#!/usr/bin/python

# Create and manage postfix instances.
# Copyright (c) 2013 Guilhem Moulin <guilhem@fripost.org>
#
# This program 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 program 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 program.  If not, see <http://www.gnu.org/licenses/>.


# Look up postfix configuration variable
def postconf(k, instance=None):
    cmd = [ os.path.join(os.sep, 'usr', 'sbin', 'postconf') ]
    if instance:
        config = os.path.join(os.sep, 'etc', 'postfix-%s' % instance)
        cmd.extend([ '-c', config ])
    cmd.extend([ '-h', k ])
    return subprocess.check_output(cmd, stderr=subprocess.STDOUT).rstrip()


def main():
    module = AnsibleModule(
        argument_spec = dict(
            instance = dict( required=True ),
            group    = dict( required=False )
        ),
        supports_check_mode=True
    )

    params = module.params
    instance = params['instance']
    group = params['group']

    changed=False
    try:
        enable  = postconf('multi_instance_enable')
        wrapper = postconf('multi_instance_wrapper')

        if enable != "yes" or not wrapper:
            # Initiate postmulti
            changed = True
            if module.check_mode:
                module.exit_json(changed=changed, msg="init postmulti")
            cmd = [ os.path.join(os.sep, 'usr', 'sbin', 'postmulti') ]
            cmd.extend([ '-e', 'init' ])
            subprocess.check_output(cmd, stderr=subprocess.STDOUT).rstrip()

        instances = postconf('multi_instance_directories').split()
        if os.path.join(os.sep, 'etc', 'postfix-%s' % instance) not in instances:
            changed = True
            # Create the instance

            if module.check_mode:
                module.exit_json(changed=changed, msg="create postmulti")
            cmd = [ os.path.join(os.sep, 'usr', 'sbin', 'postmulti') ]
            cmd.extend([ '-e', 'create' ])
            if group:
                cmd.extend([ '-G', group ])
            cmd.extend([ '-I', 'postfix-%s' % instance ])
            subprocess.check_output(cmd, stderr=subprocess.STDOUT).rstrip()

        elif group != postconf('multi_instance_group', instance):
           changed = True

           # Assign a new group, or remove the existing group
           if module.check_mode:
               module.exit_json(changed=changed, msg="assign group")
           cmd = [ os.path.join(os.sep, 'usr', 'sbin', 'postmulti') ]
           cmd.extend([ '-e', 'assign', '-i', 'postfix-%s' % instance ])
           if group:
               cmd.extend([ '-G', group ])
           else:
               cmd.extend([ '-G', '-' ])
           subprocess.check_output(cmd, stderr=subprocess.STDOUT).rstrip()

        module.exit_json(changed=changed)

    except subprocess.CalledProcessError, e:
        module.fail_json(rv=e.returncode, msg=e.output.rstrip())


# this is magic, see lib/ansible/module_common.py
#<<INCLUDE_ANSIBLE_MODULE_COMMON>>
main()