/*
 * Copyright 2014-2018 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 de.codecentric.boot.admin.server.utils.jackson;

import java.io.IOException;
import java.util.Arrays;
import java.util.Map;
import java.util.regex.Pattern;

import javax.annotation.Nullable;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.fasterxml.jackson.databind.ser.std.StdSerializer;

public class SanitizingMapSerializer extends StdSerializer<Map<String, String>> {

	private static final long serialVersionUID = 1L;

	private final Pattern[] keysToSanitize;

	@SuppressWarnings("unchecked")
	public SanitizingMapSerializer(String[] patterns) {
		super((Class<Map<String, String>>) (Class<?>) Map.class);
		this.keysToSanitize = createPatterns(patterns);
	}

	private static Pattern[] createPatterns(String... keys) {
		return Arrays.stream(keys).map((key) -> Pattern.compile(key, Pattern.CASE_INSENSITIVE)).toArray(Pattern[]::new);
	}

	@Override
	public void serialize(Map<String, String> value, JsonGenerator gen, SerializerProvider provider)
			throws IOException {
		gen.writeStartObject();
		for (Map.Entry<String, String> entry : value.entrySet()) {
			gen.writeStringField(entry.getKey(), sanitize(entry.getKey(), entry.getValue()));
		}
		gen.writeEndObject();
	}

	@Nullable
	private String sanitize(String key, @Nullable String value) {
		if (value == null) {
			return null;
		}

		boolean matchesAnyPattern = Arrays.stream(this.keysToSanitize)
				.anyMatch((pattern) -> pattern.matcher(key).matches());
		return matchesAnyPattern ? "******" : value;
	}

}
