"""Device tracker for Synology SRM routers.

For more details about this platform, please refer to the documentation at
https://home-assistant.io/components/device_tracker.synology_srm/
"""
import logging
import voluptuous as vol

import homeassistant.helpers.config_validation as cv
from homeassistant.components.device_tracker import (
    DOMAIN, PLATFORM_SCHEMA, DeviceScanner)
from homeassistant.const import (
    CONF_HOST, CONF_USERNAME, CONF_PASSWORD,
    CONF_PORT, CONF_SSL, CONF_VERIFY_SSL)

_LOGGER = logging.getLogger(__name__)

DEFAULT_USERNAME = 'admin'
DEFAULT_PORT = 8001
DEFAULT_SSL = True
DEFAULT_VERIFY_SSL = False

PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
    vol.Required(CONF_HOST): cv.string,
    vol.Required(CONF_USERNAME, default=DEFAULT_USERNAME): cv.string,
    vol.Required(CONF_PASSWORD): cv.string,
    vol.Optional(CONF_PORT, default=DEFAULT_PORT): cv.port,
    vol.Optional(CONF_SSL, default=DEFAULT_SSL): cv.boolean,
    vol.Optional(CONF_VERIFY_SSL, default=DEFAULT_VERIFY_SSL): cv.boolean,
})


def get_scanner(hass, config):
    """Validate the configuration and return Synology SRM scanner."""
    scanner = SynologySrmDeviceScanner(config[DOMAIN])

    return scanner if scanner.success_init else None


class SynologySrmDeviceScanner(DeviceScanner):
    """This class scans for devices connected to a Synology SRM router."""

    def __init__(self, config):
        """Initialize the scanner."""
        import synology_srm

        self.client = synology_srm.Client(
            host=config[CONF_HOST],
            port=config[CONF_PORT],
            username=config[CONF_USERNAME],
            password=config[CONF_PASSWORD],
            https=config[CONF_SSL]
        )

        if not config[CONF_VERIFY_SSL]:
            self.client.http.disable_https_verify()

        self.last_results = []
        self.success_init = self._update_info()

        _LOGGER.info("Synology SRM scanner initialized")

    def scan_devices(self):
        """Scan for new devices and return a list with found device IDs."""
        self._update_info()

        return [device['mac'] for device in self.last_results]

    def get_device_name(self, device):
        """Return the name of the given device or None if we don't know."""
        filter_named = [result['hostname'] for result in self.last_results if
                        result['mac'] == device]

        if filter_named:
            return filter_named[0]

        return None

    def _update_info(self):
        """Check the router for connected devices."""
        _LOGGER.debug("Scanning for connected devices")

        devices = self.client.core.network_nsm_device({'is_online': True})
        last_results = []

        for device in devices:
            last_results.append({
                'mac': device['mac'],
                'hostname': device['hostname']
            })

        _LOGGER.debug(
            "Found %d device(s) connected to the router",
            len(devices)
        )

        self.last_results = last_results
        return True