# Base class for a BLE device.  Each OS supported by the library should
# inherit from this class and implement the abstract methods.
# Author: Tony DiCola
#
# Copyright (c) 2015 Adafruit Industries
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
import abc
import uuid

# Newer version of Bluez require to handle GATT Battery as a specific DBus object
BAT_SERVICE_UUID = uuid.UUID('0000180F-0000-1000-8000-00805F9B34FB')

class Device(object):
    """Base class for a BLE device."""
    __metaclass__ = abc.ABCMeta

    @abc.abstractmethod
    def close(self):
        """Free BLE device resource."""
        raise NotImplementedError

    @abc.abstractmethod
    def connect(self, timeout_sec):
        """Connect to the BLE device."""
        raise NotImplementedError

    @abc.abstractmethod
    def disconnect(self, timeout_sec):
        """Disconnect from the BLE device."""
        raise NotImplementedError

    @abc.abstractmethod
    def list_services(self):
        """Return a list of GattService objects that have been discovered for
        this device.
        """
        raise NotImplementedError

    @abc.abstractproperty
    def discover(self, service_uuids, char_uuids, timeout_sec=30):
        """Wait up to timeout_sec for the specified services and characteristics
        to be discovered on the device.  If the timeout is exceeded without
        discovering the services and characteristics then an exception is thrown.
        """
        raise NotImplementedError

    @abc.abstractproperty
    def advertised(self):
        """Return a list of UUIDs for services that are advertised by this
        device.
        """
        raise NotImplementedError

    @abc.abstractproperty
    def id(self):
        """Return a unique identifier for this device.  On supported platforms
        this will be the MAC address of the device, however on unsupported
        platforms (Mac OSX) it will be a unique ID like a UUID.
        """
        raise NotImplementedError

    @abc.abstractproperty
    def name(self):
        """Return the name of this device."""
        raise NotImplementedError

    @abc.abstractproperty
    def is_connected(self):
        """Return True if the device is connected to the system, otherwise False.
        """
        raise NotImplementedError

    @abc.abstractproperty
    def rssi(self):
        """Return the RSSI signal strength in decibels."""
        raise NotImplementedError

    def get_rssi(self, timeout_sec):
        """Return the RSSI signal strength in decibels."""
        raise NotImplementedError

    def find_service(self, uuid):
        """Return the first child service found that has the specified
        UUID.  Will return None if no service that matches is found.
        """
        for service in self.list_services():
            if service.uuid == uuid:
                return service

        if uuid == BAT_SERVICE_UUID and hasattr(self, 'battery_service'):
            return self.battery_service()

        return None

    def __eq__(self, other):
        """Test if this device is the same as the provided device."""
        return self.id == other.id

    def __ne__(self, other):
        """Test if this device is not the same as the provided device."""
        return self.id != other.id

    def __hash__(self):
        """Hash function implementation that allows device instances to be put
        inside dictionaries and other containers.
        """
        return hash(self.id)
