#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You 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.
#

import os
import unittest

from pyspark import SparkConf, SparkContext
from pyspark.sql import SparkSession, SQLContext, Row
from pyspark.testing.sqlutils import ReusedSQLTestCase
from pyspark.testing.utils import PySparkTestCase


class SparkSessionTests(ReusedSQLTestCase):
    def test_sqlcontext_reuses_sparksession(self):
        sqlContext1 = SQLContext(self.sc)
        sqlContext2 = SQLContext(self.sc)
        self.assertTrue(sqlContext1.sparkSession is sqlContext2.sparkSession)


class SparkSessionTests1(ReusedSQLTestCase):

    # We can't include this test into SQLTests because we will stop class's SparkContext and cause
    # other tests failed.
    def test_sparksession_with_stopped_sparkcontext(self):
        self.sc.stop()
        sc = SparkContext('local[4]', self.sc.appName)
        spark = SparkSession.builder.getOrCreate()
        try:
            df = spark.createDataFrame([(1, 2)], ["c", "c"])
            df.collect()
        finally:
            spark.stop()
            sc.stop()


class SparkSessionTests2(PySparkTestCase):

    # This test is separate because it's closely related with session's start and stop.
    # See SPARK-23228.
    def test_set_jvm_default_session(self):
        spark = SparkSession.builder.getOrCreate()
        try:
            self.assertTrue(spark._jvm.SparkSession.getDefaultSession().isDefined())
        finally:
            spark.stop()
            self.assertTrue(spark._jvm.SparkSession.getDefaultSession().isEmpty())

    def test_jvm_default_session_already_set(self):
        # Here, we assume there is the default session already set in JVM.
        jsession = self.sc._jvm.SparkSession(self.sc._jsc.sc())
        self.sc._jvm.SparkSession.setDefaultSession(jsession)

        spark = SparkSession.builder.getOrCreate()
        try:
            self.assertTrue(spark._jvm.SparkSession.getDefaultSession().isDefined())
            # The session should be the same with the exiting one.
            self.assertTrue(jsession.equals(spark._jvm.SparkSession.getDefaultSession().get()))
        finally:
            spark.stop()


class SparkSessionTests3(unittest.TestCase):

    def test_active_session(self):
        spark = SparkSession.builder \
            .master("local") \
            .getOrCreate()
        try:
            activeSession = SparkSession.getActiveSession()
            df = activeSession.createDataFrame([(1, 'Alice')], ['age', 'name'])
            self.assertEqual(df.collect(), [Row(age=1, name=u'Alice')])
        finally:
            spark.stop()

    def test_get_active_session_when_no_active_session(self):
        active = SparkSession.getActiveSession()
        self.assertEqual(active, None)
        spark = SparkSession.builder \
            .master("local") \
            .getOrCreate()
        active = SparkSession.getActiveSession()
        self.assertEqual(active, spark)
        spark.stop()
        active = SparkSession.getActiveSession()
        self.assertEqual(active, None)

    def test_SparkSession(self):
        spark = SparkSession.builder \
            .master("local") \
            .config("some-config", "v2") \
            .getOrCreate()
        try:
            self.assertEqual(spark.conf.get("some-config"), "v2")
            self.assertEqual(spark.sparkContext._conf.get("some-config"), "v2")
            self.assertEqual(spark.version, spark.sparkContext.version)
            spark.sql("CREATE DATABASE test_db")
            spark.catalog.setCurrentDatabase("test_db")
            self.assertEqual(spark.catalog.currentDatabase(), "test_db")
            spark.sql("CREATE TABLE table1 (name STRING, age INT) USING parquet")
            self.assertEqual(spark.table("table1").columns, ['name', 'age'])
            self.assertEqual(spark.range(3).count(), 3)
        finally:
            spark.sql("DROP DATABASE test_db CASCADE")
            spark.stop()

    def test_global_default_session(self):
        spark = SparkSession.builder \
            .master("local") \
            .getOrCreate()
        try:
            self.assertEqual(SparkSession.builder.getOrCreate(), spark)
        finally:
            spark.stop()

    def test_default_and_active_session(self):
        spark = SparkSession.builder \
            .master("local") \
            .getOrCreate()
        activeSession = spark._jvm.SparkSession.getActiveSession()
        defaultSession = spark._jvm.SparkSession.getDefaultSession()
        try:
            self.assertEqual(activeSession, defaultSession)
        finally:
            spark.stop()

