# Copyright 2015 Google Inc. All rights reserved.
#
# Licensed 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.


module Gcloud
  module Bigquery
    ##
    # # ExtractJob
    #
    # A {Job} subclass representing an export operation that may be performed
    # on a {Table}. A ExtractJob instance is created when you call
    # {Table#extract}.
    #
    # @see https://cloud.google.com/bigquery/exporting-data-from-bigquery
    #   Exporting Data From BigQuery
    # @see https://cloud.google.com/bigquery/docs/reference/v2/jobs Jobs API
    #   reference
    #
    class ExtractJob < Job
      ##
      # The URI or URIs representing the Google Cloud Storage files to which
      # the data is exported.
      def destinations
        Array config["extract"]["destinationUris"]
      end

      ##
      # The table from which the data is exported. This is the table upon
      # which {Table#extract} was called. Returns a {Table} instance.
      def source
        table = config["extract"]["sourceTable"]
        return nil unless table
        retrieve_table table["projectId"],
                       table["datasetId"],
                       table["tableId"]
      end

      ##
      # Checks if the export operation compresses the data using gzip. The
      # default is `false`.
      def compression?
        val = config["extract"]["compression"]
        val == "GZIP"
      end

      ##
      # Checks if the destination format for the data is [newline-delimited
      # JSON](http://jsonlines.org/). The default is `false`.
      def json?
        val = config["extract"]["destinationFormat"]
        val == "NEWLINE_DELIMITED_JSON"
      end

      ##
      # Checks if the destination format for the data is CSV. Tables with nested
      # or repeated fields cannot be exported as CSV. The default is `true`.
      def csv?
        val = config["extract"]["destinationFormat"]
        return true if val.nil?
        val == "CSV"
      end

      ##
      # Checks if the destination format for the data is
      # [Avro](http://avro.apache.org/). The default is `false`.
      def avro?
        val = config["extract"]["destinationFormat"]
        val == "AVRO"
      end

      ##
      # The symbol the operation uses to delimit fields in the exported data.
      # The default is a comma (,).
      def delimiter
        val = config["extract"]["fieldDelimiter"]
        val = "," if val.nil?
        val
      end

      ##
      # Checks if the exported data contains a header row. The default is
      # `true`.
      def print_header?
        val = config["extract"]["printHeader"]
        val = true if val.nil?
        val
      end

      ##
      # The count of files per destination URI or URI pattern specified in
      # {#destinations}. Returns an Array of values in the same order as the URI
      # patterns.
      def destinations_file_counts
        Array stats["extract"]["destinationUriFileCounts"]
      end

      ##
      # The count of files per destination URI or URI pattern specified in
      # {#destinations}. Returns a Hash with the URI patterns as keys and the
      # counts as values.
      def destinations_counts
        Hash[destinations.zip destinations_file_counts]
      end
    end
  end
end