#!/usr/bin/python
# -*- coding: utf-8 -*-

# (c) 2012, Flowroute LLC
# Written by Matthew Williams <matthew@flowroute.com>
# Based on yum module written by Seth Vidal <skvidal at fedoraproject.org>
#
# This module is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This software is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this software.  If not, see <http://www.gnu.org/licenses/>.
#

DOCUMENTATION = '''
---
module: apt
short_description: Manages apt-packages
description:
  - Manages I(apt) packages (such as for Debian/Ubuntu).
version_added: "0.0.2"
options:
  name:
    description:
      - A package name, like C(foo), or package specifier with version, like C(foo=1.0). Name wildcards (fnmatch) like C(apt*) and version wildcards like C(foo=1.0*) are also supported.  Note that the apt-get commandline supports implicit regex matches here but we do not because it can let typos through easier (If you typo C(foo) as C(fo) apt-get would install packages that have "fo" in their name with a warning and a prompt for the user.  Since we don't have warnings and prompts before installing we disallow this.  Use an explicit fnmatch pattern if you want wildcarding)
    required: false
    default: null
    aliases: [ 'pkg', 'package' ]
  state:
    description:
      - Indicates the desired package state. C(latest) ensures that the latest version is installed. C(build-dep) ensures the package build dependencies are installed.
    required: false
    default: present
    choices: [ "latest", "absent", "present", "build-dep" ]
  update_cache:
    description:
      - Run the equivalent of C(apt-get update) before the operation. Can be run as part of the package installation or as a separate step.
    required: false
    default: no
    choices: [ "yes", "no" ]
  cache_valid_time:
    description:
      - If C(update_cache) is specified and the last run is less or equal than I(cache_valid_time) seconds ago, the C(update_cache) gets skipped.
    required: false
    default: no
  purge:
    description:
     - Will force purging of configuration files if the module state is set to I(absent).
    required: false
    default: no
    choices: [ "yes", "no" ]
  default_release:
    description:
      - Corresponds to the C(-t) option for I(apt) and sets pin priorities
    required: false
    default: null
  install_recommends:
    description:
      - Corresponds to the C(--no-install-recommends) option for I(apt). C(yes) installs recommended packages.  C(no) does not install recommended packages. By default, Ansible will use the same defaults as the operating system. Suggested packages are never installed.
    required: false
    default: null
    choices: [ "yes", "no" ]
  force:
    description:
      - If C(yes), force installs/removes.
    required: false
    default: "no"
    choices: [ "yes", "no" ]
  allow_unauthenticated:
    description:
      - Ignore if packages cannot be authenticated. This is useful for bootstrapping environments that manage their own apt-key setup.
    required: false
    default: "no"
    choices: [ "yes", "no" ]
    version_added: "2.1"
  upgrade:
    description:
      - 'If yes or safe, performs an aptitude safe-upgrade.'
      - 'If full, performs an aptitude full-upgrade.'
      - 'If dist, performs an apt-get dist-upgrade.'
      - 'Note: This does not upgrade a specific package, use state=latest for that.'
    version_added: "1.1"
    required: false
    default: "no"
    choices: [ "no", "yes", "safe", "full", "dist"]
  dpkg_options:
    description:
      - Add dpkg options to apt command. Defaults to '-o "Dpkg::Options::=--force-confdef" -o "Dpkg::Options::=--force-confold"'
      - Options should be supplied as comma separated list
    required: false
    default: 'force-confdef,force-confold'
  deb:
     description:
       - Path to a .deb package on the remote machine.
       - If :// in the path, ansible will attempt to download deb before installing. (Version added 2.1)
     required: false
     version_added: "1.6"
  autoremove:
    description:
      - If C(yes), remove unused dependency packages for all module states except I(build-dep).
    required: false
    default: no
    choices: [ "yes", "no" ]
    aliases: [ 'autoclean']
    version_added: "2.1"
  only_upgrade:
    description:
      - Only install/upgrade a package if it is already installed.
    required: false
    default: false
    version_added: "2.1"

requirements: [ python-apt, aptitude ]
author: "Matthew Williams (@mgwilliams)"
notes:
   - Three of the upgrade modes (C(full), C(safe) and its alias C(yes)) require C(aptitude), otherwise
     C(apt-get) suffices.
'''

