1 files changed, 72 insertions, 0 deletions
diff --git a/app/models/concerns/time_trackable.rb b/app/models/concerns/time_trackable.rb
new file mode 100644
index 00000000000..040e3a2884e
--- /dev/null
+++ b/app/models/concerns/time_trackable.rb
@@ -0,0 +1,72 @@
+# == TimeTrackable concern
+#
+# Contains functionality related to objects that support time tracking.
+#
+# Used by Issue and MergeRequest.
+#
+
+module TimeTrackable
+  extend ActiveSupport::Concern
+
+  included do
+    attr_reader :time_spent, :time_spent_user
+
+    alias_method :time_spent?, :time_spent
+
+    default_value_for :time_estimate, value: 0, allows_nil: false
+
+    validates :time_estimate, numericality: { message: 'has an invalid format' }, allow_nil: false
+    validate  :check_negative_time_spent
+
+    has_many :timelogs, as: :trackable, dependent: :destroy
+  end
+
+  def spend_time(options)
+    @time_spent = options[:duration]
+    @time_spent_user = options[:user]
+    @original_total_time_spent = nil
+
+    return if @time_spent == 0
+
+    if @time_spent == :reset
+      reset_spent_time
+    else
+      add_or_subtract_spent_time
+    end
+  end
+  alias_method :spend_time=, :spend_time
+
+  def total_time_spent
+    timelogs.sum(:time_spent)
+  end
+
+  def human_total_time_spent
+    Gitlab::TimeTrackingFormatter.output(total_time_spent)
+  end
+
+  def human_time_estimate
+    Gitlab::TimeTrackingFormatter.output(time_estimate)
+  end
+
+  private
+
+  def reset_spent_time
+    timelogs.new(time_spent: total_time_spent * -1, user: @time_spent_user)
+  end
+
+  def add_or_subtract_spent_time
+    timelogs.new(time_spent: time_spent, user: @time_spent_user)
+  end
+
+  def check_negative_time_spent
+    return if time_spent.nil? || time_spent == :reset
+
+    # we need to cache the total time spent so multiple calls to #valid?
+    # doesn't give a false error
+    @original_total_time_spent ||= total_time_spent
+
+    if time_spent < 0 && (time_spent.abs > @original_total_time_spent)
+      errors.add(:time_spent, 'Time to subtract exceeds the total time spent')
+    end
+  end
+end