from __future__ import annotations

from typing import Dict, Optional

from .contracts import ContractDefinition


class GraphOfContracts:
    """Lightweight registry graph mapping adapters to contract versions.

    This is intentionally minimal: it stores per-adapter contracts organized by
    contract name -> version -> ContractDefinition, enabling plug-and-play across
    domain adapters while keeping a canonical reference per adapter.
    """

    def __init__(self) -> None:
        # adapter_name -> contract_name -> version -> ContractDefinition
        self._graph: Dict[str, Dict[str, Dict[str, ContractDefinition]]] = {}

    def register(self, adapter: str, contract_name: str, version: str, schema: Dict[str, object]) -> None:
        self._graph.setdefault(adapter, {})
        self._graph[adapter].setdefault(contract_name, {})[version] = ContractDefinition(
            name=contract_name,
            version=version,
            schema=schema,
        )

    def get_contract(self, adapter: str, contract_name: str, version: str) -> Optional[ContractDefinition]:
        return self._graph.get(adapter, {}).get(contract_name, {}).get(version)

    def list_adapter_contracts(self, adapter: str) -> Dict[str, Dict[str, ContractDefinition]]:
        return self._graph.get(adapter, {})