gistfile1.rb

require 'csv'

Customer = Struct.new(:cust_id,
                      :elect_or_gas, 
                      :disconnect_doc, 
                      :move_in_date, 
                      :move_out_date, 
                      :bill_year,
                      :bill_month,
                      :span_days,
                      :meter_read_date,
                      :meter_read_type,
                      :consumption,
                      :exception_code,
                      :data 
                      ) 

class Parser
  attr_accessor :customers 

  def initialize filename
    self.customers = [] 
    deserialize_users filename
    serialize_users
  end

  def deserialize_users filename
    CSV.foreach(filename, col_sep: "|")  do |row|
      next if row.empty?
      #sanitized_values(cust_id, elect_or_gas, disconnect_doc, move_in_date, move_out_date, bill_year, bill_month, span_days, meter_read_date, meter_read_type, consumption, exception_code = row)
      customers << Customer.new(*row, row)
    end
    customers
  end

  def serialize_users
    CSV.open("./serialized_users.txt", "w") do |csv| #is 'a' better?
      customers.each do |c|
        csv << c.data  
      end
    end
  end
end

class Reporting 

  attr_accessor :parser, :output_size

  def initialize data , output_size
    self.parser = Parser.new data
    self.output_size = output_size
  end

  #STATISTICS

  def unique_customers
    parser.customers.uniq(&:cust_id )
  end

  def customers_with_electricity#_ONLY
    customer = parser.customers.select { |customer| customer.elect_or_gas == "1" || customer.elect_or_gas == "ElecOrGas" }
  end

  def customers_with_gas#_ONLY
    parser.customers.select { |customer| customer.elect_or_gas == "2" || customer.elect_or_gas == "ElecOrGas"}
  end

  def customers_bill_month month , resource = nil
    if resource == :gas
      customers_with_gas.select {|customer| customer.bill_month == "#{month}"} 
    elsif resource == :electricity
      customers_with_electricity.select {|customer| customer.bill_month == "#{month}"} 
    else 
      parser.customers.select { |customer| customer.bill_month == "#{month}"} 
    end
  end

  def nbr_of_meter_readings_per_customer #number of meter readings per customer

  end

  def avg_consumption_month month , resource = nil
   !customers_bill_month(month, resource).empty? ? ( (customers_bill_month(month, resource).inject(0) { |sum, n| sum + n.consumption.to_i } ) /  customers_bill_month(month, resource).length ) : 0
  end

  #REPORT

  def show_all_data
    print "\n\nALL CUSTOMERS AND DATA\n\n"
    puts format_show parser.customers
  end

  def show_unique_customers
    print "\n\nUNIQUE CUSTOMERS\n\n"
    format_show unique_customers
    puts "\nNumber of unique customers: #{unique_customers.count - 1}"
  end


  def show_customers_with_electricity
    print "\n\nCUSTOMERS WITH ELECTRICITY ONLY\n\n"
    format_show customers_with_electricity
    puts "\nNumber of customers with electricity: #{customers_with_electricity.count - 1}"
  end

  def show_customers_with_gas
    print "\n\nCUSTOMER WITH GAS ONLY\n\n"
    format_show customers_with_gas
    puts "\nNumber of customers with gas: #{customers_with_gas.count - 1}"
  end

  def show_avg_consumption_per_bill_month resource = nil
    print "\n\nAVERAGE CONSUMPTION PER BILL MONTH #{'PER ' + resource.to_s.upcase if resource} ACROSS ALL CUSTOMERS\n\n"
    total_avg_consumption = []
    (1..12).each do |i| 
      puts "\n\nMONTH OF #{ Date::MONTHNAMES[i] }: #{avg_consumption_month i, resource}"
      total_avg_consumption << avg_consumption_month(i, resource)
      end
      puts "TOTAL AVERAGE CONSUMPTION: #{total_avg_consumption.inject(:+) / total_avg_consumption.length}"
  end

  private

  def format_show foo
     foo.map {|customer| puts customer.data.map { |item| item.to_s.center output_size}.join'|'} unless foo.empty?
  end

end

r = Reporting.new "./pulse_data.txt", 15

r.show_all_data
r.show_unique_customers
#in the output theres multiple blank lines between the output of the previous line and the next. a huge gap
r.show_customers_with_gas    
r.show_customers_with_electricity
r.show_avg_consumption_per_bill_month 
r.show_avg_consumption_per_bill_month :electricity
r.show_avg_consumption_per_bill_month :gas