EXAMPLES = '''
# Update repositories cache and install "foo" package
- apt: name=foo update_cache=yes

# Remove "foo" package
- apt: name=foo state=absent

# Install the package "foo"
- apt: name=foo state=present

# Install the version '1.00' of package "foo"
- apt: name=foo=1.00 state=present

# Update the repository cache and update package "nginx" to latest version using default release squeeze-backport
- apt: name=nginx state=latest default_release=squeeze-backports update_cache=yes

# Install latest version of "openjdk-6-jdk" ignoring "install-recommends"
- apt: name=openjdk-6-jdk state=latest install_recommends=no

# Update all packages to the latest version
- apt: upgrade=dist

# Run the equivalent of "apt-get update" as a separate step
- apt: update_cache=yes

# Only run "update_cache=yes" if the last one is more than 3600 seconds ago
- apt: update_cache=yes cache_valid_time=3600

# Pass options to dpkg on run
- apt: upgrade=dist update_cache=yes dpkg_options='force-confold,force-confdef'

# Install a .deb package
- apt: deb=/tmp/mypackage.deb

# Install the build dependencies for package "foo"
- apt: pkg=foo state=build-dep

# Install a .deb package from the internet.
- apt: deb=https://example.com/python-ppq_0.1-1_all.deb
'''

RETURN = '''
cache_updated:
    description: if the cache was updated or not
    returned: success, in some cases
    type: boolean
    sample: True
cache_update_time:
    description: time of the last cache update (0 if unknown)
    returned: success, in some cases
    type: datetime
    sample: 1425828348000
stdout:
    description: output from apt
    returned: success, when needed
    type: string
    sample: "Reading package lists...\nBuilding dependency tree...\nReading state information...\nThe following extra packages will be installed:\n  apache2-bin ..."
stderr:
    description: error output from apt
    returned: success, when needed
    type: string
    sample: "AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1. Set the 'ServerName' directive globally to ..."
'''

import traceback
# added to stave off future warnings about apt api
import warnings
warnings.filterwarnings('ignore', "apt API not stable yet", FutureWarning)

import os
import datetime
import fnmatch
import itertools

# APT related constants
APT_ENV_VARS = dict(
        DEBIAN_FRONTEND = 'noninteractive',
        DEBIAN_PRIORITY = 'critical',
        # We screenscrape apt-get and aptitude output for information so we need
        # to make sure we use the C locale when running commands
        LANG = 'C',
        LC_ALL = 'C',
        LC_MESSAGES = 'C',
        LC_CTYPE = 'C',
)

DPKG_OPTIONS = 'force-confdef,force-confold'
APT_GET_ZERO = "\n0 upgraded, 0 newly installed"
APTITUDE_ZERO = "\n0 packages upgraded, 0 newly installed"
APT_LISTS_PATH = "/var/lib/apt/lists"
APT_UPDATE_SUCCESS_STAMP_PATH = "/var/lib/apt/periodic/update-success-stamp"

HAS_PYTHON_APT = True
try:
    import apt
    import apt.debfile
    import apt_pkg
except ImportError:
    HAS_PYTHON_APT = False

def package_split(pkgspec):
    parts = pkgspec.split('=', 1)
    if len(parts) > 1:
        return parts[0], parts[1]
    else:
        return parts[0], None

def package_versions(pkgname, pkg, pkg_cache):
    try:
        versions = set(p.version for p in pkg.versions)
    except AttributeError:
        # assume older version of python-apt is installed
        # apt.package.Package#versions require python-apt >= 0.7.9.
        pkg_cache_list = (p for p in pkg_cache.Packages if p.Name == pkgname)
        pkg_versions = (p.VersionList for p in pkg_cache_list)
        versions = set(p.VerStr for p in itertools.chain(*pkg_versions))

    return versions

def package_version_compare(version, other_version):
    try:
        return apt_pkg.version_compare(version, other_version)
    except AttributeError:
        return apt_pkg.VersionCompare(version, other_version)

