class MagicMoney

# File lib/magic_money.rb, line 12
def initialize(amount, currency)
  validate_currency(currency)
  @amount = amount
  @currency = currency
end

# File lib/magic_money.rb, line 22
def convert_to(new_currency)
  validate_currency(new_currency)
  MagicMoney.new(amount_in(new_currency), new_currency)
end

# File lib/magic_money.rb, line 18
def inspect
  "#{ amount_as_money } #{ @currency }"
end

# File lib/magic_money.rb, line 28
def amount_as_money
  '%.2f' % @amount
end

# File lib/magic_money.rb, line 32
def amount_in(new_currency)
  new_currency == @currency ? @amount : (@amount.to_f * RATES[@currency][new_currency]).round(2)
end

# File lib/magic_money.rb, line 36
def validate_currency(currency)
  raise ArgumentError, 'Invalid currency' if RATES[currency].nil?
end