#!/usr/bin/python -tt
# (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/>.
#

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

APT_PATH = "/usr/bin/apt-get"
APT = "DEBIAN_FRONTEND=noninteractive DEBIAN_PRIORITY=critical %s" % APT_PATH

try:
    import apt, apt_pkg
except ImportError:
    json.dumps(msg="could not import apt, please install the python-apt package on this host", failed=True)
    sys.exit(1)

def run_apt(command):
    try:
        cmd = subprocess.Popen(command, shell=True, 
            stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        out, err = cmd.communicate()
    except (OSError, IOError), e:
        rc = 1
        err = str(e)
        out = ''
    except:
        rc = 1
        err = traceback.format_exc()
        out = ''
    else:
        rc = cmd.returncode
        return rc, out, err

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

def package_status(pkgname, version, cache):
    try:
        pkg = cache[pkgname]
    except KeyError:
        fail_json(msg="No package matching '%s' is available" % pkgname)
    if version:
        try :
            return pkg.is_installed and pkg.installed.version == version, False
        except AttributeError: 
            #assume older version of python-apt is installed
            return pkg.isInstalled and pkg.installedVersion == version, False
    else:
        try :
            return pkg.is_installed, pkg.is_upgradable
        except AttributeError: 
            #assume older version of python-apt is installed
            return pkg.isInstalled, pkg.isUpgradable

def install(pkgspec, cache, upgrade=False, default_release=None, install_recommends=True, force=False):
    name, version = package_split(pkgspec)
    installed, upgradable = package_status(name, version, cache)
    if not installed or (upgrade and upgradable):
        if force:
            force_yes = '--force-yes'
        else:
            force_yes = ''

        cmd = "%s --option Dpkg::Options::=--force-confold -q -y %s install '%s'" % (APT, force_yes, pkgspec)
        if default_release:
            cmd += " -t '%s'" % (default_release,)
        if not install_recommends:
            cmd += " --no-install-recommends"

        rc, out, err = run_apt(cmd)
        return rc, out, err
    else:
        return -1, "", "" # -1 depicts that nothing was changed

def remove(pkgspec, cache, purge=False):
    name, version = package_split(pkgspec)
    installed, upgradable = package_status(name, version, cache)
    if not installed:
        return -1, "", "" # -1 depicts nothing was changed
    else:
        purge = '--purge' if purge else ''
        cmd = "%s -q -y %s remove '%s'" % (APT, purge, name)
        rc, out, err = run_apt(cmd)
        return rc, out, error
    

def main():
    module = AnsibleModule(
        argument_spec = dict(
            state = dict(default='installed', choices=['installed', 'latest', 'removed']),
            update_cache = dict(default='no', choices=['yes', 'no']),
            purge = dict(default='no', choices=['yes', 'no']),
            package = dict(default=None, aliases=['pkg', 'name']),
            default_release = dict(default=None, aliases=['default-release']),
            install_recommends = dict(default='yes', aliases=['install-recommends'], choices=['yes', 'no']),
            force = dict(default='no', choices=['yes', 'no'])
        )
    )

    if not os.path.exists(APT_PATH):
        module.fail_json(msg="Cannot find apt-get")

    p = module.params
    if p['package'] is None and p['update_cache'] != 'yes':
        module.fail_json(msg='pkg=name and/or update-cache=yes is required')
    
    install_recommends = (p['install_recommends'] == 'yes')
    
    cache = apt.Cache()
    if p['default_release']:
        apt_pkg.config['APT::Default-Release'] = p['default_release']
        # reopen cache w/ modified config
        cache.open(progress=None)
    
    if p['update_cache'] == 'yes':
        cache.update()
        cache.open(progress=None)
        if p['package'] == None:
            module.exit_json(changed=False)
    
    if p['force'] == 'yes':
        force_yes = True
    else:
        force_yes = False
    
    if p['package'].count('=') > 1:
        module.fail_json(msg='invalid package spec')
    
    if p['state'] == 'latest':
        if '=' in package:
            module.fail_json(msg='version number inconsistent with state=latest') 

        rc, out, err = install(p['package'], cache, upgrade=True,
                          default_release=p['default_release'],
                          install_recommends=install_recommends,
                          force=force_yes)

    elif p['state'] == 'installed':
        rc, out, err = install(p['package'], cache, default_release=p['default_release'],
                          install_recommends=install_recommends,force=force_yes)
    elif p['state'] == 'removed':
        rc, out, err = remove(p['package'], cache, purge == 'yes')
    
    if rc:
        if rc == -1:
            module.exit_json(changed=False)
        else:
            module.fail_json(msg=err)
    else:
        module.exit_json(changed=True)
    
# this is magic, see lib/ansible/module_common.py
#<<INCLUDE_ANSIBLE_MODULE_COMMON>>

main()