import java.security.Policy;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.codehaus.groovy.control.CompilerConfiguration;
import org.codehaus.groovy.control.customizers.SecureASTCustomizer;
import org.codehaus.groovy.runtime.InvokerHelper;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;

import groovy.lang.Binding;
import groovy.lang.GroovyShell;
import groovy.lang.Script;
import groovy.util.Eval;

public class GroovyExecutor implements ApplicationContextAware,InitializingBean{

	private static  final Log log = LogFactory.getLog(GroovyExecutor.class);

    private ApplicationContext applicationContext;

    private GroovyShell groovyShell;

    public ConcurrentHashMap<String,Class<?>> classCache = new ConcurrentHashMap<String,Class<?>>();

    public static List<String> blackList = new ArrayList<String>();

    static {
    	blackList.add(System.class.getName());
    	blackList.add(Script.class.getName());
    	blackList.add(GroovyShell.class.getName());
    	blackList.add(Eval.class.getName());
    	blackList.add(Runtime.class.getName());
    	blackList.add(ProcessBuilder.class.getName());
    }

    @Override
    public void setApplicationContext(ApplicationContext applicationContext)
	    throws BeansException {
	 this.applicationContext = applicationContext;
    }

    @Override
    public void afterPropertiesSet() throws Exception {
    	try {


    		CompilerConfiguration conf = new CompilerConfiguration();
            SecureASTCustomizer customizer = new SecureASTCustomizer();
            customizer.setReceiversBlackList(blackList);
            conf.addCompilationCustomizers(customizer);




			Map<String,Object> springBeanMap = this.applicationContext.getBeansOfType(Object.class, true, false);
			Binding springBinding = new Binding(springBeanMap);
			groovyShell = new GroovyShell(springBinding,conf);

			Policy.setPolicy(new ScriptPolicy("/groovy/script"));
			if (System.getSecurityManager() == null) {
			    System.setSecurityManager(new SecurityManager());
			}
    	}catch(Throwable t) {
    		log.error("groovy shell error",t);
    	}
    }

    public Object run(String scriptText,Map<String,Object> params){
    	Class<?> scriptClass = null;
    	Object result = null;
    	if(classCache.containsKey(scriptText)){
    		scriptClass = classCache.get(scriptText);
    	}else{
    		//if slow ,parse all at init
    		scriptClass = groovyShell.getClassLoader().parseClass(scriptText);
    		classCache.put(scriptText, scriptClass);
    	}
    	Script script = InvokerHelper.createScript(scriptClass, buildScriptContext(params));
    	try{
    		 result = script.run();
    	}catch(Throwable t){
    		log.error("run error for->"+scriptText, t);
    	}
    	return result;
    }



    @SuppressWarnings({"unchecked" })
	private Binding  buildScriptContext(Map<String,Object> params){
    	Map<String,Object> var = new HashMap<String,Object>();
    	if(groovyShell.getContext().getVariables() != null && !groovyShell.getContext().getVariables().isEmpty()){
    		var.putAll(groovyShell.getContext().getVariables());
    	}
    	if(params != null && !params.isEmpty()){
    		var.putAll(params);
    	}
    	Binding context = new Binding(var);
    	return context;
    }



}