1 files changed, 57 insertions, 0 deletions
diff --git a/lib/gitlab/conflict/file_collection.rb b/lib/gitlab/conflict/file_collection.rb
new file mode 100644
index 00000000000..bbd0427a2c8
--- /dev/null
+++ b/lib/gitlab/conflict/file_collection.rb
@@ -0,0 +1,57 @@
+module Gitlab
+  module Conflict
+    class FileCollection
+      class ConflictSideMissing < StandardError
+      end
+
+      attr_reader :merge_request, :our_commit, :their_commit
+
+      def initialize(merge_request)
+        @merge_request = merge_request
+        @our_commit = merge_request.source_branch_head.raw.raw_commit
+        @their_commit = merge_request.target_branch_head.raw.raw_commit
+      end
+
+      def repository
+        merge_request.project.repository
+      end
+
+      def merge_index
+        @merge_index ||= repository.rugged.merge_commits(our_commit, their_commit)
+      end
+
+      def files
+        @files ||= merge_index.conflicts.map do |conflict|
+          raise ConflictSideMissing unless conflict[:theirs] && conflict[:ours]
+
+          Gitlab::Conflict::File.new(merge_index.merge_file(conflict[:ours][:path]),
+                                     conflict,
+                                     merge_request: merge_request)
+        end
+      end
+
+      def as_json(opts = nil)
+        {
+          target_branch: merge_request.target_branch,
+          source_branch: merge_request.source_branch,
+          commit_sha: merge_request.diff_head_sha,
+          commit_message: default_commit_message,
+          files: files
+        }
+      end
+
+      def default_commit_message
+        conflict_filenames = merge_index.conflicts.map do |conflict|
+          "#   #{conflict[:ours][:path]}"
+        end
+
+        <<EOM.chomp
+Merge branch '#{merge_request.target_branch}' into '#{merge_request.source_branch}'
+
+# Conflicts:
+#{conflict_filenames.join("\n")}
+EOM
+      end
+    end
+  end
+end