import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;

public class EditStudent extends HttpServlet {

    public void doGet(HttpServletRequest request,
                       HttpServletResponse response)
    throws ServletException, IOException {
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();

        out.println( Global.header("Edit Student Records") );

        // Read parameters.
        String stud_id = request.getParameter("param_id");
        if( stud_id != null ){
        try
        {

            String driver = "sun.jdbc.odbc.JdbcOdbcDriver";
            String url = "jdbc:odbc:StudentDB";
            String sql ="SELECT * FROM Student " +
                         "WHERE StudentID = ? ";

            Class.forName(driver);
            Connection con = DriverManager.getConnection(url);
            PreparedStatement stm = con.prepareStatement(sql);

             stm.setString( 1, stud_id );

             ResultSet rs  = stm.executeQuery();

             int i,x;
             String[] data = new String[ Global.sql_data.length ];
             if( rs.next() )
             for( i = 0; i < Global.sql_data.length; i++ )
                 data[i] = rs.getString( Global.sql_data[i] );


            out.println("<script type='text/javascript' src='validateForm.js'></script>");
            out.println("<form action='EditStudent' method='post' onSubmit='return validateForm();' name='myForm'>");
            out.println("<div align=center><table border=0><br/>");

            for( i = 0; i < Global.sql_data.length-1; i++ ){
                out.println("<tr>");
                 out.println("<td>"+Global.sql_Name[i]+" :</td>");

                 if( i == 3 ){
                      out.println("<td><p>");
                      out.println("<label><input type='radio' name='"+Global.sql_data[i]+"' value='M' id='gender_Male' "+( ( data[i].equalsIgnoreCase( "M" ) )?"checked":"" )+" />Male</label>");
                      out.println("<br/>");
                      out.println("<label><input type='radio' name='"+Global.sql_data[i]+"' value='F' id='gender_Female' "+( ( data[i].equalsIgnoreCase( "F" ) )?"checked":"" )+"/>Female</label>");
                      out.println("<br/></p></td>");


                // program
                }else if( i == 4 ){
                      out.println("<td><label>");
                      out.println("<select name='"+Global.sql_data[i]+"' id='"+Global.sql_data[i]+"'>");
                      for( x = 0; x < Global.program_data.length; x++ )
                          out.println("<option value='"+Global.program_data[x]+"' "+( ( data[i].equalsIgnoreCase( Global.program_data[x] ) )?"selected":"" )+">"+Global.program_name[x]+"</option>");
                      out.println("</select>");
                      out.println("</label></td>");

                // year
                }else if( i == 5 ){
                      out.println("<td><label>");
                      out.println("<select name='"+Global.sql_data[i]+"' id='select2'>");
                      for( x = 1; x <= 4; x++ )
                          out.println("<option value='"+x+"' "+( ( Integer.parseInt( data[i] ) == x )?"selected":"" )+" >Year "+x+"</option>");
                      out.println("</select>");
                      out.println("</label></td>");


                // hometown
                }else if( i == 7 ){
                      out.println("<td><label>");
                      out.println("<select name='"+Global.sql_data[i]+"' id='select2'>");
                      for( x = 0; x < Global.home_data.length; x++ )
                          out.println("<option value='"+Global.home_data[x]+"' "+( ( data[i].equalsIgnoreCase(Global.home_data[x]) )?"selected":"" )+" >"+Global.home_name[x]+"</option>");
                      out.println("</select>");
                      out.println("</label></td>");


                }else{
                    out.println("<td><input type='text' name='"+Global.sql_data[i]+"' value='"+data[i]+"' "+( ( i == 0 )?"readonly":"" )+" /></td>");
                }

                out.println("</tr>");
            }

           out.println("<tr><td></td><td></td></tr> <tr><td><br/>Decision :</td><td>");

            out.println("<br/><br/><input type='Submit' value='Update' style='height: 50px; width: 100px'/>");
            out.println("<input type='reset' value='Reset' style='height: 50px; width: 100px'/>");
            out.println("</td></table></div>");
            out.println("</form>");

            rs.close();
            stm.close();
            con.close();
        }
        catch (Exception e)
        {
            out.println(e.toString());
        }

        }else{
            out.println("<h1 align=center>Please ensure you have selected 1 Student from the list.</h1>");
        }

        out.println( Global.footer() );
        out.close();
    }




    public void doPost(HttpServletRequest request,
                       HttpServletResponse response)
    throws ServletException, IOException {
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();

        out.println( Global.header("Edit Student Records") );


        int i,x,request_year = 0;
        String[] request_data = new String[ Global.sql_data.length ];

        for( i = 0; i < Global.sql_data.length-1; i++ ){
            if( i == 5 ) request_year = Integer.parseInt( request.getParameter(Global.sql_data[i]) );
            else request_data[i] = request.getParameter(Global.sql_data[i]);
            //out.println( "<h3>"+Global.sql_Name[i]+" :  "+request_data[i]+"</h3>" );
        }

        java.sql.Date sqlDate = new java.sql.Date(new java.util.Date().getTime()  );

        try
        {
            String driver = "sun.jdbc.odbc.JdbcOdbcDriver";
            String url = "jdbc:odbc:StudentDB";
            String sql = "UPDATE Student " +
                         "SET "+Global.sql_data[1]+" = ?, "+Global.sql_data[2]+" = ?, "+Global.sql_data[3]+" = ?, "+Global.sql_data[4]+" = ?, "+Global.sql_data[5]+" = ?, "+Global.sql_data[6]+" = ? , "+Global.sql_data[7]+" = ? , "+Global.sql_data[8]+" = ? " +
                         "WHERE "+Global.sql_data[0]+" = ? ";

            Class.forName(driver);
            Connection        con = DriverManager.getConnection(url);
            PreparedStatement stm = con.prepareStatement(sql);

            stm.setString(1, request_data[1]); // name
            stm.setString(2, request_data[2]); // ic
            stm.setString(3, request_data[3]); // gender
            stm.setString(4, request_data[4]); // prog
            stm.setInt(5, request_year ); // year
            stm.setString(6, request_data[6]); // phone
            stm.setString(7, request_data[7]); // hometown
            stm.setDate(8, sqlDate ); // date

            stm.setString(9, request_data[0]);  // id

            // Execute the UPDATE statement.
            // Ignore returned value.
            stm.executeUpdate();

            stm.close();
            con.close();

            out.println("<h1 align='center'>Student updated.</h1>");
        }
        catch (Exception e)
        {
            out.println(e.toString());
        }


        out.println( Global.footer() );
        out.close();
    }


}