import logging

import httpx

from app.services.search import SearchResult

logger = logging.getLogger(__name__)

_SEVERITY_RANK = {"CRITICAL": 0, "ERROR": 1, "WARN": 2, "WARNING": 2}

_PROMPT_TEMPLATE = """\
You are a homelab diagnostic assistant. A user described a symptom and the system retrieved relevant log entries.

Analyze the log entries below and write a 2-4 sentence plain-language diagnosis. Focus on errors and their likely root cause. Be specific and concise — name the services involved, not generic platitudes.

User query: {query}

Log entries ({n} shown, highest severity first):
{log_block}

Diagnosis:"""


def _build_context(entries: list[SearchResult], max_entries: int = 25) -> str:
    ranked = sorted(
        entries,
        key=lambda e: (_SEVERITY_RANK.get(e.severity or "", 3), e.timestamp_iso or ""),
    )[:max_entries]
    return "\n".join(
        f"[{e.timestamp_iso or '?'}] [{e.severity or 'INFO'}] {e.text[:200]}"
        for e in ranked
    )


def summarize(
    query: str,
    entries: list[SearchResult],
    llm_url: str,
    llm_model: str,
    api_key: str | None = None,
    timeout: float = 120.0,
) -> str | None:
    if not entries:
        return None
    log_block = _build_context(entries)
    prompt = _PROMPT_TEMPLATE.format(query=query, n=min(len(entries), 25), log_block=log_block)
    headers = {"Authorization": f"Bearer {api_key}"} if api_key else {}
    try:
        resp = httpx.post(
            f"{llm_url.rstrip('/')}/v1/chat/completions",
            json={
                "model": llm_model,
                "messages": [{"role": "user", "content": prompt}],
                "stream": False,
            },
            headers=headers,
            timeout=timeout,
        )
        resp.raise_for_status()
        choices = resp.json().get("choices") or []
        if not choices:
            return None
        return (choices[0].get("message", {}).get("content") or "").strip() or None
    except Exception as exc:
        logger.warning("LLM summarization failed (%s): %s", type(exc).__name__, exc)
        return None