"""Generate and work with PEP 425 Compatibility Tags."""

from __future__ import annotations

import re
from typing import TYPE_CHECKING

from packaging.tags import (
    compatible_tags,
    cpython_tags,
    generic_tags,
    interpreter_name,
    interpreter_version,
    mac_platforms,
)

if TYPE_CHECKING:
    from packaging.tags import PythonVersion, Tag

_osx_arch_pat = re.compile(r"(.+)_(\d+)_(\d+)_(.+)")


def version_info_to_nodot(version_info: tuple[int, ...]) -> str:
    # Only use up to the first two numbers.
    return "".join(map(str, version_info[:2]))


def _mac_platforms(arch: str) -> list[str]:
    match = _osx_arch_pat.match(arch)
    if match:
        name, major, minor, actual_arch = match.groups()
        mac_version = (int(major), int(minor))
        arches = [
            # Since we have always only checked that the platform starts
            # with "macosx", for backwards-compatibility we extract the
            # actual prefix provided by the user in case they provided
            # something like "macosxcustom_". It may be good to remove
            # this as undocumented or deprecate it in the future.
            "{}_{}".format(name, arch[len("macosx_") :])
            for arch in mac_platforms(mac_version, actual_arch)
        ]
    else:
        # arch pattern didn't match (?!)
        arches = [arch]
    return arches


def _custom_manylinux_platforms(arch: str) -> list[str]:
    arches = [arch]
    arch_prefix, arch_sep, arch_suffix = arch.partition("_")
    if arch_prefix == "manylinux2014":
        # manylinux1/manylinux2010 wheels run on most manylinux2014 systems
        # with the exception of wheels depending on ncurses. PEP 599 states
        # manylinux1/manylinux2010 wheels should be considered
        # manylinux2014 wheels:
        # https://www.python.org/dev/peps/pep-0599/#backwards-compatibility-with-manylinux2010-wheels
        if arch_suffix in {"i686", "x86_64"}:
            arches.append("manylinux2010" + arch_sep + arch_suffix)
            arches.append("manylinux1" + arch_sep + arch_suffix)
    elif arch_prefix == "manylinux2010":
        # manylinux1 wheels run on most manylinux2010 systems with the
        # exception of wheels depending on ncurses. PEP 571 states
        # manylinux1 wheels should be considered manylinux2010 wheels:
        # https://www.python.org/dev/peps/pep-0571/#backwards-compatibility-with-manylinux1-wheels
        arches.append("manylinux1" + arch_sep + arch_suffix)
    return arches


def _get_custom_platforms(arch: str) -> list[str]:
    arch_prefix, *_ = arch.partition("_")
    if arch.startswith("macosx"):
        arches = _mac_platforms(arch)
    elif arch_prefix in ["manylinux2014", "manylinux2010"]:
        arches = _custom_manylinux_platforms(arch)
    else:
        arches = [arch]
    return arches


def _expand_allowed_platforms(platforms: list[str] | None) -> list[str] | None:
    if not platforms:
        return None

    seen = set()
    result = []

    for p in platforms:
        if p in seen:
            continue
        additions = [c for c in _get_custom_platforms(p) if c not in seen]
        seen.update(additions)
        result.extend(additions)

    return result


def _get_python_version(version: str) -> PythonVersion:
    if len(version) > 1:
        return int(version[0]), int(version[1:])
    else:
        return (int(version[0]),)


def _get_custom_interpreter(
    implementation: str | None = None, version: str | None = None
) -> str:
    if implementation is None:
        implementation = interpreter_name()
    if version is None:
        version = interpreter_version()
    return f"{implementation}{version}"


def get_supported(
    version: str | None = None,
    platforms: list[str] | None = None,
    impl: str | None = None,
    abis: list[str] | None = None,
) -> list[Tag]:
    """Return a list of supported tags for each version specified in
    `versions`.

    :param version: a string version, of the form "33" or "32",
        or None. The version will be assumed to support our ABI.
    :param platform: specify a list of platforms you want valid
        tags for, or None. If None, use the local system platform.
    :param impl: specify the exact implementation you want valid
        tags for, or None. If None, use the local interpreter impl.
    :param abis: specify a list of abis you want valid
        tags for, or None. If None, use the local interpreter abi.
    """
    supported: list[Tag] = []

    python_version: PythonVersion | None = None
    if version is not None:
        python_version = _get_python_version(version)

    interpreter = _get_custom_interpreter(impl, version)

    platforms = _expand_allowed_platforms(platforms)

    is_cpython = (impl or interpreter_name()) == "cp"
    if is_cpython:
        supported.extend(
            cpython_tags(
                python_version=python_version,
                abis=abis,
                platforms=platforms,
            )
        )
    else:
        supported.extend(
            generic_tags(
                interpreter=interpreter,
                abis=abis,
                platforms=platforms,
            )
        )
    supported.extend(
        compatible_tags(
            python_version=python_version,
            interpreter=interpreter,
            platforms=platforms,
        )
    )

    return supported
