# -*- coding=utf-8 -*-

import logging
import operator
import os
import platform
import sys
from collections import defaultdict

import attr
from packaging.version import Version

from ..compat import Path, lru_cache
from ..environment import ASDF_DATA_DIR, MYPY_RUNNING, PYENV_ROOT, SYSTEM_ARCH
from ..exceptions import InvalidPythonVersion
from ..utils import (
    RE_MATCHER,
    _filter_none,
    ensure_path,
    expand_paths,
    get_python_version,
    guess_company,
    is_in_path,
    looks_like_python,
    optional_instance_of,
    parse_asdf_version_order,
    parse_pyenv_version_order,
    parse_python_version,
    path_is_pythoncore,
    unnest,
)
from .mixins import BaseFinder, BasePath

if MYPY_RUNNING:
    from typing import (
        Any,
        Callable,
        DefaultDict,
        Dict,
        Generator,
        Iterator,
        List,
        Optional,
        Tuple,
        Type,
        TypeVar,
        Union,
        overload,
    )

    from .._vendor.pep514tools.environment import Environment
    from .path import PathEntry
else:

    def overload(f):
        return f


logger = logging.getLogger(__name__)


@attr.s(slots=True)
class PythonFinder(BasePath, BaseFinder):
    root = attr.ib(default=None, validator=optional_instance_of(Path), type=Path)
    # should come before versions, because its value is used in versions's default initializer.
    #: Whether to ignore any paths which raise exceptions and are not actually python
    ignore_unsupported = attr.ib(default=True, type=bool)
    #: Glob path for python versions off of the root directory
    version_glob_path = attr.ib(default="versions/*", type=str)
    #: The function to use to sort version order when returning an ordered version set
    sort_function = attr.ib(default=None)  # type: Callable
    #: The root locations used for discovery
    roots = attr.ib(default=attr.Factory(defaultdict), type=defaultdict)
    #: List of paths discovered during search
    paths = attr.ib(type=list)
    #: shim directory
    shim_dir = attr.ib(default="shims", type=str)
    #: Versions discovered in the specified paths
    _versions = attr.ib(default=attr.Factory(defaultdict), type=defaultdict)
    _pythons = attr.ib(default=attr.Factory(defaultdict), type=defaultdict)

    def __del__(self):
        # type: () -> None
        self._versions = defaultdict()
        self._pythons = defaultdict()
        self.roots = defaultdict()
        self.paths = []

    @property
    def expanded_paths(self):
        # type: () -> Generator
        return (
            path for path in unnest(p for p in self.versions.values()) if path is not None
        )

    @property
    def is_pyenv(self):
        # type: () -> bool
        return is_in_path(str(self.root), PYENV_ROOT)

    @property
    def is_asdf(self):
        # type: () -> bool
        return is_in_path(str(self.root), ASDF_DATA_DIR)

    def get_version_order(self):
        # type: () -> List[Path]
        version_paths = [
            p
            for p in self.root.glob(self.version_glob_path)
            if not (p.parent.name == "envs" or p.name == "envs")
        ]
        versions = {v.name: v for v in version_paths}
        version_order = []  # type: List[Path]
        if self.is_pyenv:
            version_order = [
                versions[v] for v in parse_pyenv_version_order() if v in versions
            ]
        elif self.is_asdf:
            version_order = [
                versions[v] for v in parse_asdf_version_order() if v in versions
            ]
        for version in version_order:
            if version in version_paths:
                version_paths.remove(version)
        if version_order:
            version_order += version_paths
        else:
            version_order = version_paths
        return version_order

    def get_bin_dir(self, base):
        # type: (Union[Path, str]) -> Path
        if isinstance(base, str):
            base = Path(base)
        if os.name == "nt":
            return base
        return base / "bin"

    @classmethod
    def version_from_bin_dir(cls, entry):
        # type: (PathEntry) -> Optional[PathEntry]
        py_version = None
        py_version = next(iter(entry.find_all_python_versions()), None)
        return py_version

    def _iter_version_bases(self):
        # type: () -> Iterator[Tuple[Path, PathEntry]]
        from .path import PathEntry

        for p in self.get_version_order():
            bin_dir = self.get_bin_dir(p)
            if bin_dir.exists() and bin_dir.is_dir():
                entry = PathEntry.create(
                    path=bin_dir.absolute(), only_python=False, name=p.name, is_root=True
                )
                self.roots[p] = entry
                yield (p, entry)

