"""
Read a DXF drawing
==================

DXF is the dominant 2D interchange format: mechanical drawings, PCB
outlines, architectural floor plans. This example loads a real DXF
drawing from the ezdxf project (MIT) whose entities span three named
layers (``0``, ``BLUE``, ``RED``), and shows how every drawable
entity becomes a cell on a single :class:`pyvista.PolyData` with its
originating layer preserved on the ``cad.layer`` cell-data array.

Why this matters: knowing how to inspect DXF layers is the entry point
for any 2D CAM, PCB, or architectural workflow that starts from a DXF.
"""

# %%

import pyvista as pv

import pyvista_cad
from pyvista_cad.examples import downloads

# %%
# Read the real multi-layer drawing.

drawing = pyvista_cad.read_dxf(downloads.dxf_drawing_path())
drawing

# %%
# DXF layer metadata round-trips via the ``.cad`` accessor.

drawing.cad.layers

# %%
# Split the drawing by layer and render each in its own color: the
# typical first move for triaging an unknown DXF.

by_layer = drawing.cad.split_by_layer()
palette = ['steelblue', 'indianred', 'goldenrod', 'mediumseagreen', 'orchid', 'slategray']

pl = pv.Plotter()
for i, (name, block) in enumerate(zip(by_layer.keys(), by_layer)):
    if block is None or block.n_cells == 0:
        continue
    pl.add_mesh(block, color=palette[i % len(palette)], line_width=2, label=str(name))
pl.add_legend()
pl.view_xy()
pl.show()