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

from contextlib import nullcontext
from pathlib import Path

import matplotlib.pyplot as plt
import numpy as np
import pytest
from matplotlib.colors import Colormap
from matplotlib.figure import Figure
from numpy.testing import assert_allclose, assert_array_equal

from mne import (
    MixedSourceEstimate,
    SourceEstimate,
    convert_forward_solution,
    make_field_map,
    make_sphere_model,
    pick_info,
    pick_types,
    read_dipole,
    read_evokeds,
    read_forward_solution,
    read_trans,
    setup_volume_source_space,
    use_coil_def,
)
from mne._fiff._digitization import write_dig
from mne._fiff.constants import FIFF
from mne.bem import read_bem_solution, read_bem_surfaces
from mne.datasets import testing
from mne.defaults import DEFAULTS
from mne.fixes import _reshape_view
from mne.io import read_info, read_raw_bti, read_raw_ctf, read_raw_kit, read_raw_nirx
from mne.minimum_norm import apply_inverse
from mne.source_estimate import _BaseVolSourceEstimate
from mne.source_space import read_source_spaces
from mne.transforms import Transform
from mne.utils import _record_warnings, catch_logging
from mne.viz import (
    Brain,
    EvokedField,
    Figure3D,
    link_brains,
    mne_analyze_colormap,
    plot_alignment,
    plot_brain_colorbar,
    plot_head_positions,
    plot_source_estimates,
    plot_sparse_source_estimates,
    snapshot_brain_montage,
)
from mne.viz._3d import _get_map_ticks, _linearize_map, _process_clim
from mne.viz.utils import _fake_click, _fake_keypress, _fake_scroll, _get_cmap

data_dir = testing.data_path(download=False)
subjects_dir = data_dir / "subjects"
trans_fname = data_dir / "MEG" / "sample" / "sample_audvis_trunc-trans.fif"
src_fname = data_dir / "subjects" / "sample" / "bem" / "sample-oct-6-src.fif"
dip_fname = data_dir / "MEG" / "sample" / "sample_audvis_trunc_set1.dip"
ctf_fname = data_dir / "CTF" / "testdata_ctf.ds"
nirx_fname = data_dir / "NIRx" / "nirscout" / "nirx_15_2_recording_w_short"

io_dir = Path(__file__).parents[2] / "io"
base_dir = io_dir / "tests" / "data"
evoked_fname = base_dir / "test-ave.fif"

fwd_fname = data_dir / "MEG" / "sample" / "sample_audvis_trunc-meg-vol-7-fwd.fif"
fwd_fname2 = data_dir / "MEG" / "sample" / "sample_audvis_trunc-meg-eeg-oct-4-fwd.fif"

base_dir = io_dir / "bti" / "tests" / "data"
pdf_fname = base_dir / "test_pdf_linux"
config_fname = base_dir / "test_config_linux"
hs_fname = base_dir / "test_hs_linux"
sqd_fname = io_dir / "kit" / "tests" / "data" / "test.sqd"

coil_3d = """# custom cube coil def
1   9999    1   8  3e-03  0.000e+00     "QuSpin ZFOPM 3mm cube"
  0.1250 -0.750e-03 -0.750e-03 -0.750e-03  0.000  0.000  1.000
  0.1250 -0.750e-03  0.750e-03 -0.750e-03  0.000  0.000  1.000
  0.1250  0.750e-03 -0.750e-03 -0.750e-03  0.000  0.000  1.000
  0.1250  0.750e-03  0.750e-03 -0.750e-03  0.000  0.000  1.000
  0.1250 -0.750e-03 -0.750e-03  0.750e-03  0.000  0.000  1.000
  0.1250 -0.750e-03  0.750e-03  0.750e-03  0.000  0.000  1.000
  0.1250  0.750e-03 -0.750e-03  0.750e-03  0.000  0.000  1.000
  0.1250  0.750e-03  0.750e-03  0.750e-03  0.000  0.000  1.000
1   9998    1   4  3e-03  0.000e+00     "3mm square"
  0.1250 -0.750e-03 -0.750e-03 0.000  0.000  0.000  1.000
  0.1250 -0.750e-03  0.750e-03 0.000  0.000  0.000  1.000
  0.1250  0.750e-03 -0.750e-03 0.000  0.000  0.000  1.000
  0.1250  0.750e-03  0.750e-03 0.000  0.000  0.000  1.000
"""


def test_plot_head_positions():
    """Test plotting of head positions."""
    info = read_info(evoked_fname)
    pos = np.random.RandomState(0).randn(4, 10)
    pos[:, 0] = np.arange(len(pos))
    destination = (0.0, 0.0, 0.04)
    fig = plot_head_positions(pos)
    assert len(fig.axes) == 6
    plot_head_positions(pos, mode="field", info=info, destination=destination)
    fig = plot_head_positions([pos, pos], totals=True)  # list and totals support
    assert len(fig.axes) == 8
    fig, ax = plt.subplots()
    with pytest.raises(TypeError, match="instance of Axes3D"):
        plot_head_positions(pos, mode="field", info=info, axes=ax)
    fig, ax = plt.subplots(subplot_kw=dict(projection="3d"))
    plot_head_positions(pos, mode="field", info=info, axes=ax)
    with pytest.raises(TypeError, match="must be an instance of ndarray"):
        plot_head_positions(["foo"])
    with pytest.raises(ValueError, match="must be dim"):
        plot_head_positions(pos[:, :9])
    with pytest.raises(ValueError, match="Allowed values"):
        plot_head_positions(pos, "foo")
    with pytest.raises(ValueError, match="shape"):
        plot_head_positions(pos, axes=1.0)


@testing.requires_testing_data
@pytest.mark.slowtest
def test_plot_sparse_source_estimates(renderer_interactive, brain_gc):
    """Test plotting of (sparse) source estimates."""
    pytest.importorskip("nibabel")
    sample_src = read_source_spaces(src_fname)

    # dense version
    vertices = [s["vertno"] for s in sample_src]
    n_time = 5
    n_verts = sum(len(v) for v in vertices)
    stc_data = np.zeros(n_verts * n_time)
    stc_size = stc_data.size
    stc_data[(np.random.rand(stc_size // 20) * stc_size).astype(int)] = (
        np.random.RandomState(0).rand(stc_data.size // 20)
    )
    stc_data = _reshape_view(stc_data, (n_verts, n_time))
    stc = SourceEstimate(stc_data, vertices, 1, 1)

    colormap = "mne_analyze"
    brain = plot_source_estimates(
        stc,
        "sample",
        colormap=colormap,
        background=(1, 1, 0),
        subjects_dir=subjects_dir,
        colorbar=True,
        clim="auto",
    )
    brain.close()
    del brain
    with pytest.raises(TypeError, match="figure must be"):
        plot_source_estimates(
            stc,
            "sample",
            figure="foo",
            hemi="both",
            clim="auto",
            subjects_dir=subjects_dir,
        )

