def _make_casters():
    inet = new_type((869,), 'INET', cast_interface)
    ainet = new_array_type((1041,), 'INET[]', inet)

    cidr = new_type((650,), 'CIDR', cast_network)
    acidr = new_array_type((651,), 'CIDR[]', cidr)

    return [inet, ainet, cidr, acidr]

def register_inet(oid=None, conn_or_curs=None):
    """Create the INET type and an Inet adapter.

    :param oid: oid for the PostgreSQL :sql:`inet` type, or 2-items sequence
        with oids of the type and the array. If not specified, use PostgreSQL
        standard oids.
    :param conn_or_curs: where to register the typecaster. If not specified,
        register it globally.
    """
    import warnings
    warnings.warn(
        "the inet adapter is deprecated, it's not very useful",
        DeprecationWarning)

    if not oid:
        oid1 = 869
        oid2 = 1041
    elif isinstance(oid, (list, tuple)):
        oid1, oid2 = oid
    else:
        oid1 = oid
        oid2 = 1041

    _ext.INET = _ext.new_type((oid1, ), "INET",
            lambda data, cursor: data and Inet(data) or None)
    _ext.INETARRAY = _ext.new_array_type((oid2, ), "INETARRAY", _ext.INET)

    _ext.register_type(_ext.INET, conn_or_curs)
    _ext.register_type(_ext.INETARRAY, conn_or_curs)

    return _ext.INET

def register_uuid(oids=None, conn_or_curs=None):
    """Create the UUID type and an uuid.UUID adapter.

    :param oids: oid for the PostgreSQL :sql:`uuid` type, or 2-items sequence
        with oids of the type and the array. If not specified, use PostgreSQL
        standard oids.
    :param conn_or_curs: where to register the typecaster. If not specified,
        register it globally.
    """

    import uuid

    if not oids:
        oid1 = 2950
        oid2 = 2951
    elif isinstance(oids, (list, tuple)):
        oid1, oid2 = oids
    else:
        oid1 = oids
        oid2 = 2951

    _ext.UUID = _ext.new_type((oid1, ), "UUID",
            lambda data, cursor: data and uuid.UUID(data) or None)
    _ext.UUIDARRAY = _ext.new_array_type((oid2,), "UUID[]", _ext.UUID)

    _ext.register_type(_ext.UUID, conn_or_curs)
    _ext.register_type(_ext.UUIDARRAY, conn_or_curs)
    _ext.register_adapter(uuid.UUID, UUID_adapter)

    return _ext.UUID

def register_ltree(conn):
    oid = _get_ltree_oids(conn)
    if not oid[0]:
        return False
    else:
        array_oid = oid[1]
        oid = oid[0]

    if isinstance(oid, int):
        oid = (oid,)

    if array_oid is not None:
        if isinstance(array_oid, int):
            array_oid = (array_oid,)
        else:
            array_oid = tuple([x for x in array_oid if x])

    ltree = extensions.new_type(oid, "LTREE", _cast_fn)
    extensions.register_type(ltree, None)

    if array_oid:
        ltree_array = extensions.new_array_type(array_oid, "LTREEARRAY", ltree)
        extensions.register_type(ltree_array, None)

    return True

def register_ltree(conn_or_curs, globally=False, oid=None, array_oid=None):
    """Register the ltree adapter and typecaster on the connection or cursor.
    """
    register_adapter()

    conn, curs, conn_or_curs = _solve_conn_curs(conn_or_curs)

    if oid is None:
        oid = get_oids(conn_or_curs, 'ltree')
        if oid is None or not oid[0]:
            raise psycopg2.ProgrammingError(
                "ltree type not found in the database."
            )
        else:
            array_oid = oid[1]
            oid = oid[0]

    if isinstance(oid, int):
        oid = (oid,)

    if array_oid is not None:
        if isinstance(array_oid, int):
            array_oid = (array_oid,)
        else:
            array_oid = tuple([x for x in array_oid if x])

    # create and register the typecaster
    LTREE = ext.new_type(oid, "LTREE", cast_ltree)
    ext.register_type(LTREE, not globally and conn_or_curs or None)

    if array_oid:
        LTREEARRAY = ext.new_array_type(array_oid, "LTREEARRAY", LTREE)
        ext.register_type(LTREEARRAY, not globally and conn_or_curs or None)

def register_cidr(oid=None, conn_or_curs=None):
    """Create the CIDR type and an Cidr adapter.

