package com.rules; 

import com.booking.*;

import java.io.InputStreamReader;
import java.io.StringReader;
import java.io.InputStream;
import java.text.*;
import java.util.HashMap;
import java.math.BigDecimal;
import org.apache.log4j.*;

import org.drools.RuleBase;
import org.drools.WorkingMemory;
import org.drools.RuleBaseFactory;
import org.drools.audit.WorkingMemoryFileLogger;
import org.drools.compiler.PackageBuilder;
import org.drools.decisiontable.*;

public class PricingRules implements PricingService
{
    static RuleBase pricingRuleBase;
    static Logger myLogger;
    
    public void PricingRules()
    {
    }
    
    public Booking generatePrice(Reservation res) throws Exception
    {
      myLogger = Logger.getLogger(PricingRules.class.getName( ));
      myLogger.info("inside the ws method");
      Booking book = new Booking();
      firePricingRules(res, book);
      return book;
    } 

    public void firePricingRules(Reservation res, Booking booking) throws Exception{
        try
        {
        	myLogger.info("about to load rules");
        	loadRulesFromDecisionTable(); 
   //     	loadRulesFromDRL();
        	final WorkingMemory workingMemory = pricingRuleBase.newWorkingMemory();
            final WorkingMemoryFileLogger logger = new WorkingMemoryFileLogger( workingMemory );
            logger.setFileName( "log/pricing" );
            workingMemory.assertObject(res);
            workingMemory.assertObject(booking);
            workingMemory.fireAllRules();
        }
        catch(Exception ruleEx)
        {
            ruleEx.printStackTrace();
            throw ruleEx;
        }
      }
    
    private void loadRulesFromDecisionTable() throws Exception
    {
        if (pricingRuleBase == null)
            try
            { 
                final SpreadsheetCompiler converter = new SpreadsheetCompiler();
                final InputStream stream = this.getClass().getResourceAsStream( "/pricingdectbl2.xls"); 
                final String drl = converter.compile(stream, InputType.XLS);
                myLogger.info(drl);
                final PackageBuilder builder = new PackageBuilder(); 
                StringReader sr = new StringReader(drl);
                builder.addPackageFromDrl(sr);
                pricingRuleBase = RuleBaseFactory.newRuleBase();
                pricingRuleBase.addPackage(builder.getPackage());
                myLogger.info("pricingRuleBase loaded. . .");
            }
            catch (Exception e)
            {
                myLogger.info("Error at Drool rulebase loading. . .");
                e.printStackTrace();
                throw e; 
            }
    }
   
    private void loadRulesFromDRL() throws Exception{
        if (pricingRuleBase == null){
            try{
                final PackageBuilder builder = new PackageBuilder();
                builder.addPackageFromDrl( new InputStreamReader( PricingRules.class.getResourceAsStream("/pricingrules2.drl"))); 
                pricingRuleBase = RuleBaseFactory.newRuleBase();
                pricingRuleBase.addPackage(builder.getPackage());
                myLogger.info("pricingRuleBase loaded. . .");
            }
            catch (Exception e){
                myLogger.info("Error at Drool rulebase loading. . .");
                e.printStackTrace();
                throw e;
            }
        }
    }
    
   
}