/**
 * Copyright (C) 2010-2013 Alibaba Group Holding Limited
 *
 * 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.rocketmq.common.filter;

import java.net.URL;

import com.alibaba.rocketmq.common.protocol.heartbeat.SubscriptionData;


/**
 * @author shijia.wxr<vintage.wang@gmail.com>
 * @since 2013-6-15
 */
public class FilterAPI {
    public static String simpleClassName(final String className) {
        String simple = className;
        int index = className.lastIndexOf(".");
        if (index >= 0) {
            simple = className.substring(index + 1);
        }

        return simple;
    }


    public static URL classFile(final String className) {
        final String javaSource = simpleClassName(className) + ".java";
        URL url = FilterAPI.class.getClassLoader().getResource(javaSource);
        return url;
    }


    public static boolean isFilterClassMode(final String subString) {
        try {
            if (subString.contains(".")) {
                Class<?> loadClass = FilterAPI.class.getClassLoader().loadClass(subString);
                Class<?>[] interfaces = loadClass.getInterfaces();
                for (int i = 0; i < interfaces.length; i++) {
                    if (interfaces[i].getCanonicalName().equals(MessageFilter.class.getCanonicalName())) {
                        return true;
                    }
                }
            }
        }
        catch (ClassNotFoundException e) {
        }

        return false;
    }


    public static SubscriptionData buildSubscriptionData(final String consumerGroup, String topic,
            String subString) throws Exception {
        SubscriptionData subscriptionData = new SubscriptionData();
        subscriptionData.setTopic(topic);
        subscriptionData.setSubString(subString);

        if (null == subString || subString.equals(SubscriptionData.SUB_ALL) || subString.length() == 0) {
            subscriptionData.setSubString(SubscriptionData.SUB_ALL);
        }
        // eg: com.taobao.abc.FilterClassName
        else if (isFilterClassMode(subString)) {
            // if (null == classFile(subString)) {
            // throw new
            // Exception(String.format("The Filter Java Class Source[%s] not exist in class path",
            // subString + ".java"));
            // }
            subscriptionData.setClassFilterMode(true);
        }
        else {
            String[] tags = subString.split("\\|\\|");
            if (tags != null && tags.length > 0) {
                for (String tag : tags) {
                    if (tag.length() > 0) {
                        String trimString = tag.trim();
                        if (trimString.length() > 0) {
                            subscriptionData.getTagsSet().add(trimString);
                            subscriptionData.getCodeSet().add(trimString.hashCode());
                        }
                    }
                }
            }
            else {
                throw new Exception("subString split error");
            }
        }

        return subscriptionData;
    }
}
