"""Bedrock Claude provider — authenticates via boto3's default AWS credential chain.

Named ``bedrock-claude`` rather than ``bedrock`` since Bedrock hosts multiple model
families; this provider is specifically the Anthropic Claude models on Bedrock.

Model IDs are cross-region inference profiles (e.g. ``us.anthropic.claude-sonnet-4-6``)
rather than bare Bedrock model IDs — several current Claude models on Bedrock reject
on-demand invocation and require an inference profile ARN/ID instead.
"""

import boto3
from environs import Env
from langchain_aws import ChatBedrockConverse
from langchain_core.language_models import BaseChatModel

from skill_eval_runner.providers import Provider, register

MAX_TOKENS = 16384

_env = Env()
_env.read_env()


def make_model(model_name: str) -> BaseChatModel:
    """Build a ``ChatBedrockConverse`` model, requiring resolvable AWS credentials."""
    region = _env.str("AWS_REGION", _env.str("AWS_DEFAULT_REGION", "us-east-1"))
    if boto3.Session(region_name=region).get_credentials() is None:
        raise SystemExit(
            "No AWS credentials found for Bedrock.\n"
            "  Run `awsume <profile>` to assume your role and export "
            "AWS_ACCESS_KEY_ID/AWS_SECRET_ACCESS_KEY/AWS_SESSION_TOKEN."
        )
    model: BaseChatModel = ChatBedrockConverse(
        model=model_name,
        region_name=region,
        max_tokens=MAX_TOKENS,
    )
    return model


register(
    Provider(
        name="bedrock-claude",
        default_model="us.anthropic.claude-sonnet-4-6",
        small_model="us.anthropic.claude-haiku-4-5-20251001-v1:0",
        large_model="us.anthropic.claude-opus-4-8",
        make_model=make_model,
    )
)