divider

#!/usr/bin/env ruby

# Usage
# Run divider "filename" "number of files to be divided"
# Command should look like ./divider --file="/Users/mergul/Downloads/person.csv" --count=4

require "csv"
require "pry"

def process_arguments
  options = {}

  ARGV.each do |arg|
    if arg.start_with?("--")
      key_value_pair = arg.split("=")
      key = key_value_pair[0][2..-1].to_sym
      value = key_value_pair[1]
      options[key] = value
    end
  end

  file_name = options[:file]
  number_of_files = options[:count]

  if file_name.nil? || number_of_files.nil?
    puts "Please provide both arguments."
  elsif options.count > 2
    puts "Only two arguments are accepted file name and number of files to be divided"
  else
    puts "The provided arguments are file: #{file_name.split("/").last} and number_of_files: #{number_of_files}"
    run_divide(options)
  end
end

def read_csv_file(file)
  CSV.read(file, headers: true, col_sep: ",", quote_char: '"', liberal_parsing: false)
rescue => e
  puts "Something wrong with reading the file: #{e.message}"
end

def file_headers(read_csv_file)
  read_csv_file.headers
end

def run_divide(options)
  division = CSV.read(options[:file], headers: true).count / options[:count].to_i

  options[:count].to_i.times do |index|
    start = index * division
    finish = start + division - 1

    puts "#{start}-#{finish}.csv is generated.."

    CSV.open("#{start}-#{finish}_rows.csv", "w+") do |row|
      row << file_headers(read_csv_file(options[:file]))
      read_csv_file(options[:file])[start..finish].each do |d|
        row << d
      end
    end
  end
end

process_arguments