Inventory System Scan

package com.kmc.inventory.actions;

import java.util.*;

import javax.persistence.*;
import javax.swing.*;

import org.openxava.actions.*;
import org.openxava.jpa.*;

import com.kmc.inventory.lists.*;
import com.kmc.inventory.models.*;

public class ItemScanAction extends ViewBaseAction {

    public void execute() throws Exception {

        Inventory inventory = null;
        Employee employee = null;

        String scan = getView().getValueString("scanId");
        String isIssued = getView().getValueString("toIssue");

        /*
         *   Item and Employee was not found
         */
        if ( !isItemExists(scan) && !isEmployee(scan) ) {
            addError("not_found", scan);
        }

        /*
         *   Item existence
         */
        else if ( isItemExists(scan) ) {

            /*
             *   Employee must be scanned first before Item code
             */
            if ( getView().getValueString("employeeId").isEmpty() ) {
                addError("employee_scan_first");
            }
            else if ( !getView().getValueString("employeeId").isEmpty() ){
                /*
                 *   Scanned item was {available}
                 *      If the check box was checked, item will be issued to the employee
                 *      Otherwise, item will be borrowed
                 */
                if ( getInventoryStatus(scan) == 0 ) {
                    inventory = getInventoryById(scan);
                    employee = getEmployeeById(getView().getValueString("employeeId"));

                    inventory.setDateBorrowed(new Date());
                    inventory.setDateReturned(null);

                    if ( isIssued.equalsIgnoreCase("true") ) {
                        if ( JOptionPane.showConfirmDialog(null, "Are you sure?", "Issuing to " + getFullName(getView().getValueString("employeeId")), JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE) == JOptionPane.YES_OPTION ) {
                            inventory.setStatus(Status.Issued);

                            inventory.setEmployee(employee);
                            getView().setValue("itemCategory", inventory.getItemCategory().getDescription());
                            getView().setValue("brand", inventory.getBrand().getDescription());
                            getView().setValue("itemPhoto", inventory.getItemPhoto());
                            getView().setValue("department", employee.getDepartment().getDescription());

                            addMessage("item_issued", inventory.getItemName(), getFullName(getView().getValueString("employeeId")));
                        }
                    }
                    else if ( isIssued.equalsIgnoreCase("false") ) {
                        inventory.setStatus(Status.Borrowed);

                        inventory.setEmployee(employee);
                        getView().setValue("itemCategory", inventory.getItemCategory().getDescription());
                        getView().setValue("brand", inventory.getBrand().getDescription());
                        getView().setValue("itemPhoto", inventory.getItemPhoto());
                        getView().setValue("department", employee.getDepartment().getDescription());

                        addMessage("item_borrowed", inventory.getItemName(), getFullName(getView().getValueString("employeeId")));
                    }
                }
                /*
                 *   Scanned item was {borrowed}
                 *      Setting the scanned item back to its available status
                 */
                else if ( getInventoryStatus(scan) == 1 ) {
                    inventory = getInventoryById(scan);
                    employee = getEmployeeById(getView().getValueString("employeeId"));

                    inventory.setEmployee(null);
                    inventory.setStatus(Status.Available);
                    inventory.setDateBorrowed(null);
                    inventory.setDateReturned(new Date());

                    getView().setValue("itemCategory", inventory.getItemCategory().getDescription());
                    getView().setValue("brand", inventory.getBrand().getDescription());
                    getView().setValue("itemPhoto", inventory.getItemPhoto());
                    getView().setValue("department", employee.getDepartment().getDescription());

                    addMessage("item_available", inventory.getItemName(), employee.getFirstName() + " " + employee.getLastName());
                }
                /*
                 *   Scanned item was {issued}
                 *      Item was already issued, no transaction will commit
                 */
                else if ( getInventoryStatus(scan) == 2 ) {
                    inventory = getInventoryById(scan);

                    addError("item_issued", inventory.getItemName(), getFullName(getView().getValueString("employeeId")));
                }
                XPersistence.commit();
            }
        }
        else if ( isEmployee(scan) ) {
            getView().setValue("employeeId", scan);
            getView().setValue("borrowedBy", (getEmployeeById(scan).getFirstName() + " " + getEmployeeById(scan).getLastName()));
        }
    }

