import os
import pkginfo

from pkginfo.distribution import HEADER_ATTRS
from pkginfo.distribution import HEADER_ATTRS_2_0

from poetry.io import NullIO
from poetry.utils._compat import Path
from poetry.utils._compat import decode
from poetry.utils.helpers import parse_requires
from poetry.utils.toml_file import TomlFile
from poetry.utils.venv import NullVenv
from poetry.utils.venv import Venv

from .dependency import Dependency

# Patching pkginfo to support Metadata version 2.1 (PEP 566)
HEADER_ATTRS.update(
    {
        '2.1': HEADER_ATTRS_2_0 + (
            ('Provides-Extra', 'provides_extra', True),
        )
    }
)


class DirectoryDependency(Dependency):

    def __init__(self,
                 path,             # type: Path
                 category='main',  # type: str
                 optional=False,   # type: bool
                 base=None,        # type: Path
                 develop=False     # type: bool
                 ):
        from . import dependency_from_pep_508

        self._path = path
        self._base = base
        self._full_path = path
        self._develop = develop

        if self._base and not self._path.is_absolute():
            self._full_path = self._base / self._path

        if not self._full_path.exists():
            raise ValueError('Directory {} does not exist'.format(self._path))

        if self._full_path.is_file():
            raise ValueError(
                '{} is a file, expected a directory'.format(self._path)
            )

        # Checking content to dertermine actions
        setup = self._full_path / 'setup.py'
        pyproject = TomlFile(self._full_path / 'pyproject.toml')
        has_poetry = False
        if pyproject.exists():
            pyproject_content = pyproject.read(True)
            has_poetry = (
                    'tool' in pyproject_content
                    and 'poetry' in pyproject_content['tool']
            )

        if not setup.exists() and not has_poetry:
            raise ValueError(
                'Directory {} does not seem to be a Python package'.format(
                    self._full_path
                )
            )

        if has_poetry:
            from poetry.masonry.builders import SdistBuilder
            from poetry.poetry import Poetry

            poetry = Poetry.create(self._full_path)
            builder = SdistBuilder(poetry, NullVenv(), NullIO())

            with setup.open('w') as f:
                f.write(decode(builder.build_setup()))

            self._package = poetry.package
        else:
            from poetry.packages import Package
            # Execute egg_info
            current_dir = os.getcwd()
            os.chdir(str(self._full_path))

            try:
                cwd = base
                venv = Venv.create(NullIO(), cwd=cwd)
                venv.run(
                    'python', 'setup.py', 'egg_info'
                )
            finally:
                os.chdir(current_dir)

            egg_info = list(self._full_path.glob('*.egg-info'))[0]

            meta = pkginfo.UnpackedSDist(str(egg_info))

            if meta.requires_dist:
                reqs = list(meta.requires_dist)
            else:
                reqs = []
                requires = egg_info / 'requires.txt'
                if requires.exists():
                    with requires.open() as f:
                        reqs = parse_requires(f.read())

            package = Package(meta.name, meta.version)
            package.description = meta.summary

            for req in reqs:
                package.requires.append(dependency_from_pep_508(req))

            if meta.requires_python:
                package.python_versions = meta.requires_python

            if meta.platforms:
                platforms = [
                    p
                    for p in meta.platforms
                    if p.lower() != 'unknown'
                ]
                if platforms:
                    package.platform = ' || '.join(platforms)

            self._package = package

        self._package.source_type = 'directory'
        self._package.source_reference = str(self._path)

        super(DirectoryDependency, self).__init__(
            self._package.name,
            self._package.version,
            category=category,
            optional=optional,
            allows_prereleases=True
        )

    @property
    def path(self):
        return self._path

    @property
    def full_path(self):
        return self._full_path.resolve()

    @property
    def package(self):
        return self._package

    @property
    def develop(self):
        return self._develop

    def is_directory(self):
        return True