def package_status(m, pkgname, version, cache, state):
    try:
        # get the package from the cache, as well as the
        # the low-level apt_pkg.Package object which contains
        # state fields not directly acccesible from the
        # higher-level apt.package.Package object.
        pkg = cache[pkgname]
        ll_pkg = cache._cache[pkgname] # the low-level package object
    except KeyError:
        if state == 'install':
            try:
                provided_packages = cache.get_providing_packages(pkgname)
                if provided_packages:
                    is_installed = False
                    upgradable = False
                    # when virtual package providing only one package, look up status of target package
                    if cache.is_virtual_package(pkgname) and len(provided_packages) == 1:
                        package = provided_packages[0]
                        installed, upgradable, has_files = package_status(m, package.name, version, cache, state='install')
                        if installed:
                            is_installed = True
                    return is_installed, upgradable, False
                m.fail_json(msg="No package matching '%s' is available" % pkgname)
            except AttributeError:
                # python-apt version too old to detect virtual packages
                # mark as upgradable and let apt-get install deal with it
                return False, True, False
        else:
            return False, False, False
    try:
        has_files = len(pkg.installed_files) > 0
    except UnicodeDecodeError:
        has_files = True
    except AttributeError:
        has_files = False  # older python-apt cannot be used to determine non-purged

    try:
        package_is_installed = ll_pkg.current_state == apt_pkg.CURSTATE_INSTALLED
    except AttributeError: # python-apt 0.7.X has very weak low-level object
        try:
            # might not be necessary as python-apt post-0.7.X should have current_state property
            package_is_installed = pkg.is_installed
        except AttributeError:
            # assume older version of python-apt is installed
            package_is_installed = pkg.isInstalled

    if version:
        versions = package_versions(pkgname, pkg, cache._cache)
        avail_upgrades = fnmatch.filter(versions, version)

        if package_is_installed:
            try:
                installed_version = pkg.installed.version
            except AttributeError:
                installed_version = pkg.installedVersion

            # Only claim the package is installed if the version is matched as well
            package_is_installed = fnmatch.fnmatch(installed_version, version)

            # Only claim the package is upgradable if a candidate matches the version
            package_is_upgradable = False
            for candidate in avail_upgrades:
                if package_version_compare(candidate, installed_version) > 0:
                    package_is_upgradable = True
                    break
        else:
            package_is_upgradable = bool(avail_upgrades)
    else:
        try:
            package_is_upgradable = pkg.is_upgradable
        except AttributeError:
            # assume older version of python-apt is installed
            package_is_upgradable = pkg.isUpgradable

    return package_is_installed, package_is_upgradable, has_files

def expand_dpkg_options(dpkg_options_compressed):
    options_list = dpkg_options_compressed.split(',')
    dpkg_options = ""
    for dpkg_option in options_list:
        dpkg_options = '%s -o "Dpkg::Options::=--%s"' \
                       % (dpkg_options, dpkg_option)
    return dpkg_options.strip()

def expand_pkgspec_from_fnmatches(m, pkgspec, cache):
    # Note: apt-get does implicit regex matching when an exact package name
    # match is not found.  Something like this:
    # matches = [pkg.name for pkg in cache if re.match(pkgspec, pkg.name)]
    # (Should also deal with the ':' for multiarch like the fnmatch code below)
    #
    # We have decided not to do similar implicit regex matching but might take
    # a PR to add some sort of explicit regex matching:
    # https://github.com/ansible/ansible-modules-core/issues/1258
    new_pkgspec = []
    for pkgspec_pattern in pkgspec:
        pkgname_pattern, version = package_split(pkgspec_pattern)

        # note that none of these chars is allowed in a (debian) pkgname
        if frozenset('*?[]!').intersection(pkgname_pattern):
            # handle multiarch pkgnames, the idea is that "apt*" should
            # only select native packages. But "apt*:i386" should still work
            if not ":" in pkgname_pattern:
                try:
                    pkg_name_cache = _non_multiarch
                except NameError:
                    pkg_name_cache = _non_multiarch = [pkg.name for pkg in cache if not ':' in pkg.name]
            else:
                try:
                    pkg_name_cache = _all_pkg_names
                except NameError:
                    pkg_name_cache = _all_pkg_names = [pkg.name for pkg in cache]
            matches = fnmatch.filter(pkg_name_cache, pkgname_pattern)

            if len(matches) == 0:
                m.fail_json(msg="No package(s) matching '%s' available" % str(pkgname_pattern))
            else:
                new_pkgspec.extend(matches)
        else:
            # No wildcards in name
            new_pkgspec.append(pkgspec_pattern)
    return new_pkgspec

