wip: vesting schedule.

5 files changed, 71 insertions, 6 deletions

diff --git a/lib/clock.rb b/lib/clock.rb
new file mode 100644
index 0000000..41ccc77
--- /dev/null
+++ b/lib/clock.rb
@@ -0,0 +1,5 @@
+class Clock
+  def self.today
+    Date.today
+  end
+end
diff --git a/lib/employee.rb b/lib/employee.rb
index 97b1808..b29c5be 100644
--- a/lib/employee.rb
+++ b/lib/employee.rb
@@ -1,16 +1,65 @@
 class Employee
   def initialize
-    @unvested_units = []
+    #@unvested_units = []
+    @grants = []
   end
 
   def issue_grant(value_of_grant, share_price)
+    #number_of_units = value_of_grant / share_price
+    #@unvested_units = [Unit.new] * number_of_units
+    @grants.push(Grant.new(value_of_grant, share_price))
+  end
+
+  def value_of_unvested_units_at(price)
+    @grants.inject(0.00.dollars) do |memo, grant|
+      memo + grant.value_of_unvested_units_at(price)
+    end
+  end
+
+  def grant_for(date)
+    @grants.find { |grant| grant.issued_at == date }
+  end
+end
+
+class Grant
+  attr_reader :issued_at
+
+  def initialize(value_of_grant, share_price, date = Clock.today)
     number_of_units = value_of_grant / share_price
-    @unvested_units = [Unit.new] * number_of_units
+    @units = [Unit.new] * number_of_units
+    @issued_at = date
   end
 
   def value_of_unvested_units_at(price)
-    @unvested_units.inject(0.00.dollars) do |memo, unit|
+    unvested_units.inject(0.00.dollars) do |memo, unit|
+      memo + (unit * price)
+    end
+  end
+
+  def vest_at(price, portion)
+    number_of_units_to_vest = portion.to_f * @units.count
+    units_to_vest = @units.take(number_of_units_to_vest)
+    units_to_vest.each do |unit|
+      unit.vest_at(price)
+    end
+    puts unvested_units.count
+    puts vested_units.count
+    puts @units.count
+  end
+
+  private
+
+  def value_of(units, price)
+    units.inject(0.00.dollars) do |memo, unit|
       memo + (unit * price)
     end
   end
+
+  def unvested_units
+    @units - vested_units
+  end
+
+  def vested_units
+    @units.find_all { |x| x.vested? }
+  end
 end
diff --git a/lib/unit.rb b/lib/unit.rb
index 632ea95..0761c8e 100644
--- a/lib/unit.rb
+++ b/lib/unit.rb
@@ -2,4 +2,13 @@ class Unit
   def *(price)
     price
   end
+
+  def vest_at(price)
+    @vested = true
+    @vesting_price = price
+  end
+
+  def vested?
+    @vested
+  end
 end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 530ca88..3057259 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -6,4 +6,5 @@ require 'money'
 require 'float'
 require 'employee'
 require 'unit'
+require 'clock'
 
diff --git a/spec/unit/employee_spec.rb b/spec/unit/employee_spec.rb
index 2bc524b..d998c65 100644
--- a/spec/unit/employee_spec.rb
+++ b/spec/unit/employee_spec.rb
@@ -12,10 +12,11 @@ describe Employee do
 
     it "computes the value of the grant after one year" do
       today = Clock.today
+      one_year_from_now = today + 365
       sut.issue_grant(80_000, 1.00)
-      Clock.stub(:now).and_return(1.year.from_now)
-      sut.grant_for(today).vest_at(10.dollars)
-      sut.unvested_units.value_at(10.dollars).should == 200_000
+      Clock.stub(:now).and_return(one_year_from_now)
+      sut.grant_for(today).vest_at(10.dollars, 1.0/4.0)
+      sut.value_of_unvested_units_at(10.dollars).should == 200_000.dollars
     end
   end
 end