# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import base64
import datetime

try:
    import simplejson as json
except:
    import json

from libcloud.utils.py3 import httplib
from libcloud.utils.py3 import b

from libcloud.common.base import JsonResponse, ConnectionUserAndKey
from libcloud.common.types import InvalidCredsError

from libcloud.container.base import (Container, ContainerDriver,
                                     ContainerImage, ContainerCluster)

from libcloud.container.providers import Provider
from libcloud.container.types import ContainerState


VALID_RESPONSE_CODES = [httplib.OK, httplib.ACCEPTED, httplib.CREATED,
                        httplib.NO_CONTENT]

ROOT_URL = '/api/'


class KubernetesResponse(JsonResponse):

    valid_response_codes = [httplib.OK, httplib.ACCEPTED, httplib.CREATED,
                            httplib.NO_CONTENT]

    def parse_error(self):
        if self.status == 401:
            raise InvalidCredsError('Invalid credentials')
        return self.body

    def success(self):
        return self.status in self.valid_response_codes


class KubernetesException(Exception):

    def __init__(self, code, message):
        self.code = code
        self.message = message
        self.args = (code, message)

    def __str__(self):
        return "%s %s" % (self.code, self.message)

    def __repr__(self):
        return "KubernetesException %s %s" % (self.code, self.message)


class KubernetesConnection(ConnectionUserAndKey):
    responseCls = KubernetesResponse
    timeout = 60

    def add_default_headers(self, headers):
        """
        Add parameters that are necessary for every request
        If user and password are specified, include a base http auth
        header
        """
        headers['Content-Type'] = 'application/json'
        if self.key and self.secret:
            user_b64 = base64.b64encode(b('%s:%s' % (self.key, self.secret)))
            headers['Authorization'] = 'Basic %s' % (user_b64.decode('utf-8'))
        return headers


class KubernetesPod(object):
    def __init__(self, name, containers, namespace):
        """
        A Kubernetes pod
        """
        self.name = name
        self.containers = containers
        self.namespace = namespace


class KubernetesContainerDriver(ContainerDriver):
    type = Provider.KUBERNETES
    name = 'Kubernetes'
    website = 'http://kubernetes.io'
    connectionCls = KubernetesConnection
    supports_clusters = True

    def __init__(self, key=None, secret=None, secure=False, host='localhost',
                 port=4243):
        """
        :param    key: API key or username to used (required)
        :type     key: ``str``

        :param    secret: Secret password to be used (required)
        :type     secret: ``str``

        :param    secure: Whether to use HTTPS or HTTP. Note: Some providers
                only support HTTPS, and it is on by default.
        :type     secure: ``bool``

        :param    host: Override hostname used for connections.
        :type     host: ``str``

        :param    port: Override port used for connections.
        :type     port: ``int``

        :return: ``None``
        """
        super(KubernetesContainerDriver, self).__init__(key=key, secret=secret,
                                                        secure=secure,
                                                        host=host,
                                                        port=port)

        if host is not None:
            if host.startswith('https://'):
                secure = True

            # strip the prefix
            prefixes = ['http://', 'https://']
            for prefix in prefixes:
                if host.startswith(prefix):
                    host = host.strip(prefix)

            self.connection.host = host
            self.connection.port = port

        self.connection.secure = secure
        self.connection.key = key
        self.connection.secret = secret

    def list_containers(self, image=None, all=True):
        """
        List the deployed container images

        :param image: Filter to containers with a certain image
        :type  image: :class:`libcloud.container.base.ContainerImage`

        :param all: Show all container (including stopped ones)
        :type  all: ``bool``

        :rtype: ``list`` of :class:`libcloud.container.base.Container`
        """
        try:
            result = self.connection.request(
                ROOT_URL + "v1/pods").object
        except Exception as exc:
            errno = getattr(exc, 'errno', None)
            if errno == 111:
                raise KubernetesException(
                    errno,
                    'Make sure kube host is accessible'
                    'and the API port is correct')
            raise

        pods = [self._to_pod(value) for value in result['items']]
        containers = []
        for pod in pods:
            containers.extend(pod.containers)
        return containers

    def get_container(self, id):
        """
        Get a container by ID

        :param id: The ID of the container to get
        :type  id: ``str``

        :rtype: :class:`libcloud.container.base.Container`
        """
        containers = self.list_containers()
        match = [container for container in containers if container.id == id]
        return match[0]

    def list_clusters(self):
        """
        Get a list of namespaces that pods can be deployed into

        :param  location: The location to search in
        :type   location: :class:`libcloud.container.base.ClusterLocation`

