from __future__ import annotations

import contextlib
import functools
import glob
import logging
import os

from pathlib import Path
from typing import TYPE_CHECKING
from typing import Any
from typing import Mapping
from typing import Sequence

import pkginfo

from poetry.core.factory import Factory
from poetry.core.packages.dependency import Dependency
from poetry.core.packages.package import Package
from poetry.core.pyproject.toml import PyProjectTOML
from poetry.core.utils.helpers import parse_requires
from poetry.core.utils.helpers import temporary_directory
from poetry.core.version.markers import InvalidMarker
from poetry.core.version.requirements import InvalidRequirement

from poetry.utils.env import EnvCommandError
from poetry.utils.env import ephemeral_environment
from poetry.utils.helpers import extractall
from poetry.utils.setup_reader import SetupReader


if TYPE_CHECKING:
    from collections.abc import Iterator

    from packaging.metadata import RawMetadata
    from packaging.utils import NormalizedName
    from poetry.core.packages.project_package import ProjectPackage


logger = logging.getLogger(__name__)

PEP517_META_BUILD = """\
import build
import build.env
import pyproject_hooks

source = '{source}'
dest = '{dest}'

with build.env.DefaultIsolatedEnv() as env:
    builder = build.ProjectBuilder.from_isolated_env(
        env, source, runner=pyproject_hooks.quiet_subprocess_runner
    )
    env.install(builder.build_system_requires)
    env.install(builder.get_requires_for_build('wheel'))
    builder.metadata_path(dest)
"""

PEP517_META_BUILD_DEPS = ["build==1.0.3", "pyproject_hooks==1.0.0"]


class PackageInfoError(ValueError):
    def __init__(self, path: Path, *reasons: BaseException | str) -> None:
        reasons = (f"Unable to determine package info for path: {path!s}", *reasons)
        super().__init__("\n\n".join(str(msg).strip() for msg in reasons if msg))


class PackageInfo:
    def __init__(
        self,
        *,
        name: str | None = None,
        version: str | None = None,
        summary: str | None = None,
        requires_dist: list[str] | None = None,
        requires_python: str | None = None,
        files: Sequence[Mapping[str, str]] | None = None,
        yanked: str | bool = False,
        cache_version: str | None = None,
    ) -> None:
        self.name = name
        self.version = version
        self.summary = summary
        self.requires_dist = requires_dist
        self.requires_python = requires_python
        self.files = files or []
        self.yanked = yanked
        self._cache_version = cache_version
        self._source_type: str | None = None
        self._source_url: str | None = None
        self._source_reference: str | None = None

    @property
    def cache_version(self) -> str | None:
        return self._cache_version

    def update(self, other: PackageInfo) -> PackageInfo:
        self.name = other.name or self.name
        self.version = other.version or self.version
        self.summary = other.summary or self.summary
        self.requires_dist = other.requires_dist or self.requires_dist
        self.requires_python = other.requires_python or self.requires_python
        self.files = other.files or self.files
        self._cache_version = other.cache_version or self._cache_version
        return self

    def asdict(self) -> dict[str, Any]:
        """
        Helper method to convert package info into a dictionary used for caching.
        """
        return {
            "name": self.name,
            "version": self.version,
            "summary": self.summary,
            "requires_dist": self.requires_dist,
            "requires_python": self.requires_python,
            "files": self.files,
            "yanked": self.yanked,
            "_cache_version": self._cache_version,
        }

    @classmethod
    def load(cls, data: dict[str, Any]) -> PackageInfo:
        """
        Helper method to load data from a dictionary produced by `PackageInfo.asdict()`.

        :param data: Data to load. This is expected to be a `dict` object output by
            `asdict()`.
        """
        cache_version = data.pop("_cache_version", None)
        return cls(cache_version=cache_version, **data)

    def to_package(
        self,
        name: str | None = None,
        extras: list[str] | None = None,
        root_dir: Path | None = None,
    ) -> Package:
        """
        Create a new `poetry.core.packages.package.Package` instance using metadata from
        this instance.

