require 'google_drive'
require 'json'
require 'i18n'
I18n.enforce_available_locales = false

module Tabulator
  class Reader
    def initialize file_key, config_file = 'config.json'
      session = GoogleDrive::Session.from_service_account_key(config_file)
      @file = session.spreadsheet_by_key(file_key)
    end

    def [] worksheet
      Worksheet.new @file.worksheets[worksheet]
    end

    class Worksheet
      def initialize worksheet
        @worksheet = worksheet
      end

      def rows
        @worksheet.rows
      end

      def to_json
        header = rows.first.map { |raw_header_col|
          I18n.transliterate(raw_header_col.strip.gsub(/\s/, '_')).downcase.to_sym
        }

        rows.drop(1).map { |row|
          header.zip(row).to_h
        }.to_json(json_dump_options)
      end

      def save path
        File.open(path, "w") { |file|
          file.write to_json
        }
      end

      private
        def json_dump_options
          JSON::Ext::Generator::State.new indent: '  ', space: ' ', object_nl: "\n", array_nl: "\n"
        end
    end
  end
end