"""Apple //e Double Hi-Res: 140x192, 16 colours (no per-cell limit).

Each line is 560 bits = 140 four-bit colour groups, stored 7 bits per byte with
the bytes interleaved between auxiliary and main memory (aux holds the even display
bytes, main the odd).  Needs a //e (auxiliary memory).
"""

from __future__ import annotations

import numpy as np

from ... import dither, palette as c64pal
from ...convert.base import Conversion, perceptual_error
from .. import palette as apal

WIDTH, HEIGHT = 140, 192
PIXEL_ASPECT = 2.0
DATA_ADDR = 0x2000


def convert(img_rgb, palette_name="dhgr", dither_mode="floyd",
            intensive=False, base_color=None):
    plab = apal.dhgr_lab()
    prgb = apal.DHGR16.astype(np.uint8)
    img_lab = c64pal.srgb_to_lab(img_rgb)              # (192,140,3)

    allowed = np.tile(np.arange(16), (HEIGHT, WIDTH, 1))
    idx = dither.quantize(img_lab, allowed, plab, dither_mode).astype(np.int64)

    aux = bytearray(0x2000)
    main = bytearray(0x2000)
    for y in range(HEIGHT):
        stream = np.zeros(560, dtype=np.uint8)
        row = idx[y]
        for n in range(WIDTH):
            c = int(row[n])
            stream[4 * n + 0] = c & 1
            stream[4 * n + 1] = (c >> 1) & 1
            stream[4 * n + 2] = (c >> 2) & 1
            stream[4 * n + 3] = (c >> 3) & 1
        base = apal.hgr_row_addr(y)
        for col in range(40):
            ab = 0
            mb = 0
            for i in range(7):
                ab |= int(stream[7 * (2 * col) + i]) << i
                mb |= int(stream[7 * (2 * col + 1) + i]) << i
            aux[base + col] = ab
            main[base + col] = mb

    data = bytes(main) + bytes(aux)                    # main half at $2000, aux at $4000
    preview = np.repeat(prgb[idx], int(PIXEL_ASPECT), axis=1)

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