"""Unit tests for `e2e/runner/helpers/imu_replay.py` (AZ-594 AC-3)."""

from __future__ import annotations

import math
from dataclasses import dataclass, field
from pathlib import Path

import pytest

from e2e.runner.helpers.imu_replay import FcInboundEmitter, ImuReplayer, ImuSample


@dataclass
class _RecordingEmitter:
    """In-memory FcInboundEmitter that captures every sample."""

    samples: list[ImuSample] = field(default_factory=list)

    def emit(self, sample: ImuSample) -> None:
        self.samples.append(sample)


@dataclass
class _RecordingSleep:
    sleeps: list[float] = field(default_factory=list)

    def __call__(self, duration_s: float) -> None:
        self.sleeps.append(duration_s)


_HEADER = "timestamp_ms,ax,ay,az,gx,gy,gz,roll_deg,pitch_deg,yaw_deg,baro_m\n"


def _write_csv(path: Path, rows: list[str], *, header: str = _HEADER) -> None:
    path.parent.mkdir(parents=True, exist_ok=True)
    with path.open("w") as fh:
        fh.write(header)
        for r in rows:
            fh.write(r + "\n")


def test_missing_csv_raises_file_not_found(tmp_path: Path):
    # Arrange
    emitter = _RecordingEmitter()
    replayer = ImuReplayer(emitter, realtime=False)

    # Assert
    with pytest.raises(FileNotFoundError, match="IMU CSV not found"):
        replayer.replay(tmp_path / "nope.csv")


def test_rate_hz_must_be_positive():
    # Assert
    with pytest.raises(ValueError, match="rate_hz must be positive"):
        ImuReplayer(_RecordingEmitter(), rate_hz=0)


def test_missing_required_columns_raises(tmp_path: Path):
    # Arrange — missing `baro_m`.
    p = tmp_path / "imu.csv"
    _write_csv(
        p,
        ["100,0,0,9.8,0,0,0,0,0,0"],
        header="timestamp_ms,ax,ay,az,gx,gy,gz,roll_deg,pitch_deg,yaw_deg\n",
    )

    # Assert
    with pytest.raises(ValueError, match="missing required columns"):
        ImuReplayer(_RecordingEmitter(), realtime=False).replay(p)


def test_row_with_unparseable_value_raises(tmp_path: Path):
    # Arrange
    p = tmp_path / "imu.csv"
    _write_csv(p, ["100,0,0,not-a-float,0,0,0,0,0,0,300"])

    # Assert
    with pytest.raises(ValueError, match="IMU CSV row malformed"):
        ImuReplayer(_RecordingEmitter(), realtime=False).replay(p)


def test_happy_path_emits_all_rows(tmp_path: Path):
    # Arrange
    p = tmp_path / "imu.csv"
    _write_csv(
        p,
        [
            "100,0.0,0.0,9.8,0.0,0.0,0.0,0.0,0.0,0.0,300.0",
            "200,0.1,0.0,9.7,0.0,0.0,0.0,0.0,0.0,0.0,300.5",
            "300,0.0,0.2,9.6,0.0,0.0,0.0,0.0,0.0,0.0,301.0",
        ],
    )
    emitter = _RecordingEmitter()

    # Act
    emitted = ImuReplayer(emitter, realtime=False).replay(p)

    # Assert
    assert emitted == 3
    assert len(emitter.samples) == 3
    assert emitter.samples[0].timestamp_ms == 100
    assert emitter.samples[1].accel_mss == (0.1, 0.0, 9.7)


def test_scientific_notation_parses(tmp_path: Path):
    # Arrange — AZ-408 fixture style float fields.
    p = tmp_path / "imu.csv"
    _write_csv(
        p,
        [
            "100,-4.44E-16,1.23e-3,9.81,-1e-5,2e-7,0.0,1.0,2.0,3.0,300.0",
        ],
    )
    emitter = _RecordingEmitter()

    # Act
    ImuReplayer(emitter, realtime=False).replay(p)

    # Assert
    s = emitter.samples[0]
    assert s.accel_mss[0] == pytest.approx(-4.44e-16)
    assert s.accel_mss[1] == pytest.approx(1.23e-3)
    assert s.accel_mss[2] == pytest.approx(9.81)
    assert s.gyro_rps == (-1e-5, 2e-7, 0.0)


def test_attitude_radians_converted(tmp_path: Path):
    # Arrange
    p = tmp_path / "imu.csv"
    _write_csv(
        p,
        ["100,0,0,9.8,0,0,0,90,180,270,300"],
    )
    emitter = _RecordingEmitter()

    # Act
    ImuReplayer(emitter, realtime=False).replay(p)

    # Assert
    roll, pitch, yaw = emitter.samples[0].attitude_rad
    assert roll == pytest.approx(math.pi / 2)
    assert pitch == pytest.approx(math.pi)
    assert yaw == pytest.approx(3 * math.pi / 2)


def test_realtime_sleeps_per_sample(tmp_path: Path):
    # Arrange — 3 rows at 10 Hz → 3 sleeps of 0.1 s.
    p = tmp_path / "imu.csv"
    _write_csv(
        p,
        [
            "100,0,0,9.8,0,0,0,0,0,0,300",
            "200,0,0,9.8,0,0,0,0,0,0,300",
            "300,0,0,9.8,0,0,0,0,0,0,300",
        ],
    )
    emitter = _RecordingEmitter()
    sleep = _RecordingSleep()

    # Act
    ImuReplayer(emitter, rate_hz=10.0, realtime=True, sleep_fn=sleep).replay(p)

    # Assert
    assert sleep.sleeps == pytest.approx([0.1, 0.1, 0.1])


def test_non_realtime_does_not_sleep(tmp_path: Path):
    # Arrange
    p = tmp_path / "imu.csv"
    _write_csv(p, ["100,0,0,9.8,0,0,0,0,0,0,300"])
    sleep = _RecordingSleep()

    # Act
    ImuReplayer(_RecordingEmitter(), realtime=False, sleep_fn=sleep).replay(p)

    # Assert
    assert sleep.sleeps == []


def test_empty_csv_emits_nothing(tmp_path: Path):
    # Arrange — header only.
    p = tmp_path / "imu.csv"
    _write_csv(p, [])
    emitter = _RecordingEmitter()

    # Act
    emitted = ImuReplayer(emitter, realtime=False).replay(p)

    # Assert
    assert emitted == 0
    assert emitter.samples == []