/*
    * Copyright 2022 the original author or authors.
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *      http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.bremersee.apiclient.webflux.contract.spring;
  
  import static org.springframework.util.ObjectUtils.isEmpty;
  
  import java.util.function.Predicate;
  import java.util.stream.Collectors;
  import org.bremersee.apiclient.webflux.Invocation;
  import org.bremersee.apiclient.webflux.InvocationParameter;
  import org.springframework.data.domain.Sort;
  import org.springframework.data.domain.Sort.Order;
  import org.springframework.util.LinkedMultiValueMap;
  import org.springframework.util.MultiValueMap;
  
  /**
   * The sort request parameter resolver.
   *
   * @author Christian Bremer
   */
  public class SortRequestParameterResolver implements
      QueryParametersResolver,
      Predicate<InvocationParameter> {
  
    private String requestParamName = "sort";
  
    private String separatorValue = ",";
  
    private String descValue = "desc";
  
    /**
     * With request parameter name.
     *
     * @param requestParamName the request param name
     * @return the sort request parameter resolver
     */
    public SortRequestParameterResolver withRequestParamName(String requestParamName) {
      if (!isEmpty(requestParamName)) {
        this.requestParamName = requestParamName;
      }
      return this;
    }
  
    /**
     * With separator value.
     *
     * @param separatorValue the separator value
     * @return the sort request parameter resolver
     */
    public SortRequestParameterResolver withSeparatorValue(String separatorValue) {
      if (!isEmpty(separatorValue)) {
        this.separatorValue = separatorValue;
      }
      return this;
    }
  
    /**
     * With desc value.
     *
     * @param descValue the desc value
     * @return the sort request parameter resolver
     */
    public SortRequestParameterResolver withDescValue(String descValue) {
      if (!isEmpty(descValue)) {
        this.descValue = descValue;
      }
      return this;
    }
  
    @Override
    public MultiValueMap<String, Object> apply(Invocation invocation) {
      return invocation.toMethodParameterStream()
          .filter(this)
          .map(InvocationParameter::getValue)
          .map(value -> getRequestParameters((Sort) value))
          .collect(
              LinkedMultiValueMap::new,
              LinkedMultiValueMap::putAll,
              LinkedMultiValueMap::putAll);
    }
  
    @Override
    public boolean test(InvocationParameter invocationParameter) {
      return invocationParameter.getValue() instanceof Sort && invocationParameter
          .hasNoneParameterAnnotation(Extensions.ILLEGAL_EXTENSIONS_ANNOTATIONS);
   }
 
   /**
    * Gets request parameters.
    *
    * @param sort the sort
    * @return the request parameters
    */
   protected MultiValueMap<String, Object> getRequestParameters(Sort sort) {
     MultiValueMap<String, Object> map = new LinkedMultiValueMap<>();
     if (sort.isSorted()) {
       map.put(
           requestParamName,
           sort.stream().map(this::getRequestParamValue).collect(Collectors.toList()));
     }
     return map;
   }
 
   /**
    * Gets request param value.
    *
    * @param order the order
    * @return the request param value
    */
   protected String getRequestParamValue(Order order) {
     StringBuilder sb = new StringBuilder(order.getProperty());
     if (order.isDescending()) {
       sb.append(separatorValue).append(descValue);
     }
     return sb.toString();
   }
 
 }