/*

  * $Source: /usr/cvsroot/org/paneris/melati/shopping/ShoppingTrolley.java,v $

  * $Revision: 1.15 $

  *

  * Copyright (C) 2000 Tim Joyce

  *

  * Part of Melati (http://melati.org), a framework for the rapid

  * development of clean, maintainable web applications.

  *

  * Melati is free software; Permission is granted to copy, distribute

  * and/or modify this software under the terms either:

  *

  * a) the GNU General Public License as published by the Free Software

  *    Foundation; either version 2 of the License, or (at your option)

  *    any later version,

  *

  *    or

  *

  * b) any version of the Melati Software License, as published

  *    at http://melati.org

  *

  * You should have received a copy of the GNU General Public License and

  * the Melati Software License along with this program;

  * if not, write to the Free Software Foundation, Inc.,

  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the

  * GNU General Public License and visit http://melati.org to obtain the

  * Melati Software License.

  *

  * Feel free to contact the Developers of Melati (http://melati.org),

  * if you would like to work out a different arrangement than the options

  * outlined here.  It is our intention to allow Melati to be used by as

  * wide an audience as possible.

  *

  * This program is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  * GNU General Public License for more details.

  *

  * Contact details for copyright holder:

  *

  *     Tim Joyce <timj@paneris.org>

  *     http://paneris.org/

  *     68 Sandbanks Rd, Poole, Dorset. BH14 8BY. UK

  */

 package org.paneris.jammyjoes.shopping;

 import java.text.NumberFormat;

 import java.util.Enumeration;

 import java.util.Hashtable;

 import java.util.Locale;

 import java.util.Vector;

 import javax.servlet.http.HttpSession;

 import org.melati.Melati;

 import org.melati.poem.AccessPoemException;

 import org.melati.poem.AccessToken;

 import org.melati.poem.Capability;

 import org.melati.poem.PoemThread;

 import org.melati.util.InstantiationPropertyException;

 import org.paneris.jammyjoes.model.JammyjoesDatabase;

 import org.paneris.jammyjoes.util.JammyJoesUtil;

  /**

  * <p> A Shopping Trolley stored information in the user's Shopping Trolley.<p>

  * <p> It does this by storing itself in the session.</p>

  * <p> For this reason, the constructors are private, and you will be expected to

  * always get the Shopping Trolley using getInstance();</p>

  *

  * usage example:

  *

  * ShoppingTrolley trolley = ShoppingTrolley.getInstance(Melati melati);

  * context.put("trolley", trolley);

  *

  **/

 public abstract class ShoppingTrolley {

   private static String TROLLEY = "org.paneris.melati.shopping.DefaultShoppingTrolley";

   protected Locale locale;

   protected String address;

   protected String name;

   protected String tel;

   protected String town;

   protected String county;

   protected String country;

   protected String postcode;

   protected String message;

   protected String email;

   protected boolean hasDetails = false;

   Vector orderedItems = new Vector();

   Hashtable items = new Hashtable();

   public MelatiShoppingConfig config;

   public Melati melati;

   /**

    * private Constructor to build an empty ShoppingTrolley

   **/

   protected void initialise(Melati melati, MelatiShoppingConfig config) {

     this.config = config;

     this.melati = melati;

   }

   /**

    * public Constructor to build a trolley from some id

   **/

   public void initialise(Melati melati, MelatiShoppingConfig config, Integer id)

    throws InstantiationPropertyException {

     initialise(melati,config);

     load(id);

     HttpSession session = melati.getSession();

     session.setAttribute(name(),this);

   }

   /**

    * remove any trolley from the session

    */

   public void remove(Melati melati) {

     HttpSession session = melati.getSession();

     session.removeAttribute(name());

   }

   /**

    * Returns the single instance, creating one if it can't be found.

