# Parts of this code reuse code and concepts by Lubomir Stroetmann from softScheck GmbH
# licensed under the Apache License v 2.0.
# Copy of the Apache License can be found at http://www.apache.org/licenses/LICENSE-2.0
# The code from Lubomir Stroetmann is located at http://github.com/softScheck/tplink-smartplug

import logging
import socket
import codecs
import json
import datetime
import sys

_LOGGER = logging.getLogger(__name__)


class SmartPlug(object):
    """Class to access TPLink Switch.

    Usage example when used as library:
    p = SmartPlug("192.168.1.105")
    # change state of plug
    p.state = "OFF"
    p.state = "ON"
    # query and print current state of plug
    print(p.state)
    Note:
    The library references the same structure as defined for the D-Link Switch
    """

    def __init__(self, ip):
        """Create a new SmartPlug instance identified by the IP."""
        self.ip = ip
        self.port = 9999
        self._error_report = False
        self.model = self._identify_model()

    @property
    def state(self):
        """Get the device state (i.e. ON or OFF)."""
        response = self.get_info()
        relay_state = response["system"]["get_sysinfo"]["relay_state"]

        if relay_state is None:
            return 'unknown'
        elif relay_state == 0:
            return "OFF"
        elif relay_state == 1:
            return "ON"
        else:
            _LOGGER.warning("Unknown state %s returned" % str(relay_state))
            return 'unknown'

    @state.setter
    def state(self, value):
        """Set device state.
        :type value: str
        :param value: Future state (either ON or OFF)
        """
        if value.upper() == 'ON':
            self.turn_on()

        elif value.upper() == 'OFF':
            self.turn_off()

        else:
            raise TypeError("State %s is not valid." % str(value))

    def get_info(self):
        """Interrogate the switch"""
        return self._send_command('{"system":{"get_sysinfo":{}}}')

    def turn_on(self):
        """Turns the switch on

          Return values:
            True on success
            False on failure
        """
        response = self._send_command('{"system":{"set_relay_state":{"state":1}}}')

        if response["system"]["set_relay_state"]["err_code"] == 0:
            return True

        return False

    def turn_off(self):
        """Turns the switch off

          Return values:
            True on success
            False on failure
        """
        response = self._send_command('{"system":{"set_relay_state":{"state":0}}}')

        if response["system"]["set_relay_state"]["err_code"] == 0:
            return True

        return False

    def get_emeter_realtime(self):
        """Gets the current energy readings from the switch

          Return values:
            False if command is not successful or the switch doesn't support energy metering
            Dict with the current readings
        """
        if self.model != 110:
            return False

        response = self._send_command('{"emeter":{"get_realtime":{}}}')

        if response["emeter"]["get_realtime"]["err_code"] != 0:
            return False

        response["emeter"]["get_realtime"].pop('err_code', None)
        return response["emeter"]["get_realtime"]

    def get_emeter_daily(self, year=datetime.datetime.now().year, month=datetime.datetime.now().month):
        """Gets daily statistics for a given month.

          Arguments:
            year (optional): The year for which to retrieve statistics, defaults to current year
            month (optional): The mont for which to retrieve statistics, defaults to current month

          Return values:
            False if command is not successful or the switch doesn't support energy metering
            Dict where the keys represent the days, and the values are the aggregated statistics
        """
        if self.model != 110:
            return False

        response = self._send_command('{"emeter":{"get_daystat":{"month":' + str(month) + ',"year":' + str(year) + '}}}')

        if response["emeter"]["get_daystat"]["err_code"] != 0:
            return False

        data = dict()

        for i, j in enumerate(response["emeter"]["get_daystat"]["day_list"]):
            if j["energy"] > 0:
                data[j["day"]] = j["energy"]

        return data

    def get_emeter_monthly(self, year=datetime.datetime.now().year):
        """Gets monthly statistics for a given year.

        Arguments:
          year (optional): The year for which to retrieve statistics, defaults to current year

        Return values:
          False if command is not successful or the switch doesn't support energy metering
          Dict - the keys represent the months, the values are the aggregated statistics
        """
        if self.model != 110:
            return False

        response = self._send_command('{"emeter":{"get_monthstat":{"year":' + str(year) + '}}}')

        if response["emeter"]["get_monthstat"]["err_code"] != 0:
            return False

        data = dict()

        for i, j in enumerate(response["emeter"]["get_monthstat"]["month_list"]):
            if j["energy"] > 0:
                data[j["month"]] = j["energy"]

        return data

    def erase_emeter_stats(self):
        """Erases all statistics.

          Return values:
            True: Success
            False: Failure or not supported by switch
        """
        if self.model != 110:
            return False

        response = self._send_command('{"emeter":{"erase_emeter_stat":null}}')

        if response["emeter"]["erase_emeter_stat"]["err_code"] != 0:
            return False
        else:
            return True

    def current_consumption(self):
        """Get the current power consumption in Watt."""
        if self.model != 110:
            return False

        response = self.get_emeter_realtime()

        return response["power"]

    def _encrypt(self, string):
        """Encrypts a command."""

        """
        Taken from https://raw.githubusercontent.com/softScheck/tplink-smartplug/master/tplink-smartplug.py
        Changes: the return value is encoded in latin-1 in Python 3 and later
        """
        key = 171
        result = "\0\0\0\0"
        for i in string:
            a = key ^ ord(i)
            key = a
            result += chr(a)

        if sys.version_info.major > 2:
            return result.encode('latin-1')

        return result

    def _decrypt(self, string):
        """Decrypts a command."""

        """
        Taken from https://raw.githubusercontent.com/softScheck/tplink-smartplug/master/tplink-smartplug.py
        Changes: the string parameter is decoded from latin-1 in Python 3 and later
        """
        if sys.version_info.major > 2:
            string = string.decode('latin-1')

        key = 171
        result = ""
        for i in string:
            a = key ^ ord(i)
            key = ord(i)
            result += chr(a)

        return result

    def _send_command(self, command):
        """Sends a command to the switch.

          Accepts one argument - the command as a string

          Return values:
            The decrypted JSON
        """
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        s.connect((self.ip, self.port))
        s.send(self._encrypt(command))
        response = self._decrypt(s.recv(4096)[4:])
        s.shutdown(1)
        s.close()

        return json.loads(response)

    def _identify_model(self):
        """Query sysinfo and determine model"""
        sys_info = self.get_info()

        if sys_info["system"]["get_sysinfo"]["model"][:5] == 'HS100':
            model = 100
        elif sys_info["system"]["get_sysinfo"]["model"][:5] == 'HS200':
            model = 200
        elif sys_info["system"]["get_sysinfo"]["model"][:5] == 'HS110':
            model = 110

        return model