# frozen_string_literal: true

# Entry point of the BulkImport feature.
# This service receives a Gitlab Instance connection params
# and a list of groups to be imported.
#
# Process topography:
#
#       sync      |   async
#                 |
#  User +--> P1 +----> Pn +---+
#                 |     ^     | Enqueue new job
#                 |     +-----+
#
# P1 (sync)
#
# - Create a BulkImport record
# - Create a BulkImport::Entity for each group to be imported
# - Enqueue a BulkImportWorker job (P2) to import the given groups (entities)
#
# Pn (async)
#
# - For each group to be imported (BulkImport::Entity.with_status(:created))
#   - Import the group data
#   - Create entities for each subgroup of the imported group
#   - Enqueue a BulkImports::CreateService job (Pn) to import the new entities (subgroups)
#
module BulkImports
  class CreateService
    attr_reader :current_user, :params, :credentials

    def initialize(current_user, params, credentials)
      @current_user = current_user
      @params = params
      @credentials = credentials
    end

    def execute
      bulk_import = create_bulk_import

      Gitlab::Tracking.event(self.class.name, 'create', label: 'bulk_import_group')

      BulkImportWorker.perform_async(bulk_import.id)

      ServiceResponse.success(payload: bulk_import)
    rescue ActiveRecord::RecordInvalid => e
      ServiceResponse.error(
        message: e.message,
        http_status: :unprocessable_entity
      )
    end

    private

    def create_bulk_import
      BulkImport.transaction do
        bulk_import = BulkImport.create!(
          user: current_user,
          source_type: 'gitlab',
          source_version: client.instance_version
        )
        bulk_import.create_configuration!(credentials.slice(:url, :access_token))

        Array.wrap(params).each do |entity|
          BulkImports::Entity.create!(
            bulk_import: bulk_import,
            source_type: entity[:source_type],
            source_full_path: entity[:source_full_path],
            destination_slug: entity[:destination_slug],
            destination_namespace: entity[:destination_namespace]
          )
        end

        bulk_import
      end
    end

    def client
      @client ||= BulkImports::Clients::HTTP.new(
        url: @credentials[:url],
        token: @credentials[:access_token]
      )
    end
  end
end