import pytest
from matplotlib.testing.decorators import image_comparison
import matplotlib.pyplot as plt
import matplotlib.patches as mpatches
import matplotlib.lines as mlines
from matplotlib.offsetbox import (
        AnchoredOffsetbox, DrawingArea, _get_packed_offsets)


@image_comparison(baseline_images=['offsetbox_clipping'], remove_text=True)
def test_offsetbox_clipping():
    # - create a plot
    # - put an AnchoredOffsetbox with a child DrawingArea
    #   at the center of the axes
    # - give the DrawingArea a gray background
    # - put a black line across the bounds of the DrawingArea
    # - see that the black line is clipped to the edges of
    #   the DrawingArea.
    fig, ax = plt.subplots()
    size = 100
    da = DrawingArea(size, size, clip=True)
    bg = mpatches.Rectangle((0, 0), size, size,
                            facecolor='#CCCCCC',
                            edgecolor='None',
                            linewidth=0)
    line = mlines.Line2D([-size*.5, size*1.5], [size/2, size/2],
                         color='black',
                         linewidth=10)
    anchored_box = AnchoredOffsetbox(
        loc='center',
        child=da,
        pad=0.,
        frameon=False,
        bbox_to_anchor=(.5, .5),
        bbox_transform=ax.transAxes,
        borderpad=0.)

    da.add_artist(bg)
    da.add_artist(line)
    ax.add_artist(anchored_box)
    ax.set_xlim((0, 1))
    ax.set_ylim((0, 1))


def test_offsetbox_clip_children():
    # - create a plot
    # - put an AnchoredOffsetbox with a child DrawingArea
    #   at the center of the axes
    # - give the DrawingArea a gray background
    # - put a black line across the bounds of the DrawingArea
    # - see that the black line is clipped to the edges of
    #   the DrawingArea.
    fig, ax = plt.subplots()
    size = 100
    da = DrawingArea(size, size, clip=True)
    bg = mpatches.Rectangle((0, 0), size, size,
                            facecolor='#CCCCCC',
                            edgecolor='None',
                            linewidth=0)
    line = mlines.Line2D([-size*.5, size*1.5], [size/2, size/2],
                         color='black',
                         linewidth=10)
    anchored_box = AnchoredOffsetbox(
        loc='center',
        child=da,
        pad=0.,
        frameon=False,
        bbox_to_anchor=(.5, .5),
        bbox_transform=ax.transAxes,
        borderpad=0.)

    da.add_artist(bg)
    da.add_artist(line)
    ax.add_artist(anchored_box)

    fig.canvas.draw()
    assert not fig.stale
    da.clip_children = True
    assert fig.stale


def test_offsetbox_loc_codes():
    # Check that valid string location codes all work with an AnchoredOffsetbox
    codes = {'upper right': 1,
             'upper left': 2,
             'lower left': 3,
             'lower right': 4,
             'right': 5,
             'center left': 6,
             'center right': 7,
             'lower center': 8,
             'upper center': 9,
             'center': 10,
             }
    fig, ax = plt.subplots()
    da = DrawingArea(100, 100)
    for code in codes:
        anchored_box = AnchoredOffsetbox(loc=code, child=da)
        ax.add_artist(anchored_box)
    fig.canvas.draw()


def test_expand_with_tight_layout():
    # Check issue reported in #10476, and updated due to #10784
    fig, ax = plt.subplots()

    d1 = [1, 2]
    d2 = [2, 1]
    ax.plot(d1, label='series 1')
    ax.plot(d2, label='series 2')
    ax.legend(ncol=2, mode='expand')

    fig.tight_layout()  # where the crash used to happen


@pytest.mark.parametrize('wd_list',
                         ([(150, 1)], [(150, 1)]*3, [(0.1, 1)], [(0.1, 1)]*2))
@pytest.mark.parametrize('total', (250, 100, 0, -1, None))
@pytest.mark.parametrize('sep', (250, 1, 0, -1))
@pytest.mark.parametrize('mode', ("expand", "fixed", "equal"))
def test_get_packed_offsets(wd_list, total, sep, mode):
    # Check a (rather arbitrary) set of parameters due to successive similar
    # issue tickets (at least #10476 and #10784) related to corner cases
    # triggered inside this function when calling higher-level functions
    # (e.g. `Axes.legend`).
    _get_packed_offsets(wd_list, total, sep, mode=mode)