    /*
     *   Check item existence
     *      scan = value from scan field
     *
     *   Returns true if an item was found, false if item was not present in database
     */
    public static boolean isItemExists( String scan ) {

        Query query = XPersistence.getManager().createQuery(
                "FROM Inventory i " +
                "WHERE i.serviceTag = :service OR i.assetTag = :asset");
        query.setParameter("service", scan);
        query.setParameter("asset", scan);

        try {
            query.getSingleResult();
            return true;
        } catch( NoResultException nre ) {
            System.out.println(nre.toString());
            return false;
        }
    }

    /*
     *   Check employee existence
     *      scan = value from scan field
     *
     *   Returns true if an employee was found, false if employee was not present in database
     */
    private static boolean isEmployee( String scan ) {

        Query query = XPersistence.getManager().createQuery(
                "FROM Employee e " +
                "WHERE e.employeeId = :id");
        query.setParameter("id", scan);

        try {
            query.getSingleResult();
            return true;
        } catch( NoResultException nre ) {
            System.out.println(nre.toString());
            return false;
        }
    }

    /*
     *   Accessing Inventory record
     *      scan = value from scan field
     *
     *   Returns mapped Inventory if Id was found, null if Id was not found
     */
    private static Inventory getInventoryById( String scan ) {
        Query query = XPersistence.getManager().createQuery(
                "FROM Inventory i WHERE " +
                "i.assetTag = :asset OR i.serviceTag = :service");
        query.setParameter("asset", scan);
        query.setParameter("service", scan);

        try {
            return (Inventory) query.getSingleResult();
        } catch( NoResultException nre ) {
            System.out.println(nre.toString());
            nre.printStackTrace();
            return null;
        }


    }

    /*
     *   Accessing Employee record
     *      scan = value from scan field
     *
     *   Returns mapped Employee if Id was found, null if Id was not found
     */
    private static Employee getEmployeeById( String scan ) {

        Query query = XPersistence.getManager().createQuery(
                "FROM Employee e " +
                "WHERE e.employeeId = :id");
        query.setParameter("id", scan);

        try {
            return (Employee) query.getSingleResult();
        } catch( NoResultException nre ) {
            System.out.println(nre.toString());
            return null;
        }
    }

    /*
     *   Inventory status
     *      id = value from scan field
     *
     *   Returns status flag
     *      0 = Available
     *      1 = Borrowed
     *      2 = Issued
     *      3 = Transferred
     */
    private static int getInventoryStatus( String id ) {

        try {
            Query query = XPersistence.getManager().createQuery(
                    "SELECT i.status FROM Inventory i " +
                    "WHERE i.assetTag = :asset OR i.serviceTag = :service");
            query.setParameter("asset", id);
            query.setParameter("service", id);

            Status status = (Status) query.getSingleResult();
            if ( status.toString().equals("Available") ) {
                return 0;
            }
            else if ( status.toString().equals("Borrowed") ) {
                return 1;
            }
            else if ( status.toString().equals("Issued") ) {
                return 2;
            }
            else if ( status.toString().equals("Transferred") ) {
                return 3;
            }
            else {
                return 0;
            }
        } catch( NoResultException nre ) {
            return 0;
        } catch( Exception e ) {
            return 0;
        }
    }

    /*
     *   Getting Employee full name
     *      id = value from scan field
     *
     *   Returns the full name of an employee, with a space as separator
     */
    private static String getFullName( String id ) {
        Query query = XPersistence.getManager().createQuery(
                "FROM Employee e " +
                "WHERE e.employeeId = :id");
        query.setParameter("id", id);

        try {
            Employee employee = (Employee) query.getSingleResult();
            return employee.getFirstName() + " " + employee.getLastName();
        } catch( NoResultException nre ) {
            System.out.println(nre.toString());
            return null;
        }
    }

}