# -*- coding: utf-8 -*-
'''
Management of Docker images

.. versionadded:: 2017.7.0

:depends: docker_ Python module

.. note::
    Older releases of the Python bindings for Docker were called docker-py_ in
    PyPI. All releases of docker_, and releases of docker-py_ >= 1.6.0 are
    supported. These python bindings can easily be installed using
    :py:func:`pip.install <salt.modules.pip.install>`:

    .. code-block:: bash

        salt myminion pip.install docker

    To upgrade from docker-py_ to docker_, you must first uninstall docker-py_,
    and then install docker_:

    .. code-block:: bash

        salt myminion pip.uninstall docker-py
        salt myminion pip.install docker

.. _docker: https://pypi.python.org/pypi/docker
.. _docker-py: https://pypi.python.org/pypi/docker-py

These states were moved from the :mod:`docker <salt.states.docker>` state
module (formerly called **dockerng**) in the 2017.7.0 release.

.. note::
    To pull from a Docker registry, authentication must be configured. See
    :ref:`here <docker-authentication>` for more information on how to
    configure access to docker registries in :ref:`Pillar <pillar>` data.
'''
from __future__ import absolute_import, print_function, unicode_literals
import logging

# Import salt libs
import salt.utils.docker
import salt.utils.args
from salt.ext.six.moves import zip
from salt.ext import six
from salt.exceptions import CommandExecutionError

# Enable proper logging
log = logging.getLogger(__name__)  # pylint: disable=invalid-name

# Define the module's virtual name
__virtualname__ = 'docker_image'
__virtual_aliases__ = ('moby_image',)


def __virtual__():
    '''
    Only load if the docker execution module is available
    '''
    if 'docker.version' in __salt__:
        return __virtualname__
    return (False, __salt__.missing_fun_string('docker.version'))


def present(name,
            tag=None,
            build=None,
            load=None,
            force=False,
            insecure_registry=False,
            client_timeout=salt.utils.docker.CLIENT_TIMEOUT,
            dockerfile=None,
            sls=None,
            base='opensuse/python',
            saltenv='base',
            pillarenv=None,
            pillar=None,
            **kwargs):
    '''
    .. versionchanged:: 2018.3.0
        The ``tag`` argument has been added. It is now required unless pulling
        from a registry.

    Ensure that an image is present. The image can either be pulled from a
    Docker registry, built from a Dockerfile, loaded from a saved image, or
    built by running SLS files against a base image.

    If none of the ``build``, ``load``, or ``sls`` arguments are used, then Salt
    will pull from the :ref:`configured registries <docker-authentication>`. If
    the specified image already exists, it will not be pulled unless ``force``
    is set to ``True``. Here is an example of a state that will pull an image
    from the Docker Hub:

    .. code-block:: yaml

        myuser/myimage:
          docker_image.present:
            - tag: mytag

    tag
        Tag name for the image. Required when using ``build``, ``load``, or
        ``sls`` to create the image, but optional if pulling from a repository.

        .. versionadded:: 2018.3.0

    build
        Path to directory on the Minion containing a Dockerfile

        .. code-block:: yaml

            myuser/myimage:
              docker_image.present:
                - build: /home/myuser/docker/myimage
                - tag: mytag

            myuser/myimage:
              docker_image.present:
                - build: /home/myuser/docker/myimage
                - tag: mytag
                - dockerfile: Dockerfile.alternative

        The image will be built using :py:func:`docker.build
        <salt.modules.dockermod.build>` and the specified image name and tag
        will be applied to it.

        .. versionadded:: 2016.11.0
        .. versionchanged:: 2018.3.0
            The ``tag`` must be manually specified using the ``tag`` argument.

    load
        Loads a tar archive created with :py:func:`docker.load
        <salt.modules.dockermod.load>` (or the ``docker load`` Docker CLI
        command), and assigns it the specified repo and tag.

        .. code-block:: yaml

            myuser/myimage:
              docker_image.present:
                - load: salt://path/to/image.tar
                - tag: mytag

        .. versionchanged:: 2018.3.0
            The ``tag`` must be manually specified using the ``tag`` argument.

    force : False
        Set this parameter to ``True`` to force Salt to pull/build/load the
        image even if it is already present.

    client_timeout
        Timeout in seconds for the Docker client. This is not a timeout for
        the state, but for receiving a response from the API.

    dockerfile
        Allows for an alternative Dockerfile to be specified.  Path to alternative
        Dockefile is relative to the build path for the Docker container.

        .. versionadded:: 2016.11.0

    sls
        Allow for building of image with :py:func:`docker.sls_build
        <salt.modules.dockermod.sls_build>` by specifying the SLS files with
        which to build. This can be a list or comma-seperated string.

