Setup Phabricator import

This sets up all the basics for importing Phabricator tasks into
GitLab issues.

To import all tasks from a Phabricator instance into GitLab, we'll
import all of them into a new project that will have its repository
disabled.

The import is hooked into a regular ProjectImport setup, but similar
to the GitHub parallel importer takes care of all the imports itself.

In this iteration, we're importing each page of tasks in a separate
sidekiq job.

The first thing we do when requesting a new page of tasks is schedule
the next page to be imported. But to avoid deadlocks, we only allow a
single job per worker type to run at the same time.

For now we're only importing basic Issue information, this should be
extended to richer information.

2 files changed, 96 insertions, 0 deletions

diff --git a/lib/gitlab/phabricator_import/issues/importer.rb b/lib/gitlab/phabricator_import/issues/importer.rb
new file mode 100644
index 00000000000..a58438452ff
--- /dev/null
+++ b/lib/gitlab/phabricator_import/issues/importer.rb
@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+module Gitlab
+  module PhabricatorImport
+    module Issues
+      class Importer
+        def initialize(project, after = nil)
+          @project, @after = project, after
+        end
+
+        def execute
+          schedule_next_batch
+
+          tasks_response.tasks.each do |task|
+            TaskImporter.new(project, task).execute
+          end
+        end
+
+        private
+
+        attr_reader :project, :after
+
+        def schedule_next_batch
+          return unless tasks_response.pagination.has_next_page?
+
+          Gitlab::PhabricatorImport::ImportTasksWorker
+            .schedule(project.id, tasks_response.pagination.next_page)
+        end
+
+        def tasks_response
+          @tasks_response ||= client.tasks(after: after)
+        end
+
+        def client
+          @client ||=
+            Gitlab::PhabricatorImport::Conduit::Maniphest
+              .new(phabricator_url: project.import_data.data['phabricator_url'],
+                   api_token: project.import_data.credentials[:api_token])
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/phabricator_import/issues/task_importer.rb b/lib/gitlab/phabricator_import/issues/task_importer.rb
new file mode 100644
index 00000000000..40d4392cbc1
--- /dev/null
+++ b/lib/gitlab/phabricator_import/issues/task_importer.rb
@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+module Gitlab
+  module PhabricatorImport
+    module Issues
+      class TaskImporter
+        def initialize(project, task)
+          @project, @task = project, task
+        end
+
+        def execute
+          # TODO: get the user from the project namespace from the username loaded by Phab-id
+          # https://gitlab.com/gitlab-org/gitlab-ce/issues/60565
+          issue.author = User.ghost
+
+          # TODO: Reformat the description with attachments, escaping accidental
+          # links and add attachments
+          # https://gitlab.com/gitlab-org/gitlab-ce/issues/60603
+          issue.assign_attributes(task.issue_attributes)
+
+          save!
+
+          issue
+        end
+
+        private
+
+        attr_reader :project, :task
+
+        def save!
+          # Just avoiding an extra redis call, we've already updated the expiry
+          # when reading the id from the map
+          was_persisted = issue.persisted?
+
+          issue.save! if issue.changed?
+
+          object_map.set_gitlab_model(issue, task.phabricator_id) unless was_persisted
+        end
+
+        def issue
+          @issue ||= find_issue_by_phabricator_id(task.phabricator_id) ||
+            project.issues.new
+        end
+
+        def find_issue_by_phabricator_id(phabricator_id)
+          object_map.get_gitlab_model(phabricator_id)
+        end
+
+        def object_map
+          Gitlab::PhabricatorImport::Cache::Map.new(project)
+        end
+      end
+    end
+  end
+end