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),
        )


@dataclass
class PostgresVendorPlan:
    shard_id: str
    table: str
    projection: list
    predicates: list
    price: float


class PostgresAdapter(Adapter):
    """Concrete adapter mapping a PostgresVendorPlan into a CanonicalPlan."""

    def to_canonical(self, vendor_plan: VendorPlan) -> CanonicalPlan:
        # Accept either a PostgresVendorPlan or a generic VendorPlan-like object
        if isinstance(vendor_plan, PostgresVendorPlan):
            vp = vendor_plan
            return CanonicalPlan(
                projection=vp.projection,
                predicates=vp.predicates,
                estimated_cost=float(vp.price),
            )
        proj = getattr(vendor_plan, "projection", [])
        preds = getattr(vendor_plan, "predicates", [])
        price = float(getattr(vendor_plan, "price", 0.0))
        return CanonicalPlan(projection=proj, predicates=preds, estimated_cost=price)


@dataclass
class MongoVendorPlan:
    shard_id: str
    collection: str
    projection: list
    predicates: list
    price: float


class MongoAdapter(Adapter):
    """Concrete adapter mapping a MongoVendorPlan into a CanonicalPlan."""

    def to_canonical(self, vendor_plan: VendorPlan) -> CanonicalPlan:
        # Accept either a MongoVendorPlan or a generic VendorPlan-like object
        if isinstance(vendor_plan, MongoVendorPlan):
            vp = vendor_plan
            return CanonicalPlan(
                projection=vp.projection,
                predicates=vp.predicates,
                estimated_cost=float(vp.price),
            )
        # Fallback: try to treat as a generic VendorPlan
        proj = getattr(vendor_plan, "projection", [])
        preds = getattr(vendor_plan, "predicates", [])
        price = float(getattr(vendor_plan, "price", 0.0))
        return CanonicalPlan(projection=proj, predicates=preds, estimated_cost=price)