# This file is dual licensed under the terms of the Apache License, Version
# 2.0, and the BSD License. See the LICENSE file in the root of this repository
# for complete details.

import logging
import platform
import struct
import subprocess
import sys
import sysconfig
from importlib.machinery import EXTENSION_SUFFIXES
from typing import (
    Dict,
    FrozenSet,
    Iterable,
    Iterator,
    List,
    Optional,
    Sequence,
    Tuple,
    Union,
    cast,
)

from . import _manylinux, _musllinux

logger = logging.getLogger(__name__)

PythonVersion = Sequence[int]
MacVersion = Tuple[int, int]

INTERPRETER_SHORT_NAMES: Dict[str, str] = {
    "python": "py",  # Generic.
    "cpython": "cp",
    "pypy": "pp",
    "ironpython": "ip",
    "jython": "jy",
}


_32_BIT_INTERPRETER = struct.calcsize("P") == 4


class Tag:
    """
    A representation of the tag triple for a wheel.

    Instances are considered immutable and thus are hashable. Equality checking
    is also supported.
    """

    __slots__ = ["_interpreter", "_abi", "_platform", "_hash"]

    def __init__(self, interpreter: str, abi: str, platform: str) -> None:
        self._interpreter = interpreter.lower()
        self._abi = abi.lower()
        self._platform = platform.lower()
        # The __hash__ of every single element in a Set[Tag] will be evaluated each time
        # that a set calls its `.disjoint()` method, which may be called hundreds of
        # times when scanning a page of links for packages with tags matching that
        # Set[Tag]. Pre-computing the value here produces significant speedups for
        # downstream consumers.
        self._hash = hash((self._interpreter, self._abi, self._platform))

    @property
    def interpreter(self) -> str:
        return self._interpreter

    @property
    def abi(self) -> str:
        return self._abi

    @property
    def platform(self) -> str:
        return self._platform

    def __eq__(self, other: object) -> bool:
        if not isinstance(other, Tag):
            return NotImplemented

        return (
            (self._hash == other._hash)  # Short-circuit ASAP for perf reasons.
            and (self._platform == other._platform)
            and (self._abi == other._abi)
            and (self._interpreter == other._interpreter)
        )

    def __hash__(self) -> int:
        return self._hash

    def __str__(self) -> str:
        return f"{self._interpreter}-{self._abi}-{self._platform}"

    def __repr__(self) -> str:
        return f"<{self} @ {id(self)}>"


def parse_tag(tag: str) -> FrozenSet[Tag]:
    """
    Parses the provided tag (e.g. `py3-none-any`) into a frozenset of Tag instances.

    Returning a set is required due to the possibility that the tag is a
    compressed tag set.
    """
    tags = set()
    interpreters, abis, platforms = tag.split("-")
    for interpreter in interpreters.split("."):
        for abi in abis.split("."):
            for platform_ in platforms.split("."):
                tags.add(Tag(interpreter, abi, platform_))
    return frozenset(tags)


def _get_config_var(name: str, warn: bool = False) -> Union[int, str, None]:
    value: Union[int, str, None] = sysconfig.get_config_var(name)
    if value is None and warn:
        logger.debug(
            "Config variable '%s' is unset, Python ABI tag may be incorrect", name
        )
    return value


def _normalize_string(string: str) -> str:
    return string.replace(".", "_").replace("-", "_").replace(" ", "_")


def _abi3_applies(python_version: PythonVersion) -> bool:
    """
    Determine if the Python version supports abi3.
    """
    return len(python_version) > 1


def _cpython_abis(py_version: PythonVersion, warn: bool = False) -> List[str]:
    py_version = tuple(py_version)  # To allow for version comparison.
    abis = []
    version = _version_nodot(py_version[:2])
    debug = pymalloc = ucs4 = ""
    with_debug = _get_config_var("Py_DEBUG", warn)
    has_refcount = hasattr(sys, "gettotalrefcount")
    # Windows doesn't set Py_DEBUG, so checking for support of debug-compiled
    # extension modules is the best option.
    # https://github.com/pypa/pip/issues/3383#issuecomment-173267692
    has_ext = "_d.pyd" in EXTENSION_SUFFIXES
    if with_debug or (with_debug is None and (has_refcount or has_ext)):
        debug = "d"
    if debug:
        # Debug builds can also load "normal" extension modules.
        # We can also assume no UCS-4 or pymalloc requirement.
        abis.append(f"cp{version}")
    abis.insert(
        0,
        "cp{version}{debug}{pymalloc}{ucs4}".format(
            version=version, debug=debug, pymalloc=pymalloc, ucs4=ucs4
        ),
    )
    return abis


def cpython_tags(
    python_version: Optional[PythonVersion] = None,
    abis: Optional[Iterable[str]] = None,
    platforms: Optional[Iterable[str]] = None,
    *,
    warn: bool = False,
) -> Iterator[Tag]:
    """
    Yields the tags for a CPython interpreter.

