# 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.
# libcloud.org 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.

"""
Provides base classes for working with drivers
"""
import httplib, urllib
import libcloud
from zope import interface
from libcloud.interface import IConnectionUserAndKey, IResponse
from libcloud.interface import IConnectionKey, IConnectionKeyFactory
from libcloud.interface import IConnectionUserAndKeyFactory, IResponseFactory
from libcloud.interface import INodeDriverFactory, INodeDriver
from libcloud.interface import INodeFactory, INode
from libcloud.interface import INodeSizeFactory, INodeSize
from libcloud.interface import INodeImageFactory, INodeImage
import hashlib
import StringIO
from pipes import quote as pquote

class Node(object):
    """
    A Base Node class to derive from.
    """
    
    interface.implements(INode)
    interface.classProvides(INodeFactory)

    def __init__(self, id, name, state, public_ip, private_ip,
                 driver, extra=None):
        self.id = id
        self.name = name
        self.state = state
        self.public_ip = public_ip
        self.private_ip = private_ip
        self.driver = driver
        self.uuid = self.get_uuid()
        if not extra:
            self.extra = {}
        else:
            self.extra = extra
        
    def get_uuid(self):
        return hashlib.sha1("%s:%d" % (self.id,self.driver.type)).hexdigest()
        
    def reboot(self):
        return self.driver.reboot_node(self)

    def destroy(self):
        return self.driver.destroy_node(self)

    def __repr__(self):
        return (('<Node: uuid=%s, name=%s, state=%s, public_ip=%s, '
                 'provider=%s ...>')
                % (self.uuid, self.name, self.state, self.public_ip,
                   self.driver.name))


class NodeSize(object):
    """
    A Base NodeSize class to derive from.
    """
    
    interface.implements(INodeSize)
    interface.classProvides(INodeSizeFactory)

    def __init__(self, id, name, ram, disk, bandwidth, price, driver):
        self.id = id
        self.name = name
        self.ram = ram
        self.disk = disk
        self.bandwidth = bandwidth
        self.price = price
        self.driver = driver
    def __repr__(self):
        return (('<NodeSize: id=%s, name=%s, ram=%s disk=%s bandwidth=%s '
                 'price=%s driver=%s ...>')
                % (self.id, self.name, self.ram, self.disk, self.bandwidth,
                   self.price, self.driver.name))


class NodeImage(object):
    """
    A Base NodeImage class to derive from.
    """
    
    interface.implements(INodeImage)
    interface.classProvides(INodeImageFactory)

    def __init__(self, id, name, driver, extra=None):
        self.id = id
        self.name = name
        self.driver = driver
        if not extra:
            self.extra = {}
        else:
            self.extra = extra
    def __repr__(self):
        return (('<NodeImage: id=%s, name=%s, driver=%s  ...>')
                % (self.id, self.name, self.driver.name))

class NodeLocation(object):
    """
    A base NodeLocation class to derive from.
    """
    interface.implements(INodeImage)
    interface.classProvides(INodeImageFactory)
    def __init__(self, id, name, country, driver):
        self.id = id
        self.name = name
        self.country = country
        self.driver = driver
    def __repr__(self):
        return (('<NodeLocation: id=%s, name=%s, country=%s, driver=%s>')
                % (self.id, self.name, self.country, self.driver.name))

class NodeAuthSSHKey(object):
    def __init__(self, pubkey):
        self.pubkey = pubkey
    def __repr__(self):
        return '<NodeAuthSSHKey>'

class NodeAuthPassword(object):
    def __init__(self, password):
        self.password = password
    def __repr__(self):
        return '<NodeAuthPassword>'

class Response(object):
    """
    A Base Response class to derive from.
    """
    interface.implements(IResponse)
    interface.classProvides(IResponseFactory)

    NODE_STATE_MAP = {}

    object = None
    body = None
    status = httplib.OK
    headers = {}
    error = None
    connection = None

    def __init__(self, response):
        self.body = response.read()
        self.status = response.status
        self.headers = dict(response.getheaders())
        self.error = response.reason

        if not self.success():
            raise Exception(self.parse_error())

        self.object = self.parse_body()

    def parse_body(self):
        """
        Parse response body.

        Override in a provider's subclass.

        @return: Parsed body.
        """
        return self.body

    def parse_error(self):
        """
        Parse the error messages.

        Override in a provider's subclass.

        @return: Parsed error.
        """
        return self.body

    def success(self):
        """
        Determine if our request was successful.

        The meaning of this can be arbitrary; did we receive OK status? Did
        the node get created? Were we authenticated?

