package com.tutorialspoint;  

import java.io.File; 
import java.io.FileInputStream; 
import java.io.FileNotFoundException;  
import java.io.FileOutputStream; 
import java.io.IOException; 
import java.io.ObjectInputStream; 
import java.io.ObjectOutputStream; 
import java.util.ArrayList; 
import java.util.List;  

public class UserDao { 
   public List<User> getAllUsers(){ 
      
      List<User> userList = null; 
      try { 
         File file = new File("Users.dat"); 
         if (!file.exists()) { 
            User user = new User(1, "Mahesh", "Teacher"); 
            userList = new ArrayList<User>(); 
            userList.add(user); 
            saveUserList(userList); 
         } 
         else{ 
            FileInputStream fis = new FileInputStream(file); 
            ObjectInputStream ois = new ObjectInputStream(fis); 
            userList = (List<User>) ois.readObject(); 
            ois.close(); 
         } 
      } catch (IOException e) { 
         e.printStackTrace(); 
      } catch (ClassNotFoundException e) { 
         e.printStackTrace(); 
      }   
      return userList; 
   } 
   private void saveUserList(List<User> userList){ 
      try { 
         File file = new File("Users.dat"); 
         FileOutputStream fos;  
         fos = new FileOutputStream(file); 
         ObjectOutputStream oos = new ObjectOutputStream(fos); 
         oos.writeObject(userList); 
         oos.close(); 
      } catch (FileNotFoundException e) { 
         e.printStackTrace(); 
      } catch (IOException e) { 
         e.printStackTrace(); 
      } 
   }    
   
   public User getUser(int id){
	      List<User> users = getAllUsers();

	      for(User user: users){
	         if(user.getId() == id){
	            return user;
	         }
	      }
	      return null;
	   }

	   public int addUser(User pUser){
	      List<User> userList = getAllUsers();
	      boolean userExists = false;
	      for(User user: userList){
	         if(user.getId() == pUser.getId()){
	            userExists = true;
	            break;
	         }
	      }		
	      if(!userExists){
	         userList.add(pUser);
	         saveUserList(userList);
	         return 1;
	      }
	      return 0;
	   }

	   public int updateUser(User pUser){
	      List<User> userList = getAllUsers();

	      for(User user: userList){
	         if(user.getId() == pUser.getId()){
	            int index = userList.indexOf(user);			
	            userList.set(index, pUser);
	            saveUserList(userList);
	            return 1;
	         }
	      }		
	      return 0;
	   }

	   public int deleteUser(int id){
	      List<User> userList = getAllUsers();

	      for(User user: userList){
	         if(user.getId() == id){
	            int index = userList.indexOf(user);			
	            userList.remove(index);
	            saveUserList(userList);
	            return 1;   
	         }
	      }		
	      return 0;
	   }

   
   
   
   
   
   
   public List<UserJson> getAllUsersJson(){ 
	      
	      List<UserJson> userList = null; 
	      try { 
	         File file = new File("Users1.dat"); 
	         if (!file.exists()) { 
	            UserJson userJson = new UserJson(1, "Mahesh", "Teacher"); 
	            userList = new ArrayList<UserJson>(); 
	            userList.add(userJson); 
	            saveUserListJson(userList); 
	         } 
	         else{ 
	            FileInputStream fis = new FileInputStream(file); 
	            ObjectInputStream ois = new ObjectInputStream(fis); 
	            userList = (List<UserJson>) ois.readObject(); 
	            ois.close(); 
	         } 
	      } catch (IOException e) { 
	         e.printStackTrace(); 
	      } catch (ClassNotFoundException e) { 
	         e.printStackTrace(); 
	      }   
	      return userList; 
	   } 
	   private void saveUserListJson(List<UserJson> userList){ 
	      try { 
	         File file = new File("Users1.dat"); 
	         FileOutputStream fos;  
	         fos = new FileOutputStream(file); 
	         ObjectOutputStream oos = new ObjectOutputStream(fos); 
	         oos.writeObject(userList); 
	         oos.close(); 
	      } catch (FileNotFoundException e) { 
	         e.printStackTrace(); 
	      } catch (IOException e) { 
	         e.printStackTrace(); 
	      } 
	   }   
}