pop_bottle.rb

require 'pp'

# BUYING
# num_bottles = money/2

# REDEEMING
# num_bottles = caps * 0.25
# num_bottles = bottles * 0.5

def buy(investment=0)
  #puts "Customer gives me #{investment} dollars."
  num_bottles = 0
  change = investment % 2
  if investment <= 1
    puts "A bottle costs $2!" 
  elsif investment.odd?
    puts "A bottle costs $2." 
    puts "Customer's change is $#{change}." if change != 0
  else
    num_bottles = investment/2
    puts "Thanks, you now have #{num_bottles} #{num_bottles > 1 ? 'bottles' : 'bottle'}."
  end
  redeem_potential = redeem(num_bottles,0)
  puts "With these bottles you can redeem #{redeem(num_bottles,0)} bottles."
end

def redeem(bottles=0,caps=0)
  bottles_from_caps = caps * 0.25
  bottles_from_empties = bottles * 0.5
  redemption = (bottles_from_empties + bottles_from_caps).to_i
end

def openshop
  keep_going = true
  while keep_going
    puts "Hello, how much are you spending?"
    money = gets.chomp.to_i
    if money.class == Fixnum
      buy(money) 
    else
      puts "Sorry, I didn't understand that. Enter a number next time."
    end
    puts "Anything else? ('y' or 'n')"
    stopping = gets.chomp
    keep_going = false if stopping.downcase == "n"
  end
end

def test
  (2..20).each do |x|
    buy(x)
    puts "---------------------------------------------------"
  end
end

#test()
openshop