    */

   public static synchronized ShoppingTrolley getInstance(Melati melati, MelatiShoppingConfig config)

    throws InstantiationPropertyException {

     HttpSession session = melati.getSession();

     ShoppingTrolley instance = (ShoppingTrolley) session.getAttribute(name());

     if (instance == null || instance.isPaid()) {

       instance = newTrolley(config);

       instance.initialise(melati,config);

       session.setAttribute(name(),instance);

     }

     instance.configureRequest(melati);

     return instance;

   }

   private boolean isPaid() {

     return false;

   }

   public static synchronized ShoppingTrolley newTrolley(MelatiShoppingConfig config)

    throws InstantiationPropertyException {

     return config.getShoppingTrolley();

   }

   /* get the Locale for this trolley

   */

   public abstract Locale getLocale();

   /* set the Locale for this trolley

   */

   public void setLocale(Locale locale){

     this.locale = locale;

   }

   /* confirm payment of this trolley

   */

   public abstract void confirmPayment(Melati melati);

   /* load a trolley from something persistent

   */

   public abstract void load(Integer id) throws InstantiationPropertyException;

   /* save a trolley to something persistent

   */

   public abstract void save();

   /* this is done for each request, so anything special that needs to be done

    * can be put in here

   */

   public void configureRequest(Melati melati) {

     this.melati = melati;

   }

   /* do something to force users to login

    * you could perhaps throw an access poem exception in order to let the

    * servlet generate the login page

    */

   public void assertLogin(Melati melati) {

     JammyjoesDatabase db = (JammyjoesDatabase) melati.getDatabase();

     Capability operator = db.getOperatorCapability();

     AccessToken token = PoemThread.accessToken();

     if (!token.givesCapability(operator))

       throw new AccessPoemException(token, operator);

   }

   /* set the user's detault details into this trolley.  this is useful

    * if users have already logged in, and we don't want them to reenter their

    * details

    */

   public abstract void setDefaultDetails(Melati melati);

   /* return the name of the trolley (for storing in the session

   */

   public static String name() {

     return TROLLEY;

   }

   /* get the items from the trolley

   */

   public Enumeration getItems() {

     return orderedItems.elements();

   }

   /* have we got anything in the trolley

   */

   public boolean isEmpty() {

     return items.isEmpty();

   }

   /* have we entered any personal information

   */

   public boolean hasDetails() {

     return hasDetails;

   }

   /* get an item from the trolley

   */

   public ShoppingTrolleyItem getItem(Integer id) {

     return (ShoppingTrolleyItem)items.get(id);

   }

   /* remove an item from the trolley

   */

   public void removeItem(ShoppingTrolleyItem item) {

     items.remove(item.getId());

     orderedItems.removeElement(item);

   }

   /* add an item to the trolley

   */

   public void addItem(ShoppingTrolleyItem item) {

     // don't add it if it's already there

     if (!items.containsKey(item.getId())) {

       orderedItems.add(item);

     }

     items.put(item.getId(),item);

   }

   public ShoppingTrolleyItem newItem(Integer id, String description, Double price)

    throws InstantiationPropertyException {

     ShoppingTrolleyItem item = ShoppingTrolleyItem.newTrolleyItem(config);

     item.initialise(this, melati, id, description, price);

     addItem(item);

     return item;

   }

   /* calculate the value of the items in the trolley

   */

   public double getValue() {

     double value = 0;

     for (Enumeration en = items.elements(); en.hasMoreElements();) {

       ShoppingTrolleyItem product = (ShoppingTrolleyItem) en.nextElement();

       value += product.getValue();

     }

     return value;

   }

   /* format the order value for display

      this value does not include discount or delivery, but does invlude VAT

   */

   public String getValueDisplay() {

     return displayCurrency(getValue());

   }

   /* calculate the total value of this order

   */

   public double getTotalValue() {

     return getValue() + getTotalDeliveryValue() + getDiscountValue() + getVATValue();

   }

   /* format the total order value for display

      this value includes discount, delivery and VAT

   */

   public String getTotalValueDisplay() {

     return displayCurrency(getTotalValue());

   }

   /* format the total order value in pence, typically ecomerce sites

      accept the values in pence not pounds

   */

   public String getTotalValuePence() {

     return getValuePence(getTotalValue());

   }

   public static String getValuePence(double totalValue) {

     return (new Double(roundTo2dp(totalValue * 100))).intValue() + "";

   }

   /* provide a mechanism for working out if

      this order should include a delivery charge

   */

   public abstract boolean hasDelivery();

   /* you need to provide some mechanism for calculating the delivery

      value for the order (item delivery values are calculated individually

   */

   public abstract double getDeliveryValue();

   /* the delivery charge for the order is the sum of the charges on the items

      and an overall charge

   */

   public double getTotalDeliveryValue() {

     double value = 0;

     if (hasDelivery()) {

       value = getDeliveryValue();

       for (Enumeration en = items.elements(); en.hasMoreElements();) {

         ShoppingTrolleyItem item = (ShoppingTrolleyItem) en.nextElement();

         value += item.getDeliveryValue();

