/*
    * Copyright 1999-2004 The Apache Software Foundation.
    * Modifications, Copyright 2005 Stephen Colebourne
    * 
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    * 
    *      http://www.apache.org/licenses/LICENSE-2.0
   * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */ 
  package org.joda.time.contrib.jsptag;
  
  import java.io.IOException;
  import java.text.DateFormat;
  import java.util.Locale;
  
  import javax.servlet.jsp.JspException;
  import javax.servlet.jsp.JspTagException;
  import javax.servlet.jsp.PageContext;
  import javax.servlet.jsp.tagext.TagSupport;
  
  import org.joda.time.DateTimeZone;
  import org.joda.time.ReadableInstant;
  import org.joda.time.ReadablePartial;
  import org.joda.time.format.DateTimeFormat;
  import org.joda.time.format.DateTimeFormatter;
  
  /**
   * Support for tag handlers for <formatDate>, the date and time
   * formatting tag in JSTL 1.0.
   *
   * @author Jan Luehe
   * @author Jim Newsham
   */
  public abstract class FormatSupport extends TagSupport {
  
      /** The value attribute. */
      protected Object value;
      /** The pattern attribute. */
      protected String pattern;
      /** The style attribute. */
      protected String style;
      /** The dateTimeZone attribute. */
      protected DateTimeZone dateTimeZone;
      /** The locale attribute. */
      protected Locale locale;
      /** The var attribute. */
      private String var;
      /** The scope attribute. */
      private int scope;
  
      /**
       * Constructor.
       */
      public FormatSupport() {
          super();
          init();
      }
  
      private void init() {
          var = null;
          value = null;
          pattern = null;
          style = null;
          dateTimeZone = null;
          locale = null;
          scope = PageContext.PAGE_SCOPE;
      }
  
      public void setVar(String var) {
          this.var = var;
      }
  
      public void setScope(String scope) {
          this.scope = Util.getScope(scope);
      }
  
      /*
       * Formats the given instant or partial.
       */
      public int doEndTag() throws JspException {
          if (value == null) {
              if (var != null) {
                  pageContext.removeAttribute(var, scope);
              }
              return EVAL_PAGE;
          }
  
          // Create formatter
          DateTimeFormatter formatter;
          if (pattern != null) {
              formatter = DateTimeFormat.forPattern(pattern);
          } else if (style != null) {
             formatter = DateTimeFormat.forStyle(style);
         } else {
             // use a medium date (no time) style by default; same as jstl
             formatter = DateTimeFormat.mediumDate();
         }
 
         // set formatter locale
         Locale locale = this.locale;
         if (locale == null) {
             locale = Util.getFormattingLocale(pageContext, this, true,
                     DateFormat.getAvailableLocales());
         }
         if (locale != null) {
             formatter = formatter.withLocale(locale);
         }
 
         // set formatter timezone
         DateTimeZone tz = this.dateTimeZone;
         if (tz == null) {
             tz = DateTimeZoneSupport.getDateTimeZone(pageContext, this);
         }
         if (tz != null) {
             formatter = formatter.withZone(tz);
         }
 
         // format value
         String formatted;
         if (value instanceof ReadableInstant) {
             formatted = formatter.print((ReadableInstant) value);
         } else if (value instanceof ReadablePartial) {
             formatted = formatter.print((ReadablePartial) value);
         } else {
             throw new JspException(
                 "value attribute of format tag must be a ReadableInstant or ReadablePartial," +
                 " was: " + value.getClass().getName()); 
         }
 
         if (var != null) {
             pageContext.setAttribute(var, formatted, scope);
         } else {
             try {
                 pageContext.getOut().print(formatted);
             } catch (IOException ioe) {
                 throw new JspTagException(ioe.toString(), ioe);
             }
         }
 
         return EVAL_PAGE;
     }
 
     // Releases any resources we may have (or inherit)
     public void release() {
         init();
     }
 
 }