    def test_config_option_propagated_to_existing_session(self):
        session1 = SparkSession.builder \
            .master("local") \
            .config("spark-config1", "a") \
            .getOrCreate()
        self.assertEqual(session1.conf.get("spark-config1"), "a")
        session2 = SparkSession.builder \
            .config("spark-config1", "b") \
            .getOrCreate()
        try:
            self.assertEqual(session1, session2)
            self.assertEqual(session1.conf.get("spark-config1"), "b")
        finally:
            session1.stop()

    def test_new_session(self):
        session = SparkSession.builder \
            .master("local") \
            .getOrCreate()
        newSession = session.newSession()
        try:
            self.assertNotEqual(session, newSession)
        finally:
            session.stop()
            newSession.stop()

    def test_create_new_session_if_old_session_stopped(self):
        session = SparkSession.builder \
            .master("local") \
            .getOrCreate()
        session.stop()
        newSession = SparkSession.builder \
            .master("local") \
            .getOrCreate()
        try:
            self.assertNotEqual(session, newSession)
        finally:
            newSession.stop()

    def test_active_session_with_None_and_not_None_context(self):
        from pyspark.context import SparkContext
        from pyspark.conf import SparkConf
        sc = None
        session = None
        try:
            sc = SparkContext._active_spark_context
            self.assertEqual(sc, None)
            activeSession = SparkSession.getActiveSession()
            self.assertEqual(activeSession, None)
            sparkConf = SparkConf()
            sc = SparkContext.getOrCreate(sparkConf)
            activeSession = sc._jvm.SparkSession.getActiveSession()
            self.assertFalse(activeSession.isDefined())
            session = SparkSession(sc)
            activeSession = sc._jvm.SparkSession.getActiveSession()
            self.assertTrue(activeSession.isDefined())
            activeSession2 = SparkSession.getActiveSession()
            self.assertNotEqual(activeSession2, None)
        finally:
            if session is not None:
                session.stop()
            if sc is not None:
                sc.stop()


class SparkSessionTests4(ReusedSQLTestCase):

    def test_get_active_session_after_create_dataframe(self):
        session2 = None
        try:
            activeSession1 = SparkSession.getActiveSession()
            session1 = self.spark
            self.assertEqual(session1, activeSession1)
            session2 = self.spark.newSession()
            activeSession2 = SparkSession.getActiveSession()
            self.assertEqual(session1, activeSession2)
            self.assertNotEqual(session2, activeSession2)
            session2.createDataFrame([(1, 'Alice')], ['age', 'name'])
            activeSession3 = SparkSession.getActiveSession()
            self.assertEqual(session2, activeSession3)
            session1.createDataFrame([(1, 'Alice')], ['age', 'name'])
            activeSession4 = SparkSession.getActiveSession()
            self.assertEqual(session1, activeSession4)
        finally:
            if session2 is not None:
                session2.stop()


class SparkSessionTests5(unittest.TestCase):

    def setUp(self):
        # These tests require restarting the Spark context so we set up a new one for each test
        # rather than at the class level.
        self.sc = SparkContext('local[4]', self.__class__.__name__, conf=SparkConf())
        self.spark = SparkSession(self.sc)

    def tearDown(self):
        self.sc.stop()
        self.spark.stop()

    def test_sqlcontext_with_stopped_sparksession(self):
        # SPARK-30856: test that SQLContext.getOrCreate() returns a usable instance after
        # the SparkSession is restarted.
        sql_context = self.spark._wrapped
        self.spark.stop()
        sc = SparkContext('local[4]', self.sc.appName)
        spark = SparkSession(sc)  # Instantiate the underlying SQLContext
        new_sql_context = spark._wrapped

        self.assertIsNot(new_sql_context, sql_context)
        self.assertIs(SQLContext.getOrCreate(sc).sparkSession, spark)
        try:
            df = spark.createDataFrame([(1, 2)], ['c', 'c'])
            df.collect()
        finally:
            spark.stop()
            self.assertIsNone(SQLContext._instantiatedContext)
            sc.stop()

