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

# (c) 2012, Stephen Fromm <sfromm@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: user
author: Stephen Fromm
version_added: 0.2
short_description: Manage user accounts
requirements: [ useradd, userdel, usermod ]
description:
    - Manage user accounts and user attributes.
options:
    name:
        required: true
        aliases: [ "user" ]
        description:
            - Name of the user to create, remove or modify.
    comment:
        required: false
        description:
            - Optionally sets the description (aka I(GECOS)) of user account.
    uid:
        required: false
        description:
            - Optionally sets the I(UID) of the user.
    group:
        required: false
        description:
            - Optionally sets the user's primary group (takes a group name).
    groups:
        required: false
        description:
            - Puts the user in this comma-delimited list of groups.
    append:
        required: false
        description:
            - If I(yes), will only add groups, not set them to just the list
              in I(groups).
    shell:
        required: false
        description:
            - Optionally set the user's shell.
    home:
        required: false
        description:
            - Optionally set the user's home directory.
    password:
        required: false
        description:
            - Optionally set the user's password to this crypted value.  See
              the user example in the github examples directory for what this looks
              like in a playbook.
    state:
        required: false
        default: "present"
        choices: [ present, absent ]
        description:
            - Whether the account should exist.  When I(absent), removes
              the user account.
    createhome:
        required: false
        default: "yes"
        choices: [ yes, no ]
        description:
            - Unless set to I(no), a home directory will be made for the user
              when the account is created.
    system:
        required: false
        default: "no"
        choices: [ yes, no ]
        description:
            - When creating an account, setting this to I(yes) makes the user a
              system account.  This setting cannot be changed on existing users.
    force:
        required: false
        default: "no"
        choices: [ yes, no ]
        description:
            - When used with I(state=absent), behavior is as with
              I(userdel --force).
    remove:
        required: false
        default: "no"
        choices: [ yes, no ]
        description:
            - When used with I(state=absent), behavior is as with
              I(userdel --remove).
    generate_ssh_key:
        required: false
        default: "no"
        choices: [ yes, no ]
        version_added: "0.9"
        description:
            - Whether to generate a SSH key for the user in question.
              This will B(not) overwrite an existing SSH key.
    ssh_key_bits:
        required: false
        default: 2048
        version_added: "0.9"
        description:
            - Optionally specify number of bits in SSH key to create.
    ssh_key_type:
        required: false
        default: rsa
        version_added: "0.9"
        description:
            - Optionally specify the type of SSH key to generate. 
              Available SSH key types will depend on implementation
              present on target host.
    ssh_key_file:
        required: false
        default: $HOME/.ssh/id_rsa
        version_added: "0.9"
        description:
            - Optionally specify the SSH key filename.
    ssh_key_comment:
        required: false
        default: ansible-generated
        version_added: "0.9"
        description:
            - Optionally define the comment for the SSH key.
    ssh_key_passphrase:
        required: false
        version_added: "0.9"
        description:
            - Set a passphrase for the SSH key.  If no
              passphrase is provided, the SSH key will default to
              having no passphrase.
examples:
    - code: 'user: name=johnd comment="John Doe" uid=1040'
      description: "Add the user 'johnd' with a specific uid and a primary group of 'admin'"
    - code: "user: name=johnd state=absent remove=yes"
      description: "Remove the user 'johnd'"
    - code: 'user: name=jsmith generate_ssh_key=yes ssh_key_bits=2048'
      description: "Create a 2048-bit SSH key for user jsmith"
'''

import os
import pwd
import grp
import syslog
import platform

try:
    import spwd
    HAVE_SPWD=True
except:
    HAVE_SPWD=False


class User(object):
    """
    This is a generic User manipulation class that is subclassed
    based on platform.  
    
