import sys
import requests
from requests.auth import HTTPBasicAuth


class Thermostat:
    """
    A class for interacting with the OpenEnergyMonitor Thermostat's HTTP API.

    Parameters
    ----------
    host : `str`
        Hostname or IP address.

    port : `int` (optional)
        The port of the web server.

    username : `str` (optional)
        The username for HTTP auth.

    password : `str` (optional)
        The password for the HTTP auth.

    """

    def __init__(self, host, port=80, username=None, password=None):
        if username or password and not username and password:
            raise ValueError(
                "Username and Password must both be specified, if either are specified."
            )
        elif username or password:
            self.auth = HTTPBasicAuth(username, password)
        else:
            self.auth = None

        self._base_url = "http://{}:{}/{{endpoint}}.cgi".format(host, port)
        try:
            r = requests.get(self._base_url.format(endpoint="index.html")[:-4])
            assert r.status_code == 200
        except Exception as e:
            raise type(e)("Connection to Thermostat failed with: {}".format(str(e))
                         ).with_traceback(sys.exc_info()[2])

    def _get_url(self, endpoint):
        return self._base_url.format(endpoint=endpoint)

    def get(self, endpoint, **kwargs):
        """
        Perform a GET request

        Parameters
        ----------
        endpoint : `str`
            The endpoint to send the request to, will have 'cgi' appended to it.

        kwargs : `dict`
            All other kwargs are passed to `requests.get`

        Returns
        -------
        response : `requests.Response`
            The result of the request.
        """
        kwergs = {'auth': self.auth}
        kwergs.update(kwargs)

        r = requests.get(self._get_url(endpoint), **kwergs)
        return r

    def post(self, endpoint, **kwargs):
        """
        Perform a POST request

        Parameters
        ----------
        endpoint : `str`
            The endpoint to send the request to, will have 'cgi' appended to it.

        kwargs : `dict`
            All other kwargs are passed to `requests.post`

        Returns
        -------
        response : `requests.Response`
            The result of the request.
        """
        kwergs = {'auth': self.auth}
        kwergs.update(kwargs)

        r = requests.post(self._get_url(endpoint), **kwergs)
        return r

    def status(self):
        """
        Get the status dictionary from the thermostat
        """
        r = self.get("control/thermostat", params={"param": "state"})
        return r.json()

    @property
    def temperature(self):
        """
        Current value of the temperature sensor in C
        """
        return float(self.status()['temperature'])

    @property
    def setpoint(self):
        """
        Current thermostat setpoint in C
        """
        return float(self.status()['manualsetpoint']) / 100

    @setpoint.setter
    def setpoint(self, val):
        val = int(val * 100)
        setpoint = str(val).encode()
        self.post(
            "control/thermostat",
            params={'param': 'thermostat_manualsetpoint'},
            data=setpoint)

    @property
    def mode(self):
        """
        Returns the current mode of the thermostat.

        Returns
        -------
        mode : `int`
            `0` for manual mode, `1` for schedule mode and `2` for manual mode.
        """
        return self.status()['state']

    @mode.setter
    def mode(self, val):
        val = int(val)
        if not 0 <= val <= 2:
            raise ValueError("mode must be either 0,1,2")
        self.post(
            "control/thermostat",
            params={"param": "thermostat_state"},
            data=str(val).encode())

    @property
    def state(self):
        """
        Current state of the relay.

        Returns
        -------
        state : `bool`
            returns `True` if the relay is on and `False` if the relay is off.
        """
        return bool(self.status()['relay1state'])

    def switch(self):
        """
        Change the state of the relay.
        """
        return self.post(
            "control/relay", params={'relay1': int(not self.state)})