"""
Write a DXF drawing
===================

Round-trip a real 2D drawing through PyVista back out to DXF. The
layer assignment of every cell is preserved on the ``cad.layer``
array.

This example loads a real multi-layer DXF from the ezdxf project
(MIT), with entities on layers ``0``, ``BLUE``, ``RED``, writes it back
to a new DXF, and renders the source and the round-tripped result
side by side so any loss of detail is immediately visible.
"""

# %%

from pathlib import Path
import tempfile

import pyvista as pv

import pyvista_cad
from pyvista_cad.examples import downloads

# %%
# Load the real drawing.

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

# %%
# Write back. ``layer_array='cad.layer'`` is the default; every cell
# returns to its originating layer.

with tempfile.TemporaryDirectory() as tmp:
    out = Path(tmp) / 'roundtrip.dxf'
    src.cad.to_dxf(out)
    rt = pyvista_cad.read_dxf(out)

rt

# %%
# Render side by side so any geometric drift is immediately visible.

pl = pv.Plotter(shape=(1, 2))
pl.subplot(0, 0)
pl.add_mesh(src, color='steelblue', show_edges=True, line_width=2)
pl.view_xy()
pl.subplot(0, 1)
pl.add_mesh(rt, color='indianred', show_edges=True, line_width=2)
pl.view_xy()
pl.link_views()
pl.show()