        .. code-block:: yaml

            myuser/myimage:
              docker_image.present:
                - tag: latest
                - sls:
                    - webapp1
                    - webapp2
                - base: centos
                - saltenv: base

        .. versionadded: 2017.7.0
        .. versionchanged:: 2018.3.0
            The ``tag`` must be manually specified using the ``tag`` argument.

    base
        Base image with which to start :py:func:`docker.sls_build
        <salt.modules.dockermod.sls_build>`

        .. versionadded:: 2017.7.0

    saltenv
        Specify the environment from which to retrieve the SLS indicated by the
        `mods` parameter.

        .. versionadded:: 2017.7.0
        .. versionchanged:: 2018.3.0
            Now uses the effective saltenv if not explicitly passed. In earlier
            versions, ``base`` was assumed as a default.

    pillarenv
        Specify a Pillar environment to be used when applying states. This
        can also be set in the minion config file using the
        :conf_minion:`pillarenv` option. When neither the
        :conf_minion:`pillarenv` minion config option nor this CLI argument is
        used, all Pillar environments will be merged together.

        .. versionadded:: 2018.3.0

    pillar
        Custom Pillar values, passed as a dictionary of key-value pairs

        .. note::
            Values passed this way will override Pillar values set via
            ``pillar_roots`` or an external Pillar source.

        .. versionadded:: 2018.3.0
    '''
    ret = {'name': name,
           'changes': {},
           'result': False,
           'comment': ''}

    if not isinstance(name, six.string_types):
        name = six.text_type(name)

    # At most one of the args that result in an image being built can be used
    num_build_args = len([x for x in (build, load, sls) if x is not None])
    if num_build_args > 1:
        ret['comment'] = \
            'Only one of \'build\', \'load\', or \'sls\' is permitted.'
        return ret
    elif num_build_args == 1:
        # If building, we need the tag to be specified
        if not tag:
            ret['comment'] = (
                'The \'tag\' argument is required if any one of \'build\', '
                '\'load\', or \'sls\' is used.'
            )
            return ret
        if not isinstance(tag, six.string_types):
            tag = six.text_type(tag)
        full_image = ':'.join((name, tag))
    else:
        if tag:
            name = '{0}:{1}'.format(name, tag)
        full_image = name

    try:
        image_info = __salt__['docker.inspect_image'](full_image)
    except CommandExecutionError as exc:
        msg = exc.__str__()
        if '404' in msg:
            # Image not present
            image_info = None
        else:
            ret['comment'] = msg
            return ret

    if image_info is not None:
        # Specified image is present
        if not force:
            ret['result'] = True
            ret['comment'] = 'Image {0} already present'.format(full_image)
            return ret

    if build or sls:
        action = 'built'
    elif load:
        action = 'loaded'
    else:
        action = 'pulled'

    if __opts__['test']:
        ret['result'] = None
        if (image_info is not None and force) or image_info is None:
            ret['comment'] = 'Image {0} will be {1}'.format(full_image, action)
            return ret

    if build:
        # Get the functions default value and args
        argspec = salt.utils.args.get_function_argspec(__salt__['docker.build'])
        # Map any if existing args from kwargs into the build_args dictionary
        build_args = dict(list(zip(argspec.args, argspec.defaults)))
        for k, v in build_args.items():
            if k in kwargs.get('kwargs', {}):
                build_args[k] = kwargs.get('kwargs', {}).get(k)
        try:
            # map values passed from the state to the build args
            build_args['path'] = build
            build_args['repository'] = name
            build_args['tag'] = tag
            build_args['dockerfile'] = dockerfile
            image_update = __salt__['docker.build'](**build_args)
        except Exception as exc:
            ret['comment'] = (
                'Encountered error building {0} as {1}: {2}'.format(
                    build, full_image, exc
                )
            )
            return ret
        if image_info is None or image_update['Id'] != image_info['Id'][:12]:
            ret['changes'] = image_update

    elif sls:
        _locals = locals()
        sls_build_kwargs = {k: _locals[k] for k in ('saltenv', 'pillarenv', 'pillar')
                            if _locals[k] is not None}
        try:
            image_update = __salt__['docker.sls_build'](repository=name,
                                                        tag=tag,
                                                        base=base,
                                                        mods=sls,
                                                        **sls_build_kwargs)
        except Exception as exc:
            ret['comment'] = (
                'Encountered error using SLS {0} for building {1}: {2}'
                .format(sls, full_image, exc)
            )
            return ret
        if image_info is None or image_update['Id'] != image_info['Id'][:12]:
            ret['changes'] = image_update

    elif load:
        try:
            image_update = __salt__['docker.load'](path=load,
                                                   repository=name,
                                                   tag=tag)
        except Exception as exc:
            ret['comment'] = (
                'Encountered error loading {0} as {1}: {2}'
                .format(load, full_image, exc)
            )
            return ret
        if image_info is None or image_update.get('Layers', []):
            ret['changes'] = image_update

