/*
    * $Source: /usr/cvsroot/MelatiShopping/src/main/java/org/paneris/melati/shopping/ShoppingTrolley.java,v $
    * $Revision: 1.25 $
    *
    * 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 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/~timj/
   *     68 Sandbanks Rd, Poole, Dorset. BH14 8BY. UK
   */
  
  package org.paneris.melati.shopping;
  
  import java.util.Hashtable;
  import java.util.Vector;
  import java.util.Enumeration;
  import org.melati.Melati;
  import org.melati.servlet.Form;
  import org.melati.template.ServletTemplateContext;
  import javax.servlet.http.HttpSession;
  import java.text.NumberFormat;
  import java.util.Locale;
  import org.melati.util.InstantiationPropertyException;
  
   /**
   * <p> A Shopping Trolley stores 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
   * always to get the Shopping Trolley using getInstance();</p>
   * <p>
   * Usage example:
   * </p><p>
   * ShoppingTrolley trolley = ShoppingTrolley.getInstance(Melati melati);
   * context.put("trolley", trolley);
   * </p>
   **/
  
  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 static final double VAT_PERCENT_TIMES_TEN = 175.0;
    public MelatiShoppingConfig config;
    public Melati melati;
  
   /**
    * Private Constructor to build an empty ShoppingTrolley
    **/
    protected void initialise(Melati melatiIn, MelatiShoppingConfig configIn) {
      this.config = configIn;
     this.melati = melatiIn;
   }
 
   /**
    * Public Constructor to build a trolley from some id.
    */
   public void initialise(Melati melatiIn, 
                          MelatiShoppingConfig configIn, Integer id)
    throws InstantiationPropertyException {
     initialise(melatiIn,configIn);
     load(id);
     HttpSession session = melati.getSession();
     session.setAttribute(name(),this);
   }
 
   /**
    * Remove any trolley from the session.
    */
   public void remove(Melati melatiIn) {
     HttpSession session = melatiIn.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 = newTrolley(config);
       instance.initialise(melati,config);
       session.setAttribute(name(),instance);
     }
     instance.configureRequest(melati);
     return instance;
   }
 
   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 melatiIn);
 
  /**
   * 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 melatiIn) {
     this.melati = melatiIn;
   }
 
   /**
    *  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 abstract void assertLogin(Melati melatiIn);
 
   /**
    * 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 melatiIn);
 
 
  /**
   * 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);
   }
 
  /**
   * Create an item and put it in the Trolley.
   * 
   * @param id
   * @param description
   * @param price
   * @return a newly created item in the Trolley
   * @throws InstantiationPropertyException
   */
   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 (new Double(roundTo2dp(getTotalValue() * 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 delivery 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 therefore 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() * 
                         (-1 * (1.0 - (1000.0/VAT_PERCENT_TIMES_TEN)))));
     } else {
       return 0;
     }
   }
 
  /**
   * Format the vat value for display.
   */
   public String getVATDisplay() {
     return displayCurrency(getVATValue());
   }
 
  /**
   * Set values from form fileds. 
   * @param melati
   */
   public void setFromForm(Melati melati) {
     ServletTemplateContext tc = melati.getServletTemplateContext();
     setName(Form.getFormNulled(tc,"trolley_name"));
     setEmail(Form.getFormNulled(tc,"trolley_email"));
     setTel(Form.getFormNulled(tc,"trolley_tel"));
     setDeliveryAddress(Form.getFormNulled(tc,"trolley_deliveryaddress"));
     setTown(Form.getFormNulled(tc,"trolley_town"));
     setCounty(Form.getFormNulled(tc,"trolley_county"));
     setCountry(Form.getFormNulled(tc,"trolley_country"));
     setPostcode(Form.getFormNulled(tc,"trolley_postcode"));
     setMessage(Form.getFormNulled(tc,"trolley_message"));
     hasDetails = true;
   }
 
  /**
   * 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() {
     return melati.getRequest().getServletPath() + "/" +
            melati.getPoemContext().getLogicalDatabase() + "/";
   }
 
   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 static double roundTo2dp(double num) {
     int a = Math.round(new Float(num * 100).floatValue());
     double b = new Double(a).doubleValue();
     return (b/100);
   }
 
 }