py-include.py

# file: py-include.py
# vim:fileencoding=utf-8:ft=python
#
# Copyright © 2020 R.F. Smith <rsmith@xs4all.nl>.
# SPDX-License-Identifier: MIT
# Created: 2020-03-25T23:20:47+0100
# Last modified: 2020-04-01T20:37:16+0200
"""Program to prepare files for inclusion in Python code."""

import argparse
import base64
import os
import sys
import zlib

__version__ = "2020.04.01"


def main():
    args = setup()
    codec = None
    if args.text:
        codec = "utf-8"
    for path in args.files:
        print(to_include(path, args.compress, codec))


def setup():
    opts = argparse.ArgumentParser(prog="open", description=__doc__)
    opts.add_argument("-v", "--version", action="version", version=__version__)
    opts.add_argument(
        "-c",
        "--compress",
        action="store_true",
        default=False,
        help="compress files before encoding (off by default)",
    )
    opts.add_argument(
        "-t",
        "--text",
        action="store_true",
        default=False,
        help="decode the file into text (off by default)",
    )
    opts.add_argument(
        "files", metavar="file", nargs="*", help="one or more files to process"
    )
    return opts.parse_args(sys.argv[1:])


def to_include(path, compress=False, decode=None):
    """Reads a file and produces an encoded image of the file as Python source code.

    Arguments:
        path (str): Path of the file to process.
        compress (bool): If True, compress the file before encoding.
        decode (str): If not None, de codec for decoding the bytes

    Returns:
        The file as a piece of Python code to reproduce its contents.
    """
    linelen = 74
    with open(path, "rb") as img:
        data = img.read()
    if compress:
        data = zlib.compress(data, level=9)
    data = base64.b85encode(data).decode("ascii")
    i = 0
    lines = ["# " + path]
    if compress:
        lines.append("data = zlib.decompress(base64.b85decode(")
        end = "))"
    else:
        lines.append("data = base64.b85decode(")
        end = ")"
    while i < len(data):
        lines.append("    '" + data[i : i + linelen] + "'")
        i += linelen
    if decode:
        lines.append(end + f'.decode("{decode}")' + os.linesep)
    else:
        lines.append(end + os.linesep)
    return os.linesep.join(lines)


if __name__ == "__main__":
    main()