"""Anthropic provider — authenticates via ``ANTHROPIC_API_KEY``."""

from environs import Env
from langchain_anthropic import ChatAnthropic
from langchain_core.language_models import BaseChatModel
from pydantic import SecretStr

from skill_eval_runner.providers import Provider, register

_env = Env()
_env.read_env()


def make_model(model_name: str) -> BaseChatModel:
    """Build a ``ChatAnthropic`` model, requiring ``ANTHROPIC_API_KEY``."""
    api_key = _env.str("ANTHROPIC_API_KEY", None)
    if not api_key:
        raise SystemExit(
            "ANTHROPIC_API_KEY is not set.\n"
            "  Add it to a .env file or export ANTHROPIC_API_KEY=sk-..."
        )
    # ChatAnthropic's pydantic field aliases ("model", "max_tokens") aren't visible to
    # mypy without the pydantic plugin; the kwargs are valid at runtime.
    model: BaseChatModel = ChatAnthropic(  # type: ignore[call-arg]
        model=model_name,
        api_key=SecretStr(api_key),
        max_tokens=16384,
    )
    return model


register(
    Provider(
        name="anthropic",
        default_model="claude-sonnet-4-6",
        small_model="claude-haiku-4-5",
        large_model="claude-sonnet-4-6",
        make_model=make_model,
    )
)