    # now do sparse version
    vertices = sample_src[0]["vertno"]
    inds = [111, 333]
    stc_data = np.zeros((len(inds), n_time))
    stc_data[0, 1] = 1.0
    stc_data[1, 4] = 2.0
    vertices = [vertices[inds], np.empty(0, dtype=np.int64)]
    stc = SourceEstimate(stc_data, vertices, 1, 1)
    out = plot_sparse_source_estimates(
        sample_src, stc, bgcolor=(1, 1, 1), opacity=0.5, high_resolution=False
    )
    assert isinstance(out, Figure3D)


@testing.requires_testing_data
@pytest.mark.slowtest
def test_plot_evoked_field(renderer):
    """Test plotting evoked field."""
    evoked = read_evokeds(evoked_fname, condition="Left Auditory", baseline=(-0.2, 0.0))
    evoked.pick(evoked.ch_names[::10])  # speed
    for t, n_contours, up in zip(["meg", None], [21, 0], [2, 1]):
        with pytest.warns(RuntimeWarning, match="projection"), catch_logging() as log:
            maps = make_field_map(
                evoked,
                trans_fname,
                subject="sample",
                subjects_dir=subjects_dir,
                n_jobs=None,
                ch_type=t,
                upsampling=up,
                origin="auto",
                verbose=True,
            )
        log = log.getvalue()
        if up == 1:
            assert "Upsampling" not in log
        else:
            assert "Upsampling" in log
        evoked.plot_field(maps, time=0.1, n_contours=n_contours)
    renderer.backend._close_all()

    # Test plotting inside an existing Brain figure. Check that units are taken into
    # account.
    for units in ["mm", "m"]:
        brain = Brain(
            "fsaverage", "lh", "inflated", units=units, subjects_dir=subjects_dir
        )
        fig = evoked.plot_field(maps, time=0.1, fig=brain)
        assert brain._units == fig._units
        scale = 1000 if units == "mm" else 1
        assert (
            fig._surf_maps[0]["surf"]["rr"][0, 0] == scale * maps[0]["surf"]["rr"][0, 0]
        )
        renderer.backend._close_all()

    # Test some methods
    fig = evoked.plot_field(maps, time_viewer=True)
    assert isinstance(fig, EvokedField)
    fig._rescale()
    fig.set_time(0.05)
    assert fig._current_time == 0.05
    fig.set_contours(10)
    assert fig._n_contours == 10
    assert fig._widgets["contours"].get_value() == 10
    fig.set_vmax(2e-12, kind="meg")
    assert fig._surf_maps[1]["contours"][-1] == 2e-12
    assert (
        fig._widgets["vmax_slider_meg"].get_value()
        == DEFAULTS["scalings"]["grad"] * 2e-12
    )

    fig = evoked.plot_field(maps, time_viewer=False)
    assert isinstance(fig, Figure3D)
    renderer.backend._close_all()


@testing.requires_testing_data
@pytest.mark.slowtest
def test_plot_evoked_field_notebook(renderer_notebook, nbexec):
    """Test plotting the evoked field inside a notebook."""
    import pytest

    from mne import make_field_map, read_evokeds
    from mne.datasets import testing
    from mne.viz import Brain, EvokedField, Figure3D, set_3d_backend

    set_3d_backend("notebook")

    with pytest.MonkeyPatch().context() as mp:
        mp.delenv("_MNE_FAKE_HOME_DIR")
        data_path = testing.data_path(download=False)
    evoked_fname = data_path / "MEG" / "sample" / "sample_audvis_trunc-ave.fif"
    trans_fname = data_path / "MEG" / "sample" / "sample_audvis_trunc-trans.fif"
    subjects_dir = data_path / "subjects"

    evoked = read_evokeds(evoked_fname, condition="Left Auditory", baseline=(-0.2, 0.0))
    evoked.pick(evoked.ch_names[::10])  # speed
    with pytest.warns(RuntimeWarning, match="projection"):
        maps = make_field_map(
            evoked,
            trans_fname,
            subject="sample",
            subjects_dir=subjects_dir,
            n_jobs=None,
            ch_type="meg",
        )

    # Test plotting the evoked field
    fig = evoked.plot_field(maps, time_viewer=True)
    assert isinstance(fig, EvokedField)
    fig = evoked.plot_field(maps, time_viewer=False)
    assert isinstance(fig, Figure3D)

    # Test plotting inside an existing Brain figure. This should not work in a notebook.
    brain = Brain("fsaverage", "lh", "inflated", subjects_dir=subjects_dir)
    with pytest.raises(NotImplementedError):
        fig = evoked.plot_field(maps, time=0.1, fig=brain)


def _assert_n_actors(fig, renderer, n_actors):
    __tracebackhide__ = True
    assert isinstance(fig, Figure3D)
    assert len(fig.plotter.renderer.actors) == n_actors


