content: /*
   * Copyright 1999-2018 Alibaba Group Holding Ltd.
   *
   * 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 com.alibaba.nacos.core.code.condition;
  
  import org.springframework.util.ObjectUtils;
  
  import jakarta.servlet.http.HttpServletRequest;
  import java.util.Collections;
  import java.util.LinkedHashSet;
  import java.util.Set;
  
  /**
   * request param info. {@link org.springframework.web.bind.annotation.RequestMapping#params()}
   *
   * @author horizonzy
   * @since 1.3.2
   */
  public class ParamRequestCondition {
      
      private final Set<ParamExpression> expressions;
      
      public ParamRequestCondition(String... expressions) {
          this.expressions = parseExpressions(expressions);
      }
      
      private Set<ParamExpression> parseExpressions(String... params) {
          if (ObjectUtils.isEmpty(params)) {
              return Collections.emptySet();
          }
          Set<ParamExpression> expressions = new LinkedHashSet<>(params.length);
          for (String param : params) {
              expressions.add(new ParamExpression(param));
          }
          return expressions;
      }
      
      public Set<ParamExpression> getExpressions() {
          return expressions;
      }
      
      public ParamRequestCondition getMatchingCondition(HttpServletRequest request) {
          for (ParamExpression expression : this.expressions) {
              if (!expression.match(request)) {
                  return null;
              }
          }
          return this;
      }
      
      @Override
      public String toString() {
          return "ParamRequestCondition{" + "expressions=" + expressions + '}';
      }
      
      static class ParamExpression {
          
          private final String name;
          
          private final String value;
          
          private final boolean isNegated;
          
          ParamExpression(String expression) {
              int separator = expression.indexOf('=');
              if (separator == -1) {
                  this.isNegated = expression.startsWith("!");
                  this.name = isNegated ? expression.substring(1) : expression;
                  this.value = null;
              } else {
                  this.isNegated = (separator > 0) && (expression.charAt(separator - 1) == '!');
                  this.name = isNegated ? expression.substring(0, separator - 1) : expression.substring(0, separator);
                  this.value = expression.substring(separator + 1);
              }
          }
          
          public final boolean match(HttpServletRequest request) {
              boolean isMatch;
              if (this.value != null) {
                  isMatch = matchValue(request);
              } else {
                  isMatch = matchName(request);
              }
              return this.isNegated != isMatch;
          }
          
          private boolean matchName(HttpServletRequest request) {
              return request.getParameterMap().containsKey(this.name);
          }
          
          private boolean matchValue(HttpServletRequest request) {
              return ObjectUtils.nullSafeEquals(this.value, request.getParameter(this.name));
          }
          
          @Override
          public String toString() {
              return "ParamExpression{" + "name='" + name + '\'' + ", value='" + value + '\'' + ", isNegated=" + isNegated
                      + '}';
          }
      }
  }
  