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

# (c) 2012, Red Hat, inc
# Written by Seth Vidal
# based on the mount modules from salt and puppet
#
# 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: mount
short_description: Control active and configured mount points
description:
     - This module controls active and configured mount points in C(/etc/fstab).
version_added: "0.6"
options:
  name:
    description:
      - "path to the mount point, eg: C(/mnt/files)"
    required: true
  src:
    description:
        - device to be mounted on I(name). Required when C(state=present) or C(state=mounted)
    required: false
    default: null
  fstype:
    description:
      - file-system type. Required when C(state=present) or C(state=mounted)
    required: false
    default: null
  opts:
    description:
      - mount options (see fstab(5))
    required: false
    default: null
  dump:
    description:
      - "dump (see fstab(5)), Note that if nulled, C(state=present) will cease to work and duplicate entries will be made with subsequent runs."
    required: false
    default: 0
  passno:
    description:
      - "passno (see fstab(5)), Note that if nulled, C(state=present) will cease to work and duplicate entries will be made with subsequent runs."
    required: false
    default: 0
  state:
    description:
      - If C(mounted) or C(unmounted), the device will be actively mounted or unmounted as needed and appropriately configured in I(fstab).
      - C(absent) and C(present) only deal with I(fstab) but will not affect current mounting.
      - If specifying C(mounted) and the mount point is not present, the mount point will be created. Similarly.
      - Specifying C(absent) will remove the mount point directory.
    required: true
    choices: [ "present", "absent", "mounted", "unmounted" ]
  fstab:
    description:
      - file to use instead of C(/etc/fstab). You shouldn't use that option
        unless you really know what you are doing. This might be useful if
        you need to configure mountpoints in a chroot environment.
    required: false
    default: /etc/fstab

author:
    - Ansible Core Team
    - Seth Vidal
'''
EXAMPLES = '''
# Mount DVD read-only
- mount: name=/mnt/dvd src=/dev/sr0 fstype=iso9660 opts=ro state=present

# Mount up device by label
- mount: name=/srv/disk src='LABEL=SOME_LABEL' fstype=ext4 state=present

# Mount up device by UUID
- mount: name=/home src='UUID=b3e48f45-f933-4c8e-a700-22a159ec9077' fstype=xfs opts=noatime state=present
'''

from ansible.module_utils.six import iteritems

def write_fstab(lines, dest):

    fs_w = open(dest, 'w')
    for l in lines:
        fs_w.write(l)

    fs_w.flush()
    fs_w.close()

def _escape_fstab(v):
    """ escape space (040), ampersand (046) and backslash (134) which are invalid in fstab fields """
    if isinstance(v, int):
        return v
    else:
        return v.replace('\\', '\\134').replace(' ', '\\040').replace('&', '\\046')

def set_mount(module, **kwargs):
    """ set/change a mount point location in fstab """

    # kwargs: name, src, fstype, opts, dump, passno, state, fstab=/etc/fstab
    args = dict(
        opts   = 'defaults',
        dump   = '0',
        passno = '0',
        fstab  = '/etc/fstab'
    )
    args.update(kwargs)

    new_line = '%(src)s %(name)s %(fstype)s %(opts)s %(dump)s %(passno)s\n'

    to_write = []
    exists = False
    changed = False
    escaped_args = dict([(k, _escape_fstab(v)) for k, v in iteritems(args)])
    for line in open(args['fstab'], 'r').readlines():
        if not line.strip():
            to_write.append(line)
            continue
        if line.strip().startswith('#'):
            to_write.append(line)
            continue
        if len(line.split()) != 6:
            # not sure what this is or why it is here
            # but it is not our fault so leave it be
            to_write.append(line)
            continue

        ld = {}
        ld['src'], ld['name'], ld['fstype'], ld['opts'], ld['dump'], ld['passno']  = line.split()

        if ld['name'] != escaped_args['name']:
            to_write.append(line)
            continue

        # it exists - now see if what we have is different
        exists = True
        for t in ('src', 'fstype','opts', 'dump', 'passno'):
            if ld[t] != escaped_args[t]:
                changed = True
                ld[t] = escaped_args[t]

        if changed:
            to_write.append(new_line % ld)
        else:
            to_write.append(line)

    if not exists:
        to_write.append(new_line % escaped_args)
        changed = True

    if changed and not module.check_mode:
        write_fstab(to_write, args['fstab'])

    return (args['name'], changed)


def unset_mount(module, **kwargs):
    """ remove a mount point from fstab """

    # kwargs: name, src, fstype, opts, dump, passno, state, fstab=/etc/fstab
    args = dict(
        opts   = 'default',
        dump   = '0',
        passno = '0',
        fstab  = '/etc/fstab'
    )
    args.update(kwargs)

    to_write = []
    changed = False
    escaped_name = _escape_fstab(args['name'])
    for line in open(args['fstab'], 'r').readlines():
        if not line.strip():
            to_write.append(line)
            continue
        if line.strip().startswith('#'):
            to_write.append(line)
            continue
        if len(line.split()) != 6:
            # not sure what this is or why it is here
            # but it is not our fault so leave it be
            to_write.append(line)
            continue

        ld = {}
        ld['src'], ld['name'], ld['fstype'], ld['opts'], ld['dump'], ld['passno']  = line.split()

        if ld['name'] != escaped_name:
            to_write.append(line)
            continue

