"""
Save results and inspect calculation provenance
===============================================

Save a numerical result and restore it with its physical units, complex
amplitudes, diagnostics, and original calculation settings. The versioned
NumPy archive uses JSON metadata and loads without pickle.

This example uses a temporary directory so running the gallery leaves no
data files behind. For a persistent archive, pass your desired filename to
``result.save(path="scattering.npz")``. Archives contain results rather than the
original input voxel field. Retain manually supplied fields separately;
generated-volume provenance records the medium and seed, with a field hash
to identify the exact input. Exact regeneration depends on software versions.
"""

from bornsim.medium.random_medium import GaussianMedium

from pathlib import Path
from tempfile import TemporaryDirectory

import sys

import matplotlib.pyplot as plt
import numpy as np

from bornsim import Grid, Result, Solver, Source
from bornsim.units import ureg

grid = Grid(
    shape=(4, 4, 4),
    spacing=40 * ureg.nanometer,
)

medium = GaussianMedium(
    correlation_length=80 * ureg.nanometer,
    background_refractive_index=1.33,
    refractive_index_std=0.01,
)

volume = medium.to_volume(
    grid=grid,
    seed=42,
)

source_configuration_1 = Source(wavelength=633 * ureg.nanometer)

solver = Solver(
    source=source_configuration_1,
    order=3,
)

result = solver.solve(target=volume)

with TemporaryDirectory() as directory:
    path = result.save(path=Path(directory) / "scattering.npz")

    restored = Result.load(path=path)

# %%
# Inspect settings and retained amplitudes
# ----------------------------------------
# The arrays have been copied from the archive; they remain usable after the
# temporary directory is removed. Loading preserves the recorded versions.
print(f"BornSim version: {restored.provenance['bornsim_version']}")

print(f"NumPy version: {restored.provenance['numpy_version']}")

print(f"Seed: {restored.provenance['seed']}")

print(f"Grid: {restored.provenance['grid']}")

print(f"Medium: {restored.provenance['medium']}")

print(f"Coefficient scope: {restored.provenance['coefficient_scope']}")

print(f"Wavelength: {restored.source.wavelength.to('nanometer')}")

print(f"Complex amplitudes retained: {np.iscomplexobj(restored.amplitudes.magnitude)}")

# %%
# Plot restored scattering
# ------------------------
# Full angular sampling supplies normalized phase functions and finite-sample
# coefficients. They are not infinite-medium material transport coefficients.
restored.plot()

plt.show()

# %%
# Plot restored field diagnostics
# -------------------------------
# Decreasing field terms do not certify Born convergence.
restored.plot_field_norms()

plt.show()

# %%
# Inspect the medium in 3D
# ------------------------
# Inspect the actual finite input sample with physical spatial axes.
# Drag to rotate and scroll to zoom in the embedded browser view.
# Regions with higher refractive index are more opaque; opacity is not absorption.
medium_figure = volume.plot_3d(
    mode="volume",
    field="refractive_index",
    opacity_scale="increasing",
)

if "--no-browser" not in sys.argv:
    medium_figure.show(renderer="browser")