    else:
        try:
            image_update = __salt__['docker.pull'](
                name,
                insecure_registry=insecure_registry,
                client_timeout=client_timeout
            )
        except Exception as exc:
            ret['comment'] = \
                'Encountered error pulling {0}: {1}'.format(full_image, exc)
            return ret
        if (image_info is not None and image_info['Id'][:12] == image_update
                .get('Layers', {})
                .get('Already_Pulled', [None])[0]):
            # Image was pulled again (because of force) but was also
            # already there. No new image was available on the registry.
            pass
        elif image_info is None or image_update.get('Layers', {}).get('Pulled'):
            # Only add to the changes dict if layers were pulled
            ret['changes'] = image_update

    error = False

    try:
        __salt__['docker.inspect_image'](full_image)
    except CommandExecutionError as exc:
        msg = exc.__str__()
        if '404' not in msg:
            error = 'Failed to inspect image \'{0}\' after it was {1}: {2}'.format(
                full_image, action, msg
            )

    if error:
        ret['comment'] = error
    else:
        ret['result'] = True
        if not ret['changes']:
            ret['comment'] = (
                'Image \'{0}\' was {1}, but there were no changes'.format(
                    name, action
                )
            )
        else:
            ret['comment'] = 'Image \'{0}\' was {1}'.format(full_image, action)
    return ret


def absent(name=None, images=None, force=False):
    '''
    Ensure that an image is absent from the Minion. Image names can be
    specified either using ``repo:tag`` notation, or just the repo name (in
    which case a tag of ``latest`` is assumed).

    images
        Run this state on more than one image at a time. The following two
        examples accomplish the same thing:

        .. code-block:: yaml

            remove_images:
              docker_image.absent:
                - names:
                  - busybox
                  - centos:6
                  - nginx

        .. code-block:: yaml

            remove_images:
              docker_image.absent:
                - images:
                  - busybox
                  - centos:6
                  - nginx

        However, the second example will be a bit quicker since Salt will do
        all the deletions in a single run, rather than executing the state
        separately on each image (as it would in the first example).

    force : False
        Salt will fail to remove any images currently in use by a container.
        Set this option to true to remove the image even if it is already
        present.

        .. note::

            This option can also be overridden by Pillar data. If the Minion
            has a pillar variable named ``docker.running.force`` which is
            set to ``True``, it will turn on this option. This pillar variable
            can even be set at runtime. For example:

            .. code-block:: bash

                salt myminion state.sls docker_stuff pillar="{docker.force: True}"

            If this pillar variable is present and set to ``False``, then it
            will turn off this option.

            For more granular control, setting a pillar variable named
            ``docker.force.image_name`` will affect only the named image.
    '''
    ret = {'name': name,
           'changes': {},
           'result': False,
           'comment': ''}

    if not name and not images:
        ret['comment'] = 'One of \'name\' and \'images\' must be provided'
        return ret
    elif images is not None:
        targets = images
    elif name:
        targets = [name]

    to_delete = []
    for target in targets:
        resolved_tag = __salt__['docker.resolve_tag'](target)
        if resolved_tag is not False:
            to_delete.append(resolved_tag)

    if not to_delete:
        ret['result'] = True
        if len(targets) == 1:
            ret['comment'] = 'Image {0} is not present'.format(name)
        else:
            ret['comment'] = 'All specified images are not present'
        return ret

    if __opts__['test']:
        ret['result'] = None
        if len(to_delete) == 1:
            ret['comment'] = 'Image {0} will be removed'.format(to_delete[0])
        else:
            ret['comment'] = (
                'The following images will be removed: {0}'.format(
                    ', '.join(to_delete)
                )
            )
        return ret

    result = __salt__['docker.rmi'](*to_delete, force=force)
    post_tags = __salt__['docker.list_tags']()
    failed = [x for x in to_delete if x in post_tags]

    if failed:
        if [x for x in to_delete if x not in post_tags]:
            ret['changes'] = result
            ret['comment'] = (
                'The following image(s) failed to be removed: {0}'.format(
                    ', '.join(failed)
                )
            )
        else:
            ret['comment'] = 'None of the specified images were removed'
            if 'Errors' in result:
                ret['comment'] += (
                    '. The following errors were encountered: {0}'
                    .format('; '.join(result['Errors']))
                )
    else:
        ret['changes'] = result
        if len(to_delete) == 1:
            ret['comment'] = 'Image {0} was removed'.format(to_delete[0])
        else:
            ret['comment'] = (
                'The following images were removed: {0}'.format(
                    ', '.join(to_delete)
                )
            )
        ret['result'] = True

    return ret


def mod_watch(name, sfun=None, **kwargs):
    '''
    The docker_image  watcher, called to invoke the watch command.

    .. note::
        This state exists to support special handling of the ``watch``
        :ref:`requisite <requisites>`. It should not be called directly.

        Parameters for this function should be set by the state being triggered.
    '''
    if sfun == 'present':
        # Force image to be updated
        kwargs['force'] = True
        return present(name, **kwargs)

    return {'name': name,
            'changes': {},
            'result': False,
            'comment': 'watch requisite is not implemented for '
                       '{0}'.format(sfun)}
