1 files changed, 63 insertions, 0 deletions
diff --git a/app/services/merge_requests/get_urls_service.rb b/app/services/merge_requests/get_urls_service.rb
new file mode 100644
index 00000000000..08c1f72d65a
--- /dev/null
+++ b/app/services/merge_requests/get_urls_service.rb
@@ -0,0 +1,63 @@
+module MergeRequests
+  class GetUrlsService < BaseService
+    attr_reader :project
+
+    def initialize(project)
+      @project = project
+    end
+
+    def execute(changes)
+      branches = get_branches(changes)
+      merge_requests_map = opened_merge_requests_from_source_branches(branches)
+      branches.map do |branch|
+        existing_merge_request = merge_requests_map[branch]
+        if existing_merge_request
+          url_for_existing_merge_request(existing_merge_request)
+        else
+          url_for_new_merge_request(branch)
+        end
+      end
+    end
+
+    private
+
+    def opened_merge_requests_from_source_branches(branches)
+      merge_requests = MergeRequest.from_project(project).opened.from_source_branches(branches)
+      merge_requests.inject({}) do |hash, mr|
+        hash[mr.source_branch] = mr
+        hash
+      end
+    end
+
+    def get_branches(changes)
+      return [] if project.empty_repo?
+      return [] unless project.merge_requests_enabled
+
+      changes_list = Gitlab::ChangesList.new(changes)
+      changes_list.map do |change|
+        next unless Gitlab::Git.branch_ref?(change[:ref])
+
+        # Deleted branch
+        next if Gitlab::Git.blank_ref?(change[:newrev])
+
+        # Default branch
+        branch_name = Gitlab::Git.branch_name(change[:ref])
+        next if branch_name == project.default_branch
+
+        branch_name
+      end.compact
+    end
+
+    def url_for_new_merge_request(branch_name)
+      merge_request_params = { source_branch: branch_name }
+      url = Gitlab::Routing.url_helpers.new_namespace_project_merge_request_url(project.namespace, project, merge_request: merge_request_params)
+      { branch_name: branch_name, url: url, new_merge_request: true }
+    end
+
+    def url_for_existing_merge_request(merge_request)
+      target_project = merge_request.target_project
+      url = Gitlab::Routing.url_helpers.namespace_project_merge_request_url(target_project.namespace, target_project, merge_request)
+      { branch_name: merge_request.source_branch, url: url, new_merge_request: false }
+    end
+  end
+end