    def _iter_versions(self):
        # type: () -> Iterator[Tuple[Path, PathEntry, Tuple]]
        for base_path, entry in self._iter_version_bases():
            version = None
            version_entry = None
            try:
                version = PythonVersion.parse(entry.name)
            except (ValueError, InvalidPythonVersion):
                version_entry = next(iter(entry.find_all_python_versions()), None)
                if version is None:
                    if not self.ignore_unsupported:
                        raise
                    continue
                if version_entry is not None:
                    version = version_entry.py_version.as_dict()
            except Exception:
                if not self.ignore_unsupported:
                    raise
                logger.warning(
                    "Unsupported Python version %r, ignoring...",
                    base_path.name,
                    exc_info=True,
                )
                continue
            if version is not None:
                version_tuple = (
                    version.get("major"),
                    version.get("minor"),
                    version.get("patch"),
                    version.get("is_prerelease"),
                    version.get("is_devrelease"),
                    version.get("is_debug"),
                )
                yield (base_path, entry, version_tuple)

    @property
    def versions(self):
        # type: () -> DefaultDict[Tuple, PathEntry]
        if not self._versions:
            for _, entry, version_tuple in self._iter_versions():
                self._versions[version_tuple] = entry
        return self._versions

    def _iter_pythons(self):
        # type: () -> Iterator
        for path, entry, version_tuple in self._iter_versions():
            if path.as_posix() in self._pythons:
                yield self._pythons[path.as_posix()]
            elif version_tuple not in self.versions:
                for python in entry.find_all_python_versions():
                    yield python
            else:
                yield self.versions[version_tuple]

    @paths.default
    def get_paths(self):
        # type: () -> List[PathEntry]
        _paths = [base for _, base in self._iter_version_bases()]
        return _paths

    @property
    def pythons(self):
        # type: () -> DefaultDict[str, PathEntry]
        if not self._pythons:
            from .path import PathEntry

            self._pythons = defaultdict(PathEntry)  # type: DefaultDict[str, PathEntry]
            for python in self._iter_pythons():
                python_path = python.path.as_posix()  # type: ignore
                self._pythons[python_path] = python
        return self._pythons

    @pythons.setter
    def pythons(self, value):
        # type: (DefaultDict[str, PathEntry]) -> None
        self._pythons = value

    def get_pythons(self):
        # type: () -> DefaultDict[str, PathEntry]
        return self.pythons

    @overload
    @classmethod
    def create(cls, root, sort_function, version_glob_path=None, ignore_unsupported=True):
        # type: (str, Callable, Optional[str], bool) -> PythonFinder
        root = ensure_path(root)
        if not version_glob_path:
            version_glob_path = "versions/*"
        return cls(
            root=root,
            path=root,
            ignore_unsupported=ignore_unsupported,  # type: ignore
            sort_function=sort_function,
            version_glob_path=version_glob_path,
        )

    def find_all_python_versions(
        self,
        major=None,  # type: Optional[Union[str, int]]
        minor=None,  # type: Optional[int]
        patch=None,  # type: Optional[int]
        pre=None,  # type: Optional[bool]
        dev=None,  # type: Optional[bool]
        arch=None,  # type: Optional[str]
        name=None,  # type: Optional[str]
    ):
        # type: (...) -> List[PathEntry]
        """Search for a specific python version on the path. Return all copies

        :param major: Major python version to search for.
        :type major: int
        :param int minor: Minor python version to search for, defaults to None
        :param int patch: Patch python version to search for, defaults to None
        :param bool pre: Search for prereleases (default None) - prioritize releases if None
        :param bool dev: Search for devreleases (default None) - prioritize releases if None
        :param str arch: Architecture to include, e.g. '64bit', defaults to None
        :param str name: The name of a python version, e.g. ``anaconda3-5.3.0``
        :return: A list of :class:`~pythonfinder.models.PathEntry` instances matching the version requested.
        :rtype: List[:class:`~pythonfinder.models.PathEntry`]
        """

        call_method = "find_all_python_versions" if self.is_dir else "find_python_version"
        sub_finder = operator.methodcaller(
            call_method, major, minor, patch, pre, dev, arch, name
        )
        if not any([major, minor, patch, name]):
            pythons = [
                next(iter(py for py in base.find_all_python_versions()), None)
                for _, base in self._iter_version_bases()
            ]
        else:
            pythons = [sub_finder(path) for path in self.paths]
        pythons = expand_paths(pythons, True)
        version_sort = operator.attrgetter("as_python.version_sort")
        paths = [
            p for p in sorted(pythons, key=version_sort, reverse=True) if p is not None
        ]
        return paths

    def find_python_version(
        self,
        major=None,  # type: Optional[Union[str, int]]
        minor=None,  # type: Optional[int]
        patch=None,  # type: Optional[int]
        pre=None,  # type: Optional[bool]
        dev=None,  # type: Optional[bool]
        arch=None,  # type: Optional[str]
        name=None,  # type: Optional[str]
    ):
        # type: (...) -> Optional[PathEntry]
        """Search or self for the specified Python version and return the first match.

