backend: initial commit

bincio/extract/parsers/base.py

@@ -0,0 +1,34 @@
+"""Abstract base class for all activity parsers."""
+
+import gzip
+import hashlib
+from abc import ABC, abstractmethod
+from pathlib import Path
+
+from bincio.extract.models import ParsedActivity
+
+
+class BaseParser(ABC):
+    @abstractmethod
+    def parse(self, path: Path, raw_bytes: bytes) -> ParsedActivity:
+        """Parse activity from raw file bytes.
+
+        Receives pre-read bytes so the factory can compute the hash once and
+        handle decompression transparently before dispatching.
+        """
+
+    @staticmethod
+    def _sha256(data: bytes) -> str:
+        return "sha256:" + hashlib.sha256(data).hexdigest()
+
+    @staticmethod
+    def _read_file(path: Path) -> tuple[bytes, bytes]:
+        """Return (raw_bytes, decompressed_bytes).
+
+        raw_bytes is the original file content (used for hashing).
+        decompressed_bytes is what parsers should actually parse.
+        """
+        raw = path.read_bytes()
+        if path.suffix == ".gz":
+            return raw, gzip.decompress(raw)
+        return raw, raw