package csci3030u.a3;

import java.sql.DriverManager;
import java.sql.SQLException;


import com.mysql.jdbc.Connection;
import com.mysql.jdbc.Statement;

/*
 * Creates 2 connections to database and by using 2 threads, accesses the database at the same time.
 * One thread will be inserting values and deleting them, the other thread will query the database
 */
public class ConcurrentAccess {

	public static void main(String[] args) {
		String host=null, user=null, password=null, database=null;
		int trials=0;

		//collect arguments and store them in variables
		if(args.length !=5){
			System.out.println("Not enough args");
			System.exit(0);
		}else{
			host=args[0];
			user=args[1];
			password=args[2];
			database=args[3];
			trials = Integer.parseInt(args[4]);
		}

		//connect to database twice
		try {
			  Class.forName("com.mysql.jdbc.Driver");
			} catch(Exception e) {
			  System.out.println("Driver not loaded."); System.exit(0);
			}

			try {

			//initialze connection 1 and 2
			  Connection con1 = (Connection) DriverManager.getConnection(
					  			host+database, user, password);

			  Connection con2 = (Connection) DriverManager.getConnection(
			  			host+database, user, password);

			  //create table if not exists
			  Statement stmt = (Statement) con1.createStatement();
			  stmt.executeUpdate("CREATE TABLE IF NOT EXISTS A3(number INTEGER)");

			  //setup threads that will run connection
			  InsertThread t1= new InsertThread(trials,con2);
			  QueryThread t2= new QueryThread(trials,con1 );

			  //run threads
			  t1.run();
			  t2.run();

			  con1.close();
			  con2.close();
			} catch(Exception e) {
				System.out.println(e.getMessage());
			  System.out.println("Driver not loaded."); System.exit(0);
			}
	}
}

/*
 * Thread used in max min querying
 */
class QueryThread implements Runnable {
	int trials;
	 Connection con;
	 int collisions;

    QueryThread(int trials, java.sql.Connection dbCon) {
    	this.trials=trials;
    	this.con=(Connection) dbCon;
    	this.collisions=0;
    }

    /**
     * Separate thread for database Queries
     */
	public void run() {
		try {
			con.setAutoCommit(true);
			for(int i=0; i<trials; i++){
				if(AccessTable.queryMaxMin(con)){
					collisions++;
				}
			}

			System.out.println("Number of collisions: " + collisions);
		} catch (SQLException e) {
			System.out.println(e.getMessage());
			return;
		}
	}
}

/*
 * Thread used in value inserting
 */
class InsertThread implements Runnable {
	int trials;
	 Connection con;

    InsertThread(int trials, java.sql.Connection dbCon) {
    	this.con=(Connection) dbCon;
    }

    /**
     * Separate thread for database Queries
     */
	public void run() {
		try {
			con.setAutoCommit(true);

			for(int i=0; i<trials; i++){
				AccessTable.insertValues(con, 1, 10);
			}

		} catch (SQLException e) {
			System.out.println(e.getMessage());
			return;
		}
	}
}