# -*- coding: utf-8 -*-
"""
Python client for InfluxDB
"""
import json
import socket
import requests
import requests.exceptions
import warnings

from influxdb import chunked_json

try:
    xrange
except NameError:
    xrange = range

session = requests.Session()


class InfluxDBClientError(Exception):
    "Raised when an error occurs in the request"
    def __init__(self, content, code):
        super(InfluxDBClientError, self).__init__(
            "{0}: {1}".format(code, content))
        self.content = content
        self.code = code


class InfluxDBClient(object):

    """
    The ``InfluxDBClient`` object holds information necessary to connect
    to InfluxDB. Requests can be made to InfluxDB directly through the client.

    :param host: hostname to connect to InfluxDB, defaults to 'localhost'
    :type host: string
    :param port: port to connect to InfluxDB, defaults to 'localhost'
    :type port: int
    :param username: user to connect, defaults to 'root'
    :type username: string
    :param password: password of the user, defaults to 'root'
    :type password: string
    :param database: database name to connect to, defaults is None
    :type database: string
    :param ssl: use https instead of http to connect to InfluxDB, defaults is
        False
    :type ssl: boolean
    :param verify_ssl: verify SSL certificates for HTTPS requests, defaults is
        False
    :type verify_ssl: boolean
    :param timeout: number of seconds Requests will wait for your client to
        establish a connection, defaults to None
    :type timeout: int
    :param use_udp: use UDP to connect to InfluxDB, defaults is False
    :type use_udp: int
    :param udp_port: UDP port to connect to InfluxDB, defaults is 4444
    :type udp_port: int
    """

    def __init__(self,
                 host='localhost',
                 port=8086,
                 username='root',
                 password='root',
                 database=None,
                 ssl=False,
                 verify_ssl=False,
                 timeout=None,
                 use_udp=False,
                 udp_port=4444):
        """
        Construct a new InfluxDBClient object.
        """
        self._host = host
        self._port = port
        self._username = username
        self._password = password
        self._database = database
        self._timeout = timeout

        self._verify_ssl = verify_ssl

        self.use_udp = use_udp
        self.udp_port = udp_port
        if use_udp:
            self.udp_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)

        self._scheme = "http"

        if ssl is True:
            self._scheme = "https"

        self._baseurl = "{0}://{1}:{2}".format(
            self._scheme,
            self._host,
            self._port)

        self._headers = {
            'Content-type': 'application/json',
            'Accept': 'text/plain'}

    # Change member variables

    def switch_database(self, database):
        """
        switch_database()

        Change client database.

        :param database: the new database name to switch to
        :type database: string
        """
        self._database = database

    def switch_db(self, database):
        """
        DEPRECATED. Change client database.

        """
        warnings.warn(
            "switch_db is deprecated, and will be removed "
            "in future versions. Please use "
            "``InfluxDBClient.switch_database(database)`` instead.",
            FutureWarning)
        return self.switch_database(database)

    def switch_user(self, username, password):
        """
        switch_user()

        Change client username.

        :param username: the new username to switch to
        :type username: string
        :param password: the new password to switch to
        :type password: string
        """
        self._username = username
        self._password = password

    def request(self, url, method='GET', params=None, data=None,
                expected_response_code=200):
        """
        Make a http request to API
        """
        url = "{0}/{1}".format(self._baseurl, url)

        if params is None:
            params = {}

        auth = {
            'u': self._username,
            'p': self._password
        }

        params.update(auth)

        if data is not None and not isinstance(data, str):
            data = json.dumps(data)

        # Try to send the request a maximum of three times. (see #103)
        # TODO (aviau): Make this configurable.
        for i in range(0, 3):
            try:
                response = session.request(
                    method=method,
                    url=url,
                    params=params,
                    data=data,
                    headers=self._headers,
                    verify=self._verify_ssl,
                    timeout=self._timeout
                )
                break
            except requests.exceptions.ConnectionError as e:
                if i < 2:
                    continue
                else:
                    raise e

        if response.status_code == expected_response_code:
            return response
        else:
            raise InfluxDBClientError(response.content, response.status_code)

    def write(self, data):
        """ Provided as convenience for influxdb v0.9.0, this may change. """
        self.request(
            url="write",
            method='POST',
            params=None,
            data=data,
            expected_response_code=200
        )
        return True

    # Writing Data
    #
    # Assuming you have a database named foo_production you can write data
    # by doing a POST to /db/foo_production/series?u=some_user&p=some_password
    # with a JSON body of points.

    def write_points(self, data, time_precision='s', *args, **kwargs):
        """
        Write to multiple time series names.

