#!/usr/bin/env python3

# Copyright (c) 2016 Egor Tensin <Egor.Tensin@gmail.com>
# This file is part of the "Sorting algorithms" project.
# For details, see https://github.com/egor-tensin/sorting-algorithms.
# Distributed under the MIT License.

from array import array
import argparse
import sys

from ..input_kind import InputKind
from .. import registry

_DEFAULT_INPUT_KIND = InputKind.AVERAGE
_DEFAULT_LENGTH = 100


def test(algorithm, input_kind=_DEFAULT_INPUT_KIND, length=_DEFAULT_LENGTH):
    if isinstance(algorithm, str):
        algorithm = registry.get(algorithm)
    xs = algorithm.gen_input(length, input_kind)
    output = algorithm.function(xs)
    if isinstance(output, array):
        output = output.tolist()
    print(output)


def _parse_non_negative_integer(s):
    try:
        n = int(s)
    except ValueError:
        raise argparse.ArgumentTypeError("must be a non-negative integer: " + str(s))
    if n < 0:
        raise argparse.ArgumentTypeError("must be a non-negative integer")
    return n


def _parse_input_kind(s):
    try:
        return InputKind(s)
    except ValueError:
        raise argparse.ArgumentTypeError("invalid input kind: " + str(s))


def _format_algorithm(codename):
    return "* {}: {}".format(codename, registry.get(codename).display_name)


def _format_available_algorithms():
    descr = "available algorithms (in the CODENAME: DISPLAY_NAME format):\n"
    return descr + "\n".join(map(_format_algorithm, sorted(registry.get_codenames())))


def _format_description():
    return _format_available_algorithms()


def _create_argument_parser():
    return argparse.ArgumentParser(
        description=_format_description(),
        formatter_class=argparse.RawDescriptionHelpFormatter,
    )


def _parse_args(args=None):
    if args is None:
        args = sys.argv[1:]
    parser = _create_argument_parser()

    parser.add_argument(
        "algorithm",
        metavar="CODENAME",
        choices=registry.get_codenames(),
        help="algorithm codename",
    )
    parser.add_argument(
        "--input",
        "-i",
        dest="input_kind",
        choices=InputKind,
        type=_parse_input_kind,
        default=_DEFAULT_INPUT_KIND,
        help="specify input kind",
    )
    parser.add_argument(
        "--length",
        "-l",
        "-n",
        metavar="N",
        type=_parse_non_negative_integer,
        default=_DEFAULT_LENGTH,
        help="set input length",
    )

    return parser.parse_args(args)


def main(args=None):
    test(**vars(_parse_args(args)))


if __name__ == "__main__":
    main()