def parse_diff(output):
    diff = output.splitlines()
    try:
        # check for start marker from aptitude
        diff_start = diff.index('Resolving dependencies...')
    except ValueError:
        try:
            # check for start marker from apt-get
            diff_start = diff.index('Reading state information...')
        except ValueError:
            diff_start = -1
            diff.insert(0, 'Unexpected apt output for --diff. Showing everything:')
    try:
        # check for end marker line from both apt-get and aptitude
        diff_end = (i for i, item in enumerate(diff) if re.match('[0-9]+ (packages )?upgraded', item)).next()
    except StopIteration:
        diff_end = len(diff)
    diff_start += 1
    diff_end += 1
    return {'prepared': '\n'.join(diff[diff_start:diff_end])}

def install(m, pkgspec, cache, upgrade=False, default_release=None,
            install_recommends=None, force=False,
            dpkg_options=expand_dpkg_options(DPKG_OPTIONS),
            build_dep=False, autoremove=False, only_upgrade=False,
            allow_unauthenticated=False):
    pkg_list = []
    packages = ""
    pkgspec = expand_pkgspec_from_fnmatches(m, pkgspec, cache)
    for package in pkgspec:
        name, version = package_split(package)
        installed, upgradable, has_files = package_status(m, name, version, cache, state='install')
        if build_dep:
            # Let apt decide what to install
            pkg_list.append("'%s'" % package)
            continue
        if not installed or (upgrade and upgradable):
            pkg_list.append("'%s'" % package)
        if installed and upgradable and version:
            # This happens when the package is installed, a newer version is
            # available, and the version is a wildcard that matches both
            #
            # We do not apply the upgrade flag because we cannot specify both
            # a version and state=latest.  (This behaviour mirrors how apt
            # treats a version with wildcard in the package)
            pkg_list.append("'%s'" % package)
    packages = ' '.join(pkg_list)

    if len(packages) != 0:
        if force:
            force_yes = '--force-yes'
        else:
            force_yes = ''

        if m.check_mode:
            check_arg = '--simulate'
        else:
            check_arg = ''

        if autoremove:
            autoremove = '--auto-remove'
        else:
            autoremove = ''

        if only_upgrade:
            only_upgrade = '--only-upgrade'
        else:
            only_upgrade = ''

        if build_dep:
            cmd = "%s -y %s %s %s %s build-dep %s" % (APT_GET_CMD, dpkg_options, only_upgrade, force_yes, check_arg, packages)
        else:
            cmd = "%s -y %s %s %s %s %s install %s" % (APT_GET_CMD, dpkg_options, only_upgrade, force_yes, autoremove, check_arg, packages)

        if default_release:
            cmd += " -t '%s'" % (default_release,)

        if install_recommends is False:
            cmd += " -o APT::Install-Recommends=no"
        elif install_recommends is True:
            cmd += " -o APT::Install-Recommends=yes"
        # install_recommends is None uses the OS default

        if allow_unauthenticated:
            cmd += " --allow-unauthenticated"

        rc, out, err = m.run_command(cmd)
        if m._diff:
            diff = parse_diff(out)
        else:
            diff = {}
        if rc:
            return (False, dict(msg="'%s' failed: %s" % (cmd, err), stdout=out, stderr=err))
        else:
            return (True, dict(changed=True, stdout=out, stderr=err, diff=diff))
    else:
        return (True, dict(changed=False))

def get_field_of_deb(m, deb_file, field="Version"):
    cmd_dpkg = m.get_bin_path("dpkg", True)
    cmd = cmd_dpkg + " --field %s %s" % (deb_file, field)
    rc, stdout, stderr = m.run_command(cmd)
    if rc != 0:
        m.fail_json(msg="%s failed" % cmd, stdout=stdout, stderr=stderr)
    return stdout.strip('\n')

def install_deb(m, debs, cache, force, install_recommends, allow_unauthenticated, dpkg_options):
    changed=False
    deps_to_install = []
    pkgs_to_install = []
    for deb_file in debs.split(','):
        try:
            pkg = apt.debfile.DebPackage(deb_file)
            pkg_name = get_field_of_deb(m, deb_file, "Package")
            pkg_version = get_field_of_deb(m, deb_file, "Version")
            try:
                installed_pkg = apt.Cache()[pkg_name]
                installed_version = installed_pkg.installed.version
                if package_version_compare(pkg_version, installed_version) == 0:
                    # Does not need to down-/upgrade, move on to next package
                    continue
            except Exception, e:
                # Must not be installed, continue with installation
                pass
            # Check if package is installable
            if not pkg.check() and not force:
                m.fail_json(msg=pkg._failure_string)

