# 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.

"""
Enomaly ECP driver
"""
import os
import time
import socket
import binascii

from libcloud.utils.py3 import b, httplib, base64_encode_string
from libcloud.common.base import Response, ConnectionUserAndKey
from libcloud.compute.base import Node, NodeSize, NodeImage, NodeDriver, NodeLocation
from libcloud.compute.types import Provider, NodeState, InvalidCredsError
from libcloud.utils.networking import is_private_subnet

# JSON is included in the standard library starting with Python 2.6.  For 2.5
# and 2.4, there's a simplejson egg at: http://pypi.python.org/pypi/simplejson
try:
    import simplejson as json
except ImportError:
    import json


# Defaults
API_HOST = ""
API_PORT = (80, 443)


class ECPResponse(Response):
    def success(self):
        if self.status == httplib.OK or self.status == httplib.CREATED:
            try:
                j_body = json.loads(self.body)
            except ValueError:
                self.error = "JSON response cannot be decoded."
                return False
            if j_body["errno"] == 0:
                return True
            else:
                self.error = "ECP error: %s" % j_body["message"]
                return False
        elif self.status == httplib.UNAUTHORIZED:
            raise InvalidCredsError()
        else:
            self.error = "HTTP Error Code: %s" % self.status
        return False

    def parse_error(self):
        return self.error

    # Interpret the json responses - no error checking required
    def parse_body(self):
        return json.loads(self.body)

    def getheaders(self):
        return self.headers


class ECPConnection(ConnectionUserAndKey):
    """
    Connection class for the Enomaly ECP driver
    """

    responseCls = ECPResponse
    host = API_HOST
    port = API_PORT

    def add_default_headers(self, headers):
        # Authentication
        username = self.user_id
        password = self.key
        base64string = base64_encode_string(b("{}:{}".format(username, password)))[:-1]
        authheader = "Basic %s" % base64string
        headers["Authorization"] = authheader

        return headers

    def _encode_multipart_formdata(self, fields):
        """
        Based on Wade Leftwich's function:
        http://code.activestate.com/recipes/146306/
        """
        # use a random boundary that does not appear in the fields
        boundary = ""
        while boundary in "".join(fields):
            boundary = binascii.hexlify(os.urandom(16)).decode("utf-8")
        L = []
        for i in fields:
            L.append("--" + boundary)
            L.append('Content-Disposition: form-data; name="%s"' % i)
            L.append("")
            L.append(fields[i])
        L.append("--" + boundary + "--")
        L.append("")
        body = "\r\n".join(L)
        content_type = "multipart/form-data; boundary=%s" % boundary
        header = {"Content-Type": content_type}
        return header, body


class ECPNodeDriver(NodeDriver):
    """
    Enomaly ECP node driver
    """

    name = "Enomaly Elastic Computing Platform"
    website = "http://www.enomaly.com/"
    type = Provider.ECP
    connectionCls = ECPConnection

    def list_nodes(self):
        """
        Returns a list of all running Nodes

        :rtype: ``list`` of :class:`Node`
        """

        # Make the call
        res = self.connection.request("/rest/hosting/vm/list").parse_body()

        # Put together a list of node objects
        nodes = []
        for vm in res["vms"]:
            node = self._to_node(vm)
            if node is not None:
                nodes.append(node)

        # And return it
        return nodes

    def _to_node(self, vm):
        """
        Turns a (json) dictionary into a Node object.
        This returns only running VMs.
        """

        # Check state
        if not vm["state"] == "running":
            return None

        # IPs
        iplist = [
            interface["ip"] for interface in vm["interfaces"] if interface["ip"] != "127.0.0.1"
        ]

        public_ips = []
        private_ips = []
        for ip in iplist:
            try:
                socket.inet_aton(ip)
            except OSError:
                # not a valid ip
                continue
            if is_private_subnet(ip):
                private_ips.append(ip)
            else:
                public_ips.append(ip)

        # Create the node object
        n = Node(
            id=vm["uuid"],
            name=vm["name"],
            state=NodeState.RUNNING,
            public_ips=public_ips,
            private_ips=private_ips,
            driver=self,
        )

        return n

    def reboot_node(self, node):
        """
        Shuts down a VM and then starts it again.

