SimplePluginLoader.java

/**
 * MIT License
 *
 * Copyright (c) 2017 zgqq
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
package mah.plugin.loader;

import mah.app.ApplicationManager;
import mah.app.config.Config;
import mah.command.Command;
import mah.command.CommandManager;
import mah.command.event.InitializeEvent;
import mah.event.EventHandler;
import mah.plugin.Plugin;
import mah.plugin.PluginException;
import mah.plugin.PluginMetainfo;
import mah.plugin.command.PluginCommand;
import mah.plugin.config.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.Node;

import java.io.File;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.*;

/**
 * Created by zgq on 2017-01-08 19:51
 */
public class SimplePluginLoader {
    private static final Logger LOGGER = LoggerFactory.getLogger(SimplePluginLoader.class);
    private final XmlConfigReader reader;
    private final ExecutorService executorService;
    private final ScheduledExecutorService scheduledExecutor;
    private final Logger logger = LoggerFactory.getLogger(SimplePluginLoader.class);

    public SimplePluginLoader(Config config, List<String> pluginMetainfoFiles) throws Exception {
        this.reader = new XmlConfigReader(ApplicationManager.getInstance().getPluginDir(), config,pluginMetainfoFiles);
        executorService = Executors.newCachedThreadPool();
        scheduledExecutor = Executors.newScheduledThreadPool(2);
    }

    private Plugin loadPlugin(PluginMetainfo pluginMetainfo) throws Exception {
        Class<?> clazz = pluginMetainfo.getPluginLoader().loadClass(pluginMetainfo.getPluginClass());
        Object pluginObj = clazz.newInstance();
        if (pluginObj instanceof Plugin) {
            return (Plugin) pluginObj;
        } else {
            throw new PluginException("Plugin is supposed to implement the interface of Plugin");
        }
    }

    private void setPluginDir(PluginMetainfo pluginMetainfo) {
        pluginMetainfo.setPluginDataDir(ApplicationManager.getInstance().getPluginDataDir()
                + File.separator + pluginMetainfo.getName());
    }

    public final List<Plugin> loadPlugins(List<String> pluginNames) {
        List<PluginMetainfo> activePluginMetainfos = reader.getPluginMetainfos(pluginNames);
        List<Plugin> plugins;
        plugins = new ArrayList<>();
        for (PluginMetainfo pluginMetainfo : activePluginMetainfos) {
            Class<?> clazz = null;
            try {
                setPluginDir(pluginMetainfo);
                Plugin plugin = loadPlugin(pluginMetainfo);
                plugin.setPluginMetainfo(pluginMetainfo);
                plugins.add(plugin);
            } catch (Throwable e) {
                throw new PluginException("Unable to loadPlugins plugin " + clazz, e);
            }
        }
        return plugins;
    }

    private Map<String, List<CommandConfig>> loadCommands(List<String> pluginNames) {
        List<? extends PluginConfig> pluginConfigs = reader.parsePluginConfigs(pluginNames);
        Map<String, List<CommandConfig>> pluginToCommandConfigs = new HashMap<>();
        for (PluginConfig pluginConfig : pluginConfigs) {
            List<CommandConfig> commandConfigs = new ArrayList<>();
            List<? extends CommandConfig> xmlCommandConfigs = pluginConfig.getCommandConfigs();
            for (CommandConfig commandConfig : xmlCommandConfigs) {
                commandConfigs.add(commandConfig);
            }
            pluginToCommandConfigs.put(pluginConfig.getName(), commandConfigs);
        }
        return pluginToCommandConfigs;
    }

    private Command findCommand(CommandConfig commandConfig) {
        String commandName = commandConfig.getCommandName();
        Command command = CommandManager.getInstance().findCommand(commandConfig.getPluginName(), commandName);
        if (command == null) {
            throw new PluginException("Not found command " + commandName);
        }
        return command;
    }

    public final void start() {
        List<String> activePlugins = reader.getActivePluginNames();
        List<Plugin> plugins = loadPlugins(activePlugins);
        Map<String, List<CommandConfig>> pluginToCommands = loadCommands(activePlugins);
        for (Plugin plugin : plugins) {
            List<CommandConfig> commandConfigs = pluginToCommands.get(plugin.getName());
            Future<?> loadTask = executorService.submit(() -> {
                try {
                    long start = System.nanoTime();
                    startPlugin(plugin, commandConfigs);
                    long end = System.nanoTime();
                    logger.info("Loading plugin {} took {} milliseconds", plugin,
                            TimeUnit.MILLISECONDS.convert((end - start),
                            TimeUnit.NANOSECONDS));
                } catch (Throwable e) {
                    logger.error("Plugin failed to start {}",e);
                }
            });
            scheduledExecutor.schedule(() -> {
                        if (!loadTask.isDone()) {
                            loadTask.cancel(true);
                            logger.error("Plugin {} took too much time to load,already canceled", plugin);
                        }
                    } ,
                    50000, TimeUnit.MILLISECONDS);
        }

        if (plugins.isEmpty()) {
            LOGGER.warn("No Found any plugin");
        }

        try {
            executorService.shutdown();
            executorService.awaitTermination(10, TimeUnit.SECONDS);
        } catch (InterruptedException e) {
            throw new PluginException("Plugins took too much time to load,failing to startup app");
        }
    }


    private void startPlugin(Plugin plugin, List<CommandConfig> commandConfigs) throws Exception {
        checkPluginDir(plugin);
        plugin.init();
        plugin.prepare();
        if (commandConfigs != null) {
            for (CommandConfig commandConfig : commandConfigs) {
                Command command = findCommand(commandConfig);
                startCommand(plugin, command, commandConfig);
                CommandManager.getInstance().mapCommand(commandConfig.getTriggerKey(), command);
            }
        }
    }

    private void checkPluginDir(Plugin plugin) {
        String pluginDataDir = plugin.getPluginMetainfo().getPluginDataDir();
        File pluginData = new File(pluginDataDir);
        if (!pluginData.exists()) {
            pluginData.mkdirs();
        }
    }

    private void startCommand(Plugin plugin, Command command, CommandConfig commandConfig) {
        configureCommand(command, commandConfig);
        try {
            if (command instanceof PluginCommand) {
                PluginCommand pluginCommand = (PluginCommand) command;
                pluginCommand.setPlugin(plugin);
            }

            List<EventHandler<? extends InitializeEvent>> initializeHandlers = command.getInitializeHandlers();
            InitializeEvent initializeEvent = new InitializeEvent();
            for (EventHandler initializeHandler : initializeHandlers) {
                initializeHandler.handle(initializeEvent);
            }
        } catch (Exception e) {
            throw new PluginException(e);
        }
    }

    private void configureCommand(Command command, CommandConfig commandConfig) {
        if (command instanceof XmlConfigurable) {
            XmlConfigurable xmlConfigurable = (XmlConfigurable) command;
            XmlCommandConfig xmlCommandConfig = (XmlCommandConfig) commandConfig;
            try {
                Node customConfig = xmlCommandConfig.getCustomConfig();
                if (customConfig != null) {
                    xmlConfigurable.configure(xmlCommandConfig.getCustomConfig());
                }
            } catch (Exception e) {
                throw new PluginException(e);
            }
        }
    }

}