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#
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from __future__ import absolute_import, division, print_function
from tests.common.impala_test_suite import ImpalaTestSuite
from tests.common.test_dimensions import (
  create_single_exec_option_dimension,
  create_uncompressed_text_dimension)
from tests.util.event_processor_utils import EventProcessorUtils
from tests.util.filesystem_utils import get_fs_path


class TestTestcaseBuilder(ImpalaTestSuite):

  @classmethod
  def add_test_dimensions(cls):
    super(TestTestcaseBuilder, cls).add_test_dimensions()
    # This test only needs to be run once.
    cls.ImpalaTestMatrix.add_dimension(create_single_exec_option_dimension())
    cls.ImpalaTestMatrix.add_dimension(
      create_uncompressed_text_dimension(cls.get_workload()))

  def test_query_without_from(self):
    self._test_export_and_import(0, 0, 0, "SELECT 5 * 20")

  def test_query_with_tbls(self, unique_database):
    """Verify the basic usage. Use a unique database so the import won't impact the
    metadata used by other tests"""
    self.client.execute(
        "create table {0}.alltypes partitioned by (`year`, `month`) as "
        "select * from functional.alltypes".format(unique_database))
    self.client.execute(
        "create view {0}.alltypes_view as select * from {0}.alltypes"
        .format(unique_database))
    original_part_ids = self.get_partition_id_set(unique_database, "alltypes")

    # Test SELECT on a view. The view will be expanded and the underlying table will also
    # be exported.
    self._test_export_and_import(
        1, 1, 1,
        "select count(*) from {0}.alltypes_view".format(unique_database),
        [unique_database + ".alltypes"], [unique_database + ".alltypes_view"])

    res = self.execute_query(
        "show partitions {0}.alltypes".format(unique_database),
        {"PLANNER_TESTCASE_MODE": True})
    # 24 partitions with a Total line
    assert len(res.data) == 25

    res = self.execute_query(
        "show files in {0}.alltypes".format(unique_database),
        {"PLANNER_TESTCASE_MODE": True})
    # Each partition shoule have exactly one file
    assert len(res.data) == 24

    # Verify the partition ids changed
    new_part_ids = self.get_partition_id_set(unique_database, "alltypes")
    assert new_part_ids != original_part_ids

  def _test_export_and_import(self, num_dbs, num_tbls, num_views, query,
                              tbls=(), views=()):
    tmp_path = get_fs_path("/tmp")
    # Make sure /tmp dir exists
    if not self.filesystem_client.exists(tmp_path):
      self.filesystem_client.make_dir(tmp_path)
    # Generate Testcase Data for query without table reference
    testcase_generate_query = "COPY TESTCASE TO '%s' %s" % (tmp_path, query)
    result = self.execute_query(testcase_generate_query)
    assert len(result.data) == 1, "Testcase builder wrong result: {0}".format(result.data)

    # Check file exists
    testcase_path = str(result.data)[1: -1]
    index = testcase_path.index(tmp_path)
    hdfs_path = testcase_path[index:-1]
    assert self.filesystem_client.exists(hdfs_path), \
        "File not generated {0}".format(hdfs_path)

    result = self.execute_query("explain " + query, {"explain_level": 2})
    original_plan = result.data

    # Remove the original tables and views to make sure we use the imported ones.
    for t in tbls:
      self.execute_query("drop table if exists " + t)
    for v in views:
      self.execute_query("drop view if exists " + v)
    # Make sure the DROP events are processed so the imported ones won't be dropped
    # by them
    EventProcessorUtils.wait_for_event_processing(self)

    # Test load testcase works
    testcase_load_query = "COPY TESTCASE FROM {0}".format(testcase_path)
    result = self.execute_query(testcase_load_query)
    expected_msg = "{0} db(s), {1} table(s) and {2} view(s) imported for query".format(
        num_dbs, num_tbls, num_views)
    assert expected_msg in result.get_data()

    result = self.execute_query("explain " + query, {"explain_level": 2})
    new_plan = result.data
    assert new_plan == original_plan

    # Only delete testcase file if everything works fine.
    status = self.filesystem_client.delete_file_dir(hdfs_path)
    assert status, "Delete generated testcase file failed with {0}".format(status)