from __future__ import annotations

import json
from pathlib import Path

import joblib
import pandas as pd


def _load_artifact(model_dir: str | Path):
    model_path = Path(model_dir) / "mindpulse_rf.joblib"
    raw = joblib.load(model_path)
    if isinstance(raw, dict) and "model" in raw:
        model = raw["model"]
        feature_names = raw.get(
            "feature_names",
            ["heart_rate", "hrv_rmssd", "motion_level", "hr_baseline", "rmssd_baseline"],
        )
        return model, feature_names
    return raw, ["heart_rate", "hrv_rmssd", "motion_level", "hr_baseline", "rmssd_baseline"]


def predict(model_dir: str, inputs: dict):
    model, feature_names = _load_artifact(model_dir)
    row = {name: float(inputs[name]) for name in feature_names}
    x = pd.DataFrame([row], columns=feature_names)
    score = float(model.predict(x)[0])
    score = max(0.0, min(1.0, score))
    return {"engagement_score": score}