            # add any missing deps to the list of deps we need
            # to install so they're all done in one shot
            deps_to_install.extend(pkg.missing_deps)

        except Exception:
            e = get_exception()
            m.fail_json(msg="Unable to install package: %s" % str(e))

        # and add this deb to the list of packages to install
        pkgs_to_install.append(deb_file)

    # install the deps through apt
    retvals = {}
    if len(deps_to_install) > 0:
        (success, retvals) = install(m=m, pkgspec=deps_to_install, cache=cache,
                                     install_recommends=install_recommends,
                                     dpkg_options=expand_dpkg_options(dpkg_options))
        if not success:
            m.fail_json(**retvals)
        changed = retvals.get('changed', False)

    if len(pkgs_to_install) > 0:
        options = ' '.join(["--%s"% x for x in dpkg_options.split(",")])
        if m.check_mode:
            options += " --simulate"
        if force:
            options += " --force-all"

        cmd = "dpkg %s -i %s" % (options, " ".join(pkgs_to_install))
        rc, out, err = m.run_command(cmd)
        if "stdout" in retvals:
            stdout = retvals["stdout"] + out
        else:
            stdout = out
        if "diff" in retvals:
            diff = retvals["diff"]
            diff["prepared"] += '\n\n' + out
        else:
            diff = out
        if "stderr" in retvals:
            stderr = retvals["stderr"] + err
        else:
            stderr = err

        if rc == 0:
            m.exit_json(changed=True, stdout=stdout, stderr=stderr, diff=diff)
        else:
            m.fail_json(msg="%s failed" % cmd, stdout=stdout, stderr=stderr)
    else:
        m.exit_json(changed=changed, stdout=retvals.get('stdout',''), stderr=retvals.get('stderr',''), diff=retvals.get('diff', ''))

def remove(m, pkgspec, cache, purge=False,
           dpkg_options=expand_dpkg_options(DPKG_OPTIONS), autoremove=False):
    pkg_list = []
    pkgspec = expand_pkgspec_from_fnmatches(m, pkgspec, cache)
    for package in pkgspec:
        name, version = package_split(package)
        installed, upgradable, has_files = package_status(m, name, version, cache, state='remove')
        if installed or (has_files and purge):
            pkg_list.append("'%s'" % package)
    packages = ' '.join(pkg_list)

    if len(packages) == 0:
        m.exit_json(changed=False)
    else:
        if purge:
            purge = '--purge'
        else:
            purge = ''

        if autoremove:
            autoremove = '--auto-remove'
        else:
            autoremove = ''

        if m.check_mode:
            check_arg = '--simulate'
        else:
            check_arg = ''

        cmd = "%s -q -y %s %s %s %s remove %s" % (APT_GET_CMD, dpkg_options, purge, autoremove, check_arg, packages)

        rc, out, err = m.run_command(cmd)
        if m._diff:
            diff = parse_diff(out)
        else:
            diff = {}
        if rc:
            m.fail_json(msg="'apt-get remove %s' failed: %s" % (packages, err), stdout=out, stderr=err)
        m.exit_json(changed=True, stdout=out, stderr=err, diff=diff)

def upgrade(m, mode="yes", force=False, default_release=None,
            dpkg_options=expand_dpkg_options(DPKG_OPTIONS)):
    if m.check_mode:
        check_arg = '--simulate'
    else:
        check_arg = ''

    apt_cmd = None
    prompt_regex = None
    if mode == "dist":
        # apt-get dist-upgrade
        apt_cmd = APT_GET_CMD
        upgrade_command = "dist-upgrade"
    elif mode == "full":
        # aptitude full-upgrade
        apt_cmd = APTITUDE_CMD
        upgrade_command = "full-upgrade"
    else:
        # aptitude safe-upgrade # mode=yes # default
        apt_cmd = APTITUDE_CMD
        upgrade_command = "safe-upgrade"
        prompt_regex = r"(^Do you want to ignore this warning and proceed anyway\?|^\*\*\*.*\[default=.*\])"

