"""llm-connect adapter for instruction execution.

activity-core deliberately talks to llm-connect over its small HTTP surface
instead of importing provider-specific SDKs. This keeps the activity worker on
owned infrastructure while leaving provider selection, API keys, and model
routing behind the existing llm-connect boundary.
"""

from __future__ import annotations

import os
from typing import Any

import httpx


class DisabledLLMClient:
    """LLM client used when no llm-connect endpoint is configured."""

    def complete(
        self,
        prompt: str,
        model: str = "",
        config: dict[str, Any] | None = None,
    ) -> str:  # noqa: ARG002
        raise RuntimeError("LLM_CONNECT_URL is not configured")


class LLMConnectClient:
    """Small synchronous client for llm-connect server mode."""

    def __init__(self, base_url: str, timeout_seconds: float = 300.0) -> None:
        self.base_url = base_url.rstrip("/")
        self.timeout_seconds = timeout_seconds

    def complete(
        self,
        prompt: str,
        model: str = "",
        config: dict[str, Any] | None = None,
    ) -> str:
        run_config = dict(config or {})
        if model and "model_name" not in run_config:
            run_config["model_name"] = model
        run_config.setdefault("timeout_seconds", int(self.timeout_seconds))
        payload: dict[str, Any] = {
            "prompt": prompt,
            "config": run_config,
        }
        resp = httpx.post(
            f"{self.base_url}/execute",
            json=payload,
            timeout=self.timeout_seconds,
        )
        resp.raise_for_status()
        data = resp.json()
        content = data.get("content")
        if not isinstance(content, str):
            raise ValueError("llm-connect response missing string content")
        return content


def get_llm_client() -> DisabledLLMClient | LLMConnectClient:
    base_url = os.environ.get("LLM_CONNECT_URL", "").strip()
    if not base_url:
        return DisabledLLMClient()
    timeout = float(os.environ.get("LLM_CONNECT_TIMEOUT_SECONDS", "300"))
    return LLMConnectClient(base_url, timeout)