        @return: C{True} or C{False}
        """
        return self.status == httplib.OK or self.status == httplib.CREATED

#TODO: Move this to a better location/package
class LoggingHTTPSConnection(httplib.HTTPSConnection):
    """
    Debug class to log all HTTP(s) requests as they could be made
    with the C{curl} command.

    @cvar log: file-like object that logs entries are written to.
    """
    log = None

    def _log_response(self, r):
        rv = "# -------- begin %d:%d response ----------\n" % (id(self), id(r))
        ht = ""
        v = r.version
        if r.version == 10:
            v = "HTTP/1.0"
        if r.version == 11:
            v = "HTTP/1.1"
        ht += "%s %s %s\r\n" % (v, r.status, r.reason)
        body = r.read()
        for h in r.getheaders():
            ht += "%s: %s\r\n" % (h[0].title(), h[1])
        ht += "\r\n"
        # this is evil. laugh with me. ha arharhrhahahaha
        class fakesock:
            def __init__(self, s):
                self.s = s
            def makefile(self, mode, foo):
                return StringIO.StringIO(self.s)
        rr = r
        if r.chunked:
            ht += "%x\r\n" % (len(body))
            ht += body
            ht += "\r\n0\r\n"
        else:
            ht += body
        rr = httplib.HTTPResponse(fakesock(ht),
                                  method=r._method,
                                  debuglevel=r.debuglevel)
        rr.begin()
        rv += ht
        rv += ("\n# -------- end %d:%d response ----------\n"
               % (id(self), id(r)))
        return (rr, rv)

    def getresponse(self):
        r = httplib.HTTPSConnection.getresponse(self)
        if self.log is not None:
            r, rv = self._log_response(r)
            self.log.write(rv + "\n")
            self.log.flush()
        return r

    def _log_curl(self, method, url, body, headers):
        cmd = ["curl", "-i"]

        cmd.extend(["-X", pquote(method)])

        for h in headers:
          cmd.extend(["-H", pquote("%s: %s" % (h, headers[h]))])

        # TODO: in python 2.6, body can be a file-like object.
        if body is not None and len(body) > 0:
          cmd.extend(["--data-binary", pquote(body)])

        cmd.extend([pquote("https://%s:%d%s" % (self.host, self.port, url))])
        return " ".join(cmd)

    def request(self, method, url, body=None, headers=None):
        if self.log is not None:
            pre = "# -------- begin %d request ----------\n"  % id(self)
            self.log.write(pre +
                           self._log_curl(method, url, body, headers) + "\n")
            self.log.flush()
        return httplib.HTTPSConnection.request(self, method, url,
                                               body, headers)

class ConnectionKey(object):
    """
    A Base Connection class to derive from.
    """
    interface.implementsOnly(IConnectionKey)
    interface.classProvides(IConnectionKeyFactory)

    #conn_classes = (httplib.HTTPConnection, LoggingHTTPSConnection)
    conn_classes = (httplib.HTTPConnection, httplib.HTTPSConnection)

    responseCls = Response
    connection = None
    host = '127.0.0.1'
    port = (80, 443)
    secure = 1
    driver = None

    def __init__(self, key, secure=True):
        """
        Initialize `user_id` and `key`; set `secure` to an C{int} based on
        passed value.
        """
        self.key = key
        self.secure = secure and 1 or 0
        self.ua = []

    def connect(self, host=None, port=None):
        """
        Establish a connection with the API server.

        @type host: C{str}
        @param host: Optional host to override our default

        @type port: C{int}
        @param port: Optional port to override our default

        @returns: A connection
        """
        host = host or self.host
        port = port or self.port[self.secure]

        connection = self.conn_classes[self.secure](host, port)
        self.connection = connection

    def _user_agent(self):
      return 'libcloud/%s (%s)%s' % (
                libcloud.__version__,
                self.driver.name,
                "".join([" (%s)" % x for x in self.ua]))

    def user_agent_append(self, s):
      self.ua.append(s)

    def request(self,
                action,
                params=None,
                data='',
                headers=None,
                method='GET'):
        """
        Request a given `action`.
        
        Basically a wrapper around the connection
        object's `request` that does some helpful pre-processing.

        @type action: C{str}
        @param action: A path

        @type params: C{dict}
        @param params: Optional mapping of additional parameters to send. If
            None, leave as an empty C{dict}.

        @type data: C{unicode}
        @param data: A body of data to send with the request.

        @type headers: C{dict}
        @param headers: Extra headers to add to the request
            None, leave as an empty C{dict}.

        @type method: C{str}
        @param method: An HTTP method such as "GET" or "POST".