@pytest.mark.slowtest  # can be slow on OSX
@testing.requires_testing_data
@pytest.mark.parametrize(
    "test_ecog, test_seeg, sensor_colors, sensor_scales, expectation",
    [
        (
            True,
            True,
            "k",
            2,
            pytest.raises(
                TypeError,
                match="sensor_colors must be an instance of dict or "
                "None when more than one channel type",
            ),
        ),
        (
            True,
            True,
            {"ecog": "k", "seeg": "k"},
            2,
            pytest.raises(
                TypeError,
                match="sensor_scales must be an instance of dict or "
                "None when more than one channel type",
            ),
        ),
        (
            True,
            True,
            {"ecog": ["k"] * 2, "seeg": "k"},
            {"ecog": 2, "seeg": 2},
            pytest.raises(
                ValueError,
                match=r"Invalid value for the 'len\(sensor_colors\['ecog'\]\)' "
                r"parameter. Allowed values are \d+ and \d+, but got \d+ instead",
            ),
        ),
        (
            True,
            True,
            {"ecog": "k", "seeg": ["k"] * 2},
            {"ecog": 2, "seeg": 2},
            pytest.raises(
                ValueError,
                match=r"Invalid value for the 'len\(sensor_colors\['seeg'\]\)' "
                r"parameter. Allowed values are \d+ and \d+, but got \d+ instead",
            ),
        ),
        (
            True,
            True,
            {"ecog": "k", "seeg": "k"},
            {"ecog": [2] * 2, "seeg": 2},
            pytest.raises(
                ValueError,
                match=r"Invalid value for the 'len\(sensor_scales\['ecog'\]\)' "
                r"parameter. Allowed values are \d+ and \d+, but got \d+ instead",
            ),
        ),
        (
            True,
            True,
            {"ecog": "k", "seeg": "k"},
            {"ecog": 2, "seeg": [2] * 2},
            pytest.raises(
                ValueError,
                match=r"Invalid value for the 'len\(sensor_scales\['seeg'\]\)' "
                r"parameter. Allowed values are \d+ and \d+, but got \d+ instead",
            ),
        ),
        (
            True,
            True,
            {"ecog": "NotAColor", "seeg": "NotAColor"},
            {"ecog": 2, "seeg": 2},
            pytest.raises(
                ValueError,
                match=r".* is not a valid color value",
            ),
        ),
        (
            True,
            True,
            {"ecog": "k", "seeg": "k"},
            {"ecog": "k", "seeg": 2},
            pytest.raises(
                AssertionError,
                match=r"scales for .* must contain only numerical values, got .* "
                r"instead.",
            ),
        ),
        (
            True,
            True,
            {"ecog": "k", "seeg": "k"},
            {"ecog": 2, "seeg": 2},
            nullcontext(),
        ),
        (
            True,
            True,
            {"ecog": [0, 0, 0], "seeg": [0, 0, 0]},
            {"ecog": 2, "seeg": 2},
            nullcontext(),
        ),
        (
            True,
            True,
            {"ecog": ["k"] * 10, "seeg": ["k"] * 10},
            {"ecog": [2] * 10, "seeg": [2] * 10},
            nullcontext(),
        ),
        (
            True,
            False,
            "k",
            2,
            nullcontext(),
        ),
    ],
)
def test_plot_alignment_ieeg(
    renderer, test_ecog, test_seeg, sensor_colors, sensor_scales, expectation
):
    """Test plotting of iEEG sensors."""
    # Load evoked:
    evoked = read_evokeds(evoked_fname)[0]
    # EEG only
    evoked_eeg = evoked.copy().pick_types(eeg=True)
    with evoked_eeg.info._unlock():
        evoked_eeg.info["projs"] = []  # "remove" avg proj
    eeg_channels = pick_types(evoked_eeg.info, eeg=True)
    # Set 10 EEG channels to ecog, 10 to seeg
    evoked_eeg.set_channel_types(
        {evoked_eeg.ch_names[ch]: "ecog" for ch in eeg_channels[:10]}
    )
    evoked_eeg.set_channel_types(
        {evoked_eeg.ch_names[ch]: "seeg" for ch in eeg_channels[10:20]}
    )
    evoked_ecog_seeg = evoked_eeg.pick_types(seeg=True, ecog=True)
    this_info = evoked_ecog_seeg.info
    # Test plot:
    with expectation:
        fig = plot_alignment(
            this_info,
            ecog=test_ecog,
            seeg=test_seeg,
            sensor_colors=sensor_colors,
            sensor_scales=sensor_scales,
        )
        assert isinstance(fig, Figure3D)
        renderer.backend._close_all()


@pytest.mark.slowtest  # Slow on Azure
@testing.requires_testing_data  # all use trans + head surf
@pytest.mark.parametrize(
    "system",
    [
        "Neuromag",
        "CTF",
        "BTi",
        "KIT",
    ],
)
def test_plot_alignment_meg(renderer, system):
    """Test plotting of MEG sensors + helmet."""
    pytest.importorskip("nibabel")
    if system == "Neuromag":
        this_info = read_info(evoked_fname)
    elif system == "CTF":
        this_info = read_raw_ctf(ctf_fname).info
    elif system == "BTi":
        this_info = read_raw_bti(
            pdf_fname, config_fname, hs_fname, convert=True, preload=False
        ).info
    else:
        assert system == "KIT"
        this_info = read_raw_kit(sqd_fname).info

    meg = {"helmet": 0.1, "sensors": 0.2}
    sensor_colors = "k"  # should be upsampled to correct shape
    if system == "KIT":
        meg["ref"] = 0.3
        with pytest.raises(TypeError, match="instance of dict"):
            plot_alignment(this_info, meg=meg, sensor_colors=sensor_colors)
        sensor_colors = dict(meg=sensor_colors)
        sensor_colors["ref_meg"] = ["r"] * len(pick_types(this_info, ref_meg=True))
    fig = plot_alignment(
        this_info,
        read_trans(trans_fname),
        subject="sample",
        subjects_dir=subjects_dir,
        meg=meg,
        eeg=False,
        sensor_colors=sensor_colors,
    )
    assert isinstance(fig, Figure3D)
    # count the number of objects: should be n_meg_ch + 1 (helmet) + 1 (head)
    use_info = pick_info(
        this_info,
        pick_types(this_info, meg=True, eeg=False, ref_meg="ref" in meg, exclude=()),
    )
    n_actors = use_info["nchan"] + 2
    _assert_n_actors(fig, renderer, n_actors)


@testing.requires_testing_data
def test_plot_alignment_surf(renderer):
    """Test plotting of a surface."""
    pytest.importorskip("nibabel")
    info = read_info(evoked_fname)
    fig = plot_alignment(
        info,
        read_trans(trans_fname),
        subject="sample",
        subjects_dir=subjects_dir,
        meg=False,
        eeg=False,
        dig=False,
        surfaces=["white", "head"],
    )
    _assert_n_actors(fig, renderer, 3)  # left and right hemis plus head