       }

     }

     return value;

   }

   /* format the devliery value for display

   */

   public String getDeliveryDisplay() {

     return displayCurrency(getTotalDeliveryValue());

   }

   /* provide a mechanism for working out if

      this order should include a discount

   */

   public abstract boolean hasDiscount();

   /* if you want to apply a discount to this order, do it here

   */

   public abstract double getDiscountRate();

   /* work out the value of the discout applied to this order

      (returns a negative value)

   */

   public double getDiscountValue() {

     double value = 0;

     if (hasDiscount()) {

       value = 0 - roundTo2dp(getValue()*getDiscountRate());

     }

     return value;

   }

   /* display the discount (if present)

   */

   public String getDiscountRateDisplay() {

     if (hasDiscount()) {

       try {

         return (new Double(getDiscountRate())).intValue() + "%";

       } catch (NumberFormatException e) {

         return getDiscountRate() + "%";

       }

     } else {

       return "";

     }

   }

   /* format the discount value for display

   */

   public String getDiscountValueDisplay() throws Exception {

     return displayCurrency(getDiscountValue());

   }

   /* provide a mechanism for working out if

      this order should include VAT (default should be true)

   */

   public abstract boolean hasVAT();

   /* calculate the VAT value of the order

      typically items are priced inclusive of VAT and orders

      are therefor also inclusive of VAT.  If this order is

      for someone who should not be charged VAT, we need to subtract VAT

      from the order value

   */

   public double getVATValue() {

     if (!hasVAT()) {

       return roundTo2dp(getValue() * -0.14894);

     } else {

       return 0;

     }

   }

   /* format the vat value for display

   */

   public String getVATDisplay() {

     return displayCurrency(getVATValue());

   }

   /* set the address

   */

   public void setDeliveryAddress(String a) {

     address = a;

   }

   /* get the address

   */

   public String getDeliveryAddress() {

     return address;

   }

   /* set the name

   */

   public void setName(String a) {

     name = a;

   }

   /* get the name

   */

   public String getName() {

     return name;

   }

   /* set the email address

   */

   public void setEmail(String a) {

     email = a;

   }

   /* get the email address

   */

   public String getEmail() {

     return email;

   }

   /* set the postcode

   */

   public void setPostcode(String a) {

     postcode = a;

   }

   /* get the postcode

   */

   public String getPostcode() {

     return postcode;

   }

   /* set the telephone number

   */

   public void setTel(String a) {

     tel = a;

   }

   /* get the telephone number

   */

   public String getTel() {

     return tel;

   }

   /* set the town

   */

   public void setTown(String a) {

     town = a;

   }

   /* get the town

   */

   public String getTown() {

     return town;

   }

   /* set the county

   */

   public void setCounty(String a) {

     county = a;

   }

   /* get the county

   */

   public String getCounty() {

     return county;

   }

   /* set the country

   */

   public void setCountry(String a) {

     country = a;

   }

   /* get the country

   */

   public String getCountry() {

     return country;

   }

   /* set the delivery message

   */

   public void setMessage(String a) {

     message = a;

   }

   /* get the delivery message

   */

   public String getMessage() {

     return message;

   }

   /* format a number in the locale currency

   */

   public String displayCurrency(double value) {

     return new String(NumberFormat.getCurrencyInstance(getLocale()).format(value));

   }

   /* format a number in the locale currency

   */

   public String displayCurrency(Double value) {

     return displayCurrency(value.doubleValue());

   }

   public String baseURL() {

     String result = "";

     if (JammyJoesUtil.telesales(melati)) {

       result = "/telesales/";

     } else {

       result = "/jammyjoes/";

     }

     result += "Trolley/" + melati.getPoemContext().getLogicalDatabase() + "/";

     return result;

   }

   public String viewURL() {

     return baseURL() + "View/";

   }

   public String detailsURL() {

     return baseURL() + "Details/";

   }

   public String confirmURL() {

     return baseURL() + "Confirm/";

   }

   public String abandonURL() {

     return baseURL() + "Abandon/";

   }

   public String updateURL() {

     return baseURL() + "Update/";

   }

   public String paidURL() {

     return baseURL() + "Paid/";

   }

   public String catalogueURL() {

     return baseURL() + "CatalogueEntry/";

   }

   public static double roundTo2dp(double num) {

     int a = Math.round(new Float(num * 100).floatValue());

     double b = new Double(a).doubleValue();

     return (b/100);

   }

 }