        :param name: Name to use for the package, if not specified name from this
            instance is used.
        :param extras: Extras to activate for this package.
        :param root_dir:  Optional root directory to use for the package. If set,
            dependency strings will be parsed relative to this directory.
        """
        name = name or self.name

        if not name:
            raise RuntimeError("Unable to create package with no name")

        if not self.version:
            # The version could not be determined, so we raise an error since it is
            # mandatory.
            raise RuntimeError(f"Unable to retrieve the package version for {name}")

        package = Package(
            name=name,
            version=self.version,
            source_type=self._source_type,
            source_url=self._source_url,
            source_reference=self._source_reference,
            yanked=self.yanked,
        )
        if self.summary is not None:
            package.description = self.summary
        package.root_dir = root_dir
        package.python_versions = self.requires_python or "*"
        package.files = self.files

        # If this is a local poetry project, we can extract "richer" requirement
        # information, eg: development requirements etc.
        if root_dir is not None:
            path = root_dir
        elif self._source_type == "directory" and self._source_url is not None:
            path = Path(self._source_url)
        else:
            path = None

        if path is not None:
            poetry_package = self._get_poetry_package(path=path)
            if poetry_package:
                package.extras = poetry_package.extras
                for dependency in poetry_package.requires:
                    package.add_dependency(dependency)

                return package

        seen_requirements = set()

        package_extras: dict[NormalizedName, list[Dependency]] = {}
        for req in self.requires_dist or []:
            try:
                # Attempt to parse the PEP-508 requirement string
                dependency = Dependency.create_from_pep_508(req, relative_to=root_dir)
            except InvalidMarker:
                # Invalid marker, We strip the markers hoping for the best
                logger.warning(
                    "Stripping invalid marker (%s) found in %s-%s dependencies",
                    req,
                    package.name,
                    package.version,
                )
                req = req.split(";")[0]
                dependency = Dependency.create_from_pep_508(req, relative_to=root_dir)
            except InvalidRequirement:
                # Unable to parse requirement so we skip it
                logger.warning(
                    "Invalid requirement (%s) found in %s-%s dependencies, skipping",
                    req,
                    package.name,
                    package.version,
                )
                continue

            if dependency.in_extras:
                # this dependency is required by an extra package
                for extra in dependency.in_extras:
                    if extra not in package_extras:
                        # this is the first time we encounter this extra for this
                        # package
                        package_extras[extra] = []

                    package_extras[extra].append(dependency)

            req = dependency.to_pep_508(with_extras=True)

            if req not in seen_requirements:
                package.add_dependency(dependency)
                seen_requirements.add(req)

        package.extras = package_extras

        return package

    @classmethod
    def _from_distribution(
        cls, dist: pkginfo.BDist | pkginfo.SDist | pkginfo.Wheel
    ) -> PackageInfo:
        """
        Helper method to parse package information from a `pkginfo.Distribution`
        instance.

        :param dist: The distribution instance to parse information from.
        """
        if dist.metadata_version not in pkginfo.distribution.HEADER_ATTRS:
            # This check can be replaced once upstream implements strict parsing
            # https://bugs.launchpad.net/pkginfo/+bug/2058697
            raise ValueError(f"Unknown metadata version: {dist.metadata_version}")

        requirements = None

        if dist.requires_dist:
            requirements = list(dist.requires_dist)
        else:
            requires = Path(dist.filename) / "requires.txt"
            if requires.exists():
                text = requires.read_text(encoding="utf-8")
                requirements = parse_requires(text)

        info = cls(
            name=dist.name,
            version=dist.version,
            summary=dist.summary,
            requires_dist=requirements,
            requires_python=dist.requires_python,
        )

        info._source_type = "file"
        info._source_url = Path(dist.filename).resolve().as_posix()

        return info

    @classmethod
    def _from_sdist_file(cls, path: Path) -> PackageInfo:
        """
        Helper method to parse package information from an sdist file. We attempt to
        first inspect the file using `pkginfo.SDist`. If this does not provide us with
        package requirements, we extract the source and handle it as a directory.

        :param path: The sdist file to parse information from.
        """
        info = None

        with contextlib.suppress(ValueError):
            sdist = pkginfo.SDist(str(path))
            info = cls._from_distribution(sdist)

        if info is not None and info.requires_dist is not None:
            # we successfully retrieved dependencies from sdist metadata
            return info

        # Still not dependencies found
        # So, we unpack and introspect
        suffix = path.suffix
        zip = suffix == ".zip"

        if suffix == ".bz2":
            suffixes = path.suffixes
            if len(suffixes) > 1 and suffixes[-2] == ".tar":
                suffix = ".tar.bz2"
        elif not zip:
            suffix = ".tar.gz"

        with temporary_directory() as tmp_str:
            tmp = Path(tmp_str)
            extractall(source=path, dest=tmp, zip=zip)

            # a little bit of guess work to determine the directory we care about
            elements = list(tmp.glob("*"))

            if len(elements) == 1 and elements[0].is_dir():
                sdist_dir = elements[0]
            else:
                sdist_dir = tmp / path.name.rstrip(suffix)
                if not sdist_dir.is_dir():
                    sdist_dir = tmp

            # now this is an unpacked directory we know how to deal with
            new_info = cls.from_directory(path=sdist_dir)
            new_info._source_type = "file"
            new_info._source_url = path.resolve().as_posix()

        if not info:
            return new_info

        return info.update(new_info)

    @staticmethod
    def has_setup_files(path: Path) -> bool:
        return any((path / f).exists() for f in SetupReader.FILES)

    @classmethod
    def from_setup_files(cls, path: Path) -> PackageInfo:
        """
        Mechanism to parse package information from a `setup.[py|cfg]` file. This uses
        the implementation at `poetry.utils.setup_reader.SetupReader` in order to parse
        the file. This is not reliable for complex setup files and should only attempted
        as a fallback.

