"""
==========
ImageEffects
==========

"""

import matplotlib.cm as cm
import matplotlib.pyplot as plt
import matplotlib.transforms as mtransforms
from matplotlib.colors import LightSource
from matplotlib.artist import Artist
import numpy as np
from matplotlib.patheffects import Normal

from mpl_visual_context.image_effect import (
    AlphaAxb,
    Pad,
    Fill,
    Dilation,
    Gaussian,
    Offset,
    LightSource,
)

from mpl_visual_context.patheffects import StrokeOnly, GCModify, FillColor, ImageEffect
from mpl_visual_context.artist_helper import ArtistListWithPE


def filtered_text(ax):
    # mostly copied from contour_demo.py

    # prepare image
    delta = 0.025
    x = np.arange(-3.0, 3.0, delta)
    y = np.arange(-2.0, 2.0, delta)
    X, Y = np.meshgrid(x, y)
    Z1 = np.exp(-(X**2) - Y**2)
    Z2 = np.exp(-((X - 1) ** 2) - (Y - 1) ** 2)
    Z = (Z1 - Z2) * 2

    # draw
    ax.imshow(
        Z,
        interpolation='bilinear',
        origin='lower',
        cmap=cm.gray,
        extent=(-3, 3, -2, 2),
        aspect='auto',
    )
    levels = np.arange(-1.2, 1.6, 0.2)
    CS = ax.contour(Z, levels, origin='lower', linewidths=2, extent=(-3, 3, -2, 2))

    # contour label
    cl = ax.clabel(
        CS,
        levels[1::2],  # label every second level
        inline=True,
        fmt='%1.1f',
        fontsize=11,
    )

    # change clabel color to black
    from matplotlib.patheffects import Normal

    for t in cl:
        # t.set_color("k")
        # # to force TextPath (i.e., same font in all backends)
        # t.set_path_effects([Normal()])
        iel = Pad(10) | Fill("w") | Dilation(5) | Gaussian(1)
        t.set_path_effects([ImageEffect(iel), FillColor("k")])

    ax.xaxis.set_visible(False)
    ax.yaxis.set_visible(False)


def drop_shadow_line(ax):
    # copied from examples/misc/svg_filter_line.py

    # draw lines
    (l1,) = ax.plot([0.1, 0.5, 0.9], [0.1, 0.9, 0.5], "bo-")
    (l2,) = ax.plot([0.1, 0.5, 0.9], [0.5, 0.2, 0.7], "ro-")

    iel = (
        AlphaAxb((0.3, 0))
        | Pad(10)
        | Fill("k")
        | Dilation(3)
        | Gaussian(3)
        | Offset(3, -5)
    )
    pe = [ImageEffect(iel), Normal()]

    for l in [l1, l2]:
        l.set_path_effects(pe)

    ax.set_xlim(0.0, 1.0)
    ax.set_ylim(0.0, 1.0)

    ax.xaxis.set_visible(False)
    ax.yaxis.set_visible(False)


def drop_shadow_patches(ax):
    # Copied from barchart_demo.py
    N = 5
    group1_means = [20, 35, 30, 35, 27]

    ind = np.arange(N)  # the x locations for the groups
    width = 0.35  # the width of the bars

    rects1 = ax.bar(ind, group1_means, width, color='r', ec="w", lw=2)

    group2_means = [25, 32, 34, 20, 25]
    rects2 = ax.bar(ind + width + 0.1, group2_means, width, color='y', ec="w", lw=2)

    iel = (
        AlphaAxb((0.5, 0))
        | Pad(10)
        | Fill("k")
        | Dilation(3)
        | Gaussian(3)
        | Offset(-3, 3)
    )
    al = ArtistListWithPE(rects1 + rects2, [ImageEffect(iel)])

    al.set_zorder(0.5)
    ax.add_artist(al)

    ax.set_ylim(0, 40)

    ax.xaxis.set_visible(False)
    ax.yaxis.set_visible(False)


def light_filter_pie(ax):
    fracs = [15, 30, 45, 10]
    explode = (0, 0.1, 0, 0)
    pies = ax.pie(fracs, explode=explode)

    light_filter = ImageEffect(LightSource(erosion_size=4, gaussian_size=4))
    for p in pies[0]:
        p.set_path_effects([light_filter])

    shadow = ImageEffect(
        AlphaAxb((0.7, 0))
        | Pad(10)
        | Fill("k")
        | Dilation(3)
        | Gaussian(7)
        | Offset(5, -5)
    )
    al = ArtistListWithPE(pies[0], [shadow])

    al.set_zorder(0.5)
    ax.add_artist(al)


if True:
    # if __name__ == "__main__":

    fix, axs = plt.subplots(2, 2, num=1, clear=True)

    filtered_text(axs[0, 0])
    drop_shadow_line(axs[0, 1])
    drop_shadow_patches(axs[1, 0])
    light_filter_pie(axs[1, 1])
    axs[1, 1].set_frame_on(True)

    plt.show()