"""
Every radio heard on a call, as the edge node reports it (server-26#304).

The node sends `radios`: a list of {radio, start, end}, one entry per
transmission, offsets in seconds into the uploaded audio file, so a talker's
wall-clock time is audio_start_epoch + offset (the same mapping the node uses
for the audio itself). It arrives twice — on
/upload (as a JSON string form field, because the pipeline starts there) and
on the MQTT call_end — and both go through `call_fields` so the call doc gets
the same shape either way.

`radio_ids` is the distinct IDs in first-heard order, kept alongside so a
correlator or query can ask "was radio X on this call" without walking the list.
"""
import json
from typing import Any, Dict, List, Optional

from app.internal.logger import logger

# A 600 s recording polled every 0.5 s cannot honestly hold more than this.
MAX_TRANSMISSIONS = 200


def _num(value: Any) -> Optional[float]:
    try:
        number = float(value)
    except (TypeError, ValueError):
        return None
    return number if number >= 0 else None


def parse(value: Any) -> List[Dict[str, Any]]:
    """The node's radio list, validated. Accepts a list or its JSON string; junk entries are dropped."""
    if value is None or value == "":
        return []
    if isinstance(value, str):
        try:
            value = json.loads(value)
        except ValueError:
            logger.warning(f"radios: not JSON, ignored ({value[:80]!r})")
            return []
    if not isinstance(value, list):
        return []
    out: List[Dict[str, Any]] = []
    for item in value[:MAX_TRANSMISSIONS]:
        if not isinstance(item, dict):
            continue
        try:
            radio = int(item.get("radio"))
        except (TypeError, ValueError):
            continue
        start, end = _num(item.get("start")), _num(item.get("end"))
        if radio <= 0 or start is None or end is None:
            continue
        out.append({"radio": radio, "start": start, "end": max(start, end)})
    return out


def call_fields(value: Any) -> Dict[str, Any]:
    """Call-doc fields for a radio list; empty when the node sent none (older nodes, analog)."""
    radios = parse(value)
    if not radios:
        return {}
    return {"radios": radios, "radio_ids": list(dict.fromkeys(r["radio"] for r in radios))}