    A subclass may wish to override the following action methods:-
      - create_user()
      - remove_user()
      - modify_user()
      - ssh_key_gen()
      - ssh_key_fingerprint()
      - user_exists()

    All subclasses MUST define platform and distribution (which may be None).
    """

    platform = 'Generic'
    distribution = None
    SHADOWFILE = '/etc/shadow'

    def __new__(cls, *args, **kwargs):
        return load_platform_subclass(User, args, kwargs)

    def __init__(self, module):
        self.module     = module
        self.state      = module.params['state']
        self.name       = module.params['name']
        self.uid        = module.params['uid']
        self.group      = module.params['group']
        self.groups     = module.params['groups']
        self.comment    = module.params['comment']
        self.home       = module.params['home']
        self.shell      = module.params['shell']
        self.password   = module.params['password']
        self.force      = module.boolean(module.params['force'])
        self.remove     = module.boolean(module.params['remove'])
        self.createhome = module.boolean(module.params['createhome'])
        self.system     = module.boolean(module.params['system'])
        self.append     = module.boolean(module.params['append'])
        self.sshkeygen  = module.boolean(module.params['generate_ssh_key'])
        self.ssh_bits   = module.params['ssh_key_bits']
        self.ssh_type   = module.params['ssh_key_type']
        self.ssh_comment = module.params['ssh_key_comment']
        self.ssh_passphrase = module.params['ssh_key_passphrase']
        if module.params['ssh_key_file'] is not None:
            self.ssh_file = module.params['ssh_key_file']
        else:
            self.ssh_file = os.path.join('.ssh', 'id_%s' % self.ssh_type)

        # select whether we dump additional debug info through syslog
        self.syslogging = False

    def execute_command(self,cmd):
        if self.syslogging:
            syslog.openlog('ansible-%s' % os.path.basename(__file__))
            syslog.syslog(syslog.LOG_NOTICE, 'Command %s' % '|'.join(cmd))

        p = subprocess.Popen(cmd, shell=False, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        (out, err) = p.communicate()
        rc = p.returncode
        return (rc, out, err)

    def remove_user_userdel(self):
        cmd = [self.module.get_bin_path('userdel', True)]
        if self.force:
            cmd.append('-f')
        elif self.remove:
            cmd.append('-r')
        cmd.append(self.name)

        return self.execute_command(cmd)

    def create_user_useradd(self, command_name='useradd'):
        cmd = [self.module.get_bin_path(command_name, True)]

        if self.uid is not None:
            cmd.append('-u')
            cmd.append(self.uid)

        if self.group is not None:
            if not user.group_exists(self.group):
                self.module.fail_json(msg="Group %s does not exist" % self.group)
            cmd.append('-g')
            cmd.append(self.group)

        if self.groups is not None:
            for g in self.groups.split(','):
                if not self.group_exists(g):
                    self.module.fail_json(msg="Group %s does not exist" % (g))
            cmd.append('-G')
            cmd.append(self.groups)

        if self.comment is not None:
            cmd.append('-c')
            cmd.append(self.comment)

        if self.home is not None:
            cmd.append('-d')
            cmd.append(self.home)

        if self.shell is not None:
            cmd.append('-s')
            cmd.append(self.shell)

        if self.password is not None:
            cmd.append('-p')
            cmd.append(self.password)

        if self.createhome:
            cmd.append('-m')
        else:
            cmd.append('-M')

        if self.system:
            cmd.append('-r')

        cmd.append(self.name)
        return self.execute_command(cmd)


    def modify_user_usermod(self):
        cmd = [self.module.get_bin_path('usermod', True)]
        info = self.user_info()

        if self.uid is not None and info[2] != int(self.uid):
            cmd.append('-u')
            cmd.append(self.uid)

        if self.group is not None:
            if not self.group_exists(self.group):
                module.fail_json(msg="Group %s does not exist" % self.group)
            ginfo = self.group_info(self.group)
            if info[3] != ginfo[2]:
                cmd.append('-g')
                cmd.append(self.group)

        if self.groups is not None:
            current_groups = self.user_group_membership()
            groups = self.groups.split(',')
            for g in groups:
                if not self.group_exists(g):
                    module.fail_json(msg="Group %s does not exist" % (g))

            group_diff = set(sorted(current_groups)).symmetric_difference(set(sorted(groups)))
            groups_need_mod = False

            if group_diff:
                if self.append:
                    for g in groups:
                        if g in group_diff:
                            cmd.append('-a')
                            groups_need_mod = True
                            break
                else:
                    groups_need_mod = True

            if groups_need_mod:
                cmd.append('-G')
                cmd.append(','.join(groups))

        if self.comment is not None and info[4] != self.comment:
                cmd.append('-c')
                cmd.append(self.comment)

        if self.home is not None and info[5] != self.home:
            cmd.append('-d')
            cmd.append(self.home)

        if self.shell is not None and info[6] != self.shell:
            cmd.append('-s')
            cmd.append(self.shell)

        if self.password is not None and info[1] != self.password:
            cmd.append('-p')
            cmd.append(self.password)

