/*
 * Copyright The Reshapr 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 io.reshapr.json;

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonDeserializer;
import org.owasp.encoder.Encode;

import java.io.IOException;

/**
 * Custom Jackson deserializer that sanitizes HTML content from string fields. It uses the OWASP Java
 * Encoder library to escape HTML special characters and prevent XSS attacks through REST API inputs.
 * <p>
 * Use this deserializer on DTO fields that should not contain raw HTML:
 * <pre>
 * {@code @JsonDeserialize(using = HtmlEncodedStringDeserializer.class)}
 * String description
 * </pre>
 * @author laurent
 */
public class HtmlEncodedStringDeserializer extends JsonDeserializer<String> {

   @Override
   public String deserialize(JsonParser p, DeserializationContext ctx) throws IOException {
      String value = p.getValueAsString();
      if (value == null) {
         return null;
      }
      return Encode.forHtmlContent(value);
   }
}


