from __future__ import annotations

from dataclasses import dataclass
from typing import Dict, Any

from .protocol import LocalProblem, SharedVariables, CanonicalPlan


@dataclass
class VendorPlan:
    # Minimal stand-in for a vendor-specific plan representation
    shard_id: str
    projection: list
    predicates: list
    price: float


class Adapter:
    """Abstract adapter: maps a vendor-specific plan into a canonical plan."""

    def to_canonical(self, vendor_plan: VendorPlan) -> CanonicalPlan:
        # Simple, deterministic mapping; can be overridden by concrete adapters
        return CanonicalPlan(
            projection=vendor_plan.projection,
            predicates=vendor_plan.predicates,
            estimated_cost=float(vendor_plan.price),
        )