1 files changed, 65 insertions, 0 deletions
diff --git a/lib/gitlab/danger/weightage/reviewers.rb b/lib/gitlab/danger/weightage/reviewers.rb
new file mode 100644
index 00000000000..c8019be716e
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+++ b/lib/gitlab/danger/weightage/reviewers.rb
@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+
+require_relative '../weightage'
+
+module Gitlab
+  module Danger
+    module Weightage
+      # Weights after (current multiplier of 2)
+      #
+      # +------------------------------+--------------------------------+
+      # |        reviewer type         | weight(times in reviewer pool) |
+      # +------------------------------+--------------------------------+
+      # | reduced capacity reviewer    |                              1 |
+      # | reviewer                     |                              2 |
+      # | hungry reviewer              |                              4 |
+      # | reduced capacity traintainer |                              3 |
+      # | traintainer                  |                              6 |
+      # | hungry traintainer           |                              8 |
+      # +------------------------------+--------------------------------+
+      #
+      class Reviewers
+        DEFAULT_REVIEWER_WEIGHT = CAPACITY_MULTIPLIER * BASE_REVIEWER_WEIGHT
+        TRAINTAINER_WEIGHT = 3
+
+        def initialize(reviewers, traintainers)
+          @reviewers = reviewers
+          @traintainers = traintainers
+        end
+
+        def execute
+          # TODO: take CODEOWNERS into account?
+          # https://gitlab.com/gitlab-org/gitlab/issues/26723
+
+          weighted_reviewers + weighted_traintainers
+        end
+
+        private
+
+        attr_reader :reviewers, :traintainers
+
+        def weighted_reviewers
+          reviewers.each_with_object([]) do |reviewer, total_reviewers|
+            add_weighted_reviewer(total_reviewers, reviewer, BASE_REVIEWER_WEIGHT)
+          end
+        end
+
+        def weighted_traintainers
+          traintainers.each_with_object([]) do |reviewer, total_traintainers|
+            add_weighted_reviewer(total_traintainers, reviewer, TRAINTAINER_WEIGHT)
+          end
+        end
+
+        def add_weighted_reviewer(reviewers, reviewer, weight)
+          if reviewer.reduced_capacity
+            reviewers.fill(reviewer, reviewers.size, weight)
+          elsif reviewer.hungry
+            reviewers.fill(reviewer, reviewers.size, weight * CAPACITY_MULTIPLIER + DEFAULT_REVIEWER_WEIGHT)
+          else
+            reviewers.fill(reviewer, reviewers.size, weight * CAPACITY_MULTIPLIER)
+          end
+        end
+      end
+    end
+  end
+end