/*
 * Copyright 2019 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
 *
 *      https://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.springframework.cloud.dataflow.server.service.impl;

import java.io.IOException;

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.ObjectCodec;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonDeserializer;
import com.fasterxml.jackson.databind.JsonNode;

import org.springframework.cloud.dataflow.registry.support.AppResourceCommon;
import org.springframework.core.io.Resource;

/**
 * Custom Jackson deserializer used to convert the URL of a resource (as it has been serialized) back to a Resource
 *
 * @author Michael Minella
 * @since 2.3
 */
public class ResourceDeserializer extends JsonDeserializer<Resource> {

	final private AppResourceCommon appResourceCommon;

	public ResourceDeserializer(AppResourceCommon appResourceCommon) {
		this.appResourceCommon = appResourceCommon;
	}

	@Override
	public Resource deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException, JsonProcessingException {
		ObjectCodec oc = jsonParser.getCodec();
		JsonNode node = oc.readTree(jsonParser);

		final String url = node.asText();

		return this.appResourceCommon.getResource(url);
	}
}
