"""
Voronoi tessellation
====================

This example shows how to combine `iplotx` visualisations with other tools
such as `scipy` and vanilla `matplotlib`. This is one of the key strengths
of `iplotx` over custom visualisations in many other packages: `iplotx`
produces fully compliant matplotlib artists that can be combined with other
matplotlib tools, including `seaborn`.

"""

import igraph as ig
import numpy as np
import matplotlib.pyplot as plt
import iplotx as ipx
from scipy.spatial import Voronoi, voronoi_plot_2d
from scipy.spatial.distance import cdist

# Plot a graph with iplotx
g = ig.Graph.Ring(8, directed=True)
fig, ax = plt.subplots()
art = ipx.plot(
    g,
    ax=ax,
    layout="circle",
    aspect=1,
)[0]

# Add a Voronoi tasselation via scipy
vor = Voronoi(art.get_layout().values)
voronoi_plot_2d(
    vor,
    ax=ax,
    show_points=False,
    show_vertices=False,
    line_colors="tomato",
    line_style="-",
    line_width=2,
)
xmin, xmax = ax.get_xlim()
ymin, ymax = ax.get_ylim()

# Add random points and color them based on Voronoi region
palette = [
    "tomato",
    "steelblue",
    "purple",
    "yellow",
    "deeppink",
    "lawngreen",
    "grey",
    "black",
]
rngpoints = np.random.rand(10000, 2)
rngpoints *= np.array([xmax - xmin, ymax - ymin])
rngpoints += np.array([xmin, ymin])

colors = np.array(palette)[cdist(art.get_layout().values, rngpoints).argmin(axis=0)]
ax.scatter(
    rngpoints[:, 0],
    rngpoints[:, 1],
    c=colors,
    s=20,
    alpha=0.3,
    zorder=0.5,
)