"""meb_ml — SDK importabile dal codice utente dentro il container runner.

API:
    from meb_ml import emit_metric, emit_series, emit_matrix, emit_log, save_artifact

    emit_metric(iter=10, loss=0.23)
    emit_series("roc_curve", x=fpr, y=tpr, kind="line")
    emit_matrix("confusion", labels=[...], values=[[...],[...]])
    emit_log("info", "epoch done")

Scrive righe JSON su stdout; il parent (ml-service) le inoltra su Redis/Influx.
Per risultati finali scrivere `out/metrics.json` con:
    {"metrics": {...}, "plots": {"loss_curve": {"x": [...], "y": [...]}, ...}}
"""
from __future__ import annotations

import json
import os
import sys
from pathlib import Path
from typing import Any, Iterable, Sequence


def _print(obj: dict) -> None:
    sys.stdout.write(json.dumps(obj, default=float) + "\n")
    sys.stdout.flush()


def emit_metric(**fields: Any) -> None:
    _print({"type": "metric", **fields})


def emit_series(name: str, x: Sequence, y: Sequence, kind: str = "line") -> None:
    _print({
        "type": "series",
        "name": name,
        "kind": kind,
        "x": list(x),
        "y": list(y),
    })


def emit_matrix(name: str, labels: Sequence, values: Sequence[Sequence]) -> None:
    _print({
        "type": "matrix",
        "name": name,
        "labels": list(labels),
        "values": [list(row) for row in values],
    })


def emit_log(level: str, message: str) -> None:
    _print({"type": "log", "level": level, "message": message})


def save_artifact(path: str) -> str:
    """Copia `path` nella cartella artefatti (MEB_ARTIFACTS_DIR). Ritorna la dest."""
    dest_dir = Path(os.environ.get("MEB_ARTIFACTS_DIR", "/workdir/out"))
    dest_dir.mkdir(parents=True, exist_ok=True)
    src = Path(path)
    dest = dest_dir / src.name
    dest.write_bytes(src.read_bytes())
    return str(dest)


def dataset_path() -> str:
    return os.environ["MEB_DATASET_PATH"]


def artifacts_dir() -> str:
    return os.environ.get("MEB_ARTIFACTS_DIR", "/workdir/out")


def read_test_input() -> dict:
    """Legge un singolo JSON da stdin (per script di test)."""
    return json.loads(sys.stdin.readline())


def write_test_output(outputs: dict) -> None:
    _print({"type": "result", "outputs": outputs})