        :param major: Major version number.
        :type major: int
        :param int minor: Minor python version to search for, defaults to None
        :param int patch: Patch python version to search for, defaults to None
        :param bool pre: Search for prereleases (default None) - prioritize releases if None
        :param bool dev: Search for devreleases (default None) - prioritize releases if None
        :param str arch: Architecture to include, e.g. '64bit', defaults to None
        :param str name: The name of a python version, e.g. ``anaconda3-5.3.0``
        :returns: A :class:`~pythonfinder.models.PathEntry` instance matching the version requested.
        """

        sub_finder = operator.methodcaller(
            "find_python_version", major, minor, patch, pre, dev, arch, name
        )
        version_sort = operator.attrgetter("as_python.version_sort")
        unnested = [sub_finder(self.roots[path]) for path in self.roots]
        unnested = [
            p
            for p in unnested
            if p is not None and p.is_python and p.as_python is not None
        ]
        paths = sorted(list(unnested), key=version_sort, reverse=True)
        return next(iter(p for p in paths if p is not None), None)

    def which(self, name):
        # type: (str) -> Optional[PathEntry]
        """Search in this path for an executable.

        :param executable: The name of an executable to search for.
        :type executable: str
        :returns: :class:`~pythonfinder.models.PathEntry` instance.
        """

        matches = (p.which(name) for p in self.paths)
        non_empty_match = next(iter(m for m in matches if m is not None), None)
        return non_empty_match


@attr.s(slots=True)
class PythonVersion(object):
    major = attr.ib(default=0, type=int)
    minor = attr.ib(default=None)  # type: Optional[int]
    patch = attr.ib(default=None)  # type: Optional[int]
    is_prerelease = attr.ib(default=False, type=bool)
    is_postrelease = attr.ib(default=False, type=bool)
    is_devrelease = attr.ib(default=False, type=bool)
    is_debug = attr.ib(default=False, type=bool)
    version = attr.ib(default=None)  # type: Version
    architecture = attr.ib(default=None)  # type: Optional[str]
    comes_from = attr.ib(default=None)  # type: Optional[PathEntry]
    executable = attr.ib(default=None)  # type: Optional[str]
    company = attr.ib(default=None)  # type: Optional[str]
    name = attr.ib(default=None, type=str)

    def __getattribute__(self, key):
        result = super(PythonVersion, self).__getattribute__(key)
        if key in ["minor", "patch"] and result is None:
            executable = None  # type: Optional[str]
            if self.executable:
                executable = self.executable
            elif self.comes_from:
                executable = self.comes_from.path.as_posix()
            if executable is not None:
                if not isinstance(executable, str):
                    executable = executable.as_posix()
                instance_dict = self.parse_executable(executable)
                for k in instance_dict.keys():
                    try:
                        super(PythonVersion, self).__getattribute__(k)
                    except AttributeError:
                        continue
                    else:
                        setattr(self, k, instance_dict[k])
                result = instance_dict.get(key)
        return result

    @property
    def version_sort(self):
        # type: () -> Tuple[int, int, Optional[int], int, int]
        """
        A tuple for sorting against other instances of the same class.

        Returns a tuple of the python version but includes points for core python,
        non-dev,  and non-prerelease versions.  So released versions will have 2 points
        for this value.  E.g. ``(1, 3, 6, 6, 2)`` is a release, ``(1, 3, 6, 6, 1)`` is a
        prerelease, ``(1, 3, 6, 6, 0)`` is a dev release, and ``(1, 3, 6, 6, 3)`` is a
        postrelease.  ``(0, 3, 7, 3, 2)`` represents a non-core python release, e.g. by
        a repackager of python like Continuum.
        """
        company_sort = 1 if (self.company and self.company == "PythonCore") else 0
        release_sort = 2
        if self.is_postrelease:
            release_sort = 3
        elif self.is_prerelease:
            release_sort = 1
        elif self.is_devrelease:
            release_sort = 0
        elif self.is_debug:
            release_sort = 1
        return (
            company_sort,
            self.major,
            self.minor,
            self.patch if self.patch else 0,
            release_sort,
        )

    @property
    def version_tuple(self):
        # type: () -> Tuple[int, Optional[int], Optional[int], bool, bool, bool]
        """
        Provides a version tuple for using as a dictionary key.