    if force:
        if apt_cmd == APT_GET_CMD:
            force_yes = '--force-yes'
        else:
            force_yes = '--assume-yes --allow-untrusted'
    else:
        force_yes = ''

    apt_cmd_path = m.get_bin_path(apt_cmd, required=True)

    cmd = '%s -y %s %s %s %s' % (apt_cmd_path, dpkg_options,
                                    force_yes, check_arg, upgrade_command)

    if default_release:
        cmd += " -t '%s'" % (default_release,)

    rc, out, err = m.run_command(cmd, prompt_regex=prompt_regex)
    if m._diff:
        diff = parse_diff(out)
    else:
        diff = {}
    if rc:
        m.fail_json(msg="'%s %s' failed: %s" % (apt_cmd, upgrade_command, err), stdout=out)
    if (apt_cmd == APT_GET_CMD and APT_GET_ZERO in out) or (apt_cmd == APTITUDE_CMD and APTITUDE_ZERO in out):
        m.exit_json(changed=False, msg=out, stdout=out, stderr=err)
    m.exit_json(changed=True, msg=out, stdout=out, stderr=err, diff=diff)

def download(module, deb):
    tempdir = os.path.dirname(__file__)
    package = os.path.join(tempdir, str(deb.rsplit('/', 1)[1]))
    # When downloading a deb, how much of the deb to download before
    # saving to a tempfile (64k)
    BUFSIZE = 65536

    try:
        rsp, info = fetch_url(module, deb)
        f = open(package, 'w')
        # Read 1kb at a time to save on ram
        while True:
            data = rsp.read(BUFSIZE)

            if data == "":
                break # End of file, break while loop

            f.write(data)
        f.close()
        deb = package
    except Exception:
        e = get_exception()
        module.fail_json(msg="Failure downloading %s, %s" % (deb, e))

    return deb

def main():
    module = AnsibleModule(
        argument_spec = dict(
            state = dict(default='present', choices=['installed', 'latest', 'removed', 'absent', 'present', 'build-dep']),
            update_cache = dict(default=False, aliases=['update-cache'], type='bool'),
            cache_valid_time = dict(type='int'),
            purge = dict(default=False, type='bool'),
            package = dict(default=None, aliases=['pkg', 'name'], type='list'),
            deb = dict(default=None, type='path'),
            default_release = dict(default=None, aliases=['default-release']),
            install_recommends = dict(default=None, aliases=['install-recommends'], type='bool'),
            force = dict(default='no', type='bool'),
            upgrade = dict(choices=['no', 'yes', 'safe', 'full', 'dist']),
            dpkg_options = dict(default=DPKG_OPTIONS),
            autoremove = dict(type='bool', default=False, aliases=['autoclean']),
            only_upgrade = dict(type='bool', default=False),
            allow_unauthenticated = dict(default='no', aliases=['allow-unauthenticated'], type='bool'),
        ),
        mutually_exclusive = [['package', 'upgrade', 'deb']],
        required_one_of = [['package', 'upgrade', 'update_cache', 'deb']],
        supports_check_mode = True
    )

    module.run_command_environ_update = APT_ENV_VARS

    if not HAS_PYTHON_APT:
        if module.check_mode:
            module.fail_json(msg="python-apt must be installed to use check mode. If run normally this module can autoinstall it")
        try:
            module.run_command('apt-get update', check_rc=True)
            module.run_command('apt-get install python-apt -y -q', check_rc=True)
            global apt, apt_pkg
            import apt
            import apt.debfile
            import apt_pkg
        except ImportError:
            module.fail_json(msg="Could not import python modules: apt, apt_pkg. Please install python-apt package.")

    global APTITUDE_CMD
    APTITUDE_CMD = module.get_bin_path("aptitude", False)
    global APT_GET_CMD
    APT_GET_CMD = module.get_bin_path("apt-get")

    p = module.params

    if p['upgrade'] == 'no':
        p['upgrade'] = None

    if not APTITUDE_CMD and p.get('upgrade', None) in [ 'full', 'safe', 'yes' ]:
        module.fail_json(msg="Could not find aptitude. Please ensure it is installed.")

