import os
import tempfile

from subprocess import CalledProcessError

from clikit.api.io import IO
from clikit.io import NullIO

from poetry.repositories.pool import Pool
from poetry.utils._compat import encode
from poetry.utils.env import Env
from poetry.utils.helpers import safe_rmtree

from .base_installer import BaseInstaller


try:
    import urllib.parse as urlparse
except ImportError:
    import urlparse


class PipInstaller(BaseInstaller):
    def __init__(self, env, io, pool):  # type: (Env, IO, Pool) -> None
        self._env = env
        self._io = io
        self._pool = pool

    def install(self, package, update=False):
        if package.source_type == "directory":
            self.install_directory(package)

            return

        if package.source_type == "git":
            self.install_git(package)

            return

        args = ["install", "--no-deps"]

        if (
            package.source_type not in {"git", "directory", "file", "url"}
            and package.source_url
        ):
            repository = self._pool.repository(package.source_reference)
            parsed = urlparse.urlparse(package.source_url)
            if parsed.scheme == "http":
                self._io.error(
                    "    <warning>Installing from unsecure host: {}</warning>".format(
                        parsed.hostname
                    )
                )
                args += ["--trusted-host", parsed.hostname]

            if repository.cert:
                args += ["--cert", str(repository.cert)]

            if repository.client_cert:
                args += ["--client-cert", str(repository.client_cert)]

            index_url = repository.authenticated_url

            args += ["--index-url", index_url]
            if self._pool.has_default():
                if repository.name != self._pool.repositories[0].name:
                    args += [
                        "--extra-index-url",
                        self._pool.repositories[0].authenticated_url,
                    ]

        if update:
            args.append("-U")

        if package.files and not package.source_url:
            # Format as a requirements.txt
            # We need to create a requirements.txt file
            # for each package in order to check hashes.
            # This is far from optimal but we do not have any
            # other choice since this is the only way for pip
            # to verify hashes.
            req = self.create_temporary_requirement(package)
            args += ["-r", req]

            try:
                self.run(*args)
            finally:
                os.unlink(req)
        else:
            req = self.requirement(package)
            if not isinstance(req, list):
                args.append(req)
            else:
                args += req

            self.run(*args)

    def update(self, package, target):
        if package.source_type != target.source_type:
            # If the source type has changed, we remove the current
            # package to avoid perpetual updates in some cases
            self.remove(package)

        self.install(target, update=True)

    def remove(self, package):
        try:
            self.run("uninstall", package.name, "-y")
        except CalledProcessError as e:
            if "not installed" in str(e):
                return

            raise

        # This is a workaround for https://github.com/pypa/pip/issues/4176
        nspkg_pth_file = self._env.site_packages / "{}-nspkg.pth".format(package.name)
        if nspkg_pth_file.exists():
            nspkg_pth_file.unlink()

        # If we have a VCS package, remove its source directory
        if package.source_type == "git":
            src_dir = self._env.path / "src" / package.name
            if src_dir.exists():
                safe_rmtree(str(src_dir))

    def run(self, *args, **kwargs):  # type: (...) -> str
        return self._env.run_pip(*args, **kwargs)

    def requirement(self, package, formatted=False):
        if formatted and not package.source_type:
            req = "{}=={}".format(package.name, package.version)
            for f in package.files:
                hash_type = "sha256"
                h = f["hash"]
                if ":" in h:
                    hash_type, h = h.split(":")

                req += " --hash {}:{}".format(hash_type, h)

            req += "\n"

            return req

        if package.source_type in ["file", "directory"]:
            if package.root_dir:
                req = os.path.join(package.root_dir, package.source_url)
            else:
                req = os.path.realpath(package.source_url)

            if package.develop and package.source_type == "directory":
                req = ["-e", req]

            return req

        if package.source_type == "git":
            req = "git+{}@{}#egg={}".format(
                package.source_url, package.source_reference, package.name
            )

            if package.develop:
                req = ["-e", req]

            return req

        if package.source_type == "url":
            return "{}#egg={}".format(package.source_url, package.name)

        return "{}=={}".format(package.name, package.version)

    def create_temporary_requirement(self, package):
        fd, name = tempfile.mkstemp(
            "reqs.txt", "{}-{}".format(package.name, package.version)
        )

        try:
            os.write(fd, encode(self.requirement(package, formatted=True)))
        finally:
            os.close(fd)

        return name

    def install_directory(self, package):
        from poetry.factory import Factory
        from poetry.utils.env import NullEnv
        from poetry.utils.toml_file import TomlFile

        if package.root_dir:
            req = os.path.join(package.root_dir, package.source_url)
        else:
            req = os.path.realpath(package.source_url)

        args = ["install", "--no-deps", "-U"]

        pyproject = TomlFile(os.path.join(req, "pyproject.toml"))

        has_poetry = False
        has_build_system = False
        if pyproject.exists():
            pyproject_content = pyproject.read()
            has_poetry = (
                "tool" in pyproject_content and "poetry" in pyproject_content["tool"]
            )
            # Even if there is a build system specified
            # pip as of right now does not support it fully
            # TODO: Check for pip version when proper PEP-517 support lands
            # has_build_system = ("build-system" in pyproject_content)

        setup = os.path.join(req, "setup.py")
        has_setup = os.path.exists(setup)
        if has_poetry and (package.develop or not has_build_system):
            # We actually need to rely on creating a temporary setup.py
            # file since pip, as of this comment, does not support
            # build-system for editable packages
            # We also need it for non-PEP-517 packages
            from poetry.masonry.builders.editable import EditableBuilder

            builder = EditableBuilder(
                Factory().create_poetry(pyproject.parent), NullEnv(), NullIO()
            )

            builder.build()

            return

        if package.develop:
            args.append("-e")

        args.append(req)

        try:
            return self.run(*args)
        finally:
            if not has_setup and os.path.exists(setup):
                os.remove(setup)

    def install_git(self, package):
        from poetry.packages import Package
        from poetry.vcs import Git

        src_dir = self._env.path / "src" / package.name
        if src_dir.exists():
            safe_rmtree(str(src_dir))

        src_dir.parent.mkdir(exist_ok=True)

        git = Git()
        git.clone(package.source_url, src_dir)
        git.checkout(package.source_reference, src_dir)

        # Now we just need to install from the source directory
        pkg = Package(package.name, package.version)
        pkg.source_type = "directory"
        pkg.source_url = str(src_dir)
        pkg.develop = package.develop

        self.install_directory(pkg)
