# This file was extracted from the HV SDK Docusaurus examples.
# It is intended as a downloadable, runnable companion to the documentation.
# Set HSI_EXAMPLE_BASE_DIR and related env vars to use your own data.
# Source page: /hsi/hv_sdk/examples/basics#reflectance-calibration

# region: setup
import os
from pathlib import Path

import qtec_hv_sdk as hs
from qtec_hv_sdk.preprocessing import make_reference
from qtec_hv_sdk.preprocessing import reflectance_calibration


BASE_DIR = Path(os.environ.get("HSI_EXAMPLE_BASE_DIR", "/path/to/HSI_data/nuts"))
if not BASE_DIR.exists():
    raise SystemExit(
        "Run: 'export HSI_EXAMPLE_BASE_DIR=/path/to/HSI_data/' to setup the "
        "folder containing the example datacubes."
    )
CUBE = os.environ.get("HSI_EXAMPLE_CUBE", "mix1.pam")
DARK_REF = os.environ.get("HSI_EXAMPLE_DARK_REF", "dark_ref.pam")
WHITE_REF = os.environ.get("HSI_EXAMPLE_WHITE_REF", "white_ref.pam")
# end region

# region: example
cube = hs.open(str(BASE_DIR / CUBE))
dark = hs.open(str(BASE_DIR / DARK_REF))
white = hs.open(str(BASE_DIR / WHITE_REF))

dark_ref = make_reference(dark)
white_ref = make_reference(white)
reflectance = reflectance_calibration(cube, white_ref, dark_ref, clip=True)

band_index = 164
refl_band = reflectance.array_plane(band_index, hs.bands)

print(f"Reflectance band min/max: {refl_band.min():.3f}, {refl_band.max():.3f}")
# end region