"""
Tests pandas.options.backend setting
"""
from distutils.version import LooseVersion
from unittest import TestCase, SkipTest
import pandas as pd

from parameterized import parameterized

from ..converter import HoloViewsConverter


no_args = ['line', 'area', 'hist', 'box', 'kde', 'density', 'bar', 'barh']
x_y = ['scatter', 'hexbin']

no_args_mapping = [(kind, el) for kind, el in HoloViewsConverter._kind_mapping.items()
                   if kind in no_args]
x_y_mapping = [(kind, el) for kind, el in HoloViewsConverter._kind_mapping.items()
               if kind in x_y]


class TestPandasHoloviewsPlotting(TestCase):

    def setUp(self):
        if LooseVersion(pd.__version__) < '0.25.1':
            raise SkipTest('entrypoints for plotting.backends was added '
                           'in pandas 0.25.1')
        pd.options.plotting.backend = 'holoviews'

    @parameterized.expand(no_args_mapping)
    def test_pandas_series_plot_returns_holoviews_object(self, kind, el):
        series = pd.Series([0, 1, 2])
        plot = getattr(series.plot, kind)()
        self.assertIsInstance(plot, el)

    @parameterized.expand(no_args_mapping)
    def test_pandas_dataframe_plot_returns_holoviews_object(self, kind, el):
        df = pd.DataFrame([0, 1, 2])
        plot = getattr(df.plot, kind)()
        self.assertIsInstance(plot, el)

    @parameterized.expand(x_y_mapping)
    def test_pandas_dataframe_plot_returns_holoviews_object_when_x_and_y_set(self, kind, el):
        df = pd.DataFrame({'a': [0, 1, 2], 'b': [5, 7, 2]})
        plot = getattr(df.plot, kind)(x='a', y='b')
        self.assertIsInstance(plot, el)

    def test_pandas_dataframe_plot_does_not_implement_pie(self):
        df = pd.DataFrame({'a': [0, 1, 2], 'b': [5, 7, 2]})
        with self.assertRaisesRegex(NotImplementedError, "pie"):
            df.plot.pie(y='a')


class TestPandasHvplotPlotting(TestPandasHoloviewsPlotting):

    def setUp(self):
        if LooseVersion(pd.__version__) < '0.25.1':
            raise SkipTest('entrypoints for plotting.backends was added '
                           'in pandas 0.25.1')
        pd.options.plotting.backend = 'hvplot'