# This is a code snippet to analyse CSV file. This program has got functions to sort, filter by value of each column and availability of a row.
# To run this program copy payroll.rb and payroll.csv to somewhere same place in your disc and just run it by ruby command.
# $ ruby payroll.rb

require 'csv'

class Payroll
  # Indexes for columns
  COLUMN_NUM = 0
  COLUMN_NAME = 1
  COLUMN_BDAY = 2
  COLUMN_AVAILABLE = 3

  # Order of sort
  ASC = 0
  DESC = 1

  def initialize(filepath)
    @rows = []
    CSV.open(filepath, 'r', ',') { |row| @rows << row}
  end

  # show contents of a CSV file
  def show(only_available = false)
    puts '-------------------------------'
    @rows.each do |row|
      if only_available
        puts row.join('| ')  if row[COLUMN_AVAILABLE] == "1"
      else
        puts row.join('| ')
      end
    end
    puts  '-------------------------------'
  end

  def sort!(column = COLUMN_NUM, order = ASC)
    if order == ASC
      @rows.sort!{|a, b| a[column].to_i <=> b[column].to_i}
    else
      @rows.sort!{|a, b| b[column].to_i <=> a[column].to_i}
    end
    self
  end

  def filter!(keyword, column = COLUMN_NAME)
    if column == COLUMN_NAME
      @rows = @rows.select{|row| row[column] =~ /#{keyword}/ }
    else
      @rows = @rows.select{|row| row[column] == keyword }
    end
    self
  end
end

# a)Sort rows by specified column in Asc/Desc
Payroll.new("payroll.csv").sort!(Payroll::COLUMN_NUM, Payroll::ASC).show
Payroll.new("payroll.csv").sort!(Payroll::COLUMN_BDAY, Payroll::DESC).show(true)

# b)Search row by specified column matching fully
Payroll.new("payroll.csv").filter!("19821213", Payroll::COLUMN_BDAY).show
Payroll.new("payroll.csv").filter!("鈴木　達矢", Payroll::COLUMN_NAME).show

# c)Search row like a specified keyword
# Search row(s) whose name column contains "e" and "i"
Payroll.new("payroll.csv").filter!("e", Payroll::COLUMN_NAME).filter!("i", Payroll::COLUMN_NAME).show(true)