text: #  MIT License
  #
  #  Copyright (c) 2020 Evgeny Medvedev, evge.medvedev@gmail.com
  #
  #  Permission is hereby granted, free of charge, to any person obtaining a copy
  #  of this software and associated documentation files (the "Software"), to deal
  #  in the Software without restriction, including without limitation the rights
  #  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  #  copies of the Software, and to permit persons to whom the Software is
  #  furnished to do so, subject to the following conditions:
  #
  #  The above copyright notice and this permission notice shall be included in all
  #  copies or substantial portions of the Software.
  #
  #  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  #  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  #  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  #  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  #  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  #  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  #  SOFTWARE.
  
  from blockchainetl.jobs.exporters.console_item_exporter import ConsoleItemExporter
  
  
  def create_item_exporter(output):
      item_exporter_type = determine_item_exporter_type(output)
      if item_exporter_type == ItemExporterType.PUBSUB:
          from blockchainetl.jobs.exporters.google_pubsub_item_exporter import GooglePubSubItemExporter
          item_exporter = GooglePubSubItemExporter(item_type_to_topic_mapping={
              'block': output + '.blocks',
              'transaction': output + '.transactions',
              # 'contract': output + '.contracts',
          })
      elif item_exporter_type == ItemExporterType.POSTGRES:
          from blockchainetl.jobs.exporters.postgres_item_exporter import PostgresItemExporter
          from blockchainetl.streaming.postgres_utils import create_insert_statement_for_table
          from blockchainetl.jobs.exporters.converters.unix_timestamp_item_converter import UnixTimestampItemConverter
          from blockchainetl.jobs.exporters.converters.int_to_decimal_item_converter import IntToDecimalItemConverter
          from blockchainetl.jobs.exporters.converters.list_field_item_converter import ListFieldItemConverter
          from thetaetl.streaming.postgres_tables import BLOCKS, TRANSACTIONS
  
          item_exporter = PostgresItemExporter(
              output, item_type_to_insert_stmt_mapping={
                  'block': create_insert_statement_for_table(BLOCKS),
                  'transaction': create_insert_statement_for_table(TRANSACTIONS),
              },
              converters=[UnixTimestampItemConverter(), IntToDecimalItemConverter(),
                          ListFieldItemConverter('topics', 'topic', fill=4)])
      elif item_exporter_type == ItemExporterType.CONSOLE:
          item_exporter = ConsoleItemExporter()
      else:
          raise ValueError('Unable to determine item exporter type for output ' + output)
  
      return item_exporter
  
  
  def determine_item_exporter_type(output):
      if output is not None and output.startswith('projects'):
          return ItemExporterType.PUBSUB
      elif output is not None and output.startswith('postgresql'):
          return ItemExporterType.POSTGRES
      elif output is None or output == 'console':
          return ItemExporterType.CONSOLE
      else:
          return ItemExporterType.UNKNOWN
  
  
  class ItemExporterType:
      PUBSUB = 'pubsub'
      POSTGRES = 'postgres'
      CONSOLE = 'console'
      UNKNOWN = 'unknown'
  