package de.example.log.jsf;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.PrintStream;

import javax.enterprise.inject.Model;
import javax.faces.application.FacesMessage;
import javax.faces.context.FacesContext;
import javax.inject.Inject;
import javax.script.Bindings;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;

@Model
public class Scripting {

	private String script;
	private String output;


	private ScriptEngineManager mgr = new ScriptEngineManager();
	public static String utilJavaScript = "var print = function (s) { __newOut.print(s); }; var println = function (s) { __newOut.println(s); };";

	public String execute() {
		ScriptEngine jsEngine = mgr.getEngineByName("JavaScript");
		ByteArrayOutputStream outputBuffer = new ByteArrayOutputStream(8192);
		PrintStream newOut = new PrintStream(outputBuffer, true);
		Bindings bindings = jsEngine.createBindings();
		bindings.put("__newOut", newOut);
		try {
			jsEngine.eval(utilJavaScript + getScript(), bindings);
		} catch (ScriptException from) {
			FacesContext.getCurrentInstance().addMessage(
					null,
					new FacesMessage(from.getColumnNumber() + " "
							+ from.getFileName() + " " + from.getLineNumber()
							+ " " + from.getMessage()));
			return null;

		}
		newOut.close();
		String returnString = outputBuffer.toString();
		setOutput(returnString);
		try {
			outputBuffer.close();
		} catch (IOException e) {
			FacesContext.getCurrentInstance().addMessage(
					null,
					new FacesMessage(e.getLocalizedMessage()));
		}
		return null;
	}

	public String getScript() {
		return script;
	}

	public void setScript(String script) {
		this.script = script;
	}

	public String getOutput() {
		return output;
	}

	public void setOutput(String output) {
		this.output = output;
	}
}

com.sun.script.javascript.RhinoScriptEngineFactory
jdk.nashorn.api.scripting.NashornScriptEngineFactory