/*
 * This sample shows how to perform an update on the student table
 */

// You need to import the java.sql package to use JDBC
import java.sql.*;

class AddStudent
{
  public static void main (String args []) throws SQLException
  {
    if(args.length!=3){
	System.out.println("Usage:  java AddStudent <name> <major> <gradyear>");
	System.exit(1);
    }

    int sid;
    String name = args[0];
    String major = args[1];
    int majorid=0;
    int gradyear=0;
    
    try {
	gradyear = Integer.parseInt(args[2]);
    }
    catch (NumberFormatException e){
	System.out.println("Grad year must be an integer");
	System.exit(1);
    }
    if(gradyear<1900 || gradyear>2100){
	System.out.println("Grad year must be between 1900 and 2100");
	System.exit(1);
    }

    // Get the user's name and password
    java.io.Console cons = System.console();
    cons.printf("Enter username: ");
    String uname = cons.readLine();
    cons.printf("Enter password: ");
    char[] pword = cons.readPassword();
    String pwd = "";
    for(char c : pword)
	pwd += c;
    
    try {
        // Connect to the database
	// You can put a database name after the @ sign in the connection URL.
	String url = "jdbc:mysql://sql.cs.oberlin.edu/studentdb?";
	String parms = "user="+uname+"&password="+pwd+"&useSSL=false";
	
	Connection conn = DriverManager.getConnection (url+parms);

	// Create a Statement
	Statement stmt = conn.createStatement ();
	
	// find the largest student id in the student table
	ResultSet rset = stmt.executeQuery ("select max(sid) from student");
	// assign this student the max sid + 1
	if (rset.next()){
	    sid = rset.getInt(1) + 1;
	}
	else {
	    // if this is the first student, set the sid to 1
	    sid = 1;
	}
	
	// find the majorid for the specified major
	rset = stmt.executeQuery ("select did from dept"+
					    " where dname='"+major+"'");
	// assign the majorid to this student
	if (rset.next()){
	    majorid = rset.getInt(1);
	}
	else {
	    System.out.println("Unknown major: "+major);
	    System.exit(1);
	}
	
	// Perform the update on the student table
	String insertStmt = "insert into student "+
	    "values("+sid+",'"+name+"',"+majorid+","+gradyear+")";
	System.out.println(insertStmt);

	int x = stmt.executeUpdate(insertStmt);
	System.out.println(x+" student added");

	// Close the Statement
	stmt.close();
	
	// Close the connection
	conn.close();   
    }
    catch(SQLException e) {
	e.printStackTrace();
    }
    catch(Exception ee){
	ee.printStackTrace();
    }
  }
}