class UserHelper 

def self.sd_sftp_user  SftpHelper.obj.connect_sftp FigNewton.sftp.mass.sftp_host,
                              FigNewton.sftp.mass.sftp_uname,
                              FigNewton.sftp.mass.sftp_key
  SftpHelper.obj
end

def self.dynamo_user  @dynamo_db = AWS::DynamoDB.new(access_key_id: FigNewton.dynamodb.access_key_id,
                                 secret_access_key: FigNewton.dynamodb.secret_access_key,
                                 region: FigNewton.dynamodb.region)
  @dynamo_dbend 

end

class Dynamo  include Singleton  def initialize 

 # @dynamo_db = AWS::DynamoDB.new(access_key_id: FigNewton.dynamodb.access_key_id,    #                                secret_access_key: FigNewton.dynamodb.secret_access_key,    #                                region: FigNewton.dynamodb.region)
    @dynamo_db = AWS::DynamoDB.new(access_key_id: 'enter access key id ',
                                   secret_access_key: 'enter secret key here,
                                   region: 'enter region id')
  end  

  
  # {'email' => 'mai@email.com', 'rollno' => 3},'name')   

def get_col_values(table_name, ref_column_hash, col_name)
    items = []
    table = @dynamo_db.tables[table_name]
    table.load_schema
    rows = table.items
    ref_column_hash.each do |key, value|
      rows = rows.where(key.to_sym=>value)
    end    rows.each do |row|
      items.push row.attributes[col_name]
    end    items 

 end
  def get_rows(table_name, ref_column_name, ref_col_value, col_name)
    items = []
    table = @dynamo_db.tables[table_name]
    table.load_schema
    table.items.select(ref_column_name.to_sym,col_name.to_sym ) do |row|
      if row.attributes[ref_column_name].to_i.equal? ref_col_value.to_i
        items.push row      end    end    items  end
  # returns the table object  def get_table(table_name)
    table = @dynamo_db.tables[table_name]
    table.load_schema
    table  end
  
end

# A helper class to access information stored in S3.

 class S3Helper   

include Singleton 

 # creates the singleton object   

def self.obj 

 S3Helper.instance
end

 # Initialize the helper and get the AWS S3 object. 

 def initialize     

# @s3_object = AWS::S3.new access_key_id: FigNewton.s3.access_key_id,    #                          secret_access_key: FigNewton.s3.secret_access_key    
 end 

 # Read a file from an S3 bucket.  #  # ==== Attributes  #  #   +fname+ - The name of the file to read from S3.  #  # ==== Examples  #  #   # To read a file from an S3 bucket, call the .read_file method from  #   # your code in the following way:  #   @s3_user.read_file 'test.xml'  def read_file(fname)
    @s3_object.buckets[@bucket].objects[fname].read
  end

end   

UserHelper.sd_sftp_user.read_file('folder/test.csv')