module Esbuild
  class BuildState
    def initialize(service, on_rebuild)
      @service = service
      @rebuild_id = nil
      @watch_id = nil
      @on_rebuild = on_rebuild
    end

    def stop
      return unless @watch_id
      @service.stop_watch(@watch_id)
      @watch_id = nil
    end

    def dispose
      return unless @rebuild_id
      res = @service.send_request("command" => "rebuild-dispose", "rebuildID" => @rebuild_id)
      @rebuild_id = nil
      res
    end

    def rebuild
      raise "Cannot rebuild" if @rebuild_id.nil?
      rebuild_response = @service.send_request("command" => "rebuild", "rebuildID" => @rebuild_id)
      response_to_result(rebuild_response)
    end

    def handle_watch(error, response)
      return @on_rebuild.call(error, nil) if error
      unless response["errors"].empty?
        error = BuildFailureError.new(response["errors"], response["warnings"])
        @on_rebuild.call(error, nil)
        return
      end

      result = BuildResult.new(response, self)
      @on_rebuild.call(nil, result)
    end

    def response_to_result(res)
      unless res["errors"].empty?
        raise BuildFailureError.new(res["errors"], res["warnings"])
      end
      if res["writeToStdout"]
        $stdout.puts res["writeToStdout"].rstrip
      end

      result = BuildResult.new(res, self)

      # Handle incremental rebuilds
      if res["rebuildID"] && !@rebuild_id
        @rebuild_id = res["rebuildID"]
      end

      # Handle watch mode
      if res["watchID"] && !@watch_id
        @watch_id = res["watchID"]
        if @on_rebuild
          @service.start_watch(@watch_id, ->(error, watch_response) { handle_watch(error, watch_response) })
        end
      end
      result
    end
  end
end