# 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.

# This module contains utility functions for testing Parquet files,
# and other functions used for checking for strings in files and
# directories.

from __future__ import absolute_import, division, print_function
import os
import re
import shutil
import tempfile
from subprocess import check_call

from tests.util.filesystem_utils import get_fs_path, WAREHOUSE_PREFIX


def create_iceberg_table_from_directory(impala_client, unique_database, table_name,
                                        file_format):
  """Utility function to create an iceberg table from a directory. The directory must
  exist in $IMPALA_HOME/testdata/data/iceberg_test with the name 'table_name'"""

  # Only orc and parquet tested/supported
  assert file_format == "orc" or file_format == "parquet"

  local_dir = os.path.join(
    os.environ['IMPALA_HOME'], 'testdata/data/iceberg_test/{0}'.format(table_name))
  assert os.path.isdir(local_dir)

  # If using a prefix, rewrite iceberg metadata to use the prefix
  if WAREHOUSE_PREFIX:
    tmp_dir = tempfile.mktemp(table_name)
    check_call(['cp', '-r', local_dir, tmp_dir])
    rewrite = os.path.join(
        os.environ['IMPALA_HOME'], 'testdata/bin/rewrite-iceberg-metadata.py')
    check_call([rewrite, WAREHOUSE_PREFIX, os.path.join(tmp_dir, 'metadata')])
    local_dir = tmp_dir

  # Put the directory in the database's directory (not the table directory)
  hdfs_parent_dir = get_fs_path("/test-warehouse")

  hdfs_dir = os.path.join(hdfs_parent_dir, table_name)

  # Purge existing files if any
  check_call(['hdfs', 'dfs', '-rm', '-f', '-r', hdfs_dir])

  # Note: -d skips a staging copy
  check_call(['hdfs', 'dfs', '-put', '-d', local_dir, hdfs_dir])

  # Create external table
  qualified_table_name = '{0}.{1}'.format(unique_database, table_name)
  impala_client.execute("""create external table {0} stored as iceberg location '{1}'
                        tblproperties('write.format.default'='{2}', 'iceberg.catalog'=
                        'hadoop.tables')""".format(qualified_table_name, hdfs_dir,
                                                   file_format))

  # Automatic clean up after drop table
  impala_client.execute("""alter table {0} set tblproperties ('external.table.purge'=
                        'True');""".format(qualified_table_name))


def create_table_from_parquet(impala_client, unique_database, table_name):
  """Utility function to create a database table from a Parquet file. A Parquet file must
  exist in $IMPALA_HOME/testdata/data with the name 'table_name'.parquet"""
  create_table_from_file(impala_client, unique_database, table_name, 'parquet')


def create_table_from_orc(impala_client, unique_database, table_name):
  """Utility function to create a database table from a Orc file. A Orc file must
  exist in $IMPALA_HOME/testdata/data with the name 'table_name'.orc"""
  create_table_from_file(impala_client, unique_database, table_name, 'orc')


def create_table_from_file(impala_client, unique_database, table_name, file_format):
  filename = '{0}.{1}'.format(table_name, file_format)
  local_file = os.path.join(os.environ['IMPALA_HOME'],
                            'testdata/data/{0}'.format(filename))
  assert os.path.isfile(local_file)

  # Put the file in the database's directory (not the table directory) so it is
  # available for a LOAD DATA statement.
  hdfs_file = get_fs_path(
      os.path.join("/test-warehouse", "{0}.db".format(unique_database), filename))
  # Note: -d skips a staging copy
  check_call(['hdfs', 'dfs', '-put', '-f', '-d', local_file, hdfs_file])

  # Create the table and load the file
  qualified_table_name = '{0}.{1}'.format(unique_database, table_name)
  impala_client.execute('create table {0} like {1} "{2}" stored as {1}'.format(
      qualified_table_name, file_format, hdfs_file))
  impala_client.execute('load data inpath "{0}" into table {1}'.format(
      hdfs_file, qualified_table_name))


def create_table_and_copy_files(impala_client, create_stmt, unique_database, table_name,
                                files):
  # Create the table
  create_stmt = create_stmt.format(db=unique_database, tbl=table_name)
  impala_client.execute(create_stmt)

  hdfs_dir = get_fs_path(
      os.path.join("/test-warehouse", unique_database + ".db", table_name))
  copy_files_to_hdfs_dir(files, hdfs_dir)

  # Refresh the table metadata to see the new files
  refresh_stmt = "refresh {0}.{1}".format(unique_database, table_name)
  impala_client.execute(refresh_stmt)


def copy_files_to_hdfs_dir(files, hdfs_dir):
  # Copy the files
  #  - build a list of source files
  #  - issue a single put to the hdfs_dir ( -d skips a staging copy)
  source_files = []
  for local_file in files:
    # Cut off leading '/' to make os.path.join() happy
    local_file = local_file if local_file[0] != '/' else local_file[1:]
    local_file = os.path.join(os.environ['IMPALA_HOME'], local_file)
    assert os.path.isfile(local_file)
    source_files.append(local_file)
  check_call(['hdfs', 'dfs', '-put', '-f', '-d'] + source_files + [hdfs_dir])


def grep_dir(dir, search, filename_search=""):
  '''Recursively search for files that contain 'search' and have a filename that matches
     'filename_search' and return a list of matched lines grouped by file.
  '''
  filename_matcher = re.compile(filename_search)
  matching_files = dict()
  for dir_name, _, file_names in os.walk(dir):
    for file_name in file_names:
      file_path = os.path.join(dir_name, file_name)
      if os.path.islink(file_path) or not filename_matcher.search(file_path):
        continue
      with open(file_path) as file:
        matching_lines = grep_file(file, search)
        if matching_lines:
          matching_files[file_name] = matching_lines
  return matching_files


def grep_file(file, search):
  '''Return lines in 'file' that match the 'search' regex. 'file' must already be
     opened.
  '''
  matcher = re.compile(search)
  matching_lines = list()
  for line in file:
    if matcher.search(line):
      matching_lines.append(line)
  return matching_lines


def assert_file_in_dir_contains(dir, search):
  '''Asserts that at least one file in the 'dir' contains the 'search' term.'''
  results = grep_dir(dir, search)
  assert results, "%s should have a file containing '%s' but no file was found" \
      % (dir, search)


def assert_no_files_in_dir_contain(dir, search):
  '''Asserts that no files in the 'dir' contains the 'search' term.'''
  results = grep_dir(dir, search)
  assert not results, \
      "%s should not have any file containing '%s' but a file was found" \
      % (dir, search)


def make_tmp_test_dir(name):
  """Create temporary directory with prefix 'impala_test_<name>_'.
  Return the path of temporary directory as string. Caller is responsible to
  clean them. If LOG_DIR env var exist, the temporary dir will be placed inside
  LOG_DIR."""
  # TODO: Consider using tempfile.TemporaryDirectory from python3 in the future.
  parent_dir = os.getenv("LOG_DIR", None)
  return tempfile.mkdtemp(prefix='impala_test_{}_'.format(name), dir=parent_dir)


def cleanup_tmp_test_dir(dir_path):
  """Remove temporary 'dir_path' and its content.
  Ignore errors upon deletion."""
  shutil.rmtree(dir_path, ignore_errors=True)