# core/llm_client.py
import asyncio
import httpx
from tenacity import retry, stop_after_attempt, wait_exponential, retry_if_exception_type
from agents.registry import PROVIDERS, AGENT_REGISTRY

class LLMClient:
    def __init__(self):
        self.semaphore = asyncio.Semaphore(6)  # evitar saturar proveedores

    async def call(self, agent_key: str, messages: list, temperature: float = 0.7):
        agent = AGENT_REGISTRY.get(agent_key)
        if not agent:
            raise ValueError(f"Agente {agent_key} no encontrado")

        system_prompt = agent["role"]
        provider = PROVIDERS[agent["provider"]]

        full_messages = [{"role": "system", "content": system_prompt}] + messages

        @retry(
            stop=stop_after_attempt(5),
            wait=wait_exponential(multiplier=1, min=2, max=30),
            retry=retry_if_exception_type((httpx.HTTPStatusError, httpx.TimeoutException))
        )
        async def try_provider(base_url, model, api_key, headers):
            async with self.semaphore:
                payload = {
                    "model": model,
                    "messages": full_messages,
                    "temperature": temperature,
                    "max_tokens": 4096,
                    "top_p": 0.92
                }
                async with httpx.AsyncClient(timeout=90) as client:
                    resp = await client.post(
                        f"{base_url}/chat/completions",
                        headers={"Authorization": f"Bearer {api_key}", **headers},
                        json=payload
                    )
                    resp.raise_for_status()
                    return resp.json()["choices"][0]["message"]["content"]

        # Intentar modelos del proveedor principal
        for model in agent.get("models", []):
            try:
                return await try_provider(
                    provider["base_url"],
                    model,
                    provider["key"],
                    provider.get("headers", {})
                )
            except Exception as e:
                print(f"Error con {model}: {e}")

        # Fallback a openrouter si no es el principal
        if agent["provider"] != "openrouter" and PROVIDERS["openrouter"]["key"]:
            or_p = PROVIDERS["openrouter"]
            for model in or_p["models"]:
                try:
                    return await try_provider(or_p["base_url"], model, or_p["key"], or_p.get("headers", {}))
                except:
                    continue

        raise Exception("Todos los proveedores fallaron")

# Instancia global
llm = LLMClient()