"""Load H32 MSOP packets and DIFOP angles from a Medulla dlog session."""

from __future__ import annotations

import sys
from dataclasses import dataclass
from pathlib import Path

import numpy as np

_TOOLS = Path(__file__).resolve().parents[1]
_RSCAP_V2 = _TOOLS / "rscap_v2"
if str(_RSCAP_V2) not in sys.path:
    sys.path.insert(0, str(_RSCAP_V2))

from h32_msop import default_horizontal_deg, default_vertical_deg  # noqa: E402

from .difop import DifopAngles, parse_difop_angles
from .dobject import discover_records, iter_payloads, resolve_dlog_root
from .payload_v1 import parse_difop_payload, parse_msop_batch_payload


@dataclass
class H32DlogLidarSession:
    dlog_root: Path
    msop_object: str
    difop_object: str
    msop_packets: list[bytes]
    msop_host_utc_ticks: list[int]
    msop_batch_count: int
    difop_record_count: int
    angle_source: str
    vertical_deg: np.ndarray
    horizontal_deg: np.ndarray
    session_id: str | None = None
    lidar_ip: str | None = None


def load_h32_dlog_lidar(
    dlog_root: Path | str,
    *,
    msop_object: str = "frontlidar-msop-raw",
    difop_object: str = "frontlidar-difop-raw",
    require_difop: bool = False,
) -> H32DlogLidarSession:
    root = resolve_dlog_root(dlog_root)
    msop_packets: list[bytes] = []
    msop_host_utc_ticks: list[int] = []
    batch_count = 0
    session_id: str | None = None
    lidar_ip: str | None = None

    for _record, payload in iter_payloads(root, msop_object):
        batch = parse_msop_batch_payload(payload)
        batch_count += 1
        if session_id is None:
            session_id = batch.session_id
            lidar_ip = batch.lidar_ip
        for item in batch.packets:
            msop_packets.append(item.raw)
            msop_host_utc_ticks.append(int(item.host_receive_utc_ticks))

    angles: DifopAngles | None = None
    difop_count = 0
    for _record, payload in iter_payloads(root, difop_object):
        difop = parse_difop_payload(payload)
        difop_count += 1
        try:
            angles = parse_difop_angles(difop.raw)
        except ValueError:
            continue
        if session_id is None:
            session_id = difop.session_id
            lidar_ip = difop.lidar_ip

    if not msop_packets:
        msop_records = discover_records(root, msop_object)
        raise RuntimeError(
            f"no MSOP packets from DObject {msop_object!r} under {root} "
            f"(log records={len(msop_records)})"
        )

    if angles is None:
        if require_difop:
            raise RuntimeError(
                f"no valid DIFOP calibration from DObject {difop_object!r} under {root}"
            )
        vertical = default_vertical_deg()
        horizontal = default_horizontal_deg()
        angle_source = "default_msop_only_vertical_-16_to_16_deg"
    else:
        vertical = angles.vertical_deg
        horizontal = angles.horizontal_deg
        angle_source = "difop_channel_angles"

    return H32DlogLidarSession(
        dlog_root=root,
        msop_object=msop_object,
        difop_object=difop_object,
        msop_packets=msop_packets,
        msop_host_utc_ticks=msop_host_utc_ticks,
        msop_batch_count=batch_count,
        difop_record_count=difop_count,
        angle_source=angle_source,
        vertical_deg=vertical,
        horizontal_deg=horizontal,
        session_id=session_id,
        lidar_ip=lidar_ip,
    )