from __future__ import annotations

import time
from typing import Dict, Optional
from .models import SharedSignals


class GraphOfContracts:
    """In-memory contract registry for exchanged signals between fleets."""

    def __init__(self) -> None:
        self._contracts: Dict[str, SharedSignals] = {}
        self._translations: Dict[str, float] = {}

    def register_signal(self, contract_id: str, signals: SharedSignals) -> None:
        self._contracts[contract_id] = signals
        self._translations[contract_id] = time.time()

    def get_signal(self, contract_id: str) -> Optional[SharedSignals]:
        return self._contracts.get(contract_id)

    def list_contracts(self) -> Dict[str, float]:
        return dict(self._translations)