#!/usr/bin/env python3
# docstring=lists all tools and their docstrings
import argparse
import os
import os.path as path

CFG = {
    "max_lines": 20,
    "offset": 20
}
SCRIPT_PATH = os.path.dirname(os.path.realpath(__file__))


def parse_docstring(file_path, max_lines=CFG["max_lines"]):
    """
    in file `file_path` and from the top until `max_lines` is reached,
    checks if `docstring=` is present.
    """
    with open(file_path, "r") as file_fd:
        count = 0
        while count <= max_lines:
            count += 1

            line = file_fd.readline()
            if "docstring=" in line:
                try:
                    return line.split("=")[1].strip("\n").strip(" ")
                except IndexError:
                    return ""
        return ""


def offset(element, offset=CFG["offset"]):
    """
    calculates the amount of spaces until `offset` is reached for `element` length
    """
    element_length = len(element.strip(""))
    if element_length >= offset:
        return ""
    else:
        return " " * (offset - element_length)


def list_tools():
    """
    lists all tools and their docstring from the same directory this sits in
    """
    list_dir = sorted(os.listdir(SCRIPT_PATH))

    for element in list_dir:
        element_path = path.join(SCRIPT_PATH, element)
        if path.isfile(element_path):
            print(element, end="")
            docstring = parse_docstring(element_path)
            if docstring:
                print(f":{offset(element)}{docstring}", end="")
            print()


def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("-p", "--path", help="output path to tools directory", action="store_true")
    args = ap.parse_args()

    if args.path:
        print(SCRIPT_PATH)
    else:
        list_tools()


if __name__ == "__main__":
    main()