"""Headless entry point: convert an image, write a disk image and/or a preview PNG."""

from __future__ import annotations

import argparse
import sys

from PIL import Image

from . import imageprep
from .convert import MODES, convert_image, render_preview
from .palette import COLOR_NAMES


def build_parser() -> argparse.ArgumentParser:
    p = argparse.ArgumentParser(prog="c64view", description=__doc__)
    p.add_argument("image", help="source image (png/jpg/gif/bmp/webp)")
    p.add_argument("-o", "--output", help="disk image path (.d64/.d71/.d81)")
    p.add_argument("-m", "--mode", default="auto",
                   choices=["auto", *MODES], help="C64 display mode")
    p.add_argument("-f", "--format", default=None,
                   choices=["d64", "d71", "d81"],
                   help="disk format (default: from -o extension, else d64)")
    p.add_argument("-p", "--palette", default="colodore",
                   choices=["colodore", "pepto"])
    p.add_argument("-d", "--dither", default="bayer",
                   choices=["bayer", "floyd", "atkinson", "stucki", "jarvis", "none"])
    p.add_argument("--mono-base", default="grayscale",
                   choices=["grayscale", *COLOR_NAMES],
                   help="base colour for 'mono' mode (default greyscale)")
    p.add_argument("-a", "--aspect", default="fit",
                   choices=["fit", "fill", "stretch"])
    p.add_argument("--video", default="pal", choices=["pal", "ntsc"],
                   help="target video standard (affects the FLI viewer timing)")
    p.add_argument("--intensive", action="store_true",
                   help="exhaustive background search + slower, higher-quality passes")
    p.add_argument("--brightness", type=float, default=1.0)
    p.add_argument("--contrast", type=float, default=1.0)
    p.add_argument("--saturation", type=float, default=1.0)
    p.add_argument("--gamma", type=float, default=1.0)
    p.add_argument("--preview", help="also write a PNG preview to this path")
    p.add_argument("--disk-name", default=None, help="disk + viewer name (PETSCII)")
    return p


def main(argv=None) -> int:
    args = build_parser().parse_args(argv)
    prep = imageprep.PrepOptions(
        aspect=args.aspect, brightness=args.brightness, contrast=args.contrast,
        saturation=args.saturation, gamma=args.gamma,
    )
    base_color = (None if args.mono_base == "grayscale"
                  else COLOR_NAMES.index(args.mono_base))
    conv = convert_image(args.image, mode=args.mode, palette_name=args.palette,
                         dither_mode=args.dither, intensive=args.intensive,
                         prep_opt=prep, base_color=base_color)
    print(f"mode={conv.mode}  mean dE={conv.error:.2f}  "
          f"data={len(conv.data)}B  extra={[f[0] for f in conv.extra_files]}")

    if args.preview:
        rgb = render_preview(conv, args.palette, scale=2)
        Image.fromarray(rgb, "RGB").save(args.preview)
        print(f"wrote preview {args.preview}")

    if args.output:
        from .exporter import export_disk
        fmt = args.format
        path = export_disk(conv, args.output, disk_format=fmt,
                           disk_name=args.disk_name, source_path=args.image,
                           video=args.video)
        print(f"wrote disk image {path}")

    if not args.output and not args.preview:
        print("nothing to do: pass -o DISK and/or --preview PNG", file=sys.stderr)
        return 1
    return 0


if __name__ == "__main__":
    raise SystemExit(main())