import java.sql.*;
import java.util.Random;

public class test_unit {
	public test_unit(int n) {

		 try {

		   Class.forName("org.postgresql.Driver");

		   String url = "jdbc:postgresql://localhost:5432/Purchases";
		   String user = "postgres";
		   String passwd = "postgres";

		   Connection conn = DriverManager.getConnection(url, user, passwd);

		   int i = 0;

		   int customer_id;
		   long date; //date on milliseconds
		   float price;
		   String shop_c; //all categories of shops are in an array
		   String shop_n; //all shop's name are in an array
		   String customer_name; //registered customers

		   Random r = new Random();
		   Random r1 = new Random(1515135600); //those two are needed to get a long random betwen two values
		   Random r2 = new Random(1514790000); //

		   while (i< n) {

			   customer_id = r.nextInt();
			   date = r2.nextLong() - r1.nextLong();
			   price = r.nextFloat();

			   String query = "INSERT INTO purchases (Customer_ID, Date_b, Price, Shop_category, Shop_name, Customer)"
			   + " values (?, ?, ?, ?, ?, ?)";
			   PreparedStatement prepared = conn.prepareStatement(query);
			   prepared.setInt(1, customer_id);
			   prepared.setDate(2, new java.sql.Date(date));
			   prepared.setFloat(3, price);
			   prepared.setString(4, shop_c);
			   prepared.setString(5, shop_n);
			   prepared.setString(6, customer_name);
		   }


		  } catch (Exception e) {
			  e.getCause();
		  }

	}
}