# Authors: The MNE-Python contributors.
# License: BSD-3-Clause
# Copyright the MNE-Python contributors.

"""Test reading BESA fileformats."""

import inspect
from pathlib import Path

import pytest

from mne.channels import read_custom_montage
from mne.io import read_evoked_besa

FILE = Path(inspect.getfile(inspect.currentframe()))
data_dir = FILE.parent / "data"
avr_file = data_dir / "simulation.avr"
avr_file_oldstyle = data_dir / "simulation_oldstyle.avr"
mul_file = data_dir / "simulation.mul"
montage = read_custom_montage(data_dir / "simulation.elp")


@pytest.mark.filterwarnings("ignore:Fiducial point nasion not found")
@pytest.mark.parametrize("fname", (avr_file, avr_file_oldstyle, mul_file))
def test_read_evoked_besa(fname):
    """Test reading MESA .avr and .mul files."""
    ev = read_evoked_besa(fname)
    assert len(ev.ch_names) == len(ev.data) == 33
    assert ev.info["sfreq"] == 200
    assert ev.tmin == -0.1
    assert len(ev.times) == 200
    assert ev.ch_names == montage.ch_names
    assert ev.comment == "simulation"


def test_read_evoked_besa_avr_incomplete(tmp_path):
    """Test reading incomplete BESA .avr files."""
    # Check old style .avr file without an .elp sidecar
    with open(f"{tmp_path}/missing.avr", "w") as f:
        f.write("Npts= 1  TSB= 0  SB= 1.00  SC= 500.0  DI= 5\n0\n1\n2\n")
    ev = read_evoked_besa(f"{tmp_path}/missing.avr")
    assert ev.ch_names == ["CH01", "CH02", "CH03"]

    # Create BESA file with missing header fields and verify things don't break
    with open(f"{tmp_path}/missing.avr", "w") as f:
        f.write("DI= 5\n0\n")
    ev = read_evoked_besa(f"{tmp_path}/missing.avr")
    assert len(ev.ch_names) == len(ev.data) == 1
    assert ev.info["sfreq"] == 200
    assert ev.tmin == 0
    assert len(ev.times) == 1
    assert ev.ch_names == ["CH01"]
    assert ev.comment == ""

    # The DI field (sample frequency) must exist
    with open(f"{tmp_path}/missing.avr", "w") as f:
        f.write("Npts= 1  TSB= 0  SB= 1.00  SC= 500.0\n0\n")
    with pytest.raises(RuntimeError, match='No "DI" field present'):
        ev = read_evoked_besa(f"{tmp_path}/missing.avr")


def test_read_evoked_besa_mul_incomplete(tmp_path):
    """Test reading incomplete BESA .mul files."""
    # Create BESA file with missing header fields and verify things don't break
    with open(f"{tmp_path}/missing.mul", "w") as f:
        f.write("SamplingInterval[ms]= 5\nCH1\n0\n")
    ev = read_evoked_besa(f"{tmp_path}/missing.mul")
    assert len(ev.ch_names) == len(ev.data) == 1
    assert ev.info["sfreq"] == 200
    assert ev.tmin == 0
    assert len(ev.times) == 1
    assert ev.ch_names == ["CH1"]
    assert ev.comment == ""

    # The SamplingInterval[ms] field (sample frequency) must exist
    with open(f"{tmp_path}/missing.mul", "w") as f:
        f.write("TimePoints= 1 Channels= 1\nCH1\n0\n")
    with pytest.raises(RuntimeError, match=r'No "SamplingInterval\[ms\]"'):
        ev = read_evoked_besa(f"{tmp_path}/missing.mul")