        :param path: Path to `setup.py` file
        """
        if not cls.has_setup_files(path):
            raise PackageInfoError(
                path, "No setup files (setup.py, setup.cfg) was found."
            )

        try:
            result = SetupReader.read_from_directory(path)
        except Exception as e:
            raise PackageInfoError(path, e)

        python_requires = result["python_requires"]
        if python_requires is None:
            python_requires = "*"

        requires = "".join(dep + "\n" for dep in result["install_requires"])
        if result["extras_require"]:
            requires += "\n"

        for extra_name, deps in result["extras_require"].items():
            requires += f"[{extra_name}]\n"

            for dep in deps:
                requires += dep + "\n"

            requires += "\n"

        requirements = parse_requires(requires)

        info = cls(
            name=result.get("name"),
            version=result.get("version"),
            summary=result.get("description", ""),
            requires_dist=requirements or None,
            requires_python=python_requires,
        )

        if not (info.name and info.version) and not info.requires_dist:
            # there is nothing useful here
            raise PackageInfoError(
                path,
                "No core metadata (name, version, requires-dist) could be retrieved.",
            )

        return info

    @staticmethod
    def _find_dist_info(path: Path) -> Iterator[Path]:
        """
        Discover all `*.*-info` directories in a given path.

        :param path: Path to search.
        """
        pattern = "**/*.*-info"
        # Sometimes pathlib will fail on recursive symbolic links, so we need to work
        # around it and use the glob module instead. Note that this does not happen with
        # pathlib2 so it's safe to use it for Python < 3.4.
        directories = glob.iglob(path.joinpath(pattern).as_posix(), recursive=True)

        for d in directories:
            yield Path(d)

    @classmethod
    def from_metadata(cls, metadata: RawMetadata) -> PackageInfo:
        """
        Create package information from core metadata.

        :param metadata: raw metadata
        """
        return cls(
            name=metadata.get("name"),
            version=metadata.get("version"),
            summary=metadata.get("summary"),
            requires_dist=metadata.get("requires_dist"),
            requires_python=metadata.get("requires_python"),
        )

    @classmethod
    def from_metadata_directory(cls, path: Path) -> PackageInfo | None:
        """
        Helper method to parse package information from an unpacked metadata directory.

        :param path: The metadata directory to parse information from.
        """
        if path.suffix in {".dist-info", ".egg-info"}:
            directories = [path]
        else:
            directories = list(cls._find_dist_info(path=path))

        dist: pkginfo.BDist | pkginfo.SDist | pkginfo.Wheel
        for directory in directories:
            try:
                if directory.suffix == ".egg-info":
                    dist = pkginfo.UnpackedSDist(directory.as_posix())
                elif directory.suffix == ".dist-info":
                    dist = pkginfo.Wheel(directory.as_posix())
                else:
                    continue
                break
            except ValueError:
                continue
        else:
            try:
                # handle PKG-INFO in unpacked sdist root
                dist = pkginfo.UnpackedSDist(path.as_posix())
            except ValueError:
                return None

        return cls._from_distribution(dist=dist)

    @classmethod
    def from_package(cls, package: Package) -> PackageInfo:
        """
        Helper method to inspect a `Package` object, in order to generate package info.

        :param package: This must be a poetry package instance.
        """
        requires = {dependency.to_pep_508() for dependency in package.requires}

        for extra_requires in package.extras.values():
            for dependency in extra_requires:
                requires.add(dependency.to_pep_508())

        return cls(
            name=package.name,
            version=str(package.version),
            summary=package.description,
            requires_dist=list(requires),
            requires_python=package.python_versions,
            files=package.files,
            yanked=package.yanked_reason if package.yanked else False,
        )

    @staticmethod
    def _get_poetry_package(path: Path) -> ProjectPackage | None:
        # Note: we ignore any setup.py file at this step
        # TODO: add support for handling non-poetry PEP-517 builds
        if PyProjectTOML(path.joinpath("pyproject.toml")).is_poetry_project():
            with contextlib.suppress(RuntimeError):
                return Factory().create_poetry(path).package

        return None

    @classmethod
    def from_directory(cls, path: Path, disable_build: bool = False) -> PackageInfo:
        """
        Generate package information from a package source directory. If `disable_build`
        is not `True` and introspection of all available metadata fails, the package is
        attempted to be built in an isolated environment so as to generate required
        metadata.