    :param oid: oid for the PostgreSQL :sql:`cidr` type, or 2-items sequence
        with oids of the type and the array. If not specified, use PostgreSQL
        standard oids.
    :param conn_or_curs: where to register the typecaster. If not specified,
        register it globally.
    """
    if not oid:
        oid1 = 650
        oid2 = 651
    elif isinstance(oid, (list, tuple)):
        oid1, oid2 = oid
    else:
        oid1 = oid
        oid2 = 651

    _ext.CIDR = _ext.new_type((oid1, ), "CIDR",
            lambda data, cursor: data and Cidr(data) or None)
    _ext.CIDRARRAY = _ext.new_array_type((oid2, ), "CIDRARRAY", _ext.CIDR)

    _ext.register_type(_ext.CIDR, conn_or_curs)
    _ext.register_type(_ext.CIDRARRAY, conn_or_curs)

    return _ext.CIDR

def register_range_caster(pgrange, pyrange, oid, subtype_oid, array_oid, scope=None):
    # Create an adapter for this range type
    adapter = partial(cast_raw_range_string, pyrange, subtype_oid=subtype_oid)

    # Create types using adapter
    range_type = new_type((oid,), pgrange, adapter)
    range_array_type = new_array_type((array_oid,), pgrange, range_type)

    register_type(range_type, scope)
    register_type(range_array_type, scope)

    def __init__(self, pgrange, pyrange, oid, subtype_oid, array_oid=None):
        self.subtype_oid = subtype_oid
        self._create_ranges(pgrange, pyrange)

        name = self.adapter.name or self.adapter.__class__.__name__

        self.typecaster = new_type((oid,), name, self.parse)

        if array_oid is not None:
            self.array_typecaster = new_array_type((array_oid,), name + "ARRAY", self.typecaster)
        else:
            self.array_typecaster = None

def register_macaddr_type():
    from psycopg2.extensions import register_adapter, new_type, register_type, new_array_type
    import psycopg2

    oid = get_type_oid("NULL::macaddr")
    PGTYPE = new_type((oid,), "macaddr", cast_macaddr)
    register_type(PGTYPE)
    register_adapter(MacAddr, adapt_macaddr)

    mac_array_oid = get_type_oid("'{}'::macaddr[]")
    array_of_mac = new_array_type((mac_array_oid, ), 'macaddr', psycopg2.STRING)
    psycopg2.extensions.register_type(array_of_mac)

    def __init__(self, name, oid, attrs, array_oid=None):
        self.name = name
        self.oid = oid
        self.array_oid = array_oid

        self.attnames = [ a[0] for a in attrs ]
        self.atttypes = [ a[1] for a in attrs ]
        self._create_type(name, self.attnames)
        self.typecaster = new_type((oid,), name, self.parse)
        if array_oid:
            self.array_typecaster = new_array_type(
                (array_oid,), "%sARRAY" % name, self.typecaster)
        else:
            self.array_typecaster = None

def setup_connection(conn):
    # We want to use unicode everywhere
    register_type(UNICODE, conn)
    register_type(UNICODEARRAY, conn)
    conn.set_client_encoding('UTF8')
    cur = conn.cursor()
    cur.execute("SELECT NULL::numeric")
    oid = cur.description[0][1]
    NUMERIC = new_type((oid,), "NUMERIC", numeric_converter)
    cur.execute("SELECT NULL::numeric[]")
    oid = cur.description[0][1]
    NUMERICL = new_array_type((oid,), "NUMERIC[]", NUMERIC)
    register_type(NUMERIC, conn)
    register_type(NUMERICL, conn)
    register_adapter(Integer, AsIs)
    register_adapter(RealNumber, RealEncoder)
    register_adapter(dict, Json)
    register_json(conn, loads=Json.loads)

def register_hstore(conn_or_curs, globally=False, unicode=False,
        oid=None, array_oid=None):
    from psycopg2.extras import HstoreAdapter
    from psycopg2 import extensions as _ext
    import psycopg2
    import sys
    import re as regex
    from .fields import HStoreDict

    def cast(s, cur, _bsdec=regex.compile(r"\\(.)")):
        if sys.version_info[0] < 3 and unicode:
            result = HstoreAdapter.parse_unicode(s, cur)
        else:
            result = HstoreAdapter.parse(s, cur, _bsdec)
        return HStoreDict(result)

    if oid is None:
        oid = HstoreAdapter.get_oids(conn_or_curs)
        if oid is None or not oid[0]:
            raise psycopg2.ProgrammingError(
                "hstore type not found in the database. "
                "please install it from your 'contrib/hstore.sql' file")
        else:
            array_oid = oid[1]
            oid = oid[0]

    if isinstance(oid, int):
        oid = (oid,)

    if array_oid is not None:
        if isinstance(array_oid, int):
            array_oid = (array_oid,)
        else:
            array_oid = tuple([x for x in array_oid if x])

