"""Normalize Android telemetry POST body into TelemetryIn."""

from __future__ import annotations

import json
from typing import Any, Optional

from .models import TelemetryIn


def _float_or_none(value: Any) -> Optional[float]:
    if value is None:
        return None
    try:
        return float(value)
    except (TypeError, ValueError):
        return None


def merge_meta(body: dict[str, Any]) -> tuple[Optional[str], Optional[str]]:
    """Build meta JSON string and role from meta / fields keys."""
    meta = body.get("meta")
    fields = body.get("fields")
    role = body.get("role")

    if isinstance(meta, dict):
        mobj = meta
        meta = None
    elif isinstance(meta, str) and meta.strip():
        try:
            mobj = json.loads(meta)
        except json.JSONDecodeError:
            mobj = {}
    else:
        mobj = {}

    if isinstance(fields, dict):
        mobj["fields"] = fields

    if mobj:
        if role is None and mobj.get("role"):
            role = str(mobj["role"])
        return json.dumps(mobj, ensure_ascii=False), role
    if isinstance(meta, str):
        return meta, role
    return None, role


def telemetry_from_body(body: dict[str, Any]) -> TelemetryIn:
    meta, role = merge_meta(body)
    label = body.get("device_label") or body.get("label")
    device_label = str(label).strip() if label else None
    if device_label == "":
        device_label = None
    return TelemetryIn(
        device_id=str(body["device_id"]),
        lat=_float_or_none(body.get("lat")),
        lon=_float_or_none(body.get("lon")),
        rssi=_float_or_none(body.get("rssi")),
        range_m=_float_or_none(body.get("range_m")),
        raw_frame=body.get("raw_frame"),
        meta=meta,
        role=role,
        ts=_float_or_none(body.get("ts")),
        device_label=device_label,
    )