        :return: A tuple describing the python version meetadata contained.
        :rtype: tuple
        """

        return (
            self.major,
            self.minor,
            self.patch,
            self.is_prerelease,
            self.is_devrelease,
            self.is_debug,
        )

    def matches(
        self,
        major=None,  # type: Optional[int]
        minor=None,  # type: Optional[int]
        patch=None,  # type: Optional[int]
        pre=False,  # type: bool
        dev=False,  # type: bool
        arch=None,  # type: Optional[str]
        debug=False,  # type: bool
        python_name=None,  # type: Optional[str]
    ):
        # type: (...) -> bool
        result = False
        if arch:
            own_arch = self.get_architecture()
            if arch.isdigit():
                arch = "{0}bit".format(arch)
        if (
            (major is None or self.major == major)
            and (minor is None or self.minor == minor)
            and (patch is None or self.patch == patch)
            and (pre is None or self.is_prerelease == pre)
            and (dev is None or self.is_devrelease == dev)
            and (arch is None or own_arch == arch)
            and (debug is None or self.is_debug == debug)
            and (
                python_name is None
                or (python_name and self.name)
                and (self.name == python_name or self.name.startswith(python_name))
            )
        ):
            result = True
        return result

    def as_major(self):
        # type: () -> PythonVersion
        self_dict = attr.asdict(self, recurse=False, filter=_filter_none).copy()
        self_dict.update({"minor": None, "patch": None})
        return self.create(**self_dict)

    def as_minor(self):
        # type: () -> PythonVersion
        self_dict = attr.asdict(self, recurse=False, filter=_filter_none).copy()
        self_dict.update({"patch": None})
        return self.create(**self_dict)

    def as_dict(self):
        # type: () -> Dict[str, Union[int, bool, Version, None]]
        return {
            "major": self.major,
            "minor": self.minor,
            "patch": self.patch,
            "is_prerelease": self.is_prerelease,
            "is_postrelease": self.is_postrelease,
            "is_devrelease": self.is_devrelease,
            "is_debug": self.is_debug,
            "version": self.version,
            "company": self.company,
        }

    def update_metadata(self, metadata):
        # type: (Dict[str, Union[str, int, Version]]) -> None
        """
        Update the metadata on the current :class:`pythonfinder.models.python.PythonVersion`

        Given a parsed version dictionary from :func:`pythonfinder.utils.parse_python_version`,
        update the instance variables of the current version instance to reflect the newly
        supplied values.
        """

        for key in metadata:
            try:
                _ = getattr(self, key)
            except AttributeError:
                continue
            else:
                setattr(self, key, metadata[key])

    @classmethod
    @lru_cache(maxsize=1024)
    def parse(cls, version):
        # type: (str) -> Dict[str, Union[str, int, Version]]
        """
        Parse a valid version string into a dictionary

        Raises:
            ValueError -- Unable to parse version string
            ValueError -- Not a valid python version
            TypeError -- NoneType or unparsable type passed in

        :param str version: A valid version string
        :return: A dictionary with metadata about the specified python version.
        :rtype: dict
        """

        if version is None:
            raise TypeError("Must pass a value to parse!")
        version_dict = parse_python_version(str(version))
        if not version_dict:
            raise ValueError("Not a valid python version: %r" % version)
        return version_dict

    def get_architecture(self):
        # type: () -> str
        if self.architecture:
            return self.architecture
        arch = None
        if self.comes_from is not None:
            arch, _ = platform.architecture(self.comes_from.path.as_posix())
        elif self.executable is not None:
            arch, _ = platform.architecture(self.executable)
        if arch is None:
            arch, _ = platform.architecture(sys.executable)
        self.architecture = arch
        return self.architecture

    @classmethod
    def from_path(cls, path, name=None, ignore_unsupported=True, company=None):
        # type: (Union[str, PathEntry], Optional[str], bool, Optional[str]) -> PythonVersion
        """
        Parses a python version from a system path.

        Raises:
            ValueError -- Not a valid python path

        :param path: A string or :class:`~pythonfinder.models.path.PathEntry`
        :type path: str or :class:`~pythonfinder.models.path.PathEntry` instance
        :param str name: Name of the python distribution in question
        :param bool ignore_unsupported: Whether to ignore or error on unsupported paths.
        :param Optional[str] company: The company or vendor packaging the distribution.
        :return: An instance of a PythonVersion.
        :rtype: :class:`~pythonfinder.models.python.PythonVersion`
        """

        from .path import PathEntry

        if not isinstance(path, PathEntry):
            path = PathEntry.create(path, is_root=False, only_python=True, name=name)
        from ..environment import IGNORE_UNSUPPORTED