    HSTORE = _ext.new_type(oid, str("HSTORE"), cast)
    _ext.register_type(HSTORE, not globally and conn_or_curs or None)
    _ext.register_adapter(dict, HstoreAdapter)

    if array_oid:
        HSTOREARRAY = _ext.new_array_type(array_oid, str("HSTOREARRAY"), HSTORE)
        _ext.register_type(HSTOREARRAY, not globally and conn_or_curs or None)

def register_hstore(conn_or_curs, globally=False, unicode=False,
                    oid=None, array_oid=None):
    r"""Register adapter and typecaster for `!dict`\-\ |hstore| conversions.

    :param conn_or_curs: a connection or cursor: the typecaster will be
        registered only on this object unless *globally* is set to `!True`
    :param globally: register the adapter globally, not only on *conn_or_curs*
    :param unicode: if `!True`, keys and values returned from the database
        will be `!unicode` instead of `!str`. The option is not available on
        Python 3
    :param oid: the OID of the |hstore| type if known. If not, it will be
        queried on *conn_or_curs*.
    :param array_oid: the OID of the |hstore| array type if known. If not, it
        will be queried on *conn_or_curs*.

    The connection or cursor passed to the function will be used to query the
    database and look for the OID of the |hstore| type (which may be different
    across databases). If querying is not desirable (e.g. with
    :ref:`asynchronous connections <async-support>`) you may specify it in the
    *oid* parameter, which can be found using a query such as :sql:`SELECT
    'hstore'::regtype::oid`. Analogously you can obtain a value for *array_oid*
    using a query such as :sql:`SELECT 'hstore[]'::regtype::oid`.

    Note that, when passing a dictionary from Python to the database, both
    strings and unicode keys and values are supported. Dictionaries returned
    from the database have keys/values according to the *unicode* parameter.

    The |hstore| contrib module must be already installed in the database
    (executing the ``hstore.sql`` script in your ``contrib`` directory).
    Raise `~psycopg2.ProgrammingError` if the type is not found.
    """
    if oid is None:
        oid = HstoreAdapter.get_oids(conn_or_curs)
        if oid is None or not oid[0]:
            raise psycopg2.ProgrammingError(
                "hstore type not found in the database. "
                "please install it from your 'contrib/hstore.sql' file")
        else:
            array_oid = oid[1]
            oid = oid[0]

    if isinstance(oid, int):
        oid = (oid,)

    if array_oid is not None:
        if isinstance(array_oid, int):
            array_oid = (array_oid,)
        else:
            array_oid = tuple([x for x in array_oid if x])

    # create and register the typecaster
    if _sys.version_info[0] < 3 and unicode:
        cast = HstoreAdapter.parse_unicode
    else:
        cast = HstoreAdapter.parse

    HSTORE = _ext.new_type(oid, "HSTORE", cast)
    _ext.register_type(HSTORE, not globally and conn_or_curs or None)
    _ext.register_adapter(dict, HstoreAdapter)

    if array_oid:
        HSTOREARRAY = _ext.new_array_type(array_oid, "HSTOREARRAY", HSTORE)
        _ext.register_type(HSTOREARRAY, not globally and conn_or_curs or None)

except AttributeError:
    from psycopg2.extensions import new_type, new_array_type, register_type, \
        register_adapter, QuotedString

    def cast_interface(s, cur=None):
        if s is None:
            return None
        return ipaddress.ip_interface(unicode(s))

    def cast_ipnetwork(s, cur=None):
        if s is None:
            return None
        return ipaddress.ip_network(unicode(s))

    inet = new_type((869,), b'INET', cast_interface)
    ainet = new_array_type((1041,), b'INET[]', inet)

    cidr = new_type((650,), b'CIDR', cast_ipnetwork)
    acidr = new_array_type((651,), b'CIDR[]', cidr)

    for c in [inet, ainet, cidr, acidr]:
        register_type(c, None)

    def adapt_ipaddress(obj):
        return QuotedString(str(obj))

    for t in [ipaddress.IPv4Interface, ipaddress.IPv6Interface,
              ipaddress.IPv4Network, ipaddress.IPv6Network]:
        register_adapter(t, adapt_ipaddress)

    def __init__(self, oid = 2249, array_oid = 2287):
        self.oid = oid
        self.array_oid = array_oid

        self.typecaster = new_type((oid,), "RECORD", self.parse)
        self.array_typecaster = new_array_type((array_oid,), "RECORD[]", self.typecaster)