@pytest.mark.slowtest  # can be slow on OSX
@testing.requires_testing_data
def test_plot_alignment_basic(tmp_path, renderer, mixed_fwd_cov_evoked):
    """Test plotting of -trans.fif files and MEG sensor layouts."""
    # generate fiducials file for testing
    fiducials_path = tmp_path / "fiducials.fif"
    fid = [
        {
            "coord_frame": 5,
            "ident": 1,
            "kind": 1,
            "r": [-0.08061612, -0.02908875, -0.04131077],
        },
        {
            "coord_frame": 5,
            "ident": 2,
            "kind": 1,
            "r": [0.00146763, 0.08506715, -0.03483611],
        },
        {
            "coord_frame": 5,
            "ident": 3,
            "kind": 1,
            "r": [0.08436285, -0.02850276, -0.04127743],
        },
    ]
    write_dig(fiducials_path, fid, 5)
    evoked = read_evokeds(evoked_fname)[0]
    info = evoked.info

    sample_src = read_source_spaces(src_fname)
    pytest.raises(
        TypeError,
        plot_alignment,
        "foo",
        trans_fname,
        subject="sample",
        subjects_dir=subjects_dir,
    )
    pytest.raises(
        OSError,
        plot_alignment,
        info,
        trans_fname,
        subject="sample",
        subjects_dir=subjects_dir,
        src="foo",
    )
    pytest.raises(
        ValueError,
        plot_alignment,
        info,
        trans_fname,
        subject="fsaverage",
        subjects_dir=subjects_dir,
        src=sample_src,
    )
    sample_src.plot(subjects_dir=subjects_dir, head=True, skull=True, brain="white")
    # mixed source space
    mixed_src = mixed_fwd_cov_evoked[0]["src"]
    assert mixed_src.kind == "mixed"
    fig = plot_alignment(
        info,
        meg=["helmet", "sensors"],
        dig=True,
        coord_frame="head",
        trans=Path(trans_fname),
        subject="sample",
        mri_fiducials=fiducials_path,
        subjects_dir=subjects_dir,
        src=mixed_src,
    )
    assert isinstance(fig, Figure3D)
    renderer.backend._close_all()
    # no-head version
    renderer.backend._close_all()
    # trans required
    with pytest.raises(ValueError, match="transformation matrix.*in head"):
        plot_alignment(info, trans=None, src=src_fname)
    with pytest.raises(ValueError, match="transformation matrix.*in head"):
        plot_alignment(info, trans=None, mri_fiducials=True)
    with pytest.raises(ValueError, match="transformation matrix.*in head"):
        plot_alignment(info, trans=None, surfaces=["brain"])
    assert mixed_src[0]["coord_frame"] == FIFF.FIFFV_COORD_HEAD
    with pytest.raises(ValueError, match="head-coordinate source space in mr"):
        plot_alignment(trans=None, src=mixed_src, coord_frame="mri")
    # all coord frames
    plot_alignment(info)  # works: surfaces='auto' default
    for coord_frame in ("meg", "head", "mri"):
        fig = plot_alignment(
            info,
            meg=["helmet", "sensors"],
            dig=True,
            coord_frame=coord_frame,
            trans=Path(trans_fname),
            subject="sample",
            src=src_fname,
            mri_fiducials=fiducials_path,
            subjects_dir=subjects_dir,
        )

    renderer.backend._close_all()
    # EEG only with strange options
    evoked_eeg_ecog_seeg = evoked.copy().pick([f"EEG {x:03d}" for x in range(1, 13)])
    with evoked_eeg_ecog_seeg.info._unlock():
        evoked_eeg_ecog_seeg.info["projs"] = []  # "remove" avg proj
    evoked_eeg_ecog_seeg.set_channel_types({"EEG 001": "ecog", "EEG 002": "seeg"})
    with catch_logging() as log:
        fig = plot_alignment(
            evoked_eeg_ecog_seeg.info,
            subject="sample",
            trans=trans_fname,
            subjects_dir=subjects_dir,
            surfaces=["white", "outer_skin", "outer_skull"],
            eeg=["original", "projected"],
            ecog=True,
            seeg=True,
            verbose=True,
        )
    log = log.getvalue()
    assert "ecog: 1" in log
    assert "seeg: 1" in log
    assert "eeg: 10" in log
    # got the right number of actors?
    actor_names = list(fig.plotter.actors)
    # 4 surfs (both hemis, skin, skull), 1 ECoG, 1 sEEG, 5 orig EEG + 1 projected EEG
    assert len(actor_names) == 4 + 1 + 1 + 1 + 1
    renderer.backend._close_all()

