#!/usr/bin/env python3

# Copyright (c) 2015 Egor Tensin <egor@tensin.name>
# This file is part of the "Sorting algorithms" project.
# For details, see https://github.com/egor-tensin/sorting-algorithms
# Distributed under the MIT License.

import argparse
import sys

from ..input_kind import InputKind
from ..params import AlgorithmParameters
from .. import registry

_DEFAULT_ITERATIONS = 100
_DEFAULT_INPUT_KIND = InputKind.AVERAGE
_DEFAULT_MIN_LENGTH = 0
_DEFAULT_MAX_LENGTH = 200


def plot_algorithm(
    algorithm,
    input_kind=_DEFAULT_INPUT_KIND,
    min_len=_DEFAULT_MIN_LENGTH,
    max_len=_DEFAULT_MAX_LENGTH,
    iterations=_DEFAULT_ITERATIONS,
    output_path=None,
):

    if isinstance(algorithm, str):
        algorithm = registry.get(algorithm)

    params = AlgorithmParameters(
        algorithm, min_len, max_len, input_kind=input_kind, iterations=iterations
    )
    params.plot_running_time(output_path)


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


def _parse_positive_integer(s):
    try:
        n = int(s)
    except ValueError:
        raise argparse.ArgumentTypeError(f"must be a positive integer: {s}")
    if n < 1:
        raise argparse.ArgumentTypeError("must be a positive integer")
    return n


def _parse_input_kind(s):
    try:
        return InputKind(s)
    except ValueError:
        raise argparse.ArgumentTypeError(f"invalid input kind: {s}")


def _format_algorithm(codename):
    return f"* {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(
        "--iterations",
        "-r",
        metavar="N",
        type=_parse_positive_integer,
        default=_DEFAULT_ITERATIONS,
        help="set number of algorithm iterations",
    )
    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(
        "--min",
        "-a",
        metavar="N",
        dest="min_len",
        type=_parse_non_negative_integer,
        default=_DEFAULT_MIN_LENGTH,
        help="set min input length",
    )
    parser.add_argument(
        "--max",
        "-b",
        metavar="N",
        dest="max_len",
        type=_parse_non_negative_integer,
        default=_DEFAULT_MAX_LENGTH,
        help="set max input length",
    )
    parser.add_argument(
        "--output", "-o", metavar="PATH", dest="output_path", help="set plot file path"
    )

    return parser.parse_args(args)


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


if __name__ == "__main__":
    main()