# frozen_string_literal: true
# rubocop:disable Metrics/ClassLength

module Gitlab
  module BackgroundMigration
    ##
    # The class to migrate job artifacts from `ci_builds` to `ci_job_artifacts`
    class MigrateLegacyArtifacts
      FILE_LOCAL_STORE = 1 # equal to ObjectStorage::Store::LOCAL
      ARCHIVE_FILE_TYPE = 1 # equal to Ci::JobArtifact.file_types['archive']
      METADATA_FILE_TYPE = 2 # equal to Ci::JobArtifact.file_types['metadata']
      LEGACY_PATH_FILE_LOCATION = 1 # equal to Ci::JobArtifact.file_location['legacy_path']

      def perform(start_id, stop_id)
        ActiveRecord::Base.transaction do
          insert_archives(start_id, stop_id)
          insert_metadatas(start_id, stop_id)
          delete_legacy_artifacts(start_id, stop_id)
        end
      end

      private

      def insert_archives(start_id, stop_id)
        ActiveRecord::Base.connection.execute <<~SQL
          INSERT INTO
              ci_job_artifacts (
                  project_id,
                  job_id,
                  expire_at,
                  file_location,
                  created_at,
                  updated_at,
                  file,
                  size,
                  file_store,
                  file_type
              )
          SELECT
              project_id,
              id,
              artifacts_expire_at,
              #{LEGACY_PATH_FILE_LOCATION},
              created_at,
              created_at,
              artifacts_file,
              artifacts_size,
              COALESCE(artifacts_file_store, #{FILE_LOCAL_STORE}),
              #{ARCHIVE_FILE_TYPE}
          FROM
              ci_builds
          WHERE
              id BETWEEN #{start_id.to_i} AND #{stop_id.to_i}
              AND artifacts_file <> ''
              AND NOT EXISTS (
                  SELECT
                      1
                  FROM
                      ci_job_artifacts
                  WHERE
                      ci_builds.id = ci_job_artifacts.job_id
                      AND ci_job_artifacts.file_type = #{ARCHIVE_FILE_TYPE})
        SQL
      end

      def insert_metadatas(start_id, stop_id)
        ActiveRecord::Base.connection.execute <<~SQL
          INSERT INTO
              ci_job_artifacts (
                  project_id,
                  job_id,
                  expire_at,
                  file_location,
                  created_at,
                  updated_at,
                  file,
                  size,
                  file_store,
                  file_type
              )
          SELECT
              project_id,
              id,
              artifacts_expire_at,
              #{LEGACY_PATH_FILE_LOCATION},
              created_at,
              created_at,
              artifacts_metadata,
              NULL,
              COALESCE(artifacts_metadata_store, #{FILE_LOCAL_STORE}),
              #{METADATA_FILE_TYPE}
          FROM
              ci_builds
          WHERE
              id BETWEEN #{start_id.to_i} AND #{stop_id.to_i}
              AND artifacts_file <> ''
              AND artifacts_metadata <> ''
              AND NOT EXISTS (
                  SELECT
                      1
                  FROM
                      ci_job_artifacts
                  WHERE
                      ci_builds.id = ci_job_artifacts.job_id
                      AND ci_job_artifacts.file_type = #{METADATA_FILE_TYPE})
        SQL
      end

      def delete_legacy_artifacts(start_id, stop_id)
        ActiveRecord::Base.connection.execute <<~SQL
          UPDATE
              ci_builds
          SET
              artifacts_file = NULL,
              artifacts_file_store = NULL,
              artifacts_size = NULL,
              artifacts_metadata = NULL,
              artifacts_metadata_store = NULL
          WHERE
              id BETWEEN #{start_id.to_i} AND #{stop_id.to_i}
              AND artifacts_file <> ''
        SQL
      end
    end
  end
end