from __future__ import (absolute_import, division, print_function,
                        unicode_literals)

import os
import sys
import shutil
import tempfile
from contextlib import contextmanager

from nose import SkipTest
from nose.tools import assert_raises
from nose.plugins.attrib import attr

import matplotlib as mpl
from matplotlib import style
from matplotlib.style.core import USER_LIBRARY_PATHS, STYLE_EXTENSION

from matplotlib.externals import six

PARAM = 'image.cmap'
VALUE = 'pink'
DUMMY_SETTINGS = {PARAM: VALUE}


@contextmanager
def temp_style(style_name, settings=None):
    """Context manager to create a style sheet in a temporary directory."""
    settings = DUMMY_SETTINGS
    temp_file = '%s.%s' % (style_name, STYLE_EXTENSION)

    # Write style settings to file in the temp directory.
    tempdir = tempfile.mkdtemp()
    with open(os.path.join(tempdir, temp_file), 'w') as f:
        for k, v in six.iteritems(settings):
            f.write('%s: %s' % (k, v))

    # Add temp directory to style path and reload so we can access this style.
    USER_LIBRARY_PATHS.append(tempdir)
    style.reload_library()

    try:
        yield
    finally:
        shutil.rmtree(tempdir)
        style.reload_library()


def test_available():
    with temp_style('_test_', DUMMY_SETTINGS):
        assert '_test_' in style.available


def test_use():
    mpl.rcParams[PARAM] = 'gray'
    with temp_style('test', DUMMY_SETTINGS):
        with style.context('test'):
            assert mpl.rcParams[PARAM] == VALUE


@attr('network')
def test_use_url():
    with temp_style('test', DUMMY_SETTINGS):
        with style.context('https://gist.github.com/adrn/6590261/raw'):
            assert mpl.rcParams['axes.facecolor'] == "#adeade"


def test_context():
    mpl.rcParams[PARAM] = 'gray'
    with temp_style('test', DUMMY_SETTINGS):
        with style.context('test'):
            assert mpl.rcParams[PARAM] == VALUE
    # Check that this value is reset after the exiting the context.
    assert mpl.rcParams[PARAM] == 'gray'


def test_context_with_dict():
    original_value = 'gray'
    other_value = 'blue'
    mpl.rcParams[PARAM] = original_value
    with style.context({PARAM: other_value}):
        assert mpl.rcParams[PARAM] == other_value
    assert mpl.rcParams[PARAM] == original_value


def test_context_with_dict_after_namedstyle():
    # Test dict after style name where dict modifies the same parameter.
    original_value = 'gray'
    other_value = 'blue'
    mpl.rcParams[PARAM] = original_value
    with temp_style('test', DUMMY_SETTINGS):
        with style.context(['test', {PARAM: other_value}]):
            assert mpl.rcParams[PARAM] == other_value
    assert mpl.rcParams[PARAM] == original_value


def test_context_with_dict_before_namedstyle():
    # Test dict before style name where dict modifies the same parameter.
    original_value = 'gray'
    other_value = 'blue'
    mpl.rcParams[PARAM] = original_value
    with temp_style('test', DUMMY_SETTINGS):
        with style.context([{PARAM: other_value}, 'test']):
            assert mpl.rcParams[PARAM] == VALUE
    assert mpl.rcParams[PARAM] == original_value


def test_context_with_union_of_dict_and_namedstyle():
    # Test dict after style name where dict modifies the a different parameter.
    original_value = 'gray'
    other_param = 'text.usetex'
    other_value = True
    d = {other_param: other_value}
    mpl.rcParams[PARAM] = original_value
    mpl.rcParams[other_param] = (not other_value)
    with temp_style('test', DUMMY_SETTINGS):
        with style.context(['test', d]):
            assert mpl.rcParams[PARAM] == VALUE
            assert mpl.rcParams[other_param] == other_value
    assert mpl.rcParams[PARAM] == original_value
    assert mpl.rcParams[other_param] == (not other_value)


def test_context_with_badparam():
    if sys.version_info[:2] >= (2, 7):
        from collections import OrderedDict
    else:
        m = "Test can only be run in Python >= 2.7 as it requires OrderedDict"
        raise SkipTest(m)

    original_value = 'gray'
    other_value = 'blue'
    d = OrderedDict([(PARAM, original_value), ('badparam', None)])
    with style.context({PARAM: other_value}):
        assert mpl.rcParams[PARAM] == other_value
        x = style.context([d])
        assert_raises(KeyError, x.__enter__)
        assert mpl.rcParams[PARAM] == other_value


if __name__ == '__main__':
    from numpy import testing
    testing.run_module_suite()