    def test_sqlcontext_with_stopped_sparkcontext(self):
        # SPARK-30856: test initialization via SparkSession when only the SparkContext is stopped
        self.sc.stop()
        self.sc = SparkContext('local[4]', self.sc.appName)
        self.spark = SparkSession(self.sc)
        self.assertIs(SQLContext.getOrCreate(self.sc).sparkSession, self.spark)

    def test_get_sqlcontext_with_stopped_sparkcontext(self):
        # SPARK-30856: test initialization via SQLContext.getOrCreate() when only the SparkContext
        # is stopped
        self.sc.stop()
        self.sc = SparkContext('local[4]', self.sc.appName)
        self.assertIs(SQLContext.getOrCreate(self.sc)._sc, self.sc)


class SparkSessionBuilderTests(unittest.TestCase):

    def test_create_spark_context_first_then_spark_session(self):
        sc = None
        session = None
        try:
            conf = SparkConf().set("key1", "value1")
            sc = SparkContext('local[4]', "SessionBuilderTests", conf=conf)
            session = SparkSession.builder.config("key2", "value2").getOrCreate()

            self.assertEqual(session.conf.get("key1"), "value1")
            self.assertEqual(session.conf.get("key2"), "value2")
            self.assertEqual(session.sparkContext, sc)

            self.assertFalse(sc.getConf().contains("key2"))
            self.assertEqual(sc.getConf().get("key1"), "value1")
        finally:
            if session is not None:
                session.stop()
            if sc is not None:
                sc.stop()

    def test_another_spark_session(self):
        session1 = None
        session2 = None
        try:
            session1 = SparkSession.builder.config("key1", "value1").getOrCreate()
            session2 = SparkSession.builder.config("key2", "value2").getOrCreate()

            self.assertEqual(session1.conf.get("key1"), "value1")
            self.assertEqual(session2.conf.get("key1"), "value1")
            self.assertEqual(session1.conf.get("key2"), "value2")
            self.assertEqual(session2.conf.get("key2"), "value2")
            self.assertEqual(session1.sparkContext, session2.sparkContext)

            self.assertEqual(session1.sparkContext.getConf().get("key1"), "value1")
            self.assertFalse(session1.sparkContext.getConf().contains("key2"))
        finally:
            if session1 is not None:
                session1.stop()
            if session2 is not None:
                session2.stop()


class SparkExtensionsTest(unittest.TestCase):
    # These tests are separate because it uses 'spark.sql.extensions' which is
    # static and immutable. This can't be set or unset, for example, via `spark.conf`.

    @classmethod
    def setUpClass(cls):
        import glob
        from pyspark.find_spark_home import _find_spark_home

        SPARK_HOME = _find_spark_home()
        filename_pattern = (
            "sql/core/target/scala-*/test-classes/org/apache/spark/sql/"
            "SparkSessionExtensionSuite.class")
        if not glob.glob(os.path.join(SPARK_HOME, filename_pattern)):
            raise unittest.SkipTest(
                "'org.apache.spark.sql.SparkSessionExtensionSuite' is not "
                "available. Will skip the related tests.")

        # Note that 'spark.sql.extensions' is a static immutable configuration.
        cls.spark = SparkSession.builder \
            .master("local[4]") \
            .appName(cls.__name__) \
            .config(
                "spark.sql.extensions",
                "org.apache.spark.sql.MyExtensions") \
            .getOrCreate()

    @classmethod
    def tearDownClass(cls):
        cls.spark.stop()

    def test_use_custom_class_for_extensions(self):
        self.assertTrue(
            self.spark._jsparkSession.sessionState().planner().strategies().contains(
                self.spark._jvm.org.apache.spark.sql.MySparkStrategy(self.spark._jsparkSession)),
            "MySparkStrategy not found in active planner strategies")
        self.assertTrue(
            self.spark._jsparkSession.sessionState().analyzer().extendedResolutionRules().contains(
                self.spark._jvm.org.apache.spark.sql.MyRule(self.spark._jsparkSession)),
            "MyRule not found in extended resolution rules")


if __name__ == "__main__":
    from pyspark.sql.tests.test_session import *  # noqa: F401

    try:
        import xmlrunner  # type: ignore[import]
        testRunner = xmlrunner.XMLTestRunner(output='target/test-reports', verbosity=2)
    except ImportError:
        testRunner = None
    unittest.main(testRunner=testRunner, verbosity=2)
