"""Base class for evaluation rules."""

from abc import ABC, abstractmethod
from dataclasses import dataclass
from typing import Any, Optional

from agenteval.models import Case, Turn


@dataclass
class RuleResult:
    """Result of applying an evaluation rule."""

    passed: bool
    score: Optional[float] = None
    reason: str = ""


class EvalRule(ABC):
    """Abstract evaluation rule. All implementations must be async."""

    name: str = ""

    def __init__(self, params: dict[str, Any]):
        self.params = params

    @abstractmethod
    async def evaluate(self, case: Case, dialog: list[Turn]) -> RuleResult:
        """Evaluate the dialog against the case expectation."""
        ...


_RULE_REGISTRY: dict[str, type[EvalRule]] = {}


def register_rule(rule_cls: type[EvalRule]) -> type[EvalRule]:
    _RULE_REGISTRY[rule_cls.name] = rule_cls
    return rule_cls


def get_rule(rule_type: str, params: dict[str, Any]) -> EvalRule:
    """Instantiate a rule by type name."""
    if rule_type not in _RULE_REGISTRY:
        raise ValueError(f"unknown rule type: {rule_type}. Available: {list(_RULE_REGISTRY.keys())}")
    return _RULE_REGISTRY[rule_type](params)


def list_rule_types() -> list[str]:
    return list(_RULE_REGISTRY.keys())