1 files changed, 120 insertions, 0 deletions
diff --git a/lib/github/representation/pull_request.rb b/lib/github/representation/pull_request.rb
new file mode 100644
index 00000000000..55461097e8a
--- /dev/null
+++ b/lib/github/representation/pull_request.rb
@@ -0,0 +1,120 @@
+module Github
+  module Representation
+    class PullRequest < Representation::Issuable
+      delegate :user, :repo, :ref, :sha, to: :source_branch, prefix: true
+      delegate :user, :exists?, :repo, :ref, :sha, :short_sha, to: :target_branch, prefix: true
+
+      def source_project
+        project
+      end
+
+      def source_branch_name
+        @source_branch_name ||=
+          if cross_project? || !source_branch_exists?
+            source_branch_name_prefixed
+          else
+            source_branch_ref
+          end
+      end
+
+      def source_branch_exists?
+        return @source_branch_exists if defined?(@source_branch_exists)
+
+        @source_branch_exists = !cross_project? && source_branch.exists?
+      end
+
+      def target_project
+        project
+      end
+
+      def target_branch_name
+        @target_branch_name ||= target_branch_exists? ? target_branch_ref : target_branch_name_prefixed
+      end
+
+      def target_branch_exists?
+        @target_branch_exists ||= target_branch.exists?
+      end
+
+      def state
+        return 'merged' if raw['state'] == 'closed' && raw['merged_at'].present?
+        return 'closed' if raw['state'] == 'closed'
+
+        'opened'
+      end
+
+      def opened?
+        state == 'opened'
+      end
+
+      def valid?
+        source_branch.valid? && target_branch.valid?
+      end
+
+      def restore_branches!
+        restore_source_branch!
+        restore_target_branch!
+      end
+
+      def remove_restored_branches!
+        return if opened?
+
+        remove_source_branch!
+        remove_target_branch!
+      end
+
+      private
+
+      def project
+        @project ||= options.fetch(:project)
+      end
+
+      def source_branch
+        @source_branch ||= Representation::Branch.new(raw['head'], repository: project.repository)
+      end
+
+      def source_branch_name_prefixed
+        "gh-#{target_branch_short_sha}/#{iid}/#{source_branch_user}/#{source_branch_ref}"
+      end
+
+      def target_branch
+        @target_branch ||= Representation::Branch.new(raw['base'], repository: project.repository)
+      end
+
+      def target_branch_name_prefixed
+        "gl-#{target_branch_short_sha}/#{iid}/#{target_branch_user}/#{target_branch_ref}"
+      end
+
+      def cross_project?
+        return true if source_branch_repo.nil?
+
+        source_branch_repo.id != target_branch_repo.id
+      end
+
+      def restore_source_branch!
+        return if source_branch_exists?
+
+        source_branch.restore!(source_branch_name)
+      end
+
+      def restore_target_branch!
+        return if target_branch_exists?
+
+        target_branch.restore!(target_branch_name)
+      end
+
+      def remove_source_branch!
+        # We should remove the source/target branches only if they were
+        # restored. Otherwise, we'll remove branches like 'master' that
+        # target_branch_exists? returns true. In other words, we need
+        # to clean up only the restored branches that (source|target)_branch_exists?
+        # returns false for the first time it has been called, because of
+        # this that is important to memoize these values.
+        source_branch.remove!(source_branch_name) unless source_branch_exists?
+      end
+
+      def remove_target_branch!
+        target_branch.remove!(target_branch_name) unless target_branch_exists?
+      end
+    end
+  end
+end