"""Blastware sensor self-check waveform decode (minimateplus.sensor_check).

Reverse-engineered 2026-09-15 against 7 BE12844 (MiniMate Plus) oracle events.
After the main waveform record-chain and the trailing metadata / per-channel
calibration records, a series-3 binary carries four length-prefixed records
tagged 0x3c-0x3f: the sensor self-check traces the unit records when it pulses
each sensor before monitoring (Blastware draws these as the little waveforms in
the "Sensor Check" strip on the right of the Event Report).

  * 0x3c / 0x3d / 0x3e = Tran / Vert / Long geophone ring-downs.
  * 0x3f            = MicL, a pulse train at the mic self-test frequency.

The self-check injects a fixed pulse, so the response is near-identical across
events — asserted here as an invariant shape (damped one-sided ring-down for
the geophones, a multi-pulse train for the mic).
"""
from pathlib import Path

import numpy as np

from minimateplus.sensor_check import decode_sensor_check

FIXDIR = Path(__file__).parent / "fixtures" / "fft-oracle-2026-09-14"
EVENTS = sorted(p.name for p in FIXDIR.iterdir())   # 7 BE12844 event binaries


def _decode(name):
    return decode_sensor_check((FIXDIR / name).read_bytes())


def test_all_four_channels_present():
    for name in EVENTS:
        sc = _decode(name)
        assert set(sc) == {"Tran", "Vert", "Long", "MicL"}, name


def test_geo_channels_are_damped_ringdowns():
    # Each geophone self-check is a large one-sided deflection (~-990 raw) that
    # rings back and damps toward a settled value well above the trough.
    for name in EVENTS:
        sc = _decode(name)
        for ch in ("Tran", "Vert", "Long"):
            tr = np.asarray(sc[ch], dtype=float)
            assert 240 <= len(tr) <= 260, f"{name}:{ch} n={len(tr)}"
            assert abs(tr[:3].mean()) < 50, f"{name}:{ch} starts off-baseline"
            assert tr.min() < -800, f"{name}:{ch} min {tr.min()}"
            assert tr.max() < 60, f"{name}:{ch} unexpected positive swing {tr.max()}"
            # damped: settles between the trough and zero, well above the trough
            assert tr.min() < tr[-1] < 0, f"{name}:{ch} end {tr[-1]} not between trough and 0"
            assert abs(tr[-1]) < 0.6 * abs(tr.min()), f"{name}:{ch} not damped, end {tr[-1]}"


def test_mic_channel_is_a_pulse_train():
    for name in EVENTS:
        tr = np.asarray(_decode(name)["MicL"], dtype=float)
        assert 235 <= len(tr) <= 255, f"{name} mic n={len(tr)}"
        # larger dynamic range than the geo ring-down, and swings both ways
        assert tr.min() < -1500, f"{name} mic min {tr.min()}"
        assert tr.max() > 100, f"{name} mic max {tr.max()}"
        # multiple pulses: several deep local minima
        deep = (tr[1:-1] < tr[:-2]) & (tr[1:-1] < tr[2:]) & (tr[1:-1] < -800)
        assert int(deep.sum()) >= 4, f"{name} mic pulses {int(deep.sum())}"


def test_returns_empty_when_no_sensor_check_block():
    assert decode_sensor_check(b"not a blastware file") == {}
    assert decode_sensor_check(b"") == {}