    sphere = make_sphere_model(info=info, r0="auto", head_radius="auto")
    bem_sol = read_bem_solution(
        subjects_dir / "sample" / "bem" / "sample-1280-1280-1280-bem-sol.fif"
    )
    bem_surfs = read_bem_surfaces(
        subjects_dir / "sample" / "bem" / "sample-1280-1280-1280-bem.fif"
    )
    sample_src[0]["coord_frame"] = 4  # hack for coverage
    plot_alignment(
        info,
        trans_fname,
        subject="sample",
        eeg="projected",
        meg="helmet",
        bem=sphere,
        dig=True,
        surfaces=["brain", "inner_skull", "outer_skull", "outer_skin"],
    )
    plot_alignment(
        info,
        trans_fname,
        subject="sample",
        meg="helmet",
        subjects_dir=subjects_dir,
        eeg="projected",
        bem=sphere,
        surfaces=["head", "brain"],
        src=sample_src,
    )
    # no trans okay, no mri surfaces
    plot_alignment(info, bem=sphere, surfaces=["brain"])
    with pytest.raises(ValueError, match="A head surface is required"):
        plot_alignment(
            info,
            trans=trans_fname,
            subject="sample",
            subjects_dir=subjects_dir,
            eeg="projected",
            surfaces=[],
        )
    with pytest.raises(RuntimeError, match="No brain surface found"):
        plot_alignment(
            info,
            trans=trans_fname,
            subject="foo",
            subjects_dir=subjects_dir,
            surfaces=["brain"],
        )
    assert all(surf["coord_frame"] == FIFF.FIFFV_COORD_MRI for surf in bem_sol["surfs"])
    plot_alignment(
        info,
        trans_fname,
        subject="sample",
        meg=[],
        subjects_dir=subjects_dir,
        bem=bem_sol,
        eeg=True,
        surfaces=["head", "inflated", "outer_skull", "inner_skull"],
    )
    assert all(surf["coord_frame"] == FIFF.FIFFV_COORD_MRI for surf in bem_sol["surfs"])
    plot_alignment(
        info,
        trans_fname,
        subject="sample",
        meg=True,
        subjects_dir=subjects_dir,
        surfaces=["head", "inner_skull"],
        bem=bem_surfs,
    )
    # single-layer BEM can still plot head surface
    assert bem_surfs[-1]["id"] == FIFF.FIFFV_BEM_SURF_ID_BRAIN
    bem_sol_homog = read_bem_solution(
        subjects_dir / "sample" / "bem" / "sample-1280-bem-sol.fif"
    )
    for use_bem in (bem_surfs[-1:], bem_sol_homog):
        with catch_logging() as log:
            plot_alignment(
                info,
                trans_fname,
                subject="sample",
                meg=True,
                subjects_dir=subjects_dir,
                surfaces=["head", "inner_skull"],
                bem=use_bem,
                verbose=True,
            )
        log = log.getvalue()
        assert "not find the surface for head in the provided BEM model" in log
    # sphere model
    sphere = make_sphere_model("auto", "auto", info)
    src = setup_volume_source_space(sphere=sphere)
    plot_alignment(
        info,
        trans=Transform("head", "mri"),
        eeg="projected",
        meg="helmet",
        bem=sphere,
        src=src,
        dig=True,
        surfaces=["brain", "inner_skull", "outer_skull", "outer_skin"],
    )
    sphere = make_sphere_model("auto", None, info)  # one layer
    # if you ask for a brain surface with a 1-layer sphere model it's an error
    with pytest.raises(RuntimeError, match="Sphere model does not have"):
        plot_alignment(
            trans=trans_fname,
            subject="sample",
            subjects_dir=subjects_dir,
            surfaces=["brain"],
            bem=sphere,
        )
    # but you can ask for a specific brain surface, and
    # no info is permitted
    plot_alignment(
        trans=trans_fname,
        subject="sample",
        meg=False,
        coord_frame="mri",
        subjects_dir=subjects_dir,
        surfaces=["white"],
        bem=sphere,
        show_axes=True,
    )
    renderer.backend._close_all()
    # TODO: We need to make this class public and document it properly
    # assert isinstance(fig, some_public_class)
    # 3D coil with no defined draw (ConvexHull)
    info_cube = pick_info(info, np.arange(6))
    with info._unlock():
        info["dig"] = None
    info_cube["chs"][0]["coil_type"] = 9999
    info_cube["chs"][1]["coil_type"] = 9998
    with pytest.raises(RuntimeError, match="coil definition not found"):
        plot_alignment(info_cube, meg="sensors", surfaces=())
    coil_def_fname = tmp_path / "temp"
    with open(coil_def_fname, "w") as fid:
        fid.write(coil_3d)
    # make sure our other OPMs can be plotted, too
    for ii, kind in enumerate(
        (
            "QUSPIN_ZFOPM_MAG",
            "QUSPIN_ZFOPM_MAG2",
            "FIELDLINE_OPM_MAG_GEN1",
            "KERNEL_OPM_MAG_GEN1",
        ),
        2,
    ):
        info_cube["chs"][ii]["coil_type"] = getattr(FIFF, f"FIFFV_COIL_{kind}")
    with use_coil_def(coil_def_fname):
        with catch_logging() as log:
            plot_alignment(
                info_cube, meg="sensors", surfaces=(), dig=True, verbose="debug"
            )
    log = log.getvalue()
    assert "planar geometry" in log

    # one layer bem with skull surfaces:
    with pytest.raises(RuntimeError, match="Sphere model does not.*boundary"):
        plot_alignment(
            info=info,
            trans=trans_fname,
            subject="sample",
            subjects_dir=subjects_dir,
            surfaces=["brain", "head", "inner_skull"],
            bem=sphere,
        )
    # wrong eeg value:
    with pytest.raises(ValueError, match="Invalid value for the .eeg"):
        plot_alignment(
            info=info,
            trans=trans_fname,
            subject="sample",
            subjects_dir=subjects_dir,
            eeg="foo",
        )
    # wrong meg value:
    with pytest.raises(ValueError, match="Invalid value for the .meg"):
        plot_alignment(
            info=info,
            trans=trans_fname,
            subject="sample",
            subjects_dir=subjects_dir,
            meg="bar",
        )
    # multiple brain surfaces:
    with pytest.raises(ValueError, match="Only one brain surface can be plot"):
        plot_alignment(
            info=info,
            trans=trans_fname,
            subject="sample",
            subjects_dir=subjects_dir,
            surfaces=["white", "pial"],
        )
    with pytest.raises(TypeError, match="surfaces.*must be"):
        plot_alignment(
            info=info,
            trans=trans_fname,
            subject="sample",
            subjects_dir=subjects_dir,
            surfaces=[1],
        )
    with pytest.raises(ValueError, match="Unknown surface type"):
        plot_alignment(
            info=info,
            trans=trans_fname,
            subject="sample",
            subjects_dir=subjects_dir,
            surfaces=["foo"],
        )
    with pytest.raises(TypeError, match="must be an instance of "):
        plot_alignment(
            info=info,
            trans=trans_fname,
            subject="sample",
            subjects_dir=subjects_dir,
            surfaces=dict(brain="super clear"),
        )
    with pytest.raises(ValueError, match="must be between 0 and 1"):
        plot_alignment(
            info=info,
            trans=trans_fname,
            subject="sample",
            subjects_dir=subjects_dir,
            surfaces=dict(brain=42),
        )
    fwd_fname = (
        data_dir / "MEG" / "sample" / "sample_audvis_trunc-meg-eeg-oct-4-fwd.fif"
    )
    fwd = read_forward_solution(fwd_fname)
    plot_alignment(
        subject="sample",
        subjects_dir=subjects_dir,
        trans=trans_fname,
        fwd=fwd,
        surfaces="white",
        coord_frame="head",
    )
    fwd = convert_forward_solution(fwd, force_fixed=True)
    plot_alignment(
        subject="sample",
        subjects_dir=subjects_dir,
        trans=trans_fname,
        fwd=fwd,
        surfaces="white",
        coord_frame="head",
    )
    fwd["coord_frame"] = FIFF.FIFFV_COORD_MRI  # check required to get to MRI
    with pytest.raises(ValueError, match="transformation matrix.*in head coo"):
        plot_alignment(info, trans=None, fwd=fwd)
    # surfaces as dict
    plot_alignment(
        subject="sample",
        coord_frame="head",
        trans=trans_fname,
        subjects_dir=subjects_dir,
        surfaces={"white": 0.4, "outer_skull": 0.6, "head": None},
    )


@testing.requires_testing_data
def test_plot_alignment_fnirs(renderer, tmp_path):
    """Test fNIRS plotting."""
    # Here we use subjects_dir=tmp_path, since no surfaces should actually
    # be loaded!