        ignore_unsupported = ignore_unsupported or IGNORE_UNSUPPORTED
        path_name = getattr(path, "name", path.path.name)  # str
        if not path.is_python:
            if not (ignore_unsupported or IGNORE_UNSUPPORTED):
                raise ValueError("Not a valid python path: %s" % path.path)
        try:
            instance_dict = cls.parse(path_name)
        except Exception:
            instance_dict = cls.parse_executable(path.path.absolute().as_posix())
        else:
            if instance_dict.get("minor") is None and looks_like_python(path.path.name):
                instance_dict = cls.parse_executable(path.path.absolute().as_posix())

        if (
            not isinstance(instance_dict.get("version"), Version)
            and not ignore_unsupported
        ):
            raise ValueError("Not a valid python path: %s" % path)
        if instance_dict.get("patch") is None:
            instance_dict = cls.parse_executable(path.path.absolute().as_posix())
        if name is None:
            name = path_name
        if company is None:
            company = guess_company(path.path.as_posix())
        instance_dict.update(
            {"comes_from": path, "name": name, "executable": path.path.as_posix()}
        )
        return cls(**instance_dict)  # type: ignore

    @classmethod
    @lru_cache(maxsize=1024)
    def parse_executable(cls, path):
        # type: (str) -> Dict[str, Optional[Union[str, int, Version]]]
        result_dict = {}  # type: Dict[str, Optional[Union[str, int, Version]]]
        result_version = None  # type: Optional[str]
        if path is None:
            raise TypeError("Must pass a valid path to parse.")
        if not isinstance(path, str):
            path = path.as_posix()
        # if not looks_like_python(path):
        #     raise ValueError("Path %r does not look like a valid python path" % path)
        try:
            result_version = get_python_version(path)
        except Exception:
            raise ValueError("Not a valid python path: %r" % path)
        if result_version is None:
            raise ValueError("Not a valid python path: %s" % path)
        result_dict = cls.parse(result_version.strip())
        return result_dict

    @classmethod
    def from_windows_launcher(cls, launcher_entry, name=None, company=None):
        # type: (Environment, Optional[str], Optional[str]) -> PythonVersion
        """Create a new PythonVersion instance from a Windows Launcher Entry

        :param launcher_entry: A python launcher environment object.
        :param Optional[str] name: The name of the distribution.
        :param Optional[str] company: The name of the distributing company.
        :return: An instance of a PythonVersion.
        :rtype: :class:`~pythonfinder.models.python.PythonVersion`
        """

        from .path import PathEntry

        creation_dict = cls.parse(launcher_entry.info.version)
        base_path = ensure_path(launcher_entry.info.install_path.__getattr__(""))
        default_path = base_path / "python.exe"
        if not default_path.exists():
            default_path = base_path / "Scripts" / "python.exe"
        exe_path = ensure_path(
            getattr(launcher_entry.info.install_path, "executable_path", default_path)
        )
        company = getattr(launcher_entry, "company", guess_company(exe_path.as_posix()))
        creation_dict.update(
            {
                "architecture": getattr(
                    launcher_entry.info, "sys_architecture", SYSTEM_ARCH
                ),
                "executable": exe_path,
                "name": name,
                "company": company,
            }
        )
        py_version = cls.create(**creation_dict)
        comes_from = PathEntry.create(exe_path, only_python=True, name=name)
        py_version.comes_from = comes_from
        py_version.name = comes_from.name
        return py_version

    @classmethod
    def create(cls, **kwargs):
        # type: (...) -> PythonVersion
        if "architecture" in kwargs:
            if kwargs["architecture"].isdigit():
                kwargs["architecture"] = "{0}bit".format(kwargs["architecture"])
        return cls(**kwargs)


@attr.s
class VersionMap(object):
    versions = attr.ib(
        factory=defaultdict
    )  # type: DefaultDict[Tuple[int, Optional[int], Optional[int], bool, bool, bool], List[PathEntry]]

    def add_entry(self, entry):
        # type: (...) -> None
        version = entry.as_python  # type: PythonVersion
        if version:
            _ = self.versions[version.version_tuple]
            paths = {p.path for p in self.versions.get(version.version_tuple, [])}
            if entry.path not in paths:
                self.versions[version.version_tuple].append(entry)

    def merge(self, target):
        # type: (VersionMap) -> None
        for version, entries in target.versions.items():
            if version not in self.versions:
                self.versions[version] = entries
            else:
                current_entries = {
                    p.path
                    for p in self.versions[version]  # type: ignore
                    if version in self.versions
                }
                new_entries = {p.path for p in entries}
                new_entries -= current_entries
                self.versions[version].extend(
                    [e for e in entries if e.path in new_entries]
                )
