#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# (c) 2014, Richard Isaacson <richard.c.isaacson@gmail.com>
#
# This file is part of Ansible
#
# Ansible 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.
#
# Ansible 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 Ansible.  If not, see <http://www.gnu.org/licenses/>.

DOCUMENTATION = '''
---
module: at
short_description: Schedule the execution of a command or scripts via the at command.
description:
 - Use this module to schedule a command or script to run once in the future.
version_added: "0.0"
options:
  user:
    description:
     - The user to execute the at command as.
    required: false
    default: null
  command:
    description:
     - A command to be executed in the future.
    required: false
    default: null
  script_file:
    description:
     - An existing script to be executed in the future.
    required: false
    default: null
  unit_count:
    description:
     - The count of units in the future to execute the command or script.
    required: true
  unit_type:
    description:
     - The type of units in the future to execute the command or script.
    required: true
    choices: ["minutes", "hours", "days", "weeks"]
requirements:
 - at
author: Richard Isaacson
'''

EXAMPLES = '''
# Schedule a command to execute in 20 minutes as root.
- at: command="ls -d > /dev/null" unit_count=1 unit_type="minutes"

# Schedule a script to execute in 1 hour as the neo user.
- at: script_file="/some/script.sh" user="neo" unit_count=1 unit_type="hours"
'''

import os
import tempfile

ATCMD = "/usr/bin/at"

#================================================

def main():
    module = AnsibleModule(
        argument_spec = dict(
            user=dict(required=False),
            command=dict(required=False),
            script_file=dict(required=False),
            unit_count=dict(required=True),
            unit_type=dict(required=True,
                           default=None,
                           choices=["minutes", "hours", "days", "weeks"],
                           type="str")
        ),
        supports_check_mode = False,
    )

    user        = module.params['user']
    command        = module.params['command']
    script_file    = module.params['script_file']
    unit_count     = module.params['unit_count']
    unit_type      = module.params['unit_type']

    if command and script_file:
        module.fail_json(msg="command and script_file are mutually exclusive")

    result = {}

    result['unit_count'] = unit_count
    result['unit_type'] = unit_type

    if command:
        filed, path = tempfile.mkstemp(prefix='at')
        result['script_file'] = path
        fileh = os.fdopen(filed, 'w')
        fileh.write(command)
        fileh.close()
        at_command = "%s now + %s %s -f %s" % (ATCMD, unit_count, unit_type, path)
        if user:
            at_command = "chown %s %s; su '%s' -c '%s'" % (user, path, user, at_command)
        rc, out, err = module.run_command(at_command)
        if rc != 0:
            module.fail_json(msg=err)
        os.unlink(path)
        result['changed'] = True
    elif script_file:
        result['script_file'] = script_file
        at_command = "%s now + %s %s -f %s" % (ATCMD, unit_count, unit_type, script_file)
        if user:
        	# We expect that if this is an installed the permissions are already correct for the user to execute it.
            at_command = "su '%s' -c '%s'" % (user, at_command)
        rc, out, err = module.run_command(at_command)
        if rc != 0:
            module.fail_json(msg=err)
        result['changed'] = True
    else:
        module.fail_json(msg="command or script_file not specified")

    module.exit_json(**result)

# import module snippets
from ansible.module_utils.basic import *
main()