    # fNIRS (default is pairs)
    info = read_raw_nirx(nirx_fname).info
    assert info["nchan"] == 26
    kwargs = dict(
        trans="fsaverage",
        subject="fsaverage",
        surfaces=(),
        verbose=True,
        subjects_dir=tmp_path,
    )
    with catch_logging() as log:
        fig = plot_alignment(info, **kwargs)
    log = log.getvalue()
    assert f"fnirs_cw_amplitude: {info['nchan']}" in log
    _assert_n_actors(fig, renderer, info["nchan"])

    fig = plot_alignment(info, fnirs=["channels", "sources", "detectors"], **kwargs)
    _assert_n_actors(fig, renderer, 3)


@pytest.mark.slowtest  # can be slow on OSX
@testing.requires_testing_data
def test_process_clim_plot(renderer_interactive, brain_gc):
    """Test functionality for determining control points with stc.plot."""
    pytest.importorskip("nibabel")
    sample_src = read_source_spaces(src_fname)
    kwargs = dict(
        subjects_dir=subjects_dir,
        smoothing_steps=1,
        time_viewer=False,
        show_traces=False,
    )

    vertices = [s["vertno"] for s in sample_src]
    n_time = 5
    n_verts = sum(len(v) for v in vertices)
    stc_data = np.random.RandomState(0).rand(n_verts * n_time)
    stc_data = _reshape_view(stc_data, (n_verts, n_time))
    stc = SourceEstimate(stc_data, vertices, 1, 1, "sample")

    # Test for simple use cases
    brain = stc.plot(**kwargs)
    assert brain.data["center"] is None
    brain.close()
    brain = stc.plot(clim=dict(pos_lims=(10, 50, 90)), **kwargs)
    assert brain.data["center"] == 0.0
    brain.close()
    brain = stc.plot(colormap="hot", clim="auto", **kwargs)
    brain.close()
    brain = stc.plot(colormap="mne", clim="auto", **kwargs)
    brain.close()
    brain = stc.plot(clim=dict(kind="value", lims=(10, 50, 90)), figure=99, **kwargs)
    brain.close()
    with pytest.raises(TypeError, match="must be a"):
        stc.plot(clim="auto", figure=[0], **kwargs)

    # Test for correct clim values
    with pytest.raises(ValueError, match="monotonically"):
        stc.plot(clim=dict(kind="value", pos_lims=[0, 1, 0]), **kwargs)
    with pytest.raises(ValueError, match=r".*must be \(3,\)"):
        stc.plot(colormap="mne", clim=dict(pos_lims=(5, 10, 15, 20)), **kwargs)
    with pytest.raises(ValueError, match="'value', 'values', and 'percent'"):
        stc.plot(clim=dict(pos_lims=(5, 10, 15), kind="foo"), **kwargs)
    with pytest.raises(ValueError, match='must be "auto" or dict'):
        stc.plot(colormap="mne", clim="foo", **kwargs)
    with pytest.raises(TypeError, match="must be an instance of"):
        plot_source_estimates("foo", clim="auto", **kwargs)
    with pytest.raises(ValueError, match="hemi"):
        stc.plot(hemi="foo", clim="auto", **kwargs)
    with pytest.raises(ValueError, match="Exactly one"):
        stc.plot(clim=dict(lims=[0, 1, 2], pos_lims=[0, 1, 2], kind="value"), **kwargs)

    # Test handling of degenerate data: thresholded maps
    stc._data.fill(0.0)
    with pytest.warns(RuntimeWarning, match="All data were zero"):
        brain = plot_source_estimates(stc, **kwargs)
    brain.close()


def _assert_mapdata_equal(a, b):
    __tracebackhide__ = True
    assert set(a.keys()) == {"clim", "colormap", "transparent"}
    assert a.keys() == b.keys()
    assert a["transparent"] == b["transparent"], "transparent"
    aa, bb = a["clim"], b["clim"]
    assert aa.keys() == bb.keys(), "clim keys"
    assert aa["kind"] == bb["kind"] == "value"
    key = "pos_lims" if "pos_lims" in aa else "lims"
    assert_array_equal(aa[key], bb[key], err_msg=key)
    assert isinstance(a["colormap"], Colormap), "Colormap"
    assert isinstance(b["colormap"], Colormap), "Colormap"
    assert a["colormap"].name == b["colormap"].name


def test_process_clim_round_trip():
    """Test basic input-output support."""
    # With some negative data
    out = _process_clim("auto", "auto", True, -1.0)
    want = dict(
        colormap=mne_analyze_colormap([0, 0.5, 1], "matplotlib"),
        clim=dict(kind="value", pos_lims=[1, 1, 1]),
        transparent=True,
    )
    _assert_mapdata_equal(out, want)
    out2 = _process_clim(**out)
    _assert_mapdata_equal(out, out2)
    _linearize_map(out)  # smoke test
    ticks = _get_map_ticks(out)
    assert_allclose(ticks, [-1, 0, 1])

    # With some positive data
    out = _process_clim("auto", "auto", True, 1.0)
    want = dict(
        colormap=_get_cmap("hot"),
        clim=dict(kind="value", lims=[1, 1, 1]),
        transparent=True,
    )
    _assert_mapdata_equal(out, want)
    out2 = _process_clim(**out)
    _assert_mapdata_equal(out, out2)
    _linearize_map(out)
    ticks = _get_map_ticks(out)
    assert_allclose(ticks, [1])

    # With some actual inputs
    clim = dict(kind="value", pos_lims=[0, 0.5, 1])
    out = _process_clim(clim, "auto", True)
    want = dict(
        colormap=mne_analyze_colormap([0, 0.5, 1], "matplotlib"),
        clim=clim,
        transparent=True,
    )
    _assert_mapdata_equal(out, want)
    _linearize_map(out)
    ticks = _get_map_ticks(out)
    assert_allclose(ticks, [-1, -0.5, 0, 0.5, 1])

    clim = dict(kind="value", pos_lims=[0.25, 0.5, 1])
    out = _process_clim(clim, "auto", True)
    want = dict(
        colormap=mne_analyze_colormap([0, 0.5, 1], "matplotlib"),
        clim=clim,
        transparent=True,
    )
    _assert_mapdata_equal(out, want)
    _linearize_map(out)
    ticks = _get_map_ticks(out)
    assert_allclose(ticks, [-1, -0.5, -0.25, 0, 0.25, 0.5, 1])