        # if we got here we found a match - continue and mark changed
        changed = True

    if changed and not module.check_mode:
        write_fstab(to_write, args['fstab'])

    return (args['name'], changed)


def mount(module, **kwargs):
    """ mount up a path or remount if needed """

    # kwargs: name, src, fstype, opts, dump, passno, state, fstab=/etc/fstab
    args = dict(
        opts   = 'default',
        dump   = '0',
        passno = '0',
        fstab  = '/etc/fstab'
    )
    args.update(kwargs)

    mount_bin = module.get_bin_path('mount')

    name = kwargs['name']

    cmd = [ mount_bin, ]

    if ismount(name):
        cmd += [ '-o', 'remount', ]

    if get_platform().lower() == 'freebsd':
        cmd += [ '-F', args['fstab'], ]

    if get_platform().lower() == 'linux':
        cmd += [ '-T', args['fstab'], ]

    cmd += [ name, ]

    rc, out, err = module.run_command(cmd)
    if rc == 0:
        return 0, ''
    else:
        return rc, out+err

def umount(module, **kwargs):
    """ unmount a path """

    umount_bin = module.get_bin_path('umount')
    name = kwargs['name']
    cmd = [umount_bin, name]

    rc, out, err = module.run_command(cmd)
    if rc == 0:
        return 0, ''
    else:
        return rc, out+err

def main():

    module = AnsibleModule(
        argument_spec = dict(
            state  = dict(required=True, choices=['present', 'absent', 'mounted', 'unmounted']),
            name   = dict(required=True),
            opts   = dict(default=None),
            passno = dict(default=None, type='str'),
            dump   = dict(default=None),
            src    = dict(required=False),
            fstype = dict(required=False),
            fstab  = dict(default='/etc/fstab')
        ),
        supports_check_mode=True,
        required_if = (
            ['state', 'mounted', ['src', 'fstype']],
            ['state', 'present', ['src', 'fstype']]
        )
    )


    changed = False
    rc = 0
    args = {'name': module.params['name']}
    if module.params['src'] is not None:
        args['src'] = module.params['src']
    if module.params['fstype'] is not None:
        args['fstype'] = module.params['fstype']
    if module.params['passno'] is not None:
        args['passno'] = module.params['passno']
    if module.params['opts'] is not None:
        args['opts'] = module.params['opts']
    if module.params['dump'] is not None:
        args['dump'] = module.params['dump']
    if module.params['fstab'] is not None:
        args['fstab'] = module.params['fstab']

    # if fstab file does not exist, we first need to create it. This mainly
    # happens when fstab optin is passed to the module.
    if not os.path.exists(args['fstab']):
        if not os.path.exists(os.path.dirname(args['fstab'])):
            os.makedirs(os.path.dirname(args['fstab']))
        open(args['fstab'],'a').close()

    # absent == remove from fstab and unmounted
    # unmounted == do not change fstab state, but unmount
    # present == add to fstab, do not change mount state
    # mounted == add to fstab if not there and make sure it is mounted, if it has changed in fstab then remount it

    state = module.params['state']
    name  = module.params['name']
    if state == 'absent':
        name, changed = unset_mount(module, **args)
        if changed and not module.check_mode:
            if ismount(name):
                res,msg  = umount(module, **args)
                if res:
                    module.fail_json(msg="Error unmounting %s: %s" % (name, msg))

            if os.path.exists(name):
                try:
                    os.rmdir(name)
                except (OSError, IOError):
                    e = get_exception()
                    module.fail_json(msg="Error rmdir %s: %s" % (name, str(e)))

        module.exit_json(changed=changed, **args)

    if state == 'unmounted':
        if ismount(name):
            if not module.check_mode:
                res,msg  = umount(module, **args)
                if res:
                    module.fail_json(msg="Error unmounting %s: %s" % (name, msg))
            changed = True

        module.exit_json(changed=changed, **args)

    if state in ['mounted', 'present']:
        if state == 'mounted':
            if not os.path.exists(name) and not module.check_mode:
                try:
                    os.makedirs(name)
                except (OSError, IOError):
                    e = get_exception()
                    module.fail_json(msg="Error making dir %s: %s" % (name, str(e)))

        name, changed = set_mount(module, **args)
        if state == 'mounted':
            res = 0
            if ismount(name):
                if changed and not module.check_mode:
                    res,msg = mount(module, **args)
            elif 'bind' in args.get('opts', []):
                changed = True
                cmd = 'mount -l'
                rc, out, err = module.run_command(cmd)
                allmounts = out.split('\n')
                for mounts in allmounts[:-1]:
                    arguments = mounts.split()
                    if arguments[0] == args['src'] and arguments[2] == args['name'] and arguments[4] == args['fstype']:
                        changed = False
                if changed:
                    res,msg = mount(module, **args)
            else:
                changed = True
                if not module.check_mode:
                    res,msg = mount(module, **args)


            if res:
                module.fail_json(msg="Error mounting %s: %s" % (name, msg))


        module.exit_json(changed=changed, **args)

    module.fail_json(msg='Unexpected position reached')

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

main()