        :param data: A list of dicts.
        :param time_precision: [Optional, default 's'] Either 's', 'm', 'ms'
            or 'u'.
        :param batch_size: [Optional] Value to write the points in batches
            instead of all at one time. Useful for when doing data dumps from
            one database to another or when doing a massive write operation
        :type batch_size: int
        """

        def list_chunks(l, n):
            """ Yield successive n-sized chunks from l.
            """
            for i in xrange(0, len(l), n):
                yield l[i:i + n]

        batch_size = kwargs.get('batch_size')
        if batch_size:
            for item in data:
                name = item.get('name')
                columns = item.get('columns')
                point_list = item.get('points')

                for batch in list_chunks(point_list, batch_size):
                    item = [{
                        "points": batch,
                        "name": name,
                        "columns": columns
                    }]
                    self._write_points(
                        data=item,
                        time_precision=time_precision)

                return True

        return self._write_points(data=data, time_precision=time_precision)

    def write_points_with_precision(self, data, time_precision='s'):
        """
        DEPRECATED. Write to multiple time series names

        """
        warnings.warn(
            "write_points_with_precision is deprecated, and will be removed "
            "in future versions. Please use "
            "``InfluxDBClient.write_points(time_precision='..')`` instead.",
            FutureWarning)
        return self._write_points(data=data, time_precision=time_precision)

    def _write_points(self, data, time_precision):
        if time_precision not in ['s', 'm', 'ms', 'u']:
            raise Exception(
                "Invalid time precision is given. (use 's', 'm', 'ms' or 'u')")

        if self.use_udp and time_precision != 's':
            raise Exception(
                "InfluxDB only supports seconds precision for udp writes"
            )

        url = "db/{0}/series".format(self._database)

        params = {
            'time_precision': time_precision
        }

        if self.use_udp:
            self.send_packet(data)
        else:
            self.request(
                url=url,
                method='POST',
                params=params,
                data=data,
                expected_response_code=200
            )

        return True

    # One Time Deletes

    def delete_points(self, name):
        """
        Delete an entire series
        """
        url = "db/{0}/series/{1}".format(self._database, name)

        self.request(
            url=url,
            method='DELETE',
            expected_response_code=204
        )

        return True

    # Regularly Scheduled Deletes

    def create_scheduled_delete(self, json_body):
        """
        TODO: Create scheduled delete

        2013-11-08: This endpoint has not been implemented yet in ver0.0.8,
        but it is documented in http://influxdb.org/docs/api/http.html.
        See also: src/api/http/api.go:l57
        """
        raise NotImplementedError()

    # get list of deletes
    # curl http://localhost:8086/db/site_dev/scheduled_deletes
    #
    # remove a regularly scheduled delete
    # curl -X DELETE http://localhost:8086/db/site_dev/scheduled_deletes/:id

    def get_list_scheduled_delete(self):
        """
        TODO: Get list of scheduled deletes

        2013-11-08: This endpoint has not been implemented yet in ver0.0.8,
        but it is documented in http://influxdb.org/docs/api/http.html.
        See also: src/api/http/api.go:l57
        """
        raise NotImplementedError()

    def remove_scheduled_delete(self, delete_id):
        """
        TODO: Remove scheduled delete

        2013-11-08: This endpoint has not been implemented yet in ver0.0.8,
        but it is documented in http://influxdb.org/docs/api/http.html.
        See also: src/api/http/api.go:l57
        """
        raise NotImplementedError()

    def query(self, query, time_precision='s', chunked=False):
        """
        Quering data

        :param time_precision: [Optional, default 's'] Either 's', 'm', 'ms'
            or 'u'.
        :param chunked: [Optional, default=False] True if the data shall be
            retrieved in chunks, False otherwise.
        """
        return self._query(query, time_precision=time_precision,
                           chunked=chunked)

    # Querying Data
    #
    # GET db/:name/series. It takes five parameters
    def _query(self, query, time_precision='s', chunked=False):
        if time_precision not in ['s', 'm', 'ms', 'u']:
            raise Exception(
                "Invalid time precision is given. (use 's', 'm', 'ms' or 'u')")

        if chunked is True:
            chunked_param = 'true'
        else:
            chunked_param = 'false'

        # Build the URL of the serie to query
        url = "db/{0}/series".format(self._database)

        params = {
            'q': query,
            'time_precision': time_precision,
            'chunked': chunked_param
        }

        response = self.request(
            url=url,
            method='GET',
            params=params,
            expected_response_code=200
        )

        if chunked:
            return list(chunked_json.loads(response.content.decode()))
        else:
            return response.json()

    # Creating and Dropping Databases
    #
    # ### create a database
    # curl -X POST http://localhost:8086/db -d '{"name": "site_development"}'
    #
    # ### drop a database
    # curl -X DELETE http://localhost:8086/db/site_development

    def create_database(self, database):
        """
        create_database()

        Create a database on the InfluxDB server.

