import argparse
import pathlib
import subprocess
import sys
import tempfile
from typing import NoReturn

from PIL import Image

GREEN = (0, 255, 0)
RED = (255, 0, 0)


def abort(msg: str) -> NoReturn:
    print(msg, file=sys.stderr)
    sys.exit(1)


def generate_coll_map(in_path: pathlib.Path, width: int, height: int) -> str:
    png = Image.open(in_path).convert("RGB")
    if png.width % 8 != 0 or png.height % 8 != 0:
        abort(f"file '{in_path}' has invalid dimensions (should be multiple of 8)")

    if png.width // 8 != width or png.height // 8 != height:
        abort(f"file '{in_path}' has different size from map")

    out_bytes = []
    bits = []

    for y in range(png.height // 8):
        for x in range(png.width // 8):
            pixel = png.getpixel((x * 8, y * 8))

            bit = None
            if pixel == RED:
                bit = 1
            elif pixel == GREEN:
                bit = 0
            else:
                abort(f"unsupported pixel in collision map: {pixel}")

            bits.append(bit)
            if len(bits) == 8:
                byte = sum([bit << i for i, bit in enumerate(bits)])
                out_bytes.append(byte)
                bits = []

    png.close()

    lines = []
    for line_no in range(0, len(out_bytes), 16):
        line = out_bytes[line_no : line_no + 16]
        lines.append("    DB " + ", ".join(["$%02X" % b for b in line]))

    return "\n".join(lines)


def format_bytes(data: bytes) -> str:
    lines = []
    for line_no in range(0, len(data), 16):
        line = data[line_no : line_no + 16]
        lines.append("    DB " + ", ".join(["$%02X" % b for b in line]))
    return "\n".join(lines)


def generate_map(pngfile: str) -> None:
    pngpath = pathlib.Path(pngfile).resolve()
    incpath = pngpath.parent / pngpath.name.replace(".png", ".inc")
    spath = pngpath.parent / pngpath.name.replace(".png", ".s")

    png = Image.open(pngpath)
    if png.width % 8 != 0 or png.height % 8 != 0:
        abort(f"file '{pngfile}' has invalid dimensions (should be multiple of 8)")

    width = png.width // 8
    height = png.height // 8

    png.close()

    with tempfile.NamedTemporaryFile() as tilef, tempfile.NamedTemporaryFile() as mapf:
        subprocess.run(
            [
                "rgbgfx",
                "-u",
                "-t",
                tilef.name,
                "-o",
                mapf.name,
                pngfile,
            ]
        )

        map_data = format_bytes(tilef.read())
        tile_data = format_bytes(mapf.read())

    section = pngpath.name.replace(".png", "")

    collpath = pngpath.parent / pngpath.name.replace(".png", "_coll.png")
    coll_map = generate_coll_map(collpath, width, height)

    with open(incpath, "w") as outf:
        outf.write(
            f"""DEF {section}_WIDTH  EQU {width}
DEF {section}_HEIGHT EQU {height}

DEF {section}_NUM_TILES EQUS "({section}_TILES_end - {section}_TILES)"
DEF {section}_MAP_SIZE EQUS "({section}_MAP_end - {section}_MAP)"

ASSERT {section}_MAP_SIZE == {section}_WIDTH * {section}_HEIGHT
"""
        )

    with open(spath, "w") as outf:
        outf.write(
            f"""SECTION "MAP - {section}", ROMX

{section}_MAP::
{map_data}
{section}_MAP_end::

{section}_TILES::
{tile_data}
{section}_TILES_end::

{section}_COLLISION::
{coll_map}
{section}_COLLISION_end::
"""
        )


def main() -> None:
    parser = argparse.ArgumentParser("generate_map")
    parser.add_argument("png")
    args = parser.parse_args()
    generate_map(args.png)


if __name__ == "__main__":
    main()