/**
 * ============LICENSE_START=======================================================
 * org.onap.aai
 * ================================================================================
 * Copyright © 2017-2018 AT&T Intellectual Property. All rights reserved.
 * ================================================================================
 * 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.
 * ============LICENSE_END=========================================================
 */

package org.onap.aai.restclient;

import java.util.LinkedHashMap;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.springframework.context.ApplicationContextInitializer;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.env.EnumerablePropertySource;
import org.springframework.core.env.MapPropertySource;
import org.springframework.core.env.PropertySource;

public class PropertyPasswordConfiguration implements ApplicationContextInitializer<ConfigurableApplicationContext> {

    private static final Pattern decodePasswordPattern = Pattern.compile("password\\((.*?)\\)");

    private PasswordDecoder passwordDecoder = new JettyPasswordDecoder();

    @Override
    public void initialize(ConfigurableApplicationContext applicationContext) {
        ConfigurableEnvironment environment = applicationContext.getEnvironment();
        for (PropertySource<?> propertySource : environment.getPropertySources()) {
            Map<String, Object> propertyOverrides = new LinkedHashMap<>();
            decodePasswords(propertySource, propertyOverrides);
            if (!propertyOverrides.isEmpty()) {
                PropertySource<?> decodedProperties =
                        new MapPropertySource("decoded " + propertySource.getName(), propertyOverrides);
                environment.getPropertySources().addBefore(propertySource.getName(), decodedProperties);
            }
        }
    }

    private void decodePasswords(PropertySource<?> source, Map<String, Object> propertyOverrides) {
        if (source instanceof EnumerablePropertySource) {
            EnumerablePropertySource<?> enumerablePropertySource = (EnumerablePropertySource<?>) source;
            for (String key : enumerablePropertySource.getPropertyNames()) {
                Object rawValue = source.getProperty(key);
                if (rawValue instanceof String) {
                    String decodedValue = decodePasswordsInString((String) rawValue);
                    propertyOverrides.put(key, decodedValue);
                }
            }
        }
    }

    private String decodePasswordsInString(String input) {
        if (input == null)
            return null;
        StringBuffer output = new StringBuffer();
        Matcher matcher = decodePasswordPattern.matcher(input);
        while (matcher.find()) {
            String replacement = passwordDecoder.decode(matcher.group(1));
            matcher.appendReplacement(output, replacement);
        }
        matcher.appendTail(output);
        return output.toString();
    }

}