittleEndian(extendedHeaderSize);
+                    break;
+                case 0x01:
+                    FileName = GetString(in stream, extendedHeaderSize);
+                    break;
+                case 0x02:
+                    DirectoryName = GetString(in stream, extendedHeaderSize);
+                    break;
+                case 0x3f:
+                    Comment = GetString(in stream, extendedHeaderSize);
+                    break;
+                case 0x50:
+                    FilePermission = stream.ReadLittleEndian(extendedHeaderSize);
+                    break;
+                case 0x51:
+                    GroupId = stream.ReadLittleEndian(2);
+                    UserId = stream.ReadLittleEndian(2);
+                    break;
+                case 0x52:
+                    GroupName = GetString(in stream, extendedHeaderSize);
+                    break;
+                case 0x53:
+                    UserName = GetString(in stream, extendedHeaderSize);
+                    break;
+                case 0x54:
+                    LastModified = stream.ReadLittleEndianDateTime();
+                    break;
+                default: // Unknown, skip
+                    stream.Position += extendedHeaderSize;
+                    break;
+            }
+
+            extendedHeaderSize = nextSize;
+        }
+    }
+
+    private static string GetString(ref readonly Stream stream, int length)
+    {
+        var buffer = new byte[length];
+        stream.ReadExactly(buffer);
+        return Encoding.ASCII.GetString(buffer);
+    }
+
+    #region Extended Headers
+
+    public char? OperatingSystem { get; private set; }
+    public string? DirectoryName { get; private set; }
+    public string? Comment { get; private set; }
+    public int? FilePermission { get; private set; }
+    public int? GroupId { get; private set; }
+    public string? GroupName { get; private set; }
+    public int? UserId { get; private set; }
+    public string? UserName { get; private set; }
+    public DateTime? LastModified { get; private set; }
+
+    #endregion
+}