import io
from pathlib import Path
import re
import tempfile

import pytest

import matplotlib as mpl
import matplotlib.pyplot as plt
from matplotlib import cbook, patheffects
from matplotlib.testing.decorators import check_figures_equal, image_comparison
from matplotlib.cbook import MatplotlibDeprecationWarning


needs_ghostscript = pytest.mark.skipif(
    "eps" not in mpl.testing.compare.converter,
    reason="This test needs a ghostscript installation")
needs_usetex = pytest.mark.skipif(
    not mpl.checkdep_usetex(True),
    reason="This test needs a TeX installation")


# This tests tends to hit a TeX cache lock on AppVeyor.
@pytest.mark.flaky(reruns=3)
@pytest.mark.parametrize('orientation', ['portrait', 'landscape'])
@pytest.mark.parametrize('format, use_log, rcParams', [
    ('ps', False, {}),
    ('ps', False, {'ps.usedistiller': 'ghostscript'}),
    ('ps', False, {'ps.usedistiller': 'xpdf'}),
    ('ps', False, {'text.usetex': True}),
    ('eps', False, {}),
    ('eps', True, {'ps.useafm': True}),
    ('eps', False, {'text.usetex': True}),
], ids=[
    'ps',
    'ps with distiller=ghostscript',
    'ps with distiller=xpdf',
    'ps with usetex',
    'eps',
    'eps afm',
    'eps with usetex'
])
def test_savefig_to_stringio(format, use_log, rcParams, orientation):
    mpl.rcParams.update(rcParams)

    fig, ax = plt.subplots()

    with io.StringIO() as s_buf, io.BytesIO() as b_buf:

        if use_log:
            ax.set_yscale('log')

        ax.plot([1, 2], [1, 2])
        title = "Déjà vu"
        if not mpl.rcParams["text.usetex"]:
            title += " \N{MINUS SIGN}\N{EURO SIGN}"
        ax.set_title(title)
        allowable_exceptions = []
        if rcParams.get("ps.usedistiller"):
            allowable_exceptions.append(mpl.ExecutableNotFoundError)
        if rcParams.get("text.usetex"):
            allowable_exceptions.append(RuntimeError)
        if rcParams.get("ps.useafm"):
            allowable_exceptions.append(MatplotlibDeprecationWarning)
        try:
            fig.savefig(s_buf, format=format, orientation=orientation)
            fig.savefig(b_buf, format=format, orientation=orientation)
        except tuple(allowable_exceptions) as exc:
            pytest.skip(str(exc))

        s_val = s_buf.getvalue().encode('ascii')
        b_val = b_buf.getvalue()

        # Strip out CreationDate: ghostscript and cairo don't obey
        # SOURCE_DATE_EPOCH, and that environment variable is already tested in
        # test_determinism.
        s_val = re.sub(b"(?<=\n%%CreationDate: ).*", b"", s_val)
        b_val = re.sub(b"(?<=\n%%CreationDate: ).*", b"", b_val)

        assert s_val == b_val.replace(b'\r\n', b'\n')


def test_patheffects():
    mpl.rcParams['path.effects'] = [
        patheffects.withStroke(linewidth=4, foreground='w')]
    fig, ax = plt.subplots()
    ax.plot([1, 2, 3])
    with io.BytesIO() as ps:
        fig.savefig(ps, format='ps')


@needs_usetex
@needs_ghostscript
def test_tilde_in_tempfilename(tmpdir):
    # Tilde ~ in the tempdir path (e.g. TMPDIR, TMP or TEMP on windows
    # when the username is very long and windows uses a short name) breaks
    # latex before https://github.com/matplotlib/matplotlib/pull/5928
    base_tempdir = Path(tmpdir, "short-1")
    base_tempdir.mkdir()
    # Change the path for new tempdirs, which is used internally by the ps
    # backend to write a file.
    with cbook._setattr_cm(tempfile, tempdir=str(base_tempdir)):
        # usetex results in the latex call, which does not like the ~
        mpl.rcParams['text.usetex'] = True
        plt.plot([1, 2, 3, 4])
        plt.xlabel(r'\textbf{time} (s)')
        # use the PS backend to write the file...
        plt.savefig(base_tempdir / 'tex_demo.eps', format="ps")


@image_comparison(["empty.eps"])
def test_transparency():
    fig, ax = plt.subplots()
    ax.set_axis_off()
    ax.plot([0, 1], color="r", alpha=0)
    ax.text(.5, .5, "foo", color="r", alpha=0)


def test_bbox():
    fig, ax = plt.subplots()
    with io.BytesIO() as buf:
        fig.savefig(buf, format='eps')
        buf = buf.getvalue()

    bb = re.search(b'^%%BoundingBox: (.+) (.+) (.+) (.+)$', buf, re.MULTILINE)
    assert bb
    hibb = re.search(b'^%%HiResBoundingBox: (.+) (.+) (.+) (.+)$', buf,
                     re.MULTILINE)
    assert hibb

    for i in range(1, 5):
        # BoundingBox must use integers, and be ceil/floor of the hi res.
        assert b'.' not in bb.group(i)
        assert int(bb.group(i)) == pytest.approx(float(hibb.group(i)), 1)


@needs_usetex
def test_failing_latex():
    """Test failing latex subprocess call"""
    mpl.rcParams['text.usetex'] = True
    # This fails with "Double subscript"
    plt.xlabel("$22_2_2$")
    with pytest.raises(RuntimeError):
        plt.savefig(io.BytesIO(), format="ps")


@needs_usetex
def test_partial_usetex(caplog):
    caplog.set_level("WARNING")
    plt.figtext(.5, .5, "foo", usetex=True)
    plt.savefig(io.BytesIO(), format="ps")
    assert caplog.records and all("as if usetex=False" in record.getMessage()
                                  for record in caplog.records)


@image_comparison(["useafm.eps"])
def test_useafm():
    mpl.rcParams["ps.useafm"] = True
    fig, ax = plt.subplots()
    ax.set_axis_off()
    ax.axhline(.5)
    ax.text(.5, .5, "qk")


@image_comparison(["type3.eps"])
def test_type3_font():
    plt.figtext(.5, .5, "I/J")


@check_figures_equal(extensions=["eps"])
def test_text_clip(fig_test, fig_ref):
    ax = fig_test.add_subplot()
    # Fully clipped-out text should not appear.
    ax.text(0, 0, "hello", transform=fig_test.transFigure, clip_on=True)
    fig_ref.add_subplot()


@needs_ghostscript
def test_d_glyph(tmp_path):
    # Ensure that we don't have a procedure defined as /d, which would be
    # overwritten by the glyph definition for "d".
    fig = plt.figure()
    fig.text(.5, .5, "def")
    out = tmp_path / "test.eps"
    fig.savefig(out)
    mpl.testing.compare.convert(out, cache=False)  # Should not raise.