        @inherits: :class:`NodeDriver.reboot_node`
        """

        # Turn the VM off
        # Black magic to make the POST requests work
        d = self.connection._encode_multipart_formdata({"action": "stop"})
        self.connection.request(
            "/rest/hosting/vm/%s" % node.id, method="POST", headers=d[0], data=d[1]
        ).parse_body()

        node.state = NodeState.REBOOTING
        # Wait for it to turn off and then continue (to turn it on again)
        while node.state == NodeState.REBOOTING:
            # Check if it's off.
            response = self.connection.request("/rest/hosting/vm/%s" % node.id).parse_body()
            if response["vm"]["state"] == "off":
                node.state = NodeState.TERMINATED
            else:
                time.sleep(5)

        # Turn the VM back on.
        # Black magic to make the POST requests work
        d = self.connection._encode_multipart_formdata({"action": "start"})
        self.connection.request(
            "/rest/hosting/vm/%s" % node.id, method="POST", headers=d[0], data=d[1]
        ).parse_body()

        node.state = NodeState.RUNNING
        return True

    def destroy_node(self, node):
        """
        Shuts down and deletes a VM.

        @inherits: :class:`NodeDriver.destroy_node`
        """

        # Shut down first
        # Black magic to make the POST requests work
        d = self.connection._encode_multipart_formdata({"action": "stop"})
        self.connection.request(
            "/rest/hosting/vm/%s" % node.id, method="POST", headers=d[0], data=d[1]
        ).parse_body()

        # Ensure there was no application level error
        node.state = NodeState.PENDING
        # Wait for the VM to turn off before continuing
        while node.state == NodeState.PENDING:
            # Check if it's off.
            response = self.connection.request("/rest/hosting/vm/%s" % node.id).parse_body()
            if response["vm"]["state"] == "off":
                node.state = NodeState.TERMINATED
            else:
                time.sleep(5)

        # Delete the VM
        # Black magic to make the POST requests work
        d = self.connection._encode_multipart_formdata({"action": "delete"})
        self.connection.request(
            "/rest/hosting/vm/%s" % (node.id), method="POST", headers=d[0], data=d[1]
        ).parse_body()

        return True

    def list_images(self, location=None):
        """
        Returns a list of all package templates aka appliances aka images.

        @inherits: :class:`NodeDriver.list_images`
        """

        # Make the call
        response = self.connection.request("/rest/hosting/ptemplate/list").parse_body()

        # Turn the response into an array of NodeImage objects
        images = []
        for ptemplate in response["packages"]:
            images.append(
                NodeImage(
                    id=ptemplate["uuid"],
                    name="{}: {}".format(ptemplate["name"], ptemplate["description"]),
                    driver=self,
                )
            )

        return images

    def list_sizes(self, location=None):
        """
        Returns a list of all hardware templates

        @inherits: :class:`NodeDriver.list_sizes`
        """

        # Make the call
        response = self.connection.request("/rest/hosting/htemplate/list").parse_body()

        # Turn the response into an array of NodeSize objects
        sizes = []
        for htemplate in response["templates"]:
            sizes.append(
                NodeSize(
                    id=htemplate["uuid"],
                    name=htemplate["name"],
                    ram=htemplate["memory"],
                    disk=0,  # Disk is independent of hardware template.
                    bandwidth=0,  # There is no way to keep track of bandwidth.
                    price=0,  # The billing system is external.
                    driver=self,
                )
            )

        return sizes

    def list_locations(self):
        """
        This feature does not exist in ECP. Returns hard coded dummy location.

        :rtype: ``list`` of :class:`NodeLocation`
        """
        return [
            NodeLocation(id=1, name="Cloud", country="", driver=self),
        ]

    def create_node(self, name, size, image):
        """
        Creates a virtual machine.

        :keyword    name:   String with a name for this new node (required)
        :type       name:   ``str``

        :keyword    size:   The size of resources allocated to this node .
                            (required)
        :type       size:   :class:`NodeSize`

        :keyword    image:  OS Image to boot on node. (required)
        :type       image:  :class:`NodeImage`

        :rtype: :class:`Node`
        """

        # Find out what network to put the VM on.
        res = self.connection.request("/rest/hosting/network/list").parse_body()

        # Use the first / default network because there is no way to specific
        # which one
        network = res["networks"][0]["uuid"]

        # Prepare to make the VM
        data = {
            "name": str(name),
            "package": str(image.id),
            "hardware": str(size.id),
            "network_uuid": str(network),
            "disk": "",
        }

        # Black magic to make the POST requests work
        d = self.connection._encode_multipart_formdata(data)
        response = self.connection.request(
            "/rest/hosting/vm/", method="PUT", headers=d[0], data=d[1]
        ).parse_body()

        # Create a node object and return it.
        n = Node(
            id=response["machine_id"],
            name=data["name"],
            state=NodeState.PENDING,
            public_ips=[],
            private_ips=[],
            driver=self,
        )

        return n
