# This code is part of the Ansible collection community.docker, but is an independent component.
# This particular file, and this file only, is based on the Docker SDK for Python (https://github.com/docker/docker-py/)
#
# Copyright (c) 2016-2022 Docker, Inc.
#
# It is licensed under the Apache 2.0 license (see LICENSES/Apache-2.0.txt in this collection)
# SPDX-License-Identifier: Apache-2.0

# Note that this module util is **PRIVATE** to the collection. It can have breaking changes at any time.
# Do not use this from other collections or standalone plugins/modules!

"""Filename matching with shell patterns.

fnmatch(FILENAME, PATTERN) matches according to the local convention.
fnmatchcase(FILENAME, PATTERN) always takes case in account.

The functions operate by translating the pattern into a regular
expression.  They cache the compiled regular expressions for speed.

The function translate(PATTERN) returns a regular expression
corresponding to PATTERN.  (It does not compile it.)
"""

from __future__ import annotations

import re

__all__ = ["fnmatch", "fnmatchcase", "translate"]

_cache: dict[str, re.Pattern] = {}
_MAXCACHE = 100


def _purge() -> None:
    """Clear the pattern cache"""
    _cache.clear()


def fnmatch(name: str, pat: str) -> bool:
    """Test whether FILENAME matches PATTERN.

    Patterns are Unix shell style:

    *       matches everything
    ?       matches any single character
    [seq]   matches any character in seq
    [!seq]  matches any char not in seq

    An initial period in FILENAME is not special.
    Both FILENAME and PATTERN are first case-normalized
    if the operating system requires it.
    If you do not want this, use fnmatchcase(FILENAME, PATTERN).
    """

    name = name.lower()
    pat = pat.lower()
    return fnmatchcase(name, pat)


def fnmatchcase(name: str, pat: str) -> bool:
    """Test whether FILENAME matches PATTERN, including case.
    This is a version of fnmatch() which does not case-normalize
    its arguments.
    """

    try:
        re_pat = _cache[pat]
    except KeyError:
        res = translate(pat)
        if len(_cache) >= _MAXCACHE:
            _cache.clear()
        _cache[pat] = re_pat = re.compile(res)
    return re_pat.match(name) is not None


def translate(pat: str) -> str:
    """Translate a shell PATTERN to a regular expression.

    There is no way to quote meta-characters.
    """
    i, n = 0, len(pat)
    res = "^"
    while i < n:
        c = pat[i]
        i = i + 1
        if c == "*":
            if i < n and pat[i] == "*":
                # is some flavor of "**"
                i = i + 1
                # Treat **/ as ** so eat the "/"
                if i < n and pat[i] == "/":
                    i = i + 1
                if i >= n:
                    # is "**EOF" - to align with .gitignore just accept all
                    res = res + ".*"
                else:
                    # is "**"
                    # Note that this allows for any # of /'s (even 0) because
                    # the .* will eat everything, even /'s
                    res = res + "(.*/)?"
            else:
                # is "*" so map it to anything but "/"
                res = res + "[^/]*"
        elif c == "?":
            # "?" is any char except "/"
            res = res + "[^/]"
        elif c == "[":
            j = i
            if j < n and pat[j] == "!":
                j = j + 1
            if j < n and pat[j] == "]":
                j = j + 1
            while j < n and pat[j] != "]":
                j = j + 1
            if j >= n:
                res = res + "\\["
            else:
                stuff = pat[i:j].replace("\\", "\\\\")
                i = j + 1
                if stuff[0] == "!":
                    stuff = "^" + stuff[1:]
                elif stuff[0] == "^":
                    stuff = "\\" + stuff
                res = f"{res}[{stuff}]"
        else:
            res = res + re.escape(c)

    return res + "$"
