/*
 * Code by George Kichukov for SAS 11/03/2002
 * Updated 11/24/02
 *	- added check session if logged in
 	- took care of the different cases as descibed below
 	
 * This class is used to display all records from the table selected in PresentMenu
 * and/or to redirect to the appropriate input handler
 * It takes the table_name and the operation from PresentMenu
 * If a list is presented the user can choose which one they want to administer
 * if the operation is add it redirects to Input
 * There are several cases:
 	1. All Requirements (e.g. all tables ending in _REQ) are serviced by Req.java and InputReq.java
 		a) if it is major or minor req presents major or minor list to choose
 		b) else
 			- if Add go to Req
 			- else - display list to choose and operation on top
 				
 	2. All Other Tables are Serviced by Input.java
 		a) if Add - go to Input
 		b) if Modify/View/Delete 
 			- display all records to choose one 
 			  to perform the operation on
 
 * Updated 12/05/02 - add checkDelete() javascript 
 * Updated 12/08/02 - added some formatting
 	
 */

package admin;

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

import utilities.*;

public class TableDisplay extends HttpServlet
{
	private String errorTarget = "../admin/index.jsp";

        public void init(ServletConfig config) throws ServletException
        {
                super.init(config);
        }

        public void doGet(HttpServletRequest request,
                          HttpServletResponse response)
                          throws ServletException, IOException
        {

                // If it is a get request forward to doPost()
                doPost(request, response);
        }


        public void doPost(HttpServletRequest request, HttpServletResponse response)
                                throws ServletException, IOException
        {
                ResultSet rs=null;



               //name of the user
		String name="";
	
                PrintWriter out = response.getWriter();
                response.setContentType("text/html");

                //first thing that every servlet or jsp should do is check if user is logged in
                HttpSession session = request.getSession(false);
		
		//if not logged in redirect to login
 		if(session == null)
 		{
         		HTMLUtils.printRedirectPage(out, "You must login to the system prior to viewing this page.", errorTarget);
         		return;
 		}
 		
 		//else if logged in take the name from the session
 		else
 		{
 			name=(String)session.getAttribute("user");
 			
 			//if the name is null
 			if(name == null)
 			{
         			HTMLUtils.printRedirectPage(out, "You must login to the system prior to viewing this page.", errorTarget);
         			return;
 			}
 		
 		}

		HTMLUtils.printAdminHeader(out);
		
                //display welcome message to the user
                out.println("<p align=left>Welcome " + name + "</p>");

		//get the parameters
                String table=request.getParameter("table");
                String oper=request.getParameter("operation");
                String html="";

                
                try
                {
                        //if it is the MAJOR or MINOR REQs select for which major or minor first
                        if((table.equals("MAJOR_REQ")) || (table.equals("MINOR_REQ")))
                        {
                                html = html + "<form method=post action=admin.Req>Please select one:";

                                //pass the table name and the operation along
                                html = html + "<input type=hidden name=table value=" + table + ">";
                                html = html + "<input type=hidden name=oper value=" + oper + ">";

                               
                                html = html + "<select name=id>";

                                if(table.equals("MAJOR_REQ"))
                                {
                                        rs=Retriever.getMajors();
                                        while(rs.next())
                                        {
                                                html= html + "<option value=" + rs.getInt("MajorID")+ ">" + rs.getString("MajorName") + "</option>";
                                        }
                                }

                                else
                                {
                                        rs=Retriever.getMinors();
                                        while(rs.next())
                                        {
                                                html= html + "<option value=" + rs.getInt("MinorID")+ ">" + rs.getString("MinorName") + "</option>";
                                        }

                                }
                                html = html + "</select><input type=submit value=Submit></form>";
                                rs.close();
                                out.println(html);

                        }

                        //if it is any other req simply forward to Req
                        else if((table.substring(table.length()-3, table.length())).equals("REQ"))
                        {
                                String target = "/servlet/admin.Req?table=" + table + "&oper=" + oper;

                                try
                                {
                                        // Forward the request to the target named
                                        ServletContext context = getServletContext();
                                        RequestDispatcher dispatcher = context.getRequestDispatcher(target);
                                        dispatcher.forward(request, response);
                                }

                                catch(ServletException e){System.err.println("ServeltException" + e.getMessage());}
                                catch(IOException e){System.err.println("IOException" + e.getMessage());}

                        }

                        //display a list of records for the user to choose from if the Operation is Modify/Delete/View
                        //or redirect to Input of the operation is Add
                        else
                        {
                        	//redirect to Input of the operation is Add and pass the parameters (table, operation)
				if(oper.equals("Add"))
				{                                
	                                String target = "/servlet/admin.Input?table=" + table + "&oper=" + oper;
	
