rainbowtext

#!/usr/bin/env python3

# rainbowtext: render some rainbow text

import argparse
import itertools
from pathlib import Path
import platform
import shlex
import subprocess

_LIGHT_ROYGBIV = {
    "red": "#FF0000",
    "orange": "#FFA500",
    "yellow": "#FFFF00",
    "green": "#00FF00",
    "blue": "#0000FF",
    "indigo": "#B57EDC",
    "violet": "#EE82EE",
}

_DARK_ROYGBIV = {
    "red": "#AA1100",
    "orange": "#FF4400",
    "yellow": "#FFBB11",
    "green": "#55AA00",
    "blue": "#000055",
    "indigo": "#310062",
    "violet": "#4B0082",
}

_THEME_MAP = {
    "light": _LIGHT_ROYGBIV,
    "dark": _DARK_ROYGBIV,
}


def find_comic_sans() -> str:
    plat = platform.system()
    if plat == "Darwin":
        return "/System/Library/Fonts/Supplemental/Comic Sans MS.ttf"
    else:
        return "Comic-Sans-MS"  # Hope and pray.


def colorchar(args, color, char):
    label = char
    if char.isspace():
        label = f"\\{char}"

    return [
        "(",
        "-fill",
        color,
        f"label:{label}",
        ")",
    ]


if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Render some rainbow text")
    parser.add_argument(
        "-d",
        "--dryrun",
        action="store_true",
        help="Print the ImageMagick command instead of running it",
    )
    parser.add_argument(
        "-f",
        "--font",
        type=str,
        default=find_comic_sans(),
        help="The font to use",
    )
    parser.add_argument(
        "-p",
        "--pointsize",
        type=int,
        default=64,
        help="The point size for the text",
    )
    parser.add_argument(
        "-t",
        "--theme",
        choices=["light", "dark"],
        default="light",
        help="The color theme to use",
    )
    parser.add_argument(
        "input",
        type=str,
        help="The input string to render",
    )
    parser.add_argument(
        "output",
        type=Path,
        help="The filename to write to",
    )
    args = parser.parse_args()

    convert = [
        "magick",
        "convert",
        "-background",
        "none",
        "-font",
        args.font,
        "-pointsize",
        str(args.pointsize),
    ]
    for (color, char) in zip(
        itertools.cycle(_THEME_MAP[args.theme].values()), args.input
    ):
        convert += colorchar(args, color, char)

    convert += ["+append", str(args.output)]

    if args.dryrun:
        print(shlex.join(convert))
    else:
        subprocess.run(convert)