Initial commit

lib/strike_me/btc.rb

@@ -0,0 +1,82 @@
+# frozen_string_literal: true
+
+class Float
+  def btc
+    StrikeMe::BTC.new((self * 100_000_000).round)
+  end
+
+  def sats
+    StrikeMe::BTC.new(round)
+  end
+end
+
+class Integer
+  def btc
+    StrikeMe::BTC.new(self * 100_000_000)
+  end
+
+  def sats
+    StrikeMe::BTC.new(self)
+  end
+end
+
+module StrikeMe
+  class BTC
+    class Error < StandardError; end
+
+    MAX_NUMBER_OF_SATS  = 21_000_000 * 100_000_000
+    NUMERICAL_OPERATORS = %i[* /].freeze
+
+    attr_reader :sats
+
+    def initialize(sats)
+      raise Error, 'Must be initialized using an integer representing sats' unless sats.is_a? Integer
+      raise Error, "Max sats is: #{MAX_NUMBER_OF_SATS}. You have: #{sats}"  if sats > MAX_NUMBER_OF_SATS
+      raise Error, 'Must be initialized using a positive number'            if sats.negative?
+
+      @sats = sats
+    end
+
+    def to_s
+      # to_f.to_s
+      format('%.8f', to_f)
+    end
+
+    def to_f
+      sats.to_f / 100_000_000
+    end
+
+    def as_json
+      to_s
+    end
+
+    def *(other)
+      self.class.new((sats * other).to_i)
+    end
+
+    def /(other)
+      self.class.new((sats / other).to_i)
+    end
+
+    def +(other)
+      raise Error, "Addition can only be performed using a #{self.class.name} object" unless other.is_a?(self.class)
+
+      self.class.new(sats + other.sats)
+    end
+
+    def -(other)
+      raise Error, "Addition can only be performed using a #{self.class.name} object" unless other.is_a?(self.class)
+
+      self.class.new(sats - other.sats)
+    end
+
+    def ==(other)
+      case other
+      when Integer then sats == other
+      when BTC then sats == other.sats
+      else
+        false
+      end
+    end
+  end
+end