Exclude reviewers with OOO in status

danger/roulette/Dangerfile

@@ -31,26 +31,52 @@ Please consider creating a merge request to
 for them.
 MARKDOWN
 
-def spin(team, project, category, branch_name)
+def spin_for_category(team, project, category, branch_name)
   rng = Random.new(Digest::MD5.hexdigest(branch_name).to_i(16))
 
   reviewers = team.select { |member| member.reviewer?(project, category) }
   traintainers = team.select { |member| member.traintainer?(project, category) }
   maintainers = team.select { |member| member.maintainer?(project, category) }
 
-  # TODO: filter out people who are currently not in the office
-  # https://gitlab.com/gitlab-org/gitlab-ce/issues/57652
-  #
   # TODO: take CODEOWNERS into account?
   # https://gitlab.com/gitlab-org/gitlab-ce/issues/57653
 
   # Make traintainers have triple the chance to be picked as a reviewer
-  reviewer = (reviewers + traintainers + traintainers).sample(random: rng)
-  maintainer = maintainers.sample(random: rng)
+  reviewer = spin_for_person(reviewers + traintainers + traintainers, random: rng)
+  maintainer = spin_for_person(maintainers, random: rng)
 
   "| #{helper.label_for_category(category)} | #{reviewer&.markdown_name} | #{maintainer&.markdown_name} |"
 end
 
+# Known issue: If someone is rejected due to OOO, and then becomes not OOO, the
+# selection will change on next spin
+def spin_for_person(people, random:)
+  person = nil
+  people = people.dup
+
+  people.size.times do
+    person = people.sample(random: random)
+
+    return person unless out_of_office?(person)
+
+    people -= [person]
+  end
+end
+
+def out_of_office?(person)
+  username = CGI.escape(person.username)
+  api_endpoint = "https://gitlab.com/api/v4/users/#{username}/status"
+  response = HTTParty.get(api_endpoint) # rubocop:disable Gitlab/HTTParty
+
+  if response.code == 200
+    response["message"]&.match(/OOO/i)
+  else
+    false # this is no worse than not checking for OOO
+  end
+rescue
+  false
+end
+
 def build_list(items)
   list = items.map { |filename| "* `#{filename}`" }.join("\n")
 
@@ -63,7 +89,7 @@ end
 
 changes = helper.changes_by_category
 
-# Ignore any files that are known but uncategoried. Prompt for any unknown files
+# Ignore any files that are known but uncategorized. Prompt for any unknown files
 changes.delete(:none)
 categories = changes.keys - [:unknown]
 
@@ -92,7 +118,7 @@ if changes.any? && !gitlab.mr_labels.include?('single codebase') && !gitlab.mr_l
   project = helper.project_name
   unknown = changes.fetch(:unknown, [])
 
-  rows = categories.map { |category| spin(team, project, category, canonical_branch_name) }
+  rows = categories.map { |category| spin_for_category(team, project, category, canonical_branch_name) }
 
   markdown(MESSAGE)
   markdown(CATEGORY_TABLE_HEADER + rows.join("\n")) unless rows.empty?