    The tags consist of:
    - cp<python_version>-<abi>-<platform>
    - cp<python_version>-abi3-<platform>
    - cp<python_version>-none-<platform>
    - cp<less than python_version>-abi3-<platform>  # Older Python versions down to 3.2.

    If python_version only specifies a major version then user-provided ABIs and
    the 'none' ABItag will be used.

    If 'abi3' or 'none' are specified in 'abis' then they will be yielded at
    their normal position and not at the beginning.
    """
    if not python_version:
        python_version = sys.version_info[:2]

    interpreter = f"cp{_version_nodot(python_version[:2])}"

    if abis is None:
        if len(python_version) > 1:
            abis = _cpython_abis(python_version, warn)
        else:
            abis = []
    abis = list(abis)
    # 'abi3' and 'none' are explicitly handled later.
    for explicit_abi in ("abi3", "none"):
        try:
            abis.remove(explicit_abi)
        except ValueError:
            pass

    platforms = list(platforms or platform_tags())
    for abi in abis:
        for platform_ in platforms:
            yield Tag(interpreter, abi, platform_)
    if _abi3_applies(python_version):
        yield from (Tag(interpreter, "abi3", platform_) for platform_ in platforms)
    yield from (Tag(interpreter, "none", platform_) for platform_ in platforms)

    if _abi3_applies(python_version):
        for minor_version in range(python_version[1] - 1, 1, -1):
            for platform_ in platforms:
                interpreter = "cp{version}".format(
                    version=_version_nodot((python_version[0], minor_version))
                )
                yield Tag(interpreter, "abi3", platform_)


def _generic_abi() -> List[str]:
    """
    Return the ABI tag based on EXT_SUFFIX.
    """
    # The following are examples of `EXT_SUFFIX`.
    # We want to keep the parts which are related to the ABI and remove the
    # parts which are related to the platform:
    # - linux:   '.cpython-310-x86_64-linux-gnu.so' => cp310
    # - mac:     '.cpython-310-darwin.so'           => cp310
    # - win:     '.cp310-win_amd64.pyd'             => cp310
    # - win:     '.pyd'                             => cp37 (uses _cpython_abis())
    # - pypy:    '.pypy38-pp73-x86_64-linux-gnu.so' => pypy38_pp73
    # - graalpy: '.graalpy-38-native-x86_64-darwin.dylib'
    #                                               => graalpy_38_native

    ext_suffix = _get_config_var("EXT_SUFFIX", warn=True)
    if not isinstance(ext_suffix, str) or ext_suffix[0] != ".":
        raise SystemError("invalid sysconfig.get_config_var('EXT_SUFFIX')")
    parts = ext_suffix.split(".")
    if len(parts) < 3:
        # CPython3.7 and earlier uses ".pyd" on Windows.
        return _cpython_abis(sys.version_info[:2])
    soabi = parts[1]
    if soabi.startswith("cpython"):
        # non-windows
        abi = "cp" + soabi.split("-")[1]
    elif soabi.startswith("cp"):
        # windows
        abi = soabi.split("-")[0]
    elif soabi.startswith("pypy"):
        abi = "-".join(soabi.split("-")[:2])
    elif soabi.startswith("graalpy"):
        abi = "-".join(soabi.split("-")[:3])
    elif soabi:
        # pyston, ironpython, others?
        abi = soabi
    else:
        return []
    return [_normalize_string(abi)]


def generic_tags(
    interpreter: Optional[str] = None,
    abis: Optional[Iterable[str]] = None,
    platforms: Optional[Iterable[str]] = None,
    *,
    warn: bool = False,
) -> Iterator[Tag]:
    """
    Yields the tags for a generic interpreter.