        # skip if no changes to be made
        if len(cmd) == 1:
            return (None, '', '')

        cmd.append(self.name)
        return self.execute_command(cmd)

    def group_exists(self,group):
        try:
            if group.isdigit():
                if grp.getgrgid(group):
                    return True
            else:
                if grp.getgrnam(group):
                    return True
        except KeyError:
            return False

    def group_info(self,group):
        if not self.group_exists(group):
            return False
        if group.isdigit():
            return list(grp.getgrgid(group))
        else:
            return list(grp.getgrnam(group))

    def user_group_membership(self):
        groups = []
        info = self.get_pwd_info()
        for group in grp.getgrall():
            if self.name in group[3] and info[3] != group[2]:
                groups.append(group[0])
        return groups

    def user_exists(self):
        try:
            if pwd.getpwnam(self.name):
                return True
        except KeyError:
            return False

    def get_pwd_info(self):
        if not self.user_exists():
            return False
        return list(pwd.getpwnam(self.name))

    def user_info(self):
        if not self.user_exists():
            return False
        info = self.get_pwd_info()
        if len(info[1]) == 1 or len(info[1]) == 0:
            info[1] = self.user_password()
        return info

    def user_password(self):
        passwd = ''
        if HAVE_SPWD:
            try:
                passwd = spwd.getspnam(self.name)[1]
            except KeyError:
                return passwd
        if not self.user_exists():
            return passwd
        else:
            # Read shadow file for user's encrypted password string
            if os.path.exists(User.SHADOWFILE) and os.access(User.SHADOWFILE, os.R_OK):
                for line in open(User.SHADOWFILE).readlines():
                    if line.startswith('%s:' % self.name):
                        passwd = line.split(':')[1]
        return passwd

    def get_ssh_key_path(self):
        info = self.user_info()
        if os.path.isabs(self.ssh_file):
            ssh_key_file = self.ssh_file
        else:
            ssh_key_file = os.path.join(info[5], self.ssh_file)
        return ssh_key_file

    def ssh_key_gen(self):
        info = self.user_info()
        if not os.path.exists(info[5]):
            return (1, '', 'User %s home directory does not exist' % self.name)
        ssh_key_file = self.get_ssh_key_path()
        ssh_dir = os.path.dirname(ssh_key_file) 
        if not os.path.exists(ssh_dir):
            try:
                os.mkdir(ssh_dir, 0700)
                os.chown(ssh_dir, info[2], info[3])
            except OSError, e:
                return (1, '', 'Failed to create %s: %s' % (ssh_dir, str(e)))
        if os.path.exists(ssh_key_file):
            return (None, 'Key already exists', '')
        cmd = [self.module.get_bin_path('ssh-keygen', True)]
        cmd.append('-t')
        cmd.append(self.ssh_type)
        cmd.append('-b')
        cmd.append(self.ssh_bits)
        cmd.append('-C')
        cmd.append(self.ssh_comment)
        cmd.append('-f')
        cmd.append(ssh_key_file)
        cmd.append('-N')
        if self.ssh_passphrase is not None:
            cmd.append(self.ssh_passphrase)
        else:
            cmd.append('')

        (rc, out, err) = self.execute_command(cmd)
        if rc == 0:
            # If the keys were successfully created, we should be able
            # to tweak ownership.
            os.chown(ssh_key_file, info[2], info[3])
            os.chown('%s.pub' % ssh_key_file, info[2], info[3])
        return (rc, out, err)

    def ssh_key_fingerprint(self):
        ssh_key_file = self.get_ssh_key_path()
        if not os.path.exists(ssh_key_file):
            return (1, 'SSH Key file %s does not exist' % ssh_key_file, '')
        cmd = [ self.module.get_bin_path('ssh-keygen', True) ]
        cmd.append('-l')
        cmd.append('-f')
        cmd.append(ssh_key_file)

        return self.execute_command(cmd)

    def create_user(self):
        # by default we use the create_user_useradd method
        return self.create_user_useradd()

    def remove_user(self):
        # by default we use the remove_user_userdel method
        return self.remove_user_userdel()

    def modify_user(self):
        # by default we use the modify_user_usermod method
        return self.modify_user_usermod()

