private function getStatQuery($query) {

        return [

    }

    private function getMinMaxQuery($query) {

        return [

            'index' => config('elasticsearch.index'),

            'body' => [

                "size" => 0,

                "query" => $query,

                "aggs" => [

                    "datestats" => [

                        "nested"=> [

                            "path" => "creation_years"

                        ],

                        "aggs" => [

                            "minyear" => [

                                "min" => [ "field"=> "creation_years.year" ]

                            ],

                            "maxyear" => [

                                "max" => [ "field"=> "creation_years.year" ]

                            ]

                        ]

                    ]

                ]

            ]

        ];

    }

    private function getDocQuery(Request $request) {

        $filterManager = new CorpusFilterManager();

        $filters = $filterManager->prepareFilters($request);

        unset($filters['dates']);

        $qFilterParts = $filterManager->buildESFilters($filters);

        return $filterManager->buildQuery($qFilterParts);

    }

    /**

     * Display the min max date stats

     */

    public function minmax(Request $request) {

        $query = $this->getDocQuery($request);

        $esQuery = $this->getMinMaxQuery($query);

        $esRes = Es::search($esQuery);

        $datestats = [];

        $max = intval($esRes['aggregations']['datestats']['maxyear']['value']);

        $min = intval($esRes['aggregations']['datestats']['maxyear']['value']);

        return response()->json(['dateminmax' => [ $min, $max ] ]);

    }

    /**

     * Display the dates stats

     *

     * @return \Illuminate\Http\Response

     */

    public function index(Request $request)

    {

        $query = $this->getDocQuery($request);

        $esQuery = $this->getStatQuery($query);