    The tags consist of:
    - <interpreter>-<abi>-<platform>

    The "none" ABI will be added if it was not explicitly provided.
    """
    if not interpreter:
        interp_name = interpreter_name()
        interp_version = interpreter_version(warn=warn)
        interpreter = "".join([interp_name, interp_version])
    if abis is None:
        abis = _generic_abi()
    else:
        abis = list(abis)
    platforms = list(platforms or platform_tags())
    if "none" not in abis:
        abis.append("none")
    for abi in abis:
        for platform_ in platforms:
            yield Tag(interpreter, abi, platform_)


def _py_interpreter_range(py_version: PythonVersion) -> Iterator[str]:
    """
    Yields Python versions in descending order.

    After the latest version, the major-only version will be yielded, and then
    all previous versions of that major version.
    """
    if len(py_version) > 1:
        yield f"py{_version_nodot(py_version[:2])}"
    yield f"py{py_version[0]}"
    if len(py_version) > 1:
        for minor in range(py_version[1] - 1, -1, -1):
            yield f"py{_version_nodot((py_version[0], minor))}"


def compatible_tags(
    python_version: Optional[PythonVersion] = None,
    interpreter: Optional[str] = None,
    platforms: Optional[Iterable[str]] = None,
) -> Iterator[Tag]:
    """
    Yields the sequence of tags that are compatible with a specific version of Python.

    The tags consist of:
    - py*-none-<platform>
    - <interpreter>-none-any  # ... if `interpreter` is provided.
    - py*-none-any
    """
    if not python_version:
        python_version = sys.version_info[:2]
    platforms = list(platforms or platform_tags())
    for version in _py_interpreter_range(python_version):
        for platform_ in platforms:
            yield Tag(version, "none", platform_)
    if interpreter:
        yield Tag(interpreter, "none", "any")
    for version in _py_interpreter_range(python_version):
        yield Tag(version, "none", "any")


def _mac_arch(arch: str, is_32bit: bool = _32_BIT_INTERPRETER) -> str:
    if not is_32bit:
        return arch

    if arch.startswith("ppc"):
        return "ppc"

    return "i386"


def _mac_binary_formats(version: MacVersion, cpu_arch: str) -> List[str]:
    formats = [cpu_arch]
    if cpu_arch == "x86_64":
        if version < (10, 4):
            return []
        formats.extend(["intel", "fat64", "fat32"])

    elif cpu_arch == "i386":
        if version < (10, 4):
            return []
        formats.extend(["intel", "fat32", "fat"])

    elif cpu_arch == "ppc64":
        # TODO: Need to care about 32-bit PPC for ppc64 through 10.2?
        if version > (10, 5) or version < (10, 4):
            return []
        formats.append("fat64")

    elif cpu_arch == "ppc":
        if version > (10, 6):
            return []
        formats.extend(["fat32", "fat"])

    if cpu_arch in {"arm64", "x86_64"}:
        formats.append("universal2")

    if cpu_arch in {"x86_64", "i386", "ppc64", "ppc", "intel"}:
        formats.append("universal")

    return formats


def mac_platforms(
    version: Optional[MacVersion] = None, arch: Optional[str] = None
) -> Iterator[str]:
    """
    Yields the platform tags for a macOS system.

    The `version` parameter is a two-item tuple specifying the macOS version to
    generate platform tags for. The `arch` parameter is the CPU architecture to
    generate platform tags for. Both parameters default to the appropriate value
    for the current system.
    """
    version_str, _, cpu_arch = platform.mac_ver()
    if version is None:
        version = cast("MacVersion", tuple(map(int, version_str.split(".")[:2])))
        if version == (10, 16):
            # When built against an older macOS SDK, Python will report macOS 10.16
            # instead of the real version.
            version_str = subprocess.run(
                [
                    sys.executable,
                    "-sS",
                    "-c",
                    "import platform; print(platform.mac_ver()[0])",
                ],
                check=True,
                env={"SYSTEM_VERSION_COMPAT": "0"},
                stdout=subprocess.PIPE,
                text=True,
            ).stdout
            version = cast("MacVersion", tuple(map(int, version_str.split(".")[:2])))
    else:
        version = version
    if arch is None:
        arch = _mac_arch(cpu_arch)
    else:
        arch = arch