    updated_cache = False
    updated_cache_time = 0
    install_recommends = p['install_recommends']
    allow_unauthenticated = p['allow_unauthenticated']
    dpkg_options = expand_dpkg_options(p['dpkg_options'])
    autoremove = p['autoremove']

    # Deal with deprecated aliases
    if p['state'] == 'installed':
        p['state'] = 'present'
    if p['state'] == 'removed':
        p['state'] = 'absent'

    try:
        cache = apt.Cache()
        if p['default_release']:
            try:
                apt_pkg.config['APT::Default-Release'] = p['default_release']
            except AttributeError:
                apt_pkg.Config['APT::Default-Release'] = p['default_release']
            # reopen cache w/ modified config
            cache.open(progress=None)

        if p['update_cache']:
            # Default is: always update the cache
            cache_valid = False
            now = datetime.datetime.now()
            if p.get('cache_valid_time', False):
                try:
                    mtime = os.stat(APT_UPDATE_SUCCESS_STAMP_PATH).st_mtime
                except:
                    # Looks like the update-success-stamp is not available
                    # Fallback: Checking the mtime of the lists
                    try:
                        mtime = os.stat(APT_LISTS_PATH).st_mtime
                    except:
                        # No mtime could be read. We update the cache to be safe
                        mtime = False

                if mtime:
                    tdelta = datetime.timedelta(seconds=p['cache_valid_time'])
                    mtimestamp = datetime.datetime.fromtimestamp(mtime)
                    if mtimestamp + tdelta >= now:
                        cache_valid = True
                        updated_cache_time = int(time.mktime(mtimestamp.timetuple()))

            if cache_valid is not True:
                for retry in xrange(3):
                    try:
                        cache.update()
                        break
                    except apt.cache.FetchFailedException:
                        pass
                else:
                    #out of retries, pass on the exception
                    raise
                cache.open(progress=None)
                updated_cache = True
                updated_cache_time = int(time.mktime(now.timetuple()))
            if not p['package'] and not p['upgrade'] and not p['deb']:
                module.exit_json(changed=False, cache_updated=updated_cache, cache_update_time=updated_cache_time)
        else:
            updated_cache = False
            updated_cache_time = 0

        force_yes = p['force']

        if p['upgrade']:
            upgrade(module, p['upgrade'], force_yes, p['default_release'], dpkg_options)

        if p['deb']:
            if p['state'] != 'present':
                module.fail_json(msg="deb only supports state=present")
            if '://' in p['deb']:
                p['deb'] = download(module, p['deb'])
            install_deb(module, p['deb'], cache,
                        install_recommends=install_recommends,
                        allow_unauthenticated=allow_unauthenticated,
                        force=force_yes, dpkg_options=p['dpkg_options'])

        packages = p['package']
        latest = p['state'] == 'latest'
        for package in packages:
            if package.count('=') > 1:
                module.fail_json(msg="invalid package spec: %s" % package)
            if latest and '=' in package:
                module.fail_json(msg='version number inconsistent with state=latest: %s' % package)

        if p['state'] in ('latest', 'present', 'build-dep'):
            state_upgrade = False
            state_builddep = False
            if p['state'] == 'latest':
                state_upgrade = True
            if p['state'] == 'build-dep':
                state_builddep = True
            result = install(module, packages, cache, upgrade=state_upgrade,
                    default_release=p['default_release'],
                    install_recommends=install_recommends,
                    force=force_yes, dpkg_options=dpkg_options,
                    build_dep=state_builddep, autoremove=autoremove,
                    only_upgrade=p['only_upgrade'],
                    allow_unauthenticated=allow_unauthenticated)
            (success, retvals) = result
            retvals['cache_updated']=updated_cache
            retvals['cache_update_time']=updated_cache_time
            if success:
                module.exit_json(**retvals)
            else:
                module.fail_json(**retvals)
        elif p['state'] == 'absent':
            remove(module, packages, cache, p['purge'], dpkg_options, autoremove)

    except apt.cache.LockFailedException:
        module.fail_json(msg="Failed to lock apt for exclusive operation")
    except apt.cache.FetchFailedException:
        module.fail_json(msg="Could not fetch updated apt files")

# import module snippets
from ansible.module_utils.basic import *
from ansible.module_utils.urls import *

if __name__ == "__main__":
    main()