@testing.requires_testing_data
def test_stc_mpl():
    """Test plotting source estimates with matplotlib."""
    pytest.importorskip("nibabel")
    sample_src = read_source_spaces(src_fname)
    vertices = [s["vertno"] for s in sample_src]
    n_time = 5
    n_verts = sum(len(v) for v in vertices)
    stc_data = np.ones(n_verts * n_time)
    stc_data = _reshape_view(stc_data, (n_verts, n_time))
    stc = SourceEstimate(stc_data, vertices, 1, 1, "sample")
    stc.plot(
        subjects_dir=subjects_dir,
        time_unit="s",
        views="ven",
        hemi="rh",
        smoothing_steps=7,
        subject="sample",
        backend="matplotlib",
        spacing="oct1",
        initial_time=0.001,
        colormap="Reds",
    )
    fig = stc.plot(
        subjects_dir=subjects_dir,
        time_unit="ms",
        views="dor",
        hemi="lh",
        smoothing_steps=7,
        subject="sample",
        backend="matplotlib",
        spacing="ico2",
        time_viewer=True,
        colormap="mne",
    )
    time_viewer = fig.time_viewer
    _fake_click(time_viewer, time_viewer.axes[0], (0.5, 0.5))  # change t
    _fake_keypress(time_viewer, "ctrl+right")
    _fake_keypress(time_viewer, "left")
    pytest.raises(
        ValueError,
        stc.plot,
        subjects_dir=subjects_dir,
        hemi="both",
        subject="sample",
        backend="matplotlib",
    )
    pytest.raises(
        ValueError,
        stc.plot,
        subjects_dir=subjects_dir,
        time_unit="ss",
        subject="sample",
        backend="matplotlib",
    )


@pytest.mark.slowtest
@pytest.mark.timeout(60)  # can sometimes take > 60 s
@testing.requires_testing_data
@pytest.mark.parametrize(
    "coord_frame, idx, show_all, title",
    [("head", "gof", True, "Test"), ("mri", "amplitude", False, None)],
)
def test_plot_dipole_mri_orthoview(coord_frame, idx, show_all, title):
    """Test mpl dipole plotting."""
    pytest.importorskip("nibabel")
    dipoles = read_dipole(dip_fname)
    trans = read_trans(trans_fname)
    fig = dipoles.plot_locations(
        trans=trans,
        subject="sample",
        subjects_dir=subjects_dir,
        coord_frame=coord_frame,
        idx=idx,
        show_all=show_all,
        title=title,
        mode="orthoview",
    )
    _fake_scroll(fig, 0.5, 0.5, 1)  # scroll up
    _fake_scroll(fig, 0.5, 0.5, -1)  # scroll down
    _fake_keypress(fig, "up")
    _fake_keypress(fig, "down")
    _fake_keypress(fig, "a")  # some other key
    ax = fig.add_subplot(211)
    with pytest.raises(TypeError, match="instance of Axes3D"):
        dipoles.plot_locations(trans, "sample", subjects_dir, ax=ax)


@testing.requires_testing_data
@pytest.mark.parametrize(
    "surf, coord_frame, ax, title",
    [
        pytest.param("white", "mri", None, None, marks=pytest.mark.slowtest),
        pytest.param(None, "head", None, None, marks=pytest.mark.slowtest),
        (None, "mri_rotated", "mpl", "check"),
    ],
)
def test_plot_dipole_mri_outlines(surf, coord_frame, ax, title):
    """Test mpl dipole plotting."""
    pytest.importorskip("nibabel")
    dipoles = read_dipole(dip_fname)
    trans = read_trans(trans_fname)
    if ax is not None:
        assert isinstance(ax, str) and ax == "mpl", ax
        _, ax = plt.subplots(3, 1)
        ax = list(ax)
        with pytest.raises(ValueError, match="but the length is 2"):
            dipoles.plot_locations(
                trans, "sample", subjects_dir, ax=ax[:2], mode="outlines"
            )
    fig = dipoles.plot_locations(
        trans=trans,
        subject="sample",
        subjects_dir=subjects_dir,
        mode="outlines",
        coord_frame=coord_frame,
        surf=surf,
        ax=ax,
        title=title,
    )
    assert isinstance(fig, Figure)


@testing.requires_testing_data
def test_plot_dipole_orientations(renderer):
    """Test dipole plotting in 3d."""
    dipoles = read_dipole(dip_fname)
    trans = read_trans(trans_fname)
    for coord_frame, mode in zip(["head", "mri"], ["arrow", "sphere"]):
        fig = dipoles.plot_locations(
            trans=trans,
            subject="sample",
            subjects_dir=subjects_dir,
            mode=mode,
            coord_frame=coord_frame,
        )
        assert isinstance(fig, Figure3D)
    renderer.backend._close_all()


@pytest.mark.slowtest  # slow on Azure
@testing.requires_testing_data
def test_snapshot_brain_montage(renderer):
    """Test snapshot brain montage."""
    pytest.importorskip("nibabel")
    info = read_info(evoked_fname)
    fig = plot_alignment(
        info,
        trans=Transform("head", "mri"),
        subject="sample",
        subjects_dir=subjects_dir,
    )

    xyz = np.vstack([ich["loc"][:3] for ich in info["chs"]])
    ch_names = [ich["ch_name"] for ich in info["chs"]]
    xyz_dict = dict(zip(ch_names, xyz))
    xyz_dict[info["chs"][0]["ch_name"]] = [1, 2]  # Set one ch to only 2 vals

    # Make sure wrong types are checked
    pytest.raises(TypeError, snapshot_brain_montage, fig, xyz)

    # All chs must have 3 position values
    pytest.raises(ValueError, snapshot_brain_montage, fig, xyz_dict)

    # Make sure we raise error if the figure has no scene
    pytest.raises(ValueError, snapshot_brain_montage, None, info)


@pytest.mark.slowtest  # can be slow on OSX
@testing.requires_testing_data
@pytest.mark.parametrize("pick_ori", ("vector", None))
@pytest.mark.parametrize("kind", ("surface", "volume", "mixed"))
def test_plot_source_estimates(
    renderer_interactive, all_src_types_inv_evoked, pick_ori, kind, brain_gc
):
    """Test plotting of scalar and vector source estimates."""
    backend = renderer_interactive._get_3d_backend()
    invs, evoked = all_src_types_inv_evoked
    inv = invs[kind]
    with _record_warnings():  # PCA mag
        stc = apply_inverse(evoked, inv, pick_ori=pick_ori)
    stc.data[1] *= -1  # make it signed
    meth_key = "plot_3d" if isinstance(stc, _BaseVolSourceEstimate) else "plot"
    stc.subject = "sample"
    meth = getattr(stc, meth_key)
    kwargs = dict(
        subjects_dir=subjects_dir,
        time_viewer=False,
        show_traces=False,  # for speed
        smoothing_steps=1,
        verbose="error",
        src=inv["src"],
        volume_options=dict(resolution=None),  # for speed
    )
    if pick_ori != "vector":
        kwargs["surface"] = "white"
        kwargs["backend"] = backend
    brain = meth(**kwargs)
    brain.close()
    del brain

