from typing import Dict, List, Any, Optional


class ContractRegistry:
    """
    Lightweight, versioned contract registry for CatOpt-Graph MVP.
    Stores schema definitions per contract name and version.
    Provides a simple conformance check against adapter-provided data.
    """

    def __init__(self) -> None:
        # Structure: { name: { version: schema_dict } }
        self._registry: Dict[str, Dict[str, Dict[str, Any]]] = {}

    def register_contract(self, name: str, version: str, schema: Dict[str, Any]) -> None:
        if name not in self._registry:
            self._registry[name] = {}
        self._registry[name][version] = schema

    def get_contract(self, name: str, version: str) -> Optional[Dict[str, Any]]:
        return self._registry.get(name, {}).get(version)

    def list_versions(self, name: str) -> List[str]:
        return list(self._registry.get(name, {}).keys())

    def conformance_check(self, name: str, version: str, adapter_data: Dict[str, Any]) -> bool:
        """
        Very lightweight conformance check:
        - The contract schema defines required_fields.
        - adapter_data must contain all required fields at top level.
        This is a stub to be extended by real conformance tests.
        """
        contract = self.get_contract(name, version)
        if contract is None:
            return False
        required = contract.get("required_fields", [])
        # If required_fields not provided, assume no conformance requirement
        for field in required:
            if field not in adapter_data:
                return False
        return True