"""LLM clients — ONE place to build them.

Two backends, by capability:
- **Gateway** → chat for the curator, using DSPY_* when configured or direct OpenAI otherwise.
- **Embeddings** → direct OpenAI or an OpenAI-compatible embeddings API via OPENAI_API_BASE.

Both keys come from config/.env (git-ignored). Each builder returns `None` when unconfigured so the
engine degrades gracefully (white-box sift + templated cards — the safety net).
"""
from __future__ import annotations

from functools import lru_cache

from app.config import get_settings


@lru_cache
def gateway_client():
    """Chat client for curation/suggestions. Prefer DSPY_* override, otherwise use OPENAI_API_KEY."""
    s = get_settings()
    api_key = s.DSPY_API_KEY or s.OPENAI_API_KEY
    if not api_key:
        return None
    from openai import OpenAI
    kwargs = {"api_key": api_key, "timeout": 60, "max_retries": 2}
    if s.DSPY_API_BASE:
        kwargs["base_url"] = s.DSPY_API_BASE
    return OpenAI(**kwargs)


@lru_cache
def embed_client():
    """OpenAI-compatible client for embeddings. None if no key."""
    s = get_settings()
    if not s.OPENAI_API_KEY:
        return None
    from openai import OpenAI
    kwargs = {"api_key": s.OPENAI_API_KEY, "timeout": 30, "max_retries": 2}
    if s.OPENAI_API_BASE:
        kwargs["base_url"] = s.OPENAI_API_BASE
    return OpenAI(**kwargs)


def curate_enabled() -> bool:
    """Is the curator usable? (flag on + any chat key present)."""
    s = get_settings()
    return bool(s.ENGINE_LLM_ENABLED and (s.DSPY_API_KEY or s.OPENAI_API_KEY))