package org.drools.examples.simple;

import java.io.File;  
import org.drools.KnowledgeBase;  
import org.drools.KnowledgeBaseFactory;  
import org.drools.builder.KnowledgeBuilder;  
import org.drools.builder.KnowledgeBuilderFactory;  
import org.drools.builder.ResourceType;  
import org.drools.io.ResourceFactory;  
import org.drools.runtime.StatefulKnowledgeSession;  
import org.drools.runtime.StatelessKnowledgeSession;  
  
public class DroolsExample {  
    /** 
     * @param args 
     */  
    public static void main(String[] args) {
               //Create KnowledgeBase...  
                KnowledgeBase knowledgeBase = createKnowledgeBase();  
                //Create a statefull session  
        StatefulKnowledgeSession session = knowledgeBase.newStatefulKnowledgeSession();  
  
                 //Create Facts - two ban accounts  
                 Account account = new Account();  
         account.setBalance(10);  
         account.setId("N1");  
  
         Account account2 = new Account();  
         account2.setBalance(120);  
         account2.setId("N2");  
  
                 //Insert the bank account facts into a State full session  
         session.insert(account);  
         session.insert(account2);  
  
                 //Note that at this point, afetr fact insertation the Agenda has one activation ready to be fired.  
                 //Account1 is less than 100.  
  
                 //Only now we will fire the rules which are already in the agenda  
         session.fireAllRules();   
  
                 //A message of N1 is less than 100 will be printed to stdout.  
    }  
  
        /** 
        * Create new knowledge base 
        */  
    private static KnowledgeBase createKnowledgeBase() {  
        KnowledgeBuilder builder = KnowledgeBuilderFactory.newKnowledgeBuilder();  
                //Add drl file into builder  
        File accountRules = new File("rules/BasicAccountRule.drl"); //Where the account rule is.  
        builder.add(ResourceFactory.newFileResource(accountRules), ResourceType.DRL);  
        if (builder.hasErrors()) {  
            throw new RuntimeException(builder.getErrors().toString());  
        }  
  
        KnowledgeBase knowledgeBase = KnowledgeBaseFactory.newKnowledgeBase();  
  
                //Add to Knowledge Base packages from the builder which are actually the rules from the drl file.  
        knowledgeBase.addKnowledgePackages(builder.getKnowledgePackages());  
  
        return knowledgeBase;  
    }  
  
}