package com.profiler.modifier.db.mysql;

import javassist.ClassPool;
import javassist.CtClass;
import javassist.CtConstructor;
import javassist.CtMethod;

import com.profiler.config.TomcatProfilerConstant;
import com.profiler.modifier.AbstractModifier;

public class MySQLPreparedStatementModifier extends AbstractModifier{
	public static byte[] modify(ClassPool classPool,ClassLoader classLoader,String javassistClassName,byte[] classFileBuffer) {
		log("MySQLPreparedStatementModifier modifing");
//		printClassInfo(javassistClassName);
		return changeMethod(classPool,classLoader,javassistClassName,classFileBuffer);
	}
	private static byte[] changeMethod(ClassPool classPool,ClassLoader classLoader,String javassistClassName,byte[] classfileBuffer) {
		try {
			CtClass cc = classPool.get(javassistClassName);
			updateSetInternalMethod(classPool,cc);
			updateExecuteQueryMethod(classPool,cc);
			updateConstructor(classPool,cc);

			byte[] newClassfileBuffer = cc.toBytecode();
//			cc.writeFile();
			printClassConvertComplete(javassistClassName);
			return newClassfileBuffer;
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}
	private static void updateSetInternalMethod(ClassPool classPool,CtClass cc) throws Exception {
//		setInternal(int paramIndex, String   val)
		CtClass[] params1=new CtClass[2];
		params1[0]=classPool.getCtClass("int");
		params1[1]=classPool.getCtClass("java.lang.String");
		CtMethod serviceMethod1=cc.getDeclaredMethod("setInternal", params1);
		log("*** Changing setInternal(int,String) method ");
		serviceMethod1.insertBefore(getSetInternal1MethodBeforeInsertCode());
		CtClass[] params2=new CtClass[2];
		params2[0]=classPool.getCtClass("int");
		params2[1]=classPool.getCtClass("byte[]");
		CtMethod serviceMethod2=cc.getDeclaredMethod("setInternal", params2);
		log("*** Changing setInternal(int,byte[]) method ");
		serviceMethod2.insertBefore(getSetInternal2MethodBeforeInsertCode());
		
	}
	private static String getSetInternal1MethodBeforeInsertCode() {
		StringBuilder sb=new StringBuilder();
		sb.append("{");
//		sb.append("System.out.println(\"PreparedStatement.setInternal(int,String) method is called\");");
//		sb.append("System.out.println(\"-----Position=\"+$1+\" Value=\"+$2);");
		
		sb.append(TomcatProfilerConstant.CLASS_NAME_REQUEST_DATA_TRACER+".putSqlParam($1,$2);");
		sb.append("}");
		return sb.toString();
	}
	private static String getSetInternal2MethodBeforeInsertCode() {
		StringBuilder sb=new StringBuilder();
		sb.append("{");
//		sb.append("System.out.println(\"PreparedStatement.setInternal(int,byte[]) method is called\");");
//		sb.append("System.out.println(\"-----Position=\"+$1+\" Value=\"+new String($2));");
		sb.append(TomcatProfilerConstant.CLASS_NAME_REQUEST_DATA_TRACER+".putSqlParam($1,$2);");
		sb.append("}");
		return sb.toString();
	}
	private static void updateConstructor(ClassPool classPool,CtClass cc) throws Exception {
		CtConstructor []constructorList=cc.getConstructors();
		if(constructorList.length==3) {
			log("*** Changing Constructor ");
			for(CtConstructor constructor:constructorList) {
				CtClass params[]=constructor.getParameterTypes();
				if(params.length==3) {
					constructor.insertBefore(getConstructorBeforeInsertCode());
				}
			}
		}
	}
	private static String getConstructorBeforeInsertCode() {
		StringBuilder sb=new StringBuilder();
		sb.append("{");
//		sb.append("System.out.println(\"-----PreparedStatement's constructor is called\");");
//		sb.append("System.out.println(\"-----Query=[\"+$2+\"]\");");
		sb.append(TomcatProfilerConstant.CLASS_NAME_REQUEST_DATA_TRACER+".putSqlQuery("+TomcatProfilerConstant.REQ_DATA_TYPE_DB_QUERY+",$2);");
		sb.append("}");
		return sb.toString();
	}
	
	private static void updateExecuteQueryMethod(ClassPool classPool,CtClass cc) throws Exception {
		CtMethod serviceMethod=cc.getDeclaredMethod("executeQuery", null);
		log("*** Changing executeQuery method ");
//		serviceMethod.insertBefore(getExecuteQueryMethodBeforeInsertCode());
		serviceMethod.insertAfter(getExecuteQueryMethodAfterInsertCode());
	}
	@SuppressWarnings("unused")
	private static String getExecuteQueryMethodBeforeInsertCode() {
		StringBuilder sb=new StringBuilder();
//		sb.append("{");
//		sb.append("System.out.println(\"-----PreparedStatement.executeQuery() method is called\");");
//		sb.append("}");
		return sb.toString();
	}
	private static String getExecuteQueryMethodAfterInsertCode() {
		StringBuilder sb=new StringBuilder();
		sb.append("{");
//		sb.append("System.out.println(\"-----PreparedStatement.executeQuery() method is ended\");");
		sb.append(TomcatProfilerConstant.CLASS_NAME_REQUEST_DATA_TRACER+".put("+TomcatProfilerConstant.REQ_DATA_TYPE_DB_EXECUTE_QUERY+");");
		sb.append("}");
		return sb.toString();
		
	}
}