# -*- coding: utf-8 -*-
'''
Control of entries in SSH authorized_key files.
===============================================

The information stored in a user's SSH authorized key file can be easily
controlled via the ssh_auth state. Defaults can be set by the enc, options,
and comment keys. These defaults can be overridden by including them in the
name.

Since the YAML specification limits the length of simple keys to 1024
characters, and since SSH keys are often longer than that, you may have
to use a YAML 'explicit key', as demonstrated in the second example below.

.. code-block:: yaml

    AAAAB3NzaC1kc3MAAACBAL0sQ9fJ5bYTEyY==:
      ssh_auth:
        - present
        - user: root
        - enc: ssh-dss

    ? AAAAB3NzaC1kc3MAAACBAL0sQ9fJ5bYTEyY==...
    :
      ssh_auth:
        - present
        - user: root
        - enc: ssh-dss

    thatch:
      ssh_auth:
        - present
        - user: root
        - source: salt://ssh_keys/thatch.id_rsa.pub

    sshkeys:
      ssh_auth:
        - present
        - user: root
        - enc: ssh-rsa
        - options:
          - option1="value1"
          - option2="value2 flag2"
        - comment: myuser
        - names:
          - AAAAB3NzaC1kc3MAAACBAL0sQ9fJ5bYTEyY==
          - ssh-dss AAAAB3NzaCL0sQ9fJ5bYTEyY== user@domain
          - option3="value3" ssh-dss AAAAB3NzaC1kcQ9J5bYTEyY== other@testdomain
          - AAAAB3NzaC1kcQ9fJFF435bYTEyY== newcomment
'''

# Import python libs
import re
import sys


def _present_test(user, name, enc, comment, options, source, config):
    '''
    Run checks for "present"
    '''
    result = None
    if source:
        keys = __salt__['ssh.check_key_file'](
                user,
                source,
                config,
                __env__)
        if keys:
            comment = ''
            for key, status in keys.items():
                if status == 'exists':
                    continue
                comment += 'Set to {0}: {1}\n'.format(status, key)
            if comment:
                return result, comment
        err = sys.modules[
            __salt__['test.ping'].__module__
        ].__context__.pop('ssh_auth.error', None)
        if err:
            return False, err
        else:
            return (
                True,
                'All host keys in file {0} are already present'.format(source)
            )
    check = __salt__['ssh.check_key'](
            user,
            name,
            enc,
            comment,
            options,
            config)
    if check == 'update':
        comment = (
                'Key {0} for user {1} is set to be updated'
                ).format(name, user)
    elif check == 'add':
        comment = (
                'Key {0} for user {1} is set to be added'
                ).format(name, user)
    elif check == 'exists':
        result = True
        comment = ('The authorized host key {0} is already present '
                          'for user {1}'.format(name, user))

    return result, comment


def present(
        name,
        user,
        enc='ssh-rsa',
        comment='',
        source='',
        options=None,
        config='.ssh/authorized_keys',
        **kwargs):
    '''
    Verifies that the specified SSH key is present for the specified user

    name
        The SSH key to manage

    user
        The user who owns the SSH authorized keys file to modify

    enc
        Defines what type of key is being used; can be ecdsa, ssh-rsa or ssh-dss

    comment
        The comment to be placed with the SSH public key

    source
        The source file for the key(s). Can contain any number of public keys,
        in standard "authorized_keys" format. If this is set, comment, enc,
        and options will be ignored.

    .. note::
        The source file must contain keys in the format ``<enc> <key>
        <comment>``. If you have generated a keypair using PuTTYgen, then you
        will need to do the following to retrieve an OpenSSH-compatible public
        key.

        1. In PuTTYgen, click ``Load``, and select the *private* key file (not
           the public key), and click ``Open``.
        2. Copy the public key from the box labeled ``Public key for pasting
           into OpenSSH authorized_keys file``.
        3. Paste it into a new file.

    options
        The options passed to the key, pass a list object

    config
        The location of the authorized keys file relative to the user's home
        directory, defaults to ".ssh/authorized_keys"
    '''
    ret = {'name': name,
           'changes': {},
           'result': True,
           'comment': ''}

    if __opts__['test']:
        ret['result'], ret['comment'] = _present_test(
                user,
                name,
                enc,
                comment,
                options or [],
                source,
                config,
                )
        return ret

    if source != '':
        data = __salt__['ssh.set_auth_key_from_file'](
                user,
                source,
                config)
    else:
        # check if this is of form {options} {enc} {key} {comment}
        sshre = re.compile(r'^(.*?)\s?((?:ssh\-|ecds)[\w-]+\s.+)$')
        fullkey = sshre.search(name)
        # if it is {key} [comment]
        if not fullkey:
            key_and_comment = name.split()
            name = key_and_comment[0]
            if len(key_and_comment) == 2:
                comment = key_and_comment[1]
        else:
            # if there are options, set them
            if fullkey.group(1):
                options = fullkey.group(1).split(',')
            # key is of format: {enc} {key} [comment]
            comps = fullkey.group(2).split()
            enc = comps[0]
            name = comps[1]
            if len(comps) == 3:
                comment = comps[2]

        data = __salt__['ssh.set_auth_key'](
                user,
                name,
                enc,
                comment,
                options or [],
                config)

    if data == 'replace':
        ret['changes'][name] = 'Updated'
        ret['comment'] = ('The authorized host key {0} for user {1} was '
                          'updated'.format(name, user))
        return ret
    elif data == 'no change':
        ret['comment'] = ('The authorized host key {0} is already present '
                          'for user {1}'.format(name, user))
    elif data == 'new':
        ret['changes'][name] = 'New'
        ret['comment'] = ('The authorized host key {0} for user {1} was added'
                          .format(name, user))
    elif data == 'fail':
        ret['result'] = False
        err = sys.modules[
            __salt__['test.ping'].__module__
        ].__context__.pop('ssh_auth.error', None)
        if err:
            ret['comment'] = err
        else:
            ret['comment'] = ('Failed to add the ssh key. Is the home '
                              'directory available, and/or does the key file '
                              'exist?')
    elif data == 'invalid':
        ret['result'] = False
        ret['comment'] = 'Invalid public ssh key, most likely has spaces'

    return ret


def absent(name,
           user,
           enc='ssh-rsa',
           comment='',
           options=None,
           config='.ssh/authorized_keys'):
    '''
    Verifies that the specified SSH key is absent

    name
        The SSH key to manage

    user
        The user who owns the SSH authorized keys file to modify

    enc
        Defines what type of key is being used; can be ecdsa, ssh-rsa or ssh-dss

    comment
        The comment to be placed with the SSH public key

    options
        The options passed to the key, pass a list object

    config
        The location of the authorized keys file relative to the user's home
        directory, defaults to ".ssh/authorized_keys"
    '''
    ret = {'name': name,
           'changes': {},
           'result': True,
           'comment': ''}

    # Get just the key
    name = name.split(' ')[0]

    if __opts__['test']:
        check = __salt__['ssh.check_key'](
                user,
                name,
                enc,
                comment,
                options or [],
                config)
        if check == 'update' or check == 'exists':
            ret['result'] = None
            ret['comment'] = 'Key {0} is set for removal'.format(name)
            return ret
        else:
            ret['comment'] = 'Key is already absent'
            return ret

    ret['comment'] = __salt__['ssh.rm_auth_key'](user, name, config)

    if ret['comment'] == 'User authorized keys file not present':
        ret['result'] = False
        return ret
    elif ret['comment'] == 'Key removed':
        ret['changes'][name] = 'Removed'

    return ret
