from gattlib import *
from .device import Device
from .exception import handle_return
from .uuid import gattlib_uuid_to_int

GATTLIB_DISCOVER_FILTER_USE_UUID = (1 << 0)
GATTLIB_DISCOVER_FILTER_USE_RSSI = (1 << 1)


class Adapter:

    def __init__(self, name=c_char_p(None)):
        self._name = name
        self._adapter = c_void_p(None)

    @property
    def name(self):
        return self._name

    @staticmethod
    def list():
        # TODO: Add support
        return []

    def open(self):
        return gattlib_adapter_open(self._name, byref(self._adapter))

    def close(self):
        return gattlib.gattlib_adapter_close(self._adapter)

    def on_discovered_device(self, adapter, addr, name, user_data):
        device = Device(self, addr, name)
        self.on_discovered_device_callback(device, user_data)

    def scan_enable(self, on_discovered_device_callback, timeout, uuids=None, rssi_threshold=None, user_data=None):
        assert on_discovered_device_callback != None
        self.on_discovered_device_callback = on_discovered_device_callback

        enabled_filters = 0
        uuid_list = None
        rssi = 0

        if uuids is not None:
            enabled_filters |= GATTLIB_DISCOVER_FILTER_USE_UUID

            # We add 1 to make sure the array finishes with a NULL pointer
            uuid_list = (POINTER(GattlibUuid) * (len(uuids) + 1))()
            index = 0
            for uuid in uuids:
                gattlib_uuid = GattlibUuid()

                uuid_ascii = uuid.encode("utf-8")
                ret = gattlib.gattlib_string_to_uuid(uuid_ascii, len(uuid_ascii), byref(gattlib_uuid))
                handle_return(ret)

                uuid_list[index] = cast(byref(gattlib_uuid), POINTER(GattlibUuid))
                index += 1

        if rssi_threshold is not None:
            enabled_filters |= GATTLIB_DISCOVER_FILTER_USE_RSSI
            rssi = int(rssi_threshold)

        ret = gattlib_adapter_scan_enable_with_filter(self._adapter,
                                                      uuid_list, rssi, enabled_filters,
                                                      gattlib_discovered_device_type(self.on_discovered_device),
                                                      timeout, user_data)
        handle_return(ret)

    def scan_disable(self):
        ret = gattlib.gattlib_adapter_scan_disable(self._adapter)
        handle_return(ret)

    def get_rssi_from_mac(self, mac_address):
        if isinstance(mac_address, str):
            mac_address = mac_address.encode("utf-8")

        rssi = c_int16(0)
        gattlib_get_rssi_from_mac(self._adapter, mac_address, byref(rssi))
        return rssi.value

    def gattlib_get_advertisement_data_from_mac(self, mac_address):
        if isinstance(mac_address, str):
            mac_address = mac_address.encode("utf-8")

        _advertisement_data = POINTER(GattlibAdvertisementData)()
        _advertisement_data_count = c_size_t(0)
        _manufacturer_id = c_uint16(0)
        _manufacturer_data = c_void_p(None)
        _manufacturer_data_len = c_size_t(0)

        ret = gattlib_get_advertisement_data_from_mac(self._adapter, mac_address,
                                                      byref(_advertisement_data), byref(_advertisement_data_count),
                                                      byref(_manufacturer_id),
                                                      byref(_manufacturer_data), byref(_manufacturer_data_len))
        handle_return(ret)

        advertisement_data = {}
        manufacturer_data = None

        for i in range(0, _advertisement_data_count.value):
            service_data = _advertisement_data[i]
            uuid = gattlib_uuid_to_int(service_data.uuid)

            pointer_type = POINTER(c_byte * service_data.data_length)
            c_bytearray = cast(service_data.data, pointer_type)

            data = bytearray(service_data.data_length)
            for i in range(service_data.data_length):
                data[i] = c_bytearray.contents[i] & 0xFF

            advertisement_data[uuid] = data

        if _manufacturer_data_len.value > 0:
            pointer_type = POINTER(c_byte * _manufacturer_data_len.value)
            c_bytearray = cast(_manufacturer_data, pointer_type)

            manufacturer_data = bytearray(_manufacturer_data_len.value)
            for i in range(_manufacturer_data_len.value):
                manufacturer_data[i] = c_bytearray.contents[i] & 0xFF

        return advertisement_data, _manufacturer_id.value, manufacturer_data