"""Apple II HGR monochrome: 280x192, 1 bit/pixel, black & white.

Universal across the Apple II+ and //e.  Tone is carried entirely by dithering.
"""

from __future__ import annotations

import numpy as np

from ... import dither
from ...convert.base import Conversion, perceptual_error
from .. import palette as apal

WIDTH, HEIGHT = 280, 192
PIXEL_ASPECT = 1.0
DATA_ADDR = 0x2000        # HGR page 1


def convert(img_rgb, palette_name="mono", dither_mode="floyd",
            intensive=False, base_color=None):
    from ...palette import srgb_to_lab
    plab = apal.mono_lab()                      # 2 entries: black, white
    L = srgb_to_lab(img_rgb)[..., 0]
    img_mono = np.zeros((HEIGHT, WIDTH, 3))
    img_mono[..., 0] = L
    plab_mono = np.zeros((2, 3))
    plab_mono[:, 0] = plab[:, 0]

    allowed = np.tile(np.array([0, 1]), (HEIGHT, WIDTH, 1))
    idx = dither.quantize(img_mono, allowed, plab_mono, dither_mode).astype(np.uint8)

    data = apal.pack_hgr_mono(idx)              # 8192-byte HGR buffer
    preview = (apal.MONO.astype(np.uint8))[idx]

    return Conversion(
        mode="hgr_mono", width=WIDTH, height=HEIGHT, pixel_aspect=PIXEL_ASPECT,
        index_image=idx.astype(np.uint16), data=data, data_addr=DATA_ADDR,
        viewer="hgr", preview_rgb=preview,
        error=perceptual_error(idx, img_mono, plab_mono),
        meta={"palette": "mono", "dither": dither_mode},
    )