        :param database: the name of the database to create
        :type database: string
        :rtype: boolean
        """
        url = "db"

        data = {'name': database}

        self.request(
            url=url,
            method='POST',
            data=data,
            expected_response_code=201
        )

        return True

    def delete_database(self, database):
        """
        delete_database()

        Drop a database on the InfluxDB server.

        :param database: the name of the database to delete
        :type database: string
        :rtype: boolean
        """
        url = "db/{0}".format(database)

        self.request(
            url=url,
            method='DELETE',
            expected_response_code=204
        )

        return True

    # ### get list of databases
    # curl -X GET http://localhost:8086/db

    def get_list_database(self):
        """
        Get the list of databases
        """
        url = "db"

        response = self.request(
            url=url,
            method='GET',
            expected_response_code=200
        )

        return response.json()

    def get_database_list(self):
        """
        DEPRECATED. Get the list of databases

        """
        warnings.warn(
            "get_database_list is deprecated, and will be removed "
            "in future versions. Please use "
            "``InfluxDBClient.get_list_database`` instead.",
            FutureWarning)
        return self.get_list_database()

    def delete_series(self, series):
        """
        delete_series()

        Drop a series on the InfluxDB server.

        :param series: the name of the series to delete
        :type series: string
        :rtype: boolean
        """
        url = "db/{0}/series/{1}".format(
            self._database,
            series
        )

        self.request(
            url=url,
            method='DELETE',
            expected_response_code=204
        )

        return True

    def get_list_series(self):
        """
        Get a list of all time series in a database
        """

        response = self._query('list series')

        series_list = []
        for series in response[0]['points']:
            series_list.append(series[1])

        return series_list

    def get_list_continuous_queries(self):
        """
        Get a list of continuous queries
        """

        response = self._query('list continuous queries')
        queries_list = []
        for query in response[0]['points']:
            queries_list.append(query[2])

        return queries_list

    # Security
    # get list of cluster admins
    # curl http://localhost:8086/cluster_admins?u=root&p=root

    # add cluster admin
    # curl -X POST http://localhost:8086/cluster_admins?u=root&p=root \
    #      -d '{"name": "paul", "password": "i write teh docz"}'

    # update cluster admin password
    # curl -X POST http://localhost:8086/cluster_admins/paul?u=root&p=root \
    #      -d '{"password": "new pass"}'

    # delete cluster admin
    # curl -X DELETE http://localhost:8086/cluster_admins/paul?u=root&p=root

    # Database admins, with a database name of site_dev
    # get list of database admins
    # curl http://localhost:8086/db/site_dev/admins?u=root&p=root

    # add database admin
    # curl -X POST http://localhost:8086/db/site_dev/admins?u=root&p=root \
    #      -d '{"name": "paul", "password": "i write teh docz"}'

    # update database admin password
    # curl -X POST http://localhost:8086/db/site_dev/admins/paul?u=root&p=root\
    #      -d '{"password": "new pass"}'

    # delete database admin
    # curl -X DELETE \
    #        http://localhost:8086/db/site_dev/admins/paul?u=root&p=root

    def get_list_cluster_admins(self):
        """
        Get list of cluster admins
        """
        response = self.request(
            url="cluster_admins",
            method='GET',
            expected_response_code=200
        )

        return response.json()

    def add_cluster_admin(self, new_username, new_password):
        """
        Add cluster admin
        """
        data = {
            'name': new_username,
            'password': new_password
        }

        self.request(
            url="cluster_admins",
            method='POST',
            data=data,
            expected_response_code=200
        )

        return True

    def update_cluster_admin_password(self, username, new_password):
        """
        Update cluster admin password
        """
        url = "cluster_admins/{0}".format(username)

        data = {
            'password': new_password
        }

        self.request(
            url=url,
            method='POST',
            data=data,
            expected_response_code=200
        )

