# Copyright (C) Donald Stufft and individual contributors
# SPDX-License-Identifier: BSD-2-Clause
"""
This file was partially copied from the packaging.version module before the
LegacyVersion class was removed to continue to support version parsing in
a backward-compatible way where PEP 440 support can't be used.

Copyright (c) Donald Stufft and individual contributors.
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

    1. Redistributions of source code must retain the above copyright notice,
       this list of conditions and the following disclaimer.

    2. Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in the
       documentation and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
"""
import re
from typing import Iterator, List, Tuple, Union
from packaging.version import _BaseVersion, Version, InvalidVersion

LegacyCmpKey = Tuple[int, Tuple[str, ...]]


def _parse(version: str) -> Union["_LegacyVersion", "Version"]:
    """
    Parse the given version string and return either a :class:`Version` object
    or a :class:`_LegacyVersion` object depending on if the given version is
    a valid PEP 440 version or a legacy version.
    """
    try:
        return Version(version)
    except InvalidVersion:
        return _LegacyVersion(version)


class _LegacyVersion(_BaseVersion):

    def __init__(self, version: str) -> None:
        self._version = str(version)
        self._key = _legacy_cmpkey(self._version)

    def __str__(self) -> str:
        return self._version

    def __repr__(self) -> str:
        return f"<_LegacyVersion('{self}')>"

    @property
    def public(self) -> str:
        return self._version

    @property
    def base_version(self) -> str:
        return self._version

    @property
    def epoch(self) -> int:
        return -1

    @property
    def release(self) -> None:
        return None

    @property
    def pre(self) -> None:
        return None

    @property
    def post(self) -> None:
        return None

    @property
    def dev(self) -> None:
        return None

    @property
    def local(self) -> None:
        return None

    @property
    def is_prerelease(self) -> bool:
        return False

    @property
    def is_postrelease(self) -> bool:
        return False

    @property
    def is_devrelease(self) -> bool:
        return False


_legacy_version_component_re = re.compile(r"(\d+ | [a-z]+ | \.| -)", re.VERBOSE)

_legacy_version_replacement_map = {
    "pre": "c",
    "preview": "c",
    "-": "final-",
    "rc": "c",
    "dev": "@",
}


def _parse_version_parts(s: str) -> Iterator[str]:
    for part in _legacy_version_component_re.split(s):
        part = _legacy_version_replacement_map.get(part, part)

        if not part or part == ".":
            continue

        if part[:1] in "0123456789":
            # pad for numeric comparison
            yield part.zfill(8)
        else:
            yield "*" + part

    # ensure that alpha/beta/candidate are before final
    yield "*final"


def _legacy_cmpkey(version: str) -> LegacyCmpKey:

    # We hardcode an epoch of -1 here. A PEP 440 version can only have a epoch
    # greater than or equal to 0. This will effectively put the LegacyVersion,
    # which uses the defacto standard originally implemented by setuptools,
    # as before all PEP 440 versions.
    epoch = -1

    # This scheme is taken from pkg_resources.parse_version setuptools prior to
    # it's adoption of the packaging library.
    parts: List[str] = []
    for part in _parse_version_parts(version.lower()):
        if part.startswith("*"):
            # remove "-" before a prerelease tag
            if part < "*final":
                while parts and parts[-1] == "*final-":
                    parts.pop()

            # remove trailing zeros from each series of numeric parts
            while parts and parts[-1] == "00000000":
                parts.pop()

        parts.append(part)

    return epoch, tuple(parts)
