package com.vci.server.base.expression;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

public class ExpressionUtility {
	
	private static Map<String, Object> expressionMap = new HashMap<String,Object>();

	public static void removeExpression(String key) {
		if (expressionMap.containsKey(key)) {
			expressionMap.remove(key);			
		}
	}
	
	public static boolean invokeExpressionListner(String key, String expressionCode, HashMap<String, Object> parameters) {
		try {
			ExpressionIntf expression = null;
			if ( expressionMap.containsKey(key) ) {
				expression = (ExpressionIntf) expressionMap.get(key);
			} else {
				bsh.Interpreter interpreter = new bsh.Interpreter();
				expressionCode = ExpressionUtility.getCompleteExperssion(expressionCode);
				expression =  (ExpressionIntf) interpreter.eval(expressionCode);
			}
			return expression.expressionFunction(parameters);
		} catch(Exception e) {
			e.printStackTrace();
		}
		return false;
	}
	
	private static String getCompleteExperssion(String expression) {
		String expressioncode = "";
		expressioncode += " public boolean expressionFunction(Map parameters) " + "\n";
		expressioncode += " { " + "\n";
		expressioncode += expression;
		expressioncode += " } " + "\n";
		expressioncode += "  return (com.vci.base.server.expression.ExpressionIntf) this; " + "\n";
		
		return expressioncode;
	}
	
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		HashMap<String, Object> parameters = new HashMap<String, Object>();
		parameters.put("a", "10");
		parameters.put("b", "20");
		ExpressionUtility u = new ExpressionUtility();
//		String script = u.readScript();
		String script = "System.out.println(\"sss\"); return true;";
		ExpressionUtility.invokeExpressionListner("key1", script, parameters);
	}
	
	private String readScript() {
		String str = "";
		try { 
			FileReader read = new FileReader("properties/script.txt");
			BufferedReader br = new BufferedReader(read);
			String row;
			while((row = br.readLine())!=null){ 
				str += row;
			}
		} catch (FileNotFoundException e) {
	        e.printStackTrace();
		} catch (IOException e){
			e.printStackTrace();
		}

		return str;
	}
}