"""Support for haveibeenpwned (email breaches) sensor."""
from datetime import timedelta
import logging

from aiohttp.hdrs import USER_AGENT
import requests
import voluptuous as vol

from homeassistant.components.sensor import PLATFORM_SCHEMA, SensorEntity
from homeassistant.const import (
    ATTR_ATTRIBUTION,
    CONF_API_KEY,
    CONF_EMAIL,
    HTTP_NOT_FOUND,
    HTTP_OK,
)
import homeassistant.helpers.config_validation as cv
from homeassistant.helpers.event import track_point_in_time
from homeassistant.util import Throttle
import homeassistant.util.dt as dt_util

_LOGGER = logging.getLogger(__name__)

ATTRIBUTION = "Data provided by Have I Been Pwned (HIBP)"

DATE_STR_FORMAT = "%Y-%m-%d %H:%M:%S"

HA_USER_AGENT = "Home Assistant HaveIBeenPwned Sensor Component"

MIN_TIME_BETWEEN_FORCED_UPDATES = timedelta(seconds=5)
MIN_TIME_BETWEEN_UPDATES = timedelta(minutes=15)

URL = "https://haveibeenpwned.com/api/v3/breachedaccount/"

PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend(
    {
        vol.Required(CONF_EMAIL): vol.All(cv.ensure_list, [cv.string]),
        vol.Required(CONF_API_KEY): cv.string,
    }
)


def setup_platform(hass, config, add_entities, discovery_info=None):
    """Set up the HaveIBeenPwned sensor."""
    emails = config.get(CONF_EMAIL)
    api_key = config[CONF_API_KEY]
    data = HaveIBeenPwnedData(emails, api_key)

    devices = []
    for email in emails:
        devices.append(HaveIBeenPwnedSensor(data, email))

    add_entities(devices)


class HaveIBeenPwnedSensor(SensorEntity):
    """Implementation of a HaveIBeenPwned sensor."""

    def __init__(self, data, email):
        """Initialize the HaveIBeenPwned sensor."""
        self._state = None
        self._data = data
        self._email = email
        self._unit_of_measurement = "Breaches"

    @property
    def name(self):
        """Return the name of the sensor."""
        return f"Breaches {self._email}"

    @property
    def native_unit_of_measurement(self):
        """Return the unit the value is expressed in."""
        return self._unit_of_measurement

    @property
    def native_value(self):
        """Return the state of the device."""
        return self._state

    @property
    def extra_state_attributes(self):
        """Return the attributes of the sensor."""
        val = {ATTR_ATTRIBUTION: ATTRIBUTION}
        if self._email not in self._data.data:
            return val

        for idx, value in enumerate(self._data.data[self._email]):
            tmpname = f"breach {idx + 1}"
            datetime_local = dt_util.as_local(
                dt_util.parse_datetime(value["AddedDate"])
            )
            tmpvalue = f"{value['Title']} {datetime_local.strftime(DATE_STR_FORMAT)}"
            val[tmpname] = tmpvalue

        return val

    async def async_added_to_hass(self):
        """Get initial data."""
        # To make sure we get initial data for the sensors ignoring the normal
        # throttle of 15 minutes but using an update throttle of 5 seconds
        self.hass.async_add_executor_job(self.update_nothrottle)

    def update_nothrottle(self, dummy=None):
        """Update sensor without throttle."""
        self._data.update_no_throttle()

        # Schedule a forced update 5 seconds in the future if the update above
        # returned no data for this sensors email. This is mainly to make sure
        # that we don't get HTTP Error "too many requests" and to have initial
        # data after hass startup once we have the data it will update as
        # normal using update
        if self._email not in self._data.data:
            track_point_in_time(
                self.hass,
                self.update_nothrottle,
                dt_util.now() + MIN_TIME_BETWEEN_FORCED_UPDATES,
            )
            return

        self._state = len(self._data.data[self._email])
        self.schedule_update_ha_state()

    def update(self):
        """Update data and see if it contains data for our email."""
        self._data.update()

        if self._email in self._data.data:
            self._state = len(self._data.data[self._email])


class HaveIBeenPwnedData:
    """Class for handling the data retrieval."""

    def __init__(self, emails, api_key):
        """Initialize the data object."""
        self._email_count = len(emails)
        self._current_index = 0
        self.data = {}
        self._email = emails[0]
        self._emails = emails
        self._api_key = api_key

    def set_next_email(self):
        """Set the next email to be looked up."""
        self._current_index = (self._current_index + 1) % self._email_count
        self._email = self._emails[self._current_index]

    def update_no_throttle(self):
        """Get the data for a specific email."""
        self.update(no_throttle=True)

    @Throttle(MIN_TIME_BETWEEN_UPDATES, MIN_TIME_BETWEEN_FORCED_UPDATES)
    def update(self, **kwargs):
        """Get the latest data for current email from REST service."""
        try:
            url = f"{URL}{self._email}?truncateResponse=false"
            header = {USER_AGENT: HA_USER_AGENT, "hibp-api-key": self._api_key}
            _LOGGER.debug("Checking for breaches for email: %s", self._email)
            req = requests.get(url, headers=header, allow_redirects=True, timeout=5)

        except requests.exceptions.RequestException:
            _LOGGER.error("Failed fetching data for %s", self._email)
            return

        if req.status_code == HTTP_OK:
            self.data[self._email] = sorted(
                req.json(), key=lambda k: k["AddedDate"], reverse=True
            )

            # Only goto next email if we had data so that
            # the forced updates try this current email again
            self.set_next_email()

        elif req.status_code == HTTP_NOT_FOUND:
            self.data[self._email] = []

            # only goto next email if we had data so that
            # the forced updates try this current email again
            self.set_next_email()

        else:
            _LOGGER.error(
                "Failed fetching data for %s (HTTP Status_code = %d)",
                self._email,
                req.status_code,
            )