    these_kwargs = kwargs.copy()
    these_kwargs["show_traces"] = "foo"
    with pytest.raises(ValueError, match="show_traces"):
        meth(**these_kwargs)
    del these_kwargs
    if pick_ori == "vector":
        with pytest.raises(ValueError, match='use "pos_lims"'):
            meth(**kwargs, clim=dict(pos_lims=[1, 2, 3]))
    if kind in ("volume", "mixed"):
        with pytest.raises(TypeError, match="when stc is a mixed or vol"):
            these_kwargs = kwargs.copy()
            these_kwargs.pop("src")
            meth(**these_kwargs)

    with pytest.raises(ValueError, match="cannot be used"):
        these_kwargs = kwargs.copy()
        these_kwargs.update(show_traces=True, time_viewer=False)
        meth(**these_kwargs)

    # flatmaps (mostly a lot of error checking)
    these_kwargs = kwargs.copy()
    these_kwargs.update(surface="flat", views="auto", hemi="both", verbose="debug")
    if kind == "surface" and pick_ori != "vector":
        with catch_logging() as log:
            with pytest.raises(FileNotFoundError, match="flatmap"):
                meth(**these_kwargs)  # sample does not have them
        log = log.getvalue()
        assert "offset: 0" in log
    fs_stc = stc.copy()
    fs_stc.subject = "fsaverage"  # this is wrong, but don't have to care
    flat_meth = getattr(fs_stc, meth_key)
    these_kwargs.pop("src")
    if pick_ori == "vector":
        pass  # can't even pass "surface" variable
    elif kind != "surface":
        with pytest.raises(TypeError, match="SourceEstimate when a flatmap"):
            flat_meth(**these_kwargs)
    else:
        brain = flat_meth(**these_kwargs)
        brain.close()
        del brain
        these_kwargs.update(surface="inflated", views="flat")
        with pytest.raises(ValueError, match='surface="flat".*views="flat"'):
            flat_meth(**these_kwargs)

    # just test one for speed
    if kind != "mixed":
        return
    brain = meth(
        views=["lat", "med", "ven"], hemi="lh", view_layout="horizontal", **kwargs
    )
    brain.close()
    assert brain._subplot_shape == (1, 3)
    del brain
    these_kwargs = kwargs.copy()
    these_kwargs["volume_options"] = dict(blending="foo")
    with pytest.raises(ValueError, match="mip"):
        meth(**these_kwargs)
    these_kwargs["volume_options"] = dict(badkey="foo")
    with pytest.raises(ValueError, match="unknown"):
        meth(**these_kwargs)
    # with resampling (actually downsampling but it's okay)
    these_kwargs["volume_options"] = dict(resolution=20.0, surface_alpha=0.0)
    brain = meth(**these_kwargs)
    brain.close()
    del brain


@pytest.mark.parametrize("orientation", ("horizontal", "vertical"))
@pytest.mark.parametrize("diverging", (True, False))
@pytest.mark.parametrize("lims", ([0.5, 1, 10], [0, 1, 10]))
def test_brain_colorbar(orientation, diverging, lims):
    """Test brain colorbar plotting."""
    _, ax = plt.subplots()
    clim = dict(kind="value")
    if diverging:
        clim["pos_lims"] = lims
    else:
        clim["lims"] = lims
    cbar = plot_brain_colorbar(ax, clim, orientation=orientation)
    ax = cbar.ax  # in newer mpl this can be inset axes relative to the orig
    if orientation == "vertical":
        have, empty = ax.get_yticklabels, ax.get_xticklabels
    else:
        have, empty = ax.get_xticklabels, ax.get_yticklabels
    if diverging:
        if lims[0] == 0:
            ticks = list(-np.array(lims[1:][::-1])) + lims
        else:
            ticks = list(-np.array(lims[::-1])) + [0] + lims
    else:
        ticks = lims
    ax.figure.canvas.draw_idle()
    assert_array_equal([float(h.get_text().replace("−", "-")) for h in have()], ticks)
    assert_array_equal(empty(), [])


@pytest.mark.slowtest  # slow-ish on Travis OSX
@testing.requires_testing_data
def test_mixed_sources_plot_surface(renderer_interactive):
    """Test plot_surface() for mixed source space."""
    pytest.importorskip("nibabel")
    src = read_source_spaces(fwd_fname2)
    N = np.sum([s["nuse"] for s in src])  # number of sources

    T = 2  # number of time points
    S = 3  # number of source spaces

    rng = np.random.RandomState(0)
    data = rng.randn(N, T)
    vertno = S * [np.arange(N // S)]

    stc = MixedSourceEstimate(data, vertno, 0, 1)

    brain = stc.surface().plot(
        views="lat",
        hemi="split",
        subject="fsaverage",
        subjects_dir=subjects_dir,
        colorbar=False,
    )
    brain.close()
    del brain


@testing.requires_testing_data
@pytest.mark.slowtest
def test_link_brains(renderer_interactive):
    """Test plotting linked brains."""
    pytest.importorskip("nibabel")
    sample_src = read_source_spaces(src_fname)
    vertices = [s["vertno"] for s in sample_src]
    n_time = 5
    n_verts = sum(len(v) for v in vertices)
    stc_data = np.zeros(n_verts * n_time)
    stc_size = stc_data.size
    stc_data[(np.random.rand(stc_size // 20) * stc_size).astype(int)] = (
        np.random.RandomState(0).rand(stc_data.size // 20)
    )
    stc_data = _reshape_view(stc_data, (n_verts, n_time))
    stc = SourceEstimate(stc_data, vertices, 1, 1)

    colormap = "mne_analyze"
    brain = plot_source_estimates(
        stc,
        "sample",
        colormap=colormap,
        background=(1, 1, 0),
        subjects_dir=subjects_dir,
        colorbar=True,
        clim="auto",
    )
    with pytest.raises(ValueError, match="is empty"):
        link_brains([])
    with pytest.raises(TypeError, match="type is Brain"):
        link_brains("foo")
    link_brains(brain, time=True, camera=True)