        :param path: Path to generate package information from.
        :param disable_build: If not `True` and setup reader fails, PEP 517 isolated
            build is attempted in order to gather metadata.
        """
        project_package = cls._get_poetry_package(path)
        info: PackageInfo | None
        if project_package:
            info = cls.from_package(project_package)
        else:
            info = cls.from_metadata_directory(path)

            if not info or info.requires_dist is None:
                try:
                    if disable_build:
                        info = cls.from_setup_files(path)
                    else:
                        info = get_pep517_metadata(path)
                except PackageInfoError:
                    if not info:
                        raise

                    # we discovered PkgInfo but no requirements were listed

        info._source_type = "directory"
        info._source_url = path.as_posix()

        return info

    @classmethod
    def from_sdist(cls, path: Path) -> PackageInfo:
        """
        Gather package information from an sdist file, packed or unpacked.

        :param path: Path to an sdist file or unpacked directory.
        """
        if path.is_file():
            return cls._from_sdist_file(path=path)

        # if we get here then it is neither an sdist instance nor a file
        # so, we assume this is an directory
        return cls.from_directory(path=path)

    @classmethod
    def from_wheel(cls, path: Path) -> PackageInfo:
        """
        Gather package information from a wheel.

        :param path: Path to wheel.
        """
        try:
            wheel = pkginfo.Wheel(str(path))
            return cls._from_distribution(wheel)
        except ValueError as e:
            raise PackageInfoError(path, e)

    @classmethod
    def from_bdist(cls, path: Path) -> PackageInfo:
        """
        Gather package information from a bdist (wheel etc.).

        :param path: Path to bdist.
        """
        if path.suffix == ".whl":
            return cls.from_wheel(path=path)

        try:
            bdist = pkginfo.BDist(str(path))
            return cls._from_distribution(bdist)
        except ValueError as e:
            raise PackageInfoError(path, e)

    @classmethod
    def from_path(cls, path: Path) -> PackageInfo:
        """
        Gather package information from a given path (bdist, sdist, directory).

        :param path: Path to inspect.
        """
        try:
            return cls.from_bdist(path=path)
        except PackageInfoError:
            return cls.from_sdist(path=path)


@functools.lru_cache(maxsize=None)
def get_pep517_metadata(path: Path) -> PackageInfo:
    """
    Helper method to use PEP-517 library to build and read package metadata.

    :param path: Path to package source to build and read metadata for.
    """
    info = None

    with contextlib.suppress(PackageInfoError):
        info = PackageInfo.from_setup_files(path)
        if all([info.version, info.name, info.requires_dist]):
            return info

    with ephemeral_environment(
        flags={"no-pip": False, "setuptools": "bundle", "wheel": "bundle"}
    ) as venv:
        # TODO: cache PEP 517 build environment corresponding to each project venv
        dest_dir = venv.path.parent / "dist"
        dest_dir.mkdir()

        pep517_meta_build_script = PEP517_META_BUILD.format(
            source=path.as_posix(), dest=dest_dir.as_posix()
        )

        try:
            venv.run_pip(
                "install",
                "--disable-pip-version-check",
                "--ignore-installed",
                "--no-input",
                *PEP517_META_BUILD_DEPS,
            )
            venv.run_python_script(pep517_meta_build_script)
            info = PackageInfo.from_metadata_directory(dest_dir)
        except EnvCommandError as e:
            # something went wrong while attempting pep517 metadata build
            # fallback to egg_info if setup.py available
            logger.debug("PEP517 build failed: %s", e)
            setup_py = path / "setup.py"
            if not setup_py.exists():
                raise PackageInfoError(
                    path,
                    e,
                    "No fallback setup.py file was found to generate egg_info.",
                )

            cwd = Path.cwd()
            os.chdir(path)
            try:
                venv.run("python", "setup.py", "egg_info")
                info = PackageInfo.from_metadata_directory(path)
            except EnvCommandError as fbe:
                raise PackageInfoError(
                    path, e, "Fallback egg_info generation failed.", fbe
                )
            finally:
                os.chdir(cwd)

    if info:
        logger.debug("Falling back to parsed setup.py file for %s", path)
        return info

    # if we reach here, everything has failed and all hope is lost
    raise PackageInfoError(path, "Exhausted all core metadata sources.")