        return True

    def delete_cluster_admin(self, username):
        """
        Delete cluster admin
        """
        url = "cluster_admins/{0}".format(username)

        self.request(
            url=url,
            method='DELETE',
            expected_response_code=200
        )

        return True

    def set_database_admin(self, username):
        """
        Set user as database admin
        """
        return self.alter_database_admin(username, True)

    def unset_database_admin(self, username):
        """
        Unset user as database admin
        """
        return self.alter_database_admin(username, False)

    def alter_database_admin(self, username, is_admin):
        url = "db/{0}/users/{1}".format(self._database, username)

        data = {'admin': is_admin}

        self.request(
            url=url,
            method='POST',
            data=data,
            expected_response_code=200
        )

        return True

    def get_list_database_admins(self):
        """
        TODO: Get list of database admins

        2013-11-08: This endpoint has not been implemented yet in ver0.0.8,
        but it is documented in http://influxdb.org/docs/api/http.html.
        See also: src/api/http/api.go:l57
        """
        raise NotImplementedError()

    def add_database_admin(self, new_username, new_password):
        """
        TODO: Add cluster admin

        2013-11-08: This endpoint has not been implemented yet in ver0.0.8,
        but it is documented in http://influxdb.org/docs/api/http.html.
        See also: src/api/http/api.go:l57
        """
        raise NotImplementedError()

    def update_database_admin_password(self, username, new_password):
        """
        TODO: Update database admin password

        2013-11-08: This endpoint has not been implemented yet in ver0.0.8,
        but it is documented in http://influxdb.org/docs/api/http.html.
        See also: src/api/http/api.go:l57
        """
        raise NotImplementedError()

    def delete_database_admin(self, username):
        """
        TODO: Delete database admin

        2013-11-08: This endpoint has not been implemented yet in ver0.0.8,
        but it is documented in http://influxdb.org/docs/api/http.html.
        See also: src/api/http/api.go:l57
        """
        raise NotImplementedError()

    ###
    # Limiting User Access

    # Database users
    # get list of database users
    # curl http://localhost:8086/db/site_dev/users?u=root&p=root

    # add database user
    # curl -X POST http://localhost:8086/db/site_dev/users?u=root&p=root \
    #       -d '{"name": "paul", "password": "i write teh docz"}'

    # update database user password
    # curl -X POST http://localhost:8086/db/site_dev/users/paul?u=root&p=root \
    #       -d '{"password": "new pass"}'

    # delete database user
    # curl -X DELETE http://localhost:8086/db/site_dev/users/paul?u=root&p=root

    def get_database_users(self):
        """
        Get list of database users
        """
        url = "db/{0}/users".format(self._database)

        response = self.request(
            url=url,
            method='GET',
            expected_response_code=200
        )

        return response.json()

    def add_database_user(self, new_username, new_password, permissions=None):
        """
        Add database user

        :param permissions: A ``(readFrom, writeTo)`` tuple
        """
        url = "db/{0}/users".format(self._database)

        data = {
            'name': new_username,
            'password': new_password
        }

        if permissions:
            try:
                data['readFrom'], data['writeTo'] = permissions
            except (ValueError, TypeError):
                raise TypeError(
                    "'permissions' must be (readFrom, writeTo) tuple"
                )

        self.request(
            url=url,
            method='POST',
            data=data,
            expected_response_code=200
        )

        return True

    def update_database_user_password(self, username, new_password):
        """
        Update password
        """
        url = "db/{0}/users/{1}".format(self._database, username)

        data = {
            'password': new_password
        }

        self.request(
            url=url,
            method='POST',
            data=data,
            expected_response_code=200
        )

        if username == self._username:
            self._password = new_password

        return True

    def delete_database_user(self, username):
        """
        Delete database user
        """
        url = "db/{0}/users/{1}".format(self._database, username)

        self.request(
            url=url,
            method='DELETE',
            expected_response_code=200
        )

        return True

    # update the user by POSTing to db/site_dev/users/paul

    def update_permission(self, username, json_body):
        """
        TODO: Update read/write permission

        2013-11-08: This endpoint has not been implemented yet in ver0.0.8,
        but it is documented in http://influxdb.org/docs/api/http.html.
        See also: src/api/http/api.go:l57
        """
        raise NotImplementedError()

    def send_packet(self, packet):
        data = json.dumps(packet)
        byte = data.encode('utf-8')
        self.udp_socket.sendto(byte, (self._host, self.udp_port))
