/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.dubbo.remoting.telnet.support.command;

import org.apache.dubbo.common.extension.Activate;
import org.apache.dubbo.common.extension.ExtensionLoader;
import org.apache.dubbo.common.status.Status;
import org.apache.dubbo.common.status.StatusChecker;
import org.apache.dubbo.common.status.support.StatusUtils;
import org.apache.dubbo.common.utils.CollectionUtils;
import org.apache.dubbo.remoting.Channel;
import org.apache.dubbo.remoting.telnet.TelnetHandler;
import org.apache.dubbo.remoting.telnet.support.Help;
import org.apache.dubbo.remoting.telnet.support.TelnetUtils;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import static org.apache.dubbo.common.constants.CommonConstants.COMMA_SPLIT_PATTERN;

/**
 * StatusTelnetHandler
 */
@Activate
@Help(parameter = "[-l]", summary = "Show status.", detail = "Show status.")
public class StatusTelnetHandler implements TelnetHandler {

    private final ExtensionLoader<StatusChecker> extensionLoader = ExtensionLoader.getExtensionLoader(StatusChecker.class);

    @Override
    public String telnet(Channel channel, String message) {
        if ("-l".equals(message)) {
            List<StatusChecker> checkers = extensionLoader.getActivateExtension(channel.getUrl(), "status");
            String[] header = new String[]{"resource", "status", "message"};
            List<List<String>> table = new ArrayList<List<String>>();
            Map<String, Status> statuses = new HashMap<String, Status>();
            if (CollectionUtils.isNotEmpty(checkers)) {
                for (StatusChecker checker : checkers) {
                    String name = extensionLoader.getExtensionName(checker);
                    Status stat;
                    try {
                        stat = checker.check();
                    } catch (Throwable t) {
                        stat = new Status(Status.Level.ERROR, t.getMessage());
                    }
                    statuses.put(name, stat);
                    if (stat.getLevel() != null && stat.getLevel() != Status.Level.UNKNOWN) {
                        List<String> row = new ArrayList<String>();
                        row.add(name);
                        row.add(String.valueOf(stat.getLevel()));
                        row.add(stat.getMessage() == null ? "" : stat.getMessage());
                        table.add(row);
                    }
                }
            }
            Status stat = StatusUtils.getSummaryStatus(statuses);
            List<String> row = new ArrayList<String>();
            row.add("summary");
            row.add(String.valueOf(stat.getLevel()));
            row.add(stat.getMessage());
            table.add(row);
            return TelnetUtils.toTable(header, table);
        } else if (message.length() > 0) {
            return "Unsupported parameter " + message + " for status.";
        }
        String status = channel.getUrl().getParameter("status");
        Map<String, Status> statuses = new HashMap<String, Status>();
        if (CollectionUtils.isNotEmptyMap(statuses)) {
            String[] ss = COMMA_SPLIT_PATTERN.split(status);
            for (String s : ss) {
                StatusChecker handler = extensionLoader.getExtension(s);
                Status stat;
                try {
                    stat = handler.check();
                } catch (Throwable t) {
                    stat = new Status(Status.Level.ERROR, t.getMessage());
                }
                statuses.put(s, stat);
            }
        }
        Status stat = StatusUtils.getSummaryStatus(statuses);
        return String.valueOf(stat.getLevel());
    }

}
