class Multiwoven::Integrations::Destination::Postgresql::Client

def check_connection(connection_config)
  connection_config = connection_config.with_indifferent_access
  create_connection(connection_config)
  ConnectionStatus.new(
    status: ConnectionStatusType["succeeded"]
  ).to_multiwoven_message
rescue PG::Error => e
  ConnectionStatus.new(
    status: ConnectionStatusType["failed"], message: e.message
  ).to_multiwoven_message
end

def create_connection(connection_config)
  raise "Unsupported Auth type" unless connection_config[:credentials][:auth_type] == "username/password"
  PG.connect(
    host: connection_config[:host],
    dbname: connection_config[:database],
    user: connection_config[:credentials][:username],
    password: connection_config[:credentials][:password],
    port: connection_config[:port]
  )
end

def create_streams(records)
  group_by_table(records).map do |r|
    Multiwoven::Integrations::Protocol::Stream.new(name: r[:tablename], action: StreamAction["fetch"], json_schema: convert_to_json_schema(r[:columns]))
  end
end

def discover(connection_config)
  connection_config = connection_config.with_indifferent_access
  query = "SELECT table_name, column_name, data_type, is_nullable
           FROM information_schema.columns
           WHERE table_schema = '#{connection_config[:schema]}' AND table_catalog = '#{connection_config[:database]}'
           ORDER BY table_name, ordinal_position;"
  db = create_connection(connection_config)
  records = db.exec(query) do |result|
    result.map do |row|
      row
    end
  end
  catalog = Catalog.new(streams: create_streams(records))
  catalog.to_multiwoven_message
rescue StandardError => e
  handle_exception(e, {
                     context: "POSTGRESQL:DISCOVER:EXCEPTION",
                     type: "error"
                   })
ensure
  db&.close
end

def group_by_table(records)
  records.group_by { |entry| entry["table_name"] }.map do |table_name, columns|
    {
      tablename: table_name,
      columns: columns.map do |column|
        {
          column_name: column["column_name"],
          type: column["data_type"],
          optional: column["is_nullable"] == "YES"
        }
      end
    }
  end
end

def query(connection, query)
  connection.exec(query) do |result|
    result.map do |row|
      RecordMessage.new(data: row, emitted_at: Time.now.to_i).to_multiwoven_message
    end
  end
end

def tracking_message(success, failure)
  Multiwoven::Integrations::Protocol::TrackingMessage.new(
    success: success, failed: failure
  ).to_multiwoven_message
end

def write(sync_config, records, action = "destination_insert")
  connection_config = sync_config.destination.connection_specification.with_indifferent_access
  table_name = sync_config.stream.name
  primary_key = sync_config.model.primary_key
  db = create_connection(connection_config)
  write_success = 0
  write_failure = 0
  records.each do |record|
    query = Multiwoven::Integrations::Core::QueryBuilder.perform(action, table_name, record, primary_key)
    logger.debug("POSTGRESQL:WRITE:QUERY query = #{query} sync_id = #{sync_config.sync_id} sync_run_id = #{sync_config.sync_run_id}")
    begin
      db.exec(query)
      write_success += 1
    rescue StandardError => e
      handle_exception(e, {
                         context: "POSTGRESQL:RECORD:WRITE:EXCEPTION",
                         type: "error",
                         sync_id: sync_config.sync_id,
                         sync_run_id: sync_config.sync_run_id
                       })
      write_failure += 1
    end
  end
  tracking_message(write_success, write_failure)
rescue StandardError => e
  handle_exception(e, {
                     context: "POSTGRESQL:RECORD:WRITE:EXCEPTION",
                     type: "error",
                     sync_id: sync_config.sync_id,
                     sync_run_id: sync_config.sync_run_id
                   })
end