From 9a89f8024725ad62c2eead8be1ef0a904dbac9ae Mon Sep 17 00:00:00 2001
From: NinjaCheetah <58050615+NinjaCheetah@users.noreply.github.com>
Date: Wed, 8 Jan 2025 20:09:34 -0500
Subject: [PATCH] Added lz77 command to allow for decompressing LZ77-compressed
 files

---
 commands/archive/lz77.py | 28 ++++++++++++++++++++++++++++
 commands/archive/u8.py   |  9 ++++++++-
 wiipy.py                 | 25 ++++++++++++++++++++++++-
 3 files changed, 60 insertions(+), 2 deletions(-)
 create mode 100644 commands/archive/lz77.py

diff --git a/commands/archive/lz77.py b/commands/archive/lz77.py
new file mode 100644
index 0000000..e797158
--- /dev/null
+++ b/commands/archive/lz77.py
@@ -0,0 +1,28 @@
+# "commands/archive/lz77.py" from WiiPy by NinjaCheetah
+# https://github.com/NinjaCheetah/WiiPy
+
+import pathlib
+import libWiiPy
+from modules.core import fatal_error
+
+
+def handle_lz77_compress(args):
+    print("Compression is not implemented yet.")
+
+
+def handle_lz77_decompress(args):
+    input_path = pathlib.Path(args.input)
+    if args.output is not None:
+        output_path = pathlib.Path(args.output)
+    else:
+        output_path = pathlib.Path(input_path.name + ".out")
+
+    if not input_path.exists():
+        fatal_error(f"The specified file \"{input_path}\" does not exist!")
+
+    lz77_data = input_path.read_bytes()
+    data = libWiiPy.archive.decompress_lz77(lz77_data)
+    output_path.write_bytes(data)
+
+    print("LZ77 file decompressed!")
+
diff --git a/commands/archive/u8.py b/commands/archive/u8.py
index 5fe4a29..a7a128b 100644
--- a/commands/archive/u8.py
+++ b/commands/archive/u8.py
@@ -26,8 +26,15 @@ def handle_u8_unpack(args):
 
     if not input_path.exists():
         fatal_error(f"The specified input file \"{input_path}\" does not exist!")
+
+    u8_data = input_path.read_bytes()
+    # U8 archives are sometimes compressed. In the event that the provided data is LZ77 data, assume it's a compressed
+    # U8 archive and decompress it before continuing. Standard checks will then catch it if it was something else.
+    if u8_data[0:4] == b'LZ77':
+        u8_data = libWiiPy.archive.decompress_lz77(u8_data)
+
     # Output path is deliberately not checked in any way because libWiiPy already has those checks, and it's easier
     # and cleaner to only have one component doing all the checks.
-    libWiiPy.archive.extract_u8(input_path.read_bytes(), str(output_path))
+    libWiiPy.archive.extract_u8(u8_data, str(output_path))
 
     print("U8 archive unpacked!")
diff --git a/wiipy.py b/wiipy.py
index 8d72307..6f73ac1 100644
--- a/wiipy.py
+++ b/wiipy.py
@@ -5,6 +5,7 @@ import argparse
 from importlib.metadata import version
 
 from commands.archive.ash import *
+from commands.archive.lz77 import *
 from commands.archive.theme import *
 from commands.archive.u8 import *
 from commands.nand.emunand import *
@@ -30,7 +31,7 @@ if __name__ == "__main__":
     # Argument parser for the ASH subcommand.
     ash_parser = subparsers.add_parser("ash", help="compress/decompress an ASH file",
                                        description="compress/decompress an ASH file")
-    ash_subparsers = ash_parser.add_subparsers(title="emunand", dest="emunand", required=True)
+    ash_subparsers = ash_parser.add_subparsers(title="ash", dest="ash", required=True)
     # ASH compress parser.
     ash_compress_parser = ash_subparsers.add_parser("compress", help="compress a file into an ASH file",
                                                     description="compress a file into an ASH file; by default, this "
@@ -146,6 +147,28 @@ if __name__ == "__main__":
     iospatch_parser.add_argument("-ns", "--no-shared", action="store_true",
                                  help="set all patched content to be non-shared")
 
+    # Argument parser for the LZ77 subcommand.
+    lz77_parser = subparsers.add_parser("lz77", help="compress/decompress data using LZ77 compression",
+                                        description="compress/decompress data using LZ77 compression")
+    lz77_subparsers = lz77_parser.add_subparsers(title="lz77", dest="lz77", required=True)
+    # LZ77 compress parser.
+    lz77_compress_parser = lz77_subparsers.add_parser("compress", help="compress a file with LZ77 compression",
+                                                    description="compress a file with LZ77 compression; by default, "
+                                                                "this will output to <input file>.lz77")
+    lz77_compress_parser.set_defaults(func=handle_lz77_compress)
+    lz77_compress_parser.add_argument("input", metavar="IN", type=str, help="file to compress")
+    lz77_compress_parser.add_argument("-o", "--output", metavar="OUT", type=str,
+                                      help="file to output the compressed data to (optional)")
+    # LZ77 decompress parser.
+    lz77_decompress_parser = lz77_subparsers.add_parser("decompress", help="decompress an LZ77-compressed file",
+                                                        description="decompress an LZ77-compressed file; by default, "
+                                                                    "this will output to <input file>.out")
+    lz77_decompress_parser.set_defaults(func=handle_lz77_decompress)
+    lz77_decompress_parser.add_argument("input", metavar="IN", type=str,
+                                        help="LZ77-compressed file to decompress")
+    lz77_decompress_parser.add_argument("-o", "--output", metavar="OUT", type=str,
+                                        help="file to output the decompressed data to (optional)")
+
     # Argument parser for the NUS subcommand.
     nus_parser = subparsers.add_parser("nus", help="download data from the NUS",
                                        description="download from the NUS")