"""Minimal, independent OpenRouter chat-completions client.

Deliberately does not depend on llm-connect's `OpenRouterAdapter`: its
`execute_prompt(prompt: str, config)` takes a single prompt string,
builds a fixed [system, user] message pair itself, and never surfaces
`message.tool_calls` in its response — it cannot drive a multi-turn
tool-calling loop without a breaking change to llm-connect's frozen
Core `LLMAdapter` ABC (`execute_prompt` signature). Rather than force
that change onto every llm-connect consumer, rein-openweights owns this
thin transport directly. See glas-harness ADR-002.
"""

from __future__ import annotations

from typing import Any

import httpx

_DEFAULT_API_BASE = "https://openrouter.ai/api/v1"


class OpenRouterError(RuntimeError):
    pass


class OpenRouterClient:
    def __init__(
        self,
        api_key: str,
        model: str,
        api_base: str = _DEFAULT_API_BASE,
        timeout: float = 120.0,
    ) -> None:
        self.api_key = api_key
        self.model = model
        self.api_base = api_base.rstrip("/")
        self.timeout = timeout

    def chat(
        self,
        messages: list[dict[str, Any]],
        tools: list[dict[str, Any]] | None = None,
        temperature: float = 0.2,
        max_tokens: int = 4096,
    ) -> dict[str, Any]:
        payload: dict[str, Any] = {
            "model": self.model,
            "messages": messages,
            "temperature": temperature,
            "max_tokens": max_tokens,
        }
        if tools:
            payload["tools"] = tools
            payload["tool_choice"] = "auto"

        response = httpx.post(
            f"{self.api_base}/chat/completions",
            json=payload,
            headers={"Authorization": f"Bearer {self.api_key}"},
            timeout=self.timeout,
        )
        if response.status_code >= 400:
            raise OpenRouterError(f"OpenRouter {response.status_code}: {response.text[:300]}")
        return response.json()