/*
  Copyright (C) 2006 Helge Hess

  This file is part of JOPE.

  JOPE is free software; you can redistribute it and/or modify it under
  the terms of the GNU Lesser General Public License as published by the
  Free Software Foundation; either version 2, or (at your option) any
  later version.

  JOPE 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 Lesser General Public
  License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with JOPE; see the file COPYING.  If not, write to the
  Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  02111-1307, USA.
*/

package org.opengroupware.jope.appserver.elements;

import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.opengroupware.jope.appserver.core.WOAssociation;
import org.opengroupware.jope.appserver.core.WOContext;
import org.opengroupware.jope.appserver.core.WOElement;
import org.opengroupware.jope.appserver.core.WOElementWalker;
import org.opengroupware.jope.appserver.core.WORequest;
import org.opengroupware.jope.appserver.core.WOResponse;

/*
 * WOHyperlink
 * 
 * Sample:
 *   Link: WOHyperlink {
 *     directActionName = "postComment";
 *     actionClass      = "CommentPage";
 *     ?comment         = "blub";
 *   }
 * 
 * Renders:
 *   <a href="/servlet/app/wa/CommentPage/postComment?comment=blub">
 *     [sub-template]
 *   </a>
 * 
 * Bindings (WOLinkGenerator):
 *   href                 [in] - string
 *   action               [in] - action
 *   pageName             [in] - string
 *   directActionName     [in] - string
 *   actionClass          [in] - string
 *   fragmentIdentifier   [in] - string
 *   queryDictionary      [in] - Map<String,String>
 *   - all bindings starting with a ? are stored as query parameters.
 * 
 * Regular bindings:
 *   string               [in] - string
 *   target               [in] - string
 *   disabled             [in] - boolean
 *   disableOnMissingLink [in] - boolean
 * 
 * TODO: somehow make that a cluster similiar to SOPE
 */
public class WOHyperlink extends WOHTMLDynamicElement {
  protected static Log log = LogFactory.getLog("WOHyperlink");
  
  protected WOAssociation   string;
  protected WOAssociation   target;
  protected WOAssociation   disabled;
  protected WOAssociation   disableOnMissingLink;
  protected WOElement       template;
  protected WOLinkGenerator link;
  
  public WOHyperlink(String _name, Map<String, WOAssociation> _assocs,
                     WOElement _template)
  {
    super(_name, _assocs, _template);
    
    this.string   = grabAssociation(_assocs, "string");
    this.target   = grabAssociation(_assocs, "target");
    this.disabled = grabAssociation(_assocs, "disabled");
    
    this.disableOnMissingLink =
      grabAssociation(_assocs, "disableOnMissingLink");
    
    this.link     = WOLinkGenerator.linkGeneratorForAssociations(_assocs);
    this.template = _template;
    
    // TODO: warn on invalid bindings / missing template
  }
  
  /* responder */
  
  @Override
  public void takeValuesFromRequest(WORequest _rq, WOContext _ctx) {
    /* links can take form values !!!! (for query-parameters) */
    
    if (this.link != null)
      this.link.takeValuesFromRequest(_rq, _ctx);
    
    if (this.template != null)
      this.template.takeValuesFromRequest(_rq, _ctx);
  }
  
  @Override
  public Object invokeAction(WORequest _rq, WOContext _ctx) {
    Object cursor = _ctx.cursor();
    
    if (this.disabled != null) {
      if (this.disabled.booleanValueInComponent(cursor))
        return null;
    }
    
    if (_ctx.elementID().equals(_ctx.senderID())) {
      if (this.link != null)
        return this.link.invokeAction(_rq, _ctx);

      log.error("no action configured for link invocation");
      return null;
    }
    
    if (this.template != null)
      return this.template.invokeAction(_rq, _ctx);

    return null;
  }
  
  @Override
  public void appendToResponse(WOResponse _r, WOContext _ctx) {
    if (_ctx.isRenderingDisabled()) {
      if (this.template != null)
        this.template.appendToResponse(_r, _ctx);
      return;
    }
    
    Object cursor = _ctx.cursor();
    
    boolean doNotDisplay = false;
    if (this.disabled != null)
      doNotDisplay = this.disabled.booleanValueInComponent(cursor);
    
    /* calculate URL */
    
    String url = null;
    if (!doNotDisplay) {
      if (this.link != null)
        url = this.link.fullHrefInContext(_ctx);
    
      if (url == null && this.disableOnMissingLink != null) {
        doNotDisplay =
          this.disableOnMissingLink.booleanValueInComponent(cursor);
      }
    }
    
    /* render link start tag */
    
    if (!doNotDisplay) {
      _r.appendBeginTag("a");
      
      if (url != null) _r.appendAttribute("href", url);
      
      if (this.target != null) {
        String s = this.target.stringValueInComponent(cursor);
        _r.appendAttribute("target", s);
      }
      
      this.appendExtraAttributesToResponse(_r, _ctx);
      // TODO: otherTagString
      
      _r.appendBeginTagEnd();
    }
    
    /* render link content */
    
    if (this.template != null)
      this.template.appendToResponse(_r, _ctx);

    if (this.string != null)
      _r.appendContentHTMLString(this.string.stringValueInComponent(cursor));
    
    /* render link close tag */
    
    if (!doNotDisplay)
      _r.appendEndTag("a");
  }
  
  @Override
  public void walkTemplate(WOElementWalker _walker, WOContext _ctx) {
    if (this.template != null)
      _walker.processTemplate(this, this.template, _ctx);
  }
}