"""SMS background image: 256x192, 2 palettes of 16 (of 64), <=512 tiles."""
from __future__ import annotations

from ...convert.base import Conversion
from . import _common

WIDTH, HEIGHT = 256, 192
PIXEL_ASPECT = 1.0          # 256x192 is exactly 4:3 -> square pixels


def convert(img_rgb, palette_name="sms", dither_mode="floyd",
            intensive=False, base_color=None):
    pat, nt, pal, preview, err = _common.encode(img_rgb, dither_mode, mono=False)
    return Conversion(
        mode="bg", width=WIDTH, height=HEIGHT, pixel_aspect=PIXEL_ASPECT,
        index_image=None, data={"patterns": pat, "nametable": nt, "palette": pal},
        data_addr=0, viewer="sms", preview_rgb=preview, error=err,
        meta={"palette": "sms", "dither": dither_mode},
    )