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

class FreeBsdUser(User):
    """
    This is a FreeBSD User manipulation class - it uses the pw command
    to manipulate the user database, followed by the chpass command
    to change the password.
    
    This overrides the following methods from the generic class:-
      - create_user()
      - remove_user()
      - modify_user()
    """

    platform = 'FreeBSD'
    distribution = None
    SHADOWFILE = '/etc/master.passwd'

    def remove_user(self):
        cmd = [self.module.get_bin_path('pw', True),
               'userdel',
               '-n',
               self.name ]
        if self.remove:
            cmd.append('-r')

        return self.execute_command(cmd)

    def create_user(self):
        cmd = [self.module.get_bin_path('pw', True),
               'useradd',
               '-n',
               self.name ]

        if self.uid is not None:
            cmd.append('-u')
            cmd.append(self.uid)

        if self.comment is not None:
            cmd.append('-c')
            cmd.append(self.comment)

        if self.home is not None:
            cmd.append('-d')
            cmd.append(self.home)

        if self.group is not None:
            if not user.group_exists(self.group):
                self.module.fail_json(msg="Group %s does not exist" % self.group)
            cmd.append('-g')
            cmd.append(self.group)

        if self.groups is not None:
            for g in self.groups.split(','):
                if not self.group_exists(g):
                    self.module.fail_json(msg="Group %s does not exist" % (g))
            cmd.append('-G')
            cmd.append(self.groups)

        if self.createhome:
            cmd.append('-m')

        if self.shell is not None:
            cmd.append('-s')
            cmd.append(self.shell)

        # system cannot be handled currently - should we error if its requested?
        # create the user
        (rc, out, err) = self.execute_command(cmd)
        if rc is not None and rc != 0:
            module.fail_json(name=self.name, msg=err, rc=rc)

        # we have to set the password in a second command
        if self.password is not None:
            cmd = [self.module.get_bin_path('chpass', True),
                   '-p',
                   self.password,
                   self.name ]
            return self.execute_command(cmd)

        return (rc, out, err)

    def modify_user(self):
        cmd = [self.module.get_bin_path('pw', True),
               'usermod',
               '-n',
               self.name ]
        info = self.user_info()

        if self.uid is not None and info[2] != int(self.uid):
            cmd.append('-u')
            cmd.append(self.uid)

        if self.comment is not None and info[4] != self.comment:
            cmd.append('-c')
            cmd.append(self.comment)

        if self.home is not None and info[5] != self.home:
            cmd.append('-d')
            cmd.append(self.home)

        if self.group is not None:
            if not user.group_exists(self.group):
                self.module.fail_json(msg="Group %s does not exist" % self.group)
            ginfo = self.group_info(self.group)
            if info[3] != ginfo[2]:
                cmd.append('-g')
                cmd.append(self.group)

        if self.shell is not None and info[6] != self.shell:
            cmd.append('-s')
            cmd.append(self.shell)
        
        if self.groups is not None:
            current_groups = self.user_group_membership()
            groups = self.groups.split(',')
            for g in groups:
                if not self.group_exists(g):
                    module.fail_json(msg="Group %s does not exist" % (g))

            group_diff = set(sorted(current_groups)).symmetric_difference(set(sorted(groups)))
            groups_need_mod = False

            if group_diff:
                if self.append:
                    for g in groups:
                        if g in group_diff:
                            groups_need_mod = True
                            break
                else:
                    groups_need_mod = True

            if groups_need_mod:
                new_groups = groups
                if self.append:
                    new_groups.append(current_groups)           
                cmd.append(','.join(new_groups))

