from argparse import ArgumentParser
from pathlib import Path
from json import load


# Indico raises a warning for every non prefixed local variable, so we add a
# prefix to each import and declared function
PROLOGUE = (
    "import functools as _functools\n"
    "@_functools.cache\n"
    "def _read_file(name):\n"
    "    with open(name) as fd:\n"
    "        return fd.read()\n"
)


def make_value(value):
    match value["_pyType"]:
        case "str" | "int" | "bool" | "null":
            return repr(value["_value"])
        case "list":
            items = [make_value(i) for i in value["_value"]]
            return f"[{','.join(items)}]"
        case "dict":
            items = [
                f"{repr(k)}: {make_value(v)}"
                for k, v in value["_value"].items()
            ]
            return f"{{{','.join(items)}}}"
        case "read-file":
            return f"_read_file({repr(value['_value'])})"
        case _:
            raise ValueError("Unknown data type")


def mk_vars(vars):
    if not all(str.isidentifier(n) for n in vars.keys()):
        raise ValueError("At least one variable identifier is invalid")
    eqs = [f"{n} = {make_value(v)}" for n, v in vars.items()]
    return PROLOGUE + "\n".join(eqs)


def main():
    parser = ArgumentParser()
    parser.add_argument("json", type=Path)

    args = parser.parse_args()

    with args.json.open() as fd:
        print(mk_vars(load(fd)))


if __name__ == "__main__":
    main()