"""Optional narration layer.

The rule engine already produces the diagnosis and the move. This turns that
into the way a good engineer would actually say it in the room, and catches
interactions between findings that per-rule logic cannot see.

Entirely optional: with no token configured the Space runs on the rule engine
alone and says so, rather than degrading silently.
"""

from __future__ import annotations

import json
import os

DEFAULT_MODEL = os.environ.get("EAR_LLM_MODEL", "Qwen/Qwen3-235B-A22B-Instruct-2507")

SYSTEM = """You are a senior sound designer and mix engineer sitting in on a session.
You have been handed measurements and a rule-based diagnosis of a piece of audio.

How you talk:
- Like an engineer in the room, not a manual. Short sentences. No hedging.
- Never repeat a number without saying what it means for the listener.
- Name the move, the device, and the value. "Cut 3 dB at 250" beats "consider EQ".
- If the measurements disagree with each other, say which one you trust and why.
- If nothing is wrong, say so in one line and talk about what to do next instead
  of inventing problems.
- Never mention that you were given JSON or that you are an AI.

Structure your answer as exactly three short sections:
**What I'm hearing** — two or three sentences, the sound not the stats.
**The one thing to fix first** — a single highest-leverage move, with the reason.
**Then** — at most three more moves as a tight bulleted list.
"""


def _token() -> str | None:
    return os.environ.get("HF_TOKEN") or os.environ.get("HUGGING_FACE_HUB_TOKEN")


def available() -> tuple[bool, str]:
    if not _token():
        return False, "no HF_TOKEN set — running on the rule engine only"
    return True, f"ready ({DEFAULT_MODEL})"


def critique(
    report: dict,
    diagnoses: list[dict],
    semantic_tags: dict,
    genre: str,
    source: str,
    intent: str = "",
) -> str:
    ok, _ = available()
    if not ok:
        return ""

    from huggingface_hub import InferenceClient

    payload = {
        "genre": genre,
        "listening_to": source,
        "producer_intent": intent or "(not stated)",
        "measurements": {
            "lufs_integrated": round(report.get("lufs_i", -120), 1),
            "true_peak_dbtp": round(report.get("true_peak", -120), 2),
            "crest_db": round(report.get("crest", 0), 1),
            "loudness_range_lu": round(report.get("lra", 0), 1),
            "band_balance_db": {k: round(v, 1) for k, v in report.get("bands", {}).items()},
            "ratios_db": {k: round(v, 1) for k, v in report.get("ratios", {}).items()},
            "stereo": {k: round(v, 2) for k, v in report.get("stereo", {}).items()},
            "tempo_bpm": round(report.get("rhythm", {}).get("bpm", 0), 1),
            "key": report.get("key", {}).get("key", "—"),
        },
        "rule_findings": [
            {"severity": d["severity"], "headline": d["headline"],
             "evidence": d["evidence"], "suggested_move": d["move"]}
            for d in diagnoses[:6]
        ],
        "sounds_like": {g: [t for t, _ in v] for g, v in (semantic_tags or {}).items()},
    }

    try:
        client = InferenceClient(api_key=_token(), provider="auto")
        resp = client.chat_completion(
            model=DEFAULT_MODEL,
            messages=[
                {"role": "system", "content": SYSTEM},
                {"role": "user", "content": json.dumps(payload, ensure_ascii=False)},
            ],
            max_tokens=700,
            temperature=0.6,
        )
        return (resp.choices[0].message.content or "").strip()
    except Exception as exc:  # noqa: BLE001 - narration is optional by design
        return (f"_Narration unavailable ({type(exc).__name__}: {exc}). "
                f"The analysis above stands on its own._")