#!/usr/bin/env python3
# vim:tabstop=4 softtabstop=4 shiftwidth=4 textwidth=160 smarttab expandtab colorcolumn=160
#
# Copyright 2021 Birte Kristina Friesel
#
# SPDX-License-Identifier: BSD-2-Clause

"""deflate - compression utility for zlib-deflate-nostdlib

deflate compresses the input file (or, if the argument is not a filename, the input string) using zlib
and outputs the compressed data in a format suitable for C/C++ files.
"""

import argparse
import sys
import zlib


def main():
    parser = argparse.ArgumentParser(
        formatter_class=argparse.RawDescriptionHelpFormatter, description=__doc__
    )
    parser.add_argument(
        "--variable-name",
        type=str,
        default="inflate_input",
        help="variable name for compressed data",
    )
    parser.add_argument(
        "--data-type",
        type=str,
        default="unsigned char const",
        help="variable type for compressed data",
    )
    parser.add_argument(
        "--size-type",
        type=str,
        default="unsigned short const",
        help="variable type for compressed data size",
    )
    parser.add_argument("--level", type=int, default=-1, help="zlib compression level")
    parser.add_argument(
        "file_or_string", type=str, help="filename or string to compress"
    )
    args = parser.parse_args()

    try:
        with open(args.file_or_string, "rb") as f:
            input_data = f.read()
    except FileNotFoundError:
        input_data = args.file_or_string.encode("utf-8")

    output = zlib.compress(input_data, args.level)

    fdict = output[1] & 0x20
    assert fdict == 0

    print(f"// {args.file_or_string}")
    print(f"{args.size_type} {args.variable_name}_size = {len(output)};")
    print(
        f"{args.data_type} {args.variable_name}[] = {{"
        + ", ".join(map(str, output))
        + "};"
    )


if __name__ == "__main__":
    main()