# vim: tabstop=4 shiftwidth=4 softtabstop=4

#    Copyright (C) 2012 Yahoo! Inc. All Rights Reserved.
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.

from tempfile import TemporaryFile
import time

from devstack import log as logging
from devstack import packager as pack
from devstack import settings
from devstack import shell as sh

LOG = logging.getLogger("devstack.packaging.apt")

#base apt commands
APT_GET = ['apt-get']
APT_PURGE = ["purge", "-y"]
APT_REMOVE = ["remove", "-y"]
APT_INSTALL = ["install", "-y"]
APT_AUTOREMOVE = ['autoremove', '-y']

#should we use remove or purge?
APT_DO_REMOVE = APT_PURGE

#make sure its non-interactive
ENV_ADDITIONS = {'DEBIAN_FRONTEND': 'noninteractive'}

#apt separates its pkg names and versions with a equal sign
VERSION_TEMPL = "%s=%s"


class AptPackager(pack.Packager):
    def __init__(self, distro, keep_packages):
        pack.Packager.__init__(self, distro, keep_packages)
        self.auto_remove = True

    def _format_pkg(self, name, version):
        if version:
            pkg_full_name = VERSION_TEMPL % (name, version)
        else:
            pkg_full_name = name
        return pkg_full_name

    def _execute_apt(self, cmd, **kargs):
        return sh.execute(*cmd, run_as_root=True,
            check_exit_code=True,
            env_overrides=ENV_ADDITIONS,
            **kargs)

    def _remove_batch(self, pkgs):
        pkgnames = sorted(pkgs.keys())
        #form the needed commands
        cmds = []
        which_removed = []
        for name in pkgnames:
            info = pkgs.get(name) or {}
            removable = info.get('removable', True)
            if not removable:
                continue
            if self._pkg_remove_special(name, info):
                which_removed.append(name)
                continue
            pkg_full = self._format_pkg(name, info.get("version"))
            if pkg_full:
                cmds.append(pkg_full)
                which_removed.append(name)
        if cmds:
            cmd = APT_GET + APT_DO_REMOVE + cmds
            self._execute_apt(cmd)
        #clean them out (if we did anything)
        if which_removed and self.auto_remove:
            cmd = APT_GET + APT_AUTOREMOVE
            self._execute_apt(cmd)
        return which_removed

    def install_batch(self, pkgs):
        pkgnames = sorted(pkgs.keys())
        #form the needed commands
        cmds = []
        for name in pkgnames:
            info = pkgs.get(name) or {}
            if self._pkg_install_special(name, info):
                continue
            pkg_full = self._format_pkg(name, info.get("version"))
            cmds.append(pkg_full)
        #install them
        if cmds:
            cmd = APT_GET + APT_INSTALL + cmds
            self._execute_apt(cmd)

    def _pkg_remove_special(self, name, pkginfo):
        #TODO: maybe this should be a subclass that handles these differences
        if name == 'rabbitmq-server' and self.distro == settings.UBUNTU11:
            #https://bugs.launchpad.net/ubuntu/+source/rabbitmq-server/+bug/878597
            #https://bugs.launchpad.net/ubuntu/+source/rabbitmq-server/+bug/878600
            LOG.info("Handling special remove of %s." % (name))
            pkg_full = self._format_pkg(name, pkginfo.get("version"))
            cmd = APT_GET + APT_REMOVE + [pkg_full]
            self._execute_apt(cmd)
            #probably useful to do this
            time.sleep(1)
            #purge
            cmd = APT_GET + APT_PURGE + [pkg_full]
            self._execute_apt(cmd)
            return True
        return False

    def _pkg_install_special(self, name, pkginfo):
        #TODO: maybe this should be a subclass that handles these differences
        if name == 'rabbitmq-server' and self.distro == settings.UBUNTU11:
            #https://bugs.launchpad.net/ubuntu/+source/rabbitmq-server/+bug/878597
            #https://bugs.launchpad.net/ubuntu/+source/rabbitmq-server/+bug/878600
            LOG.info("Handling special install of %s." % (name))
            #this seems to be a temporary fix for that bug
            with TemporaryFile() as f:
                pkg_full = self._format_pkg(name, pkginfo.get("version"))
                cmd = APT_GET + APT_INSTALL + [pkg_full]
                self._execute_apt(cmd, stdout_fh=f, stderr_fh=f)
                return True
        return False