	                                try
	                                {
	                                        // Forward the request to the target named
	                                        ServletContext context = getServletContext();
	                                        RequestDispatcher dispatcher = context.getRequestDispatcher(target);
	                                        dispatcher.forward(request, response);
	                                }
	
	                                catch(ServletException e){System.err.println("ServeltException" + e.getMessage());}
	                                catch(IOException e){System.err.println("IOException" + e.getMessage());}
	                        }
				
				//display a list of records for the user to choose from if the Operation is Modify/Delete/View
				else
				{
                                	
                                	if(oper.equals("Delete"))
					{   
                                		//set up the confirm script
		                		out.println("<SCRIPT language=\"JavaScript\" SRC=\"../admin/delete_confirm.js\"></SCRIPT>");
		                	}
                                
	                                //get exact field names from table names e.g. from SCHOOLS to SchoolID or SchoolName
	                                String fieldID=table.substring(0,1) + (table.substring(1,table.length()-1)).toLowerCase() + "ID";
	                                String fieldName=table.substring(0,1) + (table.substring(1,table.length()-1)).toLowerCase() + "Name";
	
	                                html=html + "Please select the exact record that you want to " + oper.toLowerCase() + ": ";
	                                html=html + "<form method=post action=admin.Input onSubmit='return checkDelete()'>";
	                                html = html + "<input type=hidden name=table value=" + table + ">";
	                                html = html + "<input type=hidden name=oper value=" + oper + ">";
	                                
	                                //for courses we need the course code as well
	                                if(table.equals("COURSES"))
	                                {
	                                	rs=Retriever.getCourseList();
	                                	
	                                	
					        // Get the number of rows from the result set
					        ResultSet rs2 = Retriever.getRowCount(table);
					        rs2.next();
					        int rowcount = rs2.getInt(1);
	                                	
	                                	
	                                	//use this to divide in three columns
	                                	rowcount=rowcount/3;
	                                	int counter=0;
	                                	
	                                	//set up the table
	                                	html= html + "<TABLE cellpadding=0 cellspacing=0 border=0 width=730><tr><td valign=top width=230>";
	                                	
	                                	while(rs.next())
	                                	{
	                                        	if(counter++==rowcount)
							{
	                                        		html= html + "</td><td width=20>&nbsp</td><td valign=top width=230>";
	                                        		counter=0;
	                                        	}
	                                        	html= html + "<input type=radio name=id" + " value=" + rs.getInt(1)+ ">" + rs.getString(2) + "<br>";
	                                		
	                                	}
	                                
	                                	//end table
	                                	html = html + "</td></tr></table>";
	                                	
	                                }
	                                
	                                else
	                                {
	                                	rs=Retriever.getList(fieldID,fieldName, table);
	                                	
	                                	 // Get the number of rows from the result set
					        ResultSet rs2 = Retriever.getRowCount(table);
					        rs2.next();
					        int rowcount = rs2.getInt(1);
	                                	
						if(rowcount>9)
						{
	                                	
	                                		//use this to divide in three columns
		                                	rowcount=rowcount/3;
		                                	int counter=0;					                                	

		                                	//set up the table
		                                	html= html + "<TABLE cellpadding=0 cellspacing=0 border=0 width=730><tr><td valign=top width=230>";
	                                	
	                	                	while(rs.next())
	        	                        	{
	                        	                	if(counter++==rowcount+1)
	                                	        	{
	                                        			html= html + "</td><td width=20>&nbsp</td><td valign=top width=230>";
	                                        			counter=0;
	                                        		}
		                                        	html= html + "<input type=radio name=id" + " value=" + rs.getInt(1)+ ">" + rs.getString(2)+ "<br>";
	        			                        		
	                                		}
							//end table
	                                                html = html + "</td></tr></table>";

		                                }
						
						//no three columns
						else
						{

                                                        while(rs.next())
                                                        {
                                                                
                                                                html= html + "<input type=radio name=id" + " value=" + rs.getInt(1)+ ">" + rs.getString(2)+ "<br>";

                                                        }

						}

					}
	                     
	                              
	                                html = html + "<input type=Submit value=Submit></form>";
	                                rs.close();
	                                out.println(html);
	                         }
                        }
               }

               catch(SQLException e){out.println("SQLException " + e.getMessage());}
               
               HTMLUtils.printAdminFooter(out);
        }
}