# vim: set encoding=utf-8

#  Copyright (c) 2016 Intel Corporation 
#
#  Licensed under the Apache License, Version 2.0 (the "License");
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#
#       http://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
#  limitations under the License.
#

from py4j import java_gateway as _py4j_gateway
from jconvert import JConvert

class JUtils(object):
    def __init__(self, sc):
        self.sc = sc
        self.convert = JConvert(self)

    @staticmethod
    def is_java(item):
        return isinstance(item, _py4j_gateway.JavaObject)

    def is_jvm_instance_of(self, item, scala_type):
        if self.is_java(item):
            return _py4j_gateway.is_instance_of(self.sc._gateway, item, scala_type)
        return False

    def validate_is_jvm_instance_of(self, item, scala_type):
        if not self.is_jvm_instance_of(item, scala_type):
            try:
                received = self.jtypestr(item)
            except:
                received = str(item)
            try:
                expected = self.jtypestr(scala_type)
            except:
                expected = str(scala_type)
            raise ValueError("Mismatched JVM type.  Expected %s, received %s" % (expected, received))

    def jhelp(self, item):
        """shortcut to py4j's help method"""
        self.sc._gateway.help(item)

    @staticmethod
    def jtypestr(item):
        """string representation of the item's Java Type"""
        if JUtils.is_java(item):
            return item.getClass().getName()
        return ""

    def get_scala_sc(self):
        return self.convert.scala.toScalaSparkContext(self.sc._jsc)