@Service
public class SearchProductsMapper {

    private static final String REGEX = "(\\[|\\])";

    @Autowired
    private ElasticsearchClient esClient;

    @SneakyThrows
    public List<Product> search(SearchProductsDto searchProductsDto) {
        final SearchResponse<Product> response;
        if (searchProductsDto.isRelevance()) {
            if (!ObjectUtils.isEmpty(searchProductsDto.getPriceAsc()) && searchProductsDto.getPriceAsc().equals("price_asc")) {
                response = esClient.search(s -> getBuilder(searchProductsDto, s)
                                .sort(sort -> getSortObjects(sort, SortOrder.Asc, "price.p1"))
                                .highlight(SearchProductsMapper::getFields),
                        Product.class);
                return getProducts(response);
            }
            else if (!ObjectUtils.isEmpty(searchProductsDto.getPriceDesc()) && searchProductsDto.getPriceDesc().equals("price_desc")) {
                response = esClient.search(s -> getBuilder(searchProductsDto, s)
                                .sort(sort -> getSortObjects(sort, SortOrder.Desc, "price.p1"))
                                .highlight(SearchProductsMapper::getFields),
                        Product.class);
                return getProducts(response);
            }
            else if (!ObjectUtils.isEmpty(searchProductsDto.getQuantityAsc()) && searchProductsDto.getQuantityAsc().equals("quantity_asc")) {
                response = esClient.search(s -> getBuilder(searchProductsDto, s)
                                .sort(sort -> getSortObjects(sort, SortOrder.Asc, "quantity.tv"))
                                .highlight(SearchProductsMapper::getFields),
                        Product.class);
                return getProducts(response);
            }
            else if (!ObjectUtils.isEmpty(searchProductsDto.getQuantityDesc()) && searchProductsDto.getQuantityDesc().equals("quantity_desc")) {
                response = esClient.search(s -> getBuilder(searchProductsDto, s)
                                .sort(sort -> getSortObjects(sort, SortOrder.Desc, "quantity.tv"))
                                .highlight(SearchProductsMapper::getFields),
                        Product.class);
                return getProducts(response);
            }
        }
        response = esClient.search(s -> getBuilder(searchProductsDto, s)
                        .highlight(SearchProductsMapper::getFields),
                Product.class);
        return getProducts(response);
    }

    private static ObjectBuilder<SortOptions> getSortObjects(SortOptions.Builder sort, SortOrder desc, String value) {
        return sort
                .field(f -> f
                        .order(desc)
                        .field(value)
                );
    }

    private static Highlight.Builder getFields(Highlight.Builder h) {
        return h
                .preTags("[<em><b>]")
                .postTags("[</b></em> ]")
                .fields("productDescription", f -> f.withJson(new StringReader("{}")))
                .fields("vendorArticle", f -> f.withJson(new StringReader("{}")))
                .fields("itemCode", f -> f.withJson(new StringReader("{}")));
    }

    private static SearchRequest.Builder getBuilder(SearchProductsDto searchProductsDto, SearchRequest.Builder s) {
        return s
                .index("product")
                .from(searchProductsDto.getFrom())
                .size(searchProductsDto.getPageSize())
                .query(q -> q
                        .bool(bool -> bool
                                .must(must -> must
                                        .multiMatch(t -> t
                                                .fields("productDescription", "vendorArticle", "itemCode")
                                                .query(searchProductsDto.getQuery())
                                        )
                                )
                                .should(should -> should
                                        .match(match -> match
                                                .field("vendorArticle")
                                                .query(searchProductsDto.getQuery())
                                                .boost(1.0F)
                                        )
                                )
                                .should(should -> should
                                        .match(match -> match
                                                .field("itemCode")
                                                .query(searchProductsDto.getQuery())
                                                .boost(0.7F)
                                        )
                                )
                                .should(should -> should
                                        .match(match -> match
                                                .field("inStock")
                                                .query(true)
                                                .boost(1.0F)
                                        )
                                )
                        )
                );
    }

    private List<Product> getProducts(SearchResponse<Product> response) {
        return response.hits().hits().stream().map(hit -> {
            Product product = hit.source();
            assert product != null;
            if (hit.highlight().get("productDescription") != null) {
                product.setProductDescription(hit.highlight().get("productDescription").toString()
                        .replace(REGEX, EMPTY));
            }
            if (hit.highlight().get("vendorArticle") != null) {
                product.setVendorArticle(hit.highlight().get("vendorArticle").toString()
                        .replace(REGEX, EMPTY));
            }
            if (hit.highlight().get("itemCode") != null) {
                product.setItemCode(hit.highlight().get("itemCode").toString()
                        .replace(REGEX, EMPTY));
            }
            return product;
        }).collect(Collectors.toList());
    }

}