#!/usr/bin/env python3

"""
A wrapper of apt module that is actually usable.
"""

import os

import utils as u

try:
    import apt
except ModuleNotFoundError:
    u.warning("apt python module not found")
    exit(2)


class AptInstallProgress(apt.progress.base.InstallProgress):
    def fork(self):
        pid = os.fork()
        if pid == 0:
            logfd = os.open("/tmp/envsetup-dpkg.log", os.O_RDWR | os.O_CREAT, 0o644)
            os.dup2(logfd, 1)
            os.dup2(logfd, 2)
        return pid


class Apt:
    # cache: apt.cache.Cache
    # packages: list
    # _installed_packages: list
    # installed_packages: list
    # _removable_packages: list
    # removable_packages: list
    # _purgeable_packages: list
    # purgeable_packages: list
    # _upgradable_packages: list
    # upgradable_packages: list

    def __init__(self, update: bool = False):
        os.environ["DEBIAN_FRONTEND"] = "noninteractive"
        os.environ[
            "PATH"
        ] = "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
        self.cache = self.get_cache(update)
        self.packages = self.get_packages()
        self._installed_packages = self.get_installed_packages()
        self.installed_packages = list(map(str, self._installed_packages))
        self._removable_packages = self.get_removable_packages()
        self.removable_packages = list(map(str, self._removable_packages))
        self._purgeable_packages = self.get_purgeable_packages()
        self.purgeable_packages = list(map(str, self._purgeable_packages))
        self._upgradable_packages = self.get_upgradable_packages()
        self.upgradable_packages = list(map(str, self._upgradable_packages))

    def install(self, name: str) -> bool:
        """Install a package with APT.

        :param name: Package name
        :type name: str
        :return: Wether installation is successful or not
        :rtype: bool
        """

        pkg = self.cache[name]
        if not pkg.installed:
            pkg.mark_install(auto_fix=False)
        success = self.cache.commit(install_progress=AptInstallProgress())
        self.reload()

        return success

    def is_installed(self, name: str) -> bool:
        """Check a package is installed.

        :param name: Package name
        :type name: str
        :return: Wether package is installed or not
        :rtype: bool
        """

        if name in self.cache:
            return self.cache[name].installed

        return False

    def remove(self, name: str, purge: bool = False) -> bool:
        """Remove a package with APT.

        :param name: Package name
        :type name: str
        :param purge: Wether to purge package configuration files ot not, default=False
        :type purge: str
        :return: Wether uninstallation is successful or not
        :rtype: bool
        """

        pkg = self.cache[name]
        if pkg.installed:
            pkg.mark_delete(auto_fix=False, purge=purge)
        success = self.cache.commit(install_progress=AptInstallProgress())
        self.reload()

        return success

    def purge(self, name: str) -> bool:
        """Purge a package with APT.

        :param name: Package name
        :type name: str
        :return: Wether uninstallation is successful or not
        :rtype: bool
        """

        return self.remove(name, purge=True)

    def reload(self):
        """Reload object."""

        self.cache.clear()
        self.__init__()

    def get_cache(self, update: bool = False) -> apt.cache.Cache:
        """Get an eventually updated Cache object.

        :param update: Wether to update cache or not, default=False
        :type update: bool
        :return: An APT Cache object
        :rtype: apt.cache.Cache
        """

        apt_cache = apt.cache.Cache()
        if update:
            apt_cache.update()
            apt_cache.open()

        return apt_cache

    def get_packages(self) -> list:
        """Get packages list.

        :return: Packages list
        :rtype: list
        """

        packages = list(self.cache)

        return packages

    def get_installed_packages(self) -> list:
        """Get installed packages list.

        :return: Installed packages list
        :rtype: list
        """

        _installed_packages = [p for p in self.packages if p.is_installed]

        return _installed_packages

    def get_removable_packages(self) -> list:
        """Get auto-removable packages list.

        :return: Auto-removable packages list
        :rtype: list
        """

        _removable_packages = [
            p for p in self._installed_packages if p.is_auto_removable
        ]

        return _removable_packages

    def get_purgeable_packages(self) -> list:
        """Get auto-removable packages list.

        :return: Auto-removable packages list
        :rtype: list
        """

        _removable_packages = [
            p for p in self.packages if not p.is_installed and p.has_config_files
        ]

        return _removable_packages

    def get_upgradable_packages(self) -> list:
        """Get upgradable packages list.

        :return: Upgradable packages list
        :rtype: list
        """

        _upgradable_packages = [p for p in self._installed_packages if p.is_upgradable]

        return _upgradable_packages