Implement LZSS decompression with optional XOR decryption

- Added `lzss_decompress_simple` function for LZSS decompression in `lzss.rs`.
- Introduced `XorState` struct and `xor_stream` function for XOR decryption in `xor.rs`.
- Updated `mod.rs` to include new LZSS and XOR modules.
- Refactored `parse_library` function in `parse.rs` to utilize the new XOR decryption functionality.
- Cleaned up and organized code in `lib.rs` by removing redundant functions and structures.
- Added tests for new functionality in `tests.rs`.

1 files changed, 19 insertions, 0 deletions

diff --git a/crates/rsli/src/compress/deflate.rs b/crates/rsli/src/compress/deflate.rs
new file mode 100644
index 0000000..154e0e3
--- /dev/null
+++ b/crates/rsli/src/compress/deflate.rs
@@ -0,0 +1,19 @@
+use crate::error::Error;
+use crate::Result;
+use flate2::read::{DeflateDecoder, ZlibDecoder};
+use std::io::Read;
+
+/// Decode Deflate or Zlib compressed data
+pub fn decode_deflate(packed: &[u8]) -> Result<Vec<u8>> {
+    let mut out = Vec::new();
+    let mut decoder = DeflateDecoder::new(packed);
+    if decoder.read_to_end(&mut out).is_ok() {
+        return Ok(out);
+    }
+
+    out.clear();
+    let mut zlib = ZlibDecoder::new(packed);
+    zlib.read_to_end(&mut out)
+        .map_err(|_| Error::DecompressionFailed("deflate"))?;
+    Ok(out)
+}