        # modify the user
        (rc, out, err) = self.execute_command(cmd)
        if rc is not None and rc != 0:
            module.fail_json(name=self.name, msg=err, rc=rc)

        # we have to set the password in a second command
        if self.password is not None and info[1] != self.password:
            cmd = [self.module.get_bin_path('chpass', True),
                   '-p',
                   self.password,
                   self.name ]
            return self.execute_command(cmd)

        return (rc, out, err)
    
# ===========================================

def main():
    ssh_defaults = {
            'bits': '2048',
            'type': 'rsa',
            'passphrase': None,
            'comment': 'ansible-generated'
    }
    module = AnsibleModule(
        argument_spec = dict(
            state=dict(default='present', choices=['present', 'absent']),
            name=dict(required=True, aliases=['user']),
            uid=dict(default=None),
            group=dict(default=None),
            groups=dict(default=None),
            comment=dict(default=None),
            home=dict(default=None),
            shell=dict(default=None),
            password=dict(default=None),
            # following options are specific to userdel
            force=dict(default='no', choices=BOOLEANS),
            remove=dict(default='no', choices=BOOLEANS),
            # following options are specific to useradd
            createhome=dict(default='yes', choices=BOOLEANS),
            system=dict(default='no', choices=BOOLEANS),
            # following options are specific to usermod
            append=dict(default='no', choices=BOOLEANS),
            # following are specific to ssh key generation
            generate_ssh_key=dict(choices=BOOLEANS),
            ssh_key_bits=dict(default=ssh_defaults['bits']),
            ssh_key_type=dict(default=ssh_defaults['type']),
            ssh_key_file=dict(default=None),
            ssh_key_comment=dict(default=ssh_defaults['comment']),
            ssh_key_passphrase=dict(default=None)
        )
    )

    user = User(module)

    if user.syslogging:
        syslog.openlog('ansible-%s' % os.path.basename(__file__))
        syslog.syslog(syslog.LOG_NOTICE, 'User instantiated - platform %s' % user.platform)
        if user.distribution:
            syslog.syslog(syslog.LOG_NOTICE, 'User instantiated - distribution %s' % user.distribution)

    rc = None
    out = ''
    err = ''
    result = {}
    result['name'] = user.name
    result['state'] = user.state
    if user.state == 'absent':
        if user.user_exists():
            (rc, out, err) = user.remove_user()
            if rc != 0:
                module.fail_json(name=name, msg=err, rc=rc)
            result['force'] = user.force
            result['remove'] = user.remove
    elif user.state == 'present':
        if not user.user_exists():
            (rc, out, err) = user.create_user()
            result['system'] = user.system
            result['createhome'] = user.createhome
        else:
            (rc, out, err) = user.modify_user()
            result['append'] = user.append
        if rc is not None and rc != 0:
            module.fail_json(name=user.name, msg=err, rc=rc)
        if user.password is not None:
            result['password'] = 'NOT_LOGGING_PASSWORD'

    if rc is None:
        result['changed'] = False
    else:
        result['changed'] = True
    if out:
        result['stdout'] = out
    if err:
        result['stderr'] = err

    if user.user_exists():
        info = user.user_info()
        if info == False:
            result['msg'] = "failed to look up user name: %s" % user.name
            result['failed'] = True
        result['uid'] = info[2]
        result['group'] = info[3]
        result['comment'] = info[4]
        result['home'] = info[5]
        result['shell'] = info[6]
        groups = user.user_group_membership()
        result['uid'] = info[2]
        if user.groups is not None:
            result['groups'] = user.groups

        # deal with ssh key
        if user.sshkeygen:
            (rc, out, err) = user.ssh_key_gen()
            if rc is not None and rc != 0:
                module.fail_json(name=user.name, msg=err, rc=rc)
            if rc == 0:
                result['changed'] = True
            (rc, out, err) = user.ssh_key_fingerprint()
            if rc == 0:
                result['ssh_fingerprint'] = out.strip()
            else:
                result['ssh_fingerprint'] = err.strip()
            result['ssh_key_file'] = user.get_ssh_key_path()


    module.exit_json(**result)

# include magic from lib/ansible/module_common.py
#<<INCLUDE_ANSIBLE_MODULE_COMMON>>
main()