        @return: An instance of type I{responseCls}
        """
        if params is None:
          params = {}
        if headers is None:
          headers = {}
        # Extend default parameters
        params = self.add_default_params(params)
        # Extend default headers
        headers = self.add_default_headers(headers)
        # We always send a content length and user-agent header
        headers.update({'Content-Length': len(data)})
        headers.update({'User-Agent': self._user_agent()})
        headers.update({'Host': self.host})
        # Encode data if necessary
        if data != '':
            data = self.encode_data(data)
        url = '?'.join((action, urllib.urlencode(params)))
        
        # Removed terrible hack...this a less-bad hack that doesn't execute a
        # request twice, but it's still a hack.
        self.connect()
        self.connection.request(method=method, url=url, body=data,
                                headers=headers)
        response = self.responseCls(self.connection.getresponse())
        response.connection = self
        return response

    def add_default_params(self, params):
        """
        Adds default parameters (such as API key, version, etc.)
        to the passed `params`

        Should return a dictionary.
        """
        return params

    def add_default_headers(self, headers):
        """
        Adds default headers (such as Authorization, X-Foo-Bar)
        to the passed `headers`

        Should return a dictionary.
        """
        return headers

    def encode_data(self, data):
        """
        Encode body data.

        Override in a provider's subclass.
        """
        return data


class ConnectionUserAndKey(ConnectionKey):
    """
    Base connection which accepts a user_id and key
    """
    interface.implementsOnly(IConnectionUserAndKey)
    interface.classProvides(IConnectionUserAndKeyFactory)

    user_id = None

    def __init__(self, user_id, key, secure=True):
        super(ConnectionUserAndKey, self).__init__(key, secure)
        self.user_id = user_id


class NodeDriver(object):
    """
    A base NodeDriver class to derive from
    """
    interface.implements(INodeDriver)
    interface.classProvides(INodeDriverFactory)

    connectionCls = ConnectionKey
    name = None
    type = None
    features = {"create_node": []}
    """
    List of available features for a driver.
        - L{create_node}
            - ssh_key: Supports L{NodeAuthSSHKey} as an authentication method
              for nodes.
            - password: Supports L{NodeAuthPassword} as an authentication
              method for nodes.
    """
    NODE_STATE_MAP = {}

    def __init__(self, key, secret=None, secure=True):
        """
        @keyword    key:    API key or username to used
        @type       key:    str

        @keyword    secret: Secret password to be used
        @type       secret: str

        @keyword    secure: Weither to use HTTPS or HTTP. Note: Some providers 
                            only support HTTPS, and it is on by default.
        @type       secure: bool
        """
        self.key = key
        self.secret = secret
        self.secure = secure
        if self.secret:
          self.connection = self.connectionCls(key, secret, secure)
        else:
          self.connection = self.connectionCls(key, secure)

        self.connection.driver = self
        self.connection.connect()

    def create_node(self, **kwargs):
        """Create a new node instance.

        @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:   L{NodeSize}

        @keyword    image:  OS Image to boot on node. (required)
        @type       image:  L{NodeImage}

        @keyword    location: Which data center to create a node in. If empty,
                              undefined behavoir will be selected. (optional)
        @type       location: L{NodeLocation}

        @keyword    auth:   Initial authentication information for the node
                            (optional)
        @type       auth:   L{NodeAuthSSHKey} or L{NodeAuthPassword}

        @return: The newly created L{Node}.
        """
        raise NotImplementedError, \
            'create_node not implemented for this driver'

    def destroy_node(self, node):
        """Destroy a node.

        Depending upon the provider, this may destroy all data associated with
        the node, including backups.

        @return: C{bool} True if the destroy was successful, otherwise False
        """
        raise NotImplementedError, \
            'destroy_node not implemented for this driver'

    def reboot_node(self, node):
        """
        Reboot a node.
        @return: C{bool} True if the reboot was successful, otherwise False
        """
        raise NotImplementedError, \
            'reboot_node not implemented for this driver'

    def list_nodes(self):
        """
        List all nodes
        @return: C{list} of L{Node} objects
        """
        raise NotImplementedError, \
            'list_nodes not implemented for this driver'

    def list_images(self, location=None):
        """
        List images on a provider
        @return: C{list} of L{NodeImage} objects
        """
        raise NotImplementedError, \
            'list_images not implemented for this driver'

    def list_sizes(self, location=None):
        """
        List sizes on a provider
        @return: C{list} of L{NodeSize} objects
        """
        raise NotImplementedError, \
            'list_sizes not implemented for this driver'

    def list_locations(self):
        """
        List data centers for a provider
        @return: C{list} of L{NodeLocation} objects
        """
        raise NotImplementedError, \
            'list_locations not implemented for this driver'