        :rtype: ``list`` of :class:`libcloud.container.base.ContainerCluster`
        """
        try:
            result = self.connection.request(
                ROOT_URL + "v1/namespaces/").object
        except Exception as exc:
            errno = getattr(exc, 'errno', None)
            if errno == 111:
                raise KubernetesException(
                    errno,
                    'Make sure kube host is accessible'
                    'and the API port is correct')
            raise

        clusters = [self._to_cluster(value) for value in result['items']]
        return clusters

    def get_cluster(self, id):
        """
        Get a cluster by ID

        :param id: The ID of the cluster to get
        :type  id: ``str``

        :rtype: :class:`libcloud.container.base.ContainerCluster`
        """
        result = self.connection.request(ROOT_URL + "v1/namespaces/%s" %
                                         id).object

        return self._to_cluster(result)

    def destroy_cluster(self, cluster):
        """
        Delete a cluster (namespace)

        :return: ``True`` if the destroy was successful, otherwise ``False``.
        :rtype: ``bool``
        """
        self.connection.request(ROOT_URL + "v1/namespaces/%s" %
                                cluster.id, method='DELETE').object
        return True

    def create_cluster(self, name, location=None):
        """
        Create a container cluster (a namespace)

        :param  name: The name of the cluster
        :type   name: ``str``

        :param  location: The location to create the cluster in
        :type   location: :class:`.ClusterLocation`

        :rtype: :class:`.ContainerCluster`
        """
        request = {
            'metadata': {
                'name': name
            }
        }
        result = self.connection.request(ROOT_URL + "v1/namespaces",
                                         method='POST',
                                         data=json.dumps(request)).object
        return self._to_cluster(result)

    def deploy_container(self, name, image, cluster=None,
                         parameters=None, start=True):
        """
        Deploy an installed container image.
        In kubernetes this deploys a single container Pod.
        https://cloud.google.com/container-engine/docs/pods/single-container

        :param name: The name of the new container
        :type  name: ``str``

        :param image: The container image to deploy
        :type  image: :class:`.ContainerImage`

        :param cluster: The cluster to deploy to, None is default
        :type  cluster: :class:`.ContainerCluster`

        :param parameters: Container Image parameters
        :type  parameters: ``str``

        :param start: Start the container on deployment
        :type  start: ``bool``

        :rtype: :class:`.Container`
        """
        if cluster is None:
            namespace = 'default'
        else:
            namespace = cluster.id
        request = {
            "metadata": {
                "name": name
            },
            "spec": {
                "containers": [
                    {
                        "name": name,
                        "image": image.name
                    }
                ]
            }
        }
        result = self.connection.request(ROOT_URL + "v1/namespaces/%s/pods"
                                         % namespace,
                                         method='POST',
                                         data=json.dumps(request)).object
        return self._to_cluster(result)

    def destroy_container(self, container):
        """
        Destroy a deployed container. Because the containers are single
        container pods, this will delete the pod.

        :param container: The container to destroy
        :type  container: :class:`.Container`

        :rtype: ``bool``
        """
        return self.ex_destroy_pod(container.extra['namespace'],
                                   container.extra['pod'])

    def ex_list_pods(self):
        """
        List available Pods

        :rtype: ``list`` of :class:`.KubernetesPod`
        """
        result = self.connection.request(ROOT_URL + "v1/pods").object
        return [self._to_pod(value) for value in result['items']]

    def ex_destroy_pod(self, namespace, pod_name):
        """
        Delete a pod and the containers within it.
        """
        self.connection.request(
            ROOT_URL + "v1/namespaces/%s/pods/%s" % (
                namespace, pod_name),
            method='DELETE').object
        return True

    def _to_pod(self, data):
        """
        Convert an API response to a Pod object
        """
        container_statuses = data['status']['containerStatuses']
        containers = []
        # response contains the status of the containers in a separate field
        for container in data['spec']['containers']:
            spec = list(filter(lambda i: i['name'] == container['name'],
                               container_statuses))[0]
            containers.append(
                self._to_container(container, spec, data)
            )
        return KubernetesPod(
            name=data['metadata']['name'],
            namespace=data['metadata']['namespace'],
            containers=containers)

    def _to_container(self, data, container_status, pod_data):
        """
        Convert container in Container instances
        """
        return Container(
            id=container_status['containerID'],
            name=data['name'],
            image=ContainerImage(
                id=container_status['imageID'],
                name=data['image'],
                path=None,
                version=None,
                driver=self.connection.driver),
            ip_addresses=None,
            state=ContainerState.RUNNING,
            driver=self.connection.driver,
            extra={
                'pod': pod_data['metadata']['name'],
                'namespace': pod_data['metadata']['namespace']
            })

    def _to_cluster(self, data):
        """
        Convert namespace to a cluster
        """
        metadata = data['metadata']
        status = data['status']
        return ContainerCluster(
            id=metadata['name'],
            name=metadata['name'],
            driver=self.connection.driver,
            extra={'phase': status['phase']})


def ts_to_str(timestamp):
    """
    Return a timestamp as a nicely formated datetime string.
    """
    date = datetime.datetime.fromtimestamp(timestamp)
    date_string = date.strftime("%d/%m/%Y %H:%M %Z")
    return date_string
