From fc95c0ae33e562ce799800b0a212bf78b11de344 Mon Sep 17 00:00:00 2001
From: Gabriel Levcovitz <g.levcovitz@gmail.com>
Date: Mon, 23 Jun 2025 11:55:00 -0300
Subject: [PATCH] feat(nano): update OCB serialization

---
 hathorlib/nanocontracts/on_chain_blueprint.py | 21 +++++++++----------
 pyproject.toml                                |  2 +-
 tests/test_on_chain_blueprint.py              |  2 +-
 3 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/hathorlib/nanocontracts/on_chain_blueprint.py b/hathorlib/nanocontracts/on_chain_blueprint.py
index 67a91d2..2dea5fe 100644
--- a/hathorlib/nanocontracts/on_chain_blueprint.py
+++ b/hathorlib/nanocontracts/on_chain_blueprint.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from enum import Enum
+from enum import IntEnum, unique
 from typing import NamedTuple
 
 from hathorlib.conf import HathorSettings
@@ -25,14 +25,15 @@
 ON_CHAIN_BLUEPRINT_VERSION: int = 1
 
 
-class CodeKind(Enum):
+@unique
+class CodeKind(IntEnum):
     """ Represents what type of code and format is being used, to allow new code/compression types in the future.
     """
 
-    PYTHON_GZIP = 'python+gzip'
+    PYTHON_ZLIB = 1
 
     def __bytes__(self) -> bytes:
-        return self.value.encode()
+        return int_to_bytes(number=self.value, size=1)
 
 
 class Code(NamedTuple):
@@ -47,11 +48,10 @@ class Code(NamedTuple):
 
     def __bytes__(self) -> bytes:
         # Code serialization format: [kind:variable bytes][null byte][data:variable bytes]
-        if self.kind is not CodeKind.PYTHON_GZIP:
+        if self.kind is not CodeKind.PYTHON_ZLIB:
             raise ValueError('Invalid code kind value')
         buf = bytearray()
         buf.extend(bytes(self.kind))
-        buf.append(0)
         buf.extend(self.data)
         return bytes(buf)
 
@@ -63,11 +63,10 @@ def from_bytes(cls, data: bytes) -> 'Code':
         check that.
         """
         data = bytearray(data)
-        cut_at = data.index(0)
-        kind = CodeKind(data[0:cut_at].decode())
-        if kind is not CodeKind.PYTHON_GZIP:
+        kind = CodeKind(data[0])
+        if kind is not CodeKind.PYTHON_ZLIB:
             raise ValueError('Code kind not supported')
-        compressed_code = data[cut_at + 1:]
+        compressed_code = data[1:]
         return cls(kind, compressed_code)
 
 
@@ -83,7 +82,7 @@ def __init__(self) -> None:
         self.nc_pubkey: bytes = b''
         self.nc_signature: bytes = b''
 
-        self.code: Code = Code(CodeKind.PYTHON_GZIP, b'')
+        self.code: Code = Code(CodeKind.PYTHON_ZLIB, b'')
 
     def serialize_code(self) -> bytes:
         """Serialization of self.code, to be used for the serialization of this transaction type."""
diff --git a/pyproject.toml b/pyproject.toml
index 471710a..b9c78e9 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -14,7 +14,7 @@
 
 [tool.poetry]
 name = "hathorlib"
-version = "0.10.0"
+version = "0.11.0"
 description = "Hathor Network base objects library"
 authors = ["Hathor Team <contact@hathor.network>"]
 license = "Apache-2.0"
diff --git a/tests/test_on_chain_blueprint.py b/tests/test_on_chain_blueprint.py
index 69e3dd4..d70838b 100644
--- a/tests/test_on_chain_blueprint.py
+++ b/tests/test_on_chain_blueprint.py
@@ -19,7 +19,7 @@ def _get_ocb(self):
                            b'\xf6\xf0`g\x1b0\xb6\xca\x1b\xed\x83:N\xa0\x98\xd2'   \
                            b'\xdf\x02!\x00\xbe\xf85\xf6O`\xfed`Ip\xe2a\xc4\x03vv' \
                            b'\xec\x94\ny?\xde\x90\xc3\x12\x9c\xd8\xdd\xd8\xe5\r'
-        code = Code(CodeKind.PYTHON_GZIP, b'')
+        code = Code(CodeKind.PYTHON_ZLIB, b'')
         ocb.code = code
         return ocb