refactor: optimize json parsing in pydantic schemas

Optimized `parse_pokemon_types` by adding a private `_parse_types_json` helper decorated with `@functools.lru_cache(maxsize=1024)`. The helper returns an immutable tuple to prevent cache pollution and the public function casts it back to a list. This significantly speeds up repeated parsing of identical JSON strings, which is common when processing lists of Pokemon.

Author: google-labs-jules[bot]

src/app/schemas/pokemon.py

@@ -1,10 +1,38 @@
 """Pokemon module."""
 
+import functools
 import json
+import logging
 from typing import Any
 
 from pydantic import BaseModel, ConfigDict, field_validator
 
+logger = logging.getLogger(__name__)
+
+
+@functools.lru_cache(maxsize=1024)
+def _parse_types_json(value: str) -> tuple[str, ...]:
+    """Helper function to parse and cache the types JSON string.
+
+    Args:
+        value: The value to parse, expected to be a JSON string.
+
+    Returns:
+        An immutable tuple of parsed types.
+
+    Raises:
+        ValueError: If the string is not valid JSON or not a list.
+    """
+    try:
+        parsed = json.loads(value)
+        if not isinstance(parsed, list):
+            logger.error("invalid types format: expected list")
+            raise ValueError("invalid types format")
+        return tuple(parsed)
+    except json.JSONDecodeError as e:
+        logger.error("malformed types JSON: %s", value)
+        raise ValueError("malformed types JSON") from e
+
 
 def parse_pokemon_types(value: Any) -> Any:
     """Helper function to parse the types JSON string.
@@ -19,13 +47,7 @@ def parse_pokemon_types(value: Any) -> Any:
         ValueError: If the string is not valid JSON or not a list.
     """
     if isinstance(value, str):
-        try:
-            parsed = json.loads(value)
-            if not isinstance(parsed, list):
-                raise ValueError("invalid types format")
-            return parsed
-        except json.JSONDecodeError as e:
-            raise ValueError("malformed types JSON") from e
+        return list(_parse_types_json(value))
     return value