import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
import myBean.Course;
import java.util.regex.*;

public class CourseSvlt extends HttpServlet{
	
public void doGet(HttpServletRequest req, HttpServletResponse res)
    throws ServletException, IOException {
    String cour_id =req.getParameter("id");
    int success = 0,period;
    String action = req.getParameter("action");
    Course cour = null;
    String message="",name,dep,prepare;
    Pattern p = Pattern.compile("[0-9]*");
   
    if ("new".equalsIgnoreCase(action)) {
      cour_id=req.getParameter("id");
      prepare =req.getParameter("prepare");
      name=new String(req.getParameter("name").getBytes("ISO8859_1"));
      dep=new String (req.getParameter("dep").getBytes("ISO8859_1"));
      Matcher m = p.matcher(req.getParameter("period"));
      boolean b = m.matches();
      if(b){
        period = Integer.parseInt(req.getParameter("period"));
        if(isTrue(req,res,cour_id,name,period) && hasLogin(req,res,cour_id) && isCompare(prepare,dep,req,res)){
          cour = doNew(req,res,cour_id,name,period,prepare,dep);
          sendBean(req, res, cour, "/getCourse.jsp");
        }
      }else{doError(req,res,"學時只能為正整數！");}
    }  
    
    if ("update".equalsIgnoreCase(action)) {
    	name=new String(req.getParameter("name").getBytes("ISO8859_1"));
    	dep=new String (req.getParameter("dep").getBytes("ISO8859_1"));
    	prepare =req.getParameter("prepare");
      Matcher m = p.matcher(req.getParameter("period"));
      boolean b = m.matches();
      if(b){
        period = Integer.parseInt(req.getParameter("period"));
        if(isTrue(req,res,cour_id,name,period) && isCompare(prepare,dep,req,res)){
    	     try{		
     	       cour = doUpdate(req,res,cour_id,name,period,prepare,dep);
     	       sendBean(req,res,cour,"/getCourse.jsp");
     	     }
     	     catch(SQLException e){} 
     	  }
     	}else{doError(req,res,"學時只能為正整數！");}
    }
			   
    if ("delete".equalsIgnoreCase(action)) {
    	try{			
      	success = doDelete(cour_id);	
      	    }
      	    catch(SQLException e){}				
    	if (success != 1) {
    		doError(req, res, "CourseSvlt: Delete unsuccessful. Rows affected: " + success);
    	} else {
    		res.sendRedirect("http://localhost:8080/0903/getCourse.jsp");
    	}}
    	
    	if("updateScore".equalsIgnoreCase(action)){
    		String stu_id = req.getParameter("stu_id");
    		String grade = req.getParameter("mark");
    		Matcher m = p.matcher(grade);
        boolean b = m.matches();
        if(b){
    		   cour = new Course();
    		   cour.updateMark(stu_id,cour_id,grade);   		
    		   sendBean(req,res,cour,"/getCourse.jsp");
    		  }else{doError(req,res,"成績只能為正整數！");}
    		}
       
    }
    
    
 public Course doNew(HttpServletRequest req,HttpServletResponse res,String cour_id,String name,int period,String prepare,String dep)
                           throws ServletException,IOException{
      float credit = Float.valueOf(req.getParameter("mark")).floatValue();
      String semester=new String(req.getParameter("semester").getBytes("ISO8859_1"));
      Course cour= new Course();                    	
     
      cour.setId(cour_id);
      cour.setName(name);
      cour.setCredit(credit);
      cour.setDep(dep);
      cour.setPrepare(prepare);
      cour.setPeriod(period);
      cour.setSemester(semester);
      
      cour.addCourse();
      
      return cour;                	
                           	
  }
                           	
   public boolean isCompare(String prepare,String dep,
   HttpServletRequest req,HttpServletResponse res)throws ServletException,IOException{
   	   boolean f=true;
   	   String tempDep=null;
   	   String message=null;
  	   Course cour= new Course();
   	  if( !prepare.equalsIgnoreCase("0")){
         tempDep=cour.getPrepareDep(prepare);
         if(tempDep.equals("public"))
            return true;
         else if(dep.equalsIgnoreCase(tempDep))
            f=true;
         else {
      	    f=false;      
      	    message="錯誤，課程所在系與預修課所在系不一致！";
      	    doError(req,res,message);
         }
      }
      return f; 
   	  }                     	
                           	
                           	
  public Course doUpdate(HttpServletRequest req,HttpServletResponse res , String id,String name,int period,String prepare,String dep)
                           throws ServletException,IOException,SQLException {                      	   
    float credit = Float.valueOf(req.getParameter("mark")).floatValue();         
    String semester=new String(req.getParameter("semester").getBytes("ISO8859_1"));  
    Course cour = new Course();
    
    cour.setName(name);
    cour.setCredit(credit);
    cour.setDep(dep);
    cour.setPrepare(prepare);
    cour.setPeriod(period);
    cour.setSemester(semester);

    cour.updateCourse(id);
    
		return cour;
  }
  
    public int doDelete(String id) throws SQLException {
  	int num=0;
    Course cour=new Course();
    num=cour.deleteCourse(id);
    return num;
  }
  
  public void sendBean(HttpServletRequest req, HttpServletResponse res,
                       Course cour, String target)
                       throws ServletException, IOException {
    req.setAttribute("cour", cour);
    RequestDispatcher rd = getServletContext().getRequestDispatcher(target);
    rd.forward(req, res);
  } 
  
    public void doError(HttpServletRequest req,
                      HttpServletResponse res,
                      String str)
                      throws ServletException, IOException {


    req.setAttribute("problem", str);
    RequestDispatcher rd = getServletContext().getRequestDispatcher("/errorpage.jsp");
    rd.forward(req, res);
  }
  
  
    public boolean hasLogin(HttpServletRequest req, HttpServletResponse res,String id)
  throws ServletException, IOException{
  	boolean f=true;
  	String message="對不起，該課程號已經被注冊過了!";
  	Course cour= new Course();
  	f= cour.hasLogin(id);
  	if(f==false){
  	doError(req,res,message);	
  		}
  		return f;
  	}
  	
  public boolean isTrue(HttpServletRequest req, HttpServletResponse res,
                        String id,String name,int period)
                        throws ServletException, IOException {
   boolean f=true;                     	
   String message ="";
   if(id==null || id.equals(""))  {
   	f=false;
   	message="錯誤，課程號不能為空！";
   	doError(req,res,message);	}
   
   else if(name==null || name.equals(""))  {
   	f=false;
   	message="課程名不能為空，請重新填寫！";
   	doError(req,res,message);	}
   else if(period<=0)
   {f=false;
    message = "學時必須為正整數,請重新填寫!";
    doError(req,res,message);
   }
  	
     return f;
     
  }
  
    public void doPost(HttpServletRequest req, HttpServletResponse res)
    throws ServletException, IOException {

    doGet(req, res);

   } 
  }