    if (10, 0) <= version and version < (11, 0):
        # Prior to Mac OS 11, each yearly release of Mac OS bumped the
        # "minor" version number.  The major version was always 10.
        for minor_version in range(version[1], -1, -1):
            compat_version = 10, minor_version
            binary_formats = _mac_binary_formats(compat_version, arch)
            for binary_format in binary_formats:
                yield "macosx_{major}_{minor}_{binary_format}".format(
                    major=10, minor=minor_version, binary_format=binary_format
                )

    if version >= (11, 0):
        # Starting with Mac OS 11, each yearly release bumps the major version
        # number.   The minor versions are now the midyear updates.
        for major_version in range(version[0], 10, -1):
            compat_version = major_version, 0
            binary_formats = _mac_binary_formats(compat_version, arch)
            for binary_format in binary_formats:
                yield "macosx_{major}_{minor}_{binary_format}".format(
                    major=major_version, minor=0, binary_format=binary_format
                )

    if version >= (11, 0):
        # Mac OS 11 on x86_64 is compatible with binaries from previous releases.
        # Arm64 support was introduced in 11.0, so no Arm binaries from previous
        # releases exist.
        #
        # However, the "universal2" binary format can have a
        # macOS version earlier than 11.0 when the x86_64 part of the binary supports
        # that version of macOS.
        if arch == "x86_64":
            for minor_version in range(16, 3, -1):
                compat_version = 10, minor_version
                binary_formats = _mac_binary_formats(compat_version, arch)
                for binary_format in binary_formats:
                    yield "macosx_{major}_{minor}_{binary_format}".format(
                        major=compat_version[0],
                        minor=compat_version[1],
                        binary_format=binary_format,
                    )
        else:
            for minor_version in range(16, 3, -1):
                compat_version = 10, minor_version
                binary_format = "universal2"
                yield "macosx_{major}_{minor}_{binary_format}".format(
                    major=compat_version[0],
                    minor=compat_version[1],
                    binary_format=binary_format,
                )


def _linux_platforms(is_32bit: bool = _32_BIT_INTERPRETER) -> Iterator[str]:
    linux = _normalize_string(sysconfig.get_platform())
    if not linux.startswith("linux_"):
        # we should never be here, just yield the sysconfig one and return
        yield linux
        return
    if is_32bit:
        if linux == "linux_x86_64":
            linux = "linux_i686"
        elif linux == "linux_aarch64":
            linux = "linux_armv8l"
    _, arch = linux.split("_", 1)
    archs = {"armv8l": ["armv8l", "armv7l"]}.get(arch, [arch])
    yield from _manylinux.platform_tags(archs)
    yield from _musllinux.platform_tags(archs)
    for arch in archs:
        yield f"linux_{arch}"


def _generic_platforms() -> Iterator[str]:
    yield _normalize_string(sysconfig.get_platform())


def platform_tags() -> Iterator[str]:
    """
    Provides the platform tags for this installation.
    """
    if platform.system() == "Darwin":
        return mac_platforms()
    elif platform.system() == "Linux":
        return _linux_platforms()
    else:
        return _generic_platforms()


def interpreter_name() -> str:
    """
    Returns the name of the running interpreter.

    Some implementations have a reserved, two-letter abbreviation which will
    be returned when appropriate.
    """
    name = sys.implementation.name
    return INTERPRETER_SHORT_NAMES.get(name) or name


def interpreter_version(*, warn: bool = False) -> str:
    """
    Returns the version of the running interpreter.
    """
    version = _get_config_var("py_version_nodot", warn=warn)
    if version:
        version = str(version)
    else:
        version = _version_nodot(sys.version_info[:2])
    return version


def _version_nodot(version: PythonVersion) -> str:
    return "".join(map(str, version))


def sys_tags(*, warn: bool = False) -> Iterator[Tag]:
    """
    Returns the sequence of tag triples for the running interpreter.

    The order of the sequence corresponds to priority order for the
    interpreter, from most to least important.
    """

    interp_name = interpreter_name()
    if interp_name == "cp":
        yield from cpython_tags(warn=warn)
    else:
        yield from generic_tags()

    if interp_name == "pp":
        interp = "pp3"
    elif interp_name == "cp":
        interp = "cp" + interpreter_version(warn=warn)
    else:
        interp = None
    yield from compatible_tags(interpreter=interp)
