/*
  Copyright (C) 2006-2008 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.List;
import java.util.Map;

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.WORequest;
import org.opengroupware.jope.appserver.core.WOResponse;

/**
 * WOPopUpButton
 * <p>
 * Create HTML form single-selection popups.
 * <p>
 * Sample:<pre>
 * Country: WOPopUpButton {
 *   name      = "country";
 *   list      = ( "UK", "US", "Germany" );
 *   item      = item;
 *   selection = selectedCountry;
 * }</pre>
 * Renders:<pre>
 *   &lt;select name="country"&gt;
 *     &lt;option value="UK"&gt;UK&lt;/option&gt;
 *     &lt;option value="US" selected&gt;US&lt;/option&gt;
 *     &lt;option value="Germany"&gt;Germany&lt;/option&gt;
 *     [sub-template]
 *   &lt;/select&gt;</pre>
 * 
 * Bindings (WOInput):<pre>
 *   id       [in] - string
 *   name     [in]  - string
 *   value    [io]  - object
 *   disabled [in]  - boolean
 * </pre>
 * Bindings:<pre>
 *   list              [in]  - List
 *   item              [out] - object
 *   selection         [out] - object
 *   string            [in]  - String
 *   noSelectionString [in]  - String
 *   selectedValue     [out] - String
 *   escapeHTML        [in]  - boolean
 *   itemGroup
 * </pre>
 */
public class WOPopUpButton extends WOInput {
  
  public static final String WONoSelectionString = "WONoSelectionString";
  
  protected WOAssociation list;
  protected WOAssociation item;
  protected WOAssociation selection;
  protected WOAssociation string;
  protected WOAssociation noSelectionString;
  protected WOAssociation selectedValue;
  protected WOAssociation escapeHTML;
  protected WOAssociation itemGroup;
  protected WOElement     template;

  public WOPopUpButton
    (String _name, Map<String, WOAssociation> _assocs, WOElement _template)
  {
    super(_name, _assocs, _template);
    
    this.list              = grabAssociation(_assocs, "list");
    this.item              = grabAssociation(_assocs, "item");
    this.selection         = grabAssociation(_assocs, "selection");
    this.string            = grabAssociation(_assocs, "string");
    this.noSelectionString = grabAssociation(_assocs, "noSelectionString");
    this.selectedValue     = grabAssociation(_assocs, "selectedValue");
    this.escapeHTML        = grabAssociation(_assocs, "escapeHTML");
    this.itemGroup         = grabAssociation(_assocs, "itemGroup");
    
    if (this.list == null)
      log.warn("missing 'list' binding in WOPopUpButton");
    
    this.template = _template;
  }
  
  /* responder */

  @Override
  public void takeValuesFromRequest(final WORequest _rq, final WOContext _ctx) {
    final Object cursor = _ctx.cursor();
    if (this.disabled != null) {
      if (this.disabled.booleanValueInComponent(cursor))
        return;
    }
    
    final boolean isDebugOn = log.isDebugEnabled();
    final String formName  = this.elementNameInContext(_ctx);
    final String formValue = _rq.stringFormValueForKey(formName);
    if (formValue == null) {
      /* nothing changed, or not in submitted form */
      if (isDebugOn) log.debug("found no form value!");

      /* We need to return here and NOT reset the selection. This is because the
       * page might have been invoked w/o a form POST! If we do not, this
       * resets the selection.
       * 
       * TODO: check whether HTML forms MUST submit an empty form value for
       *       popups.
       */
      return;
    }
    
    final boolean isNoSelection = formValue.equals(WONoSelectionString);
    
    List   objects = null;
    Object object  = null;
    if (this.list != null)
      objects = WOListWalker.listForValue(this.list.valueInComponent(cursor));
    
    if (this.value != null) {
      /* has a 'value' binding, walk list to find object */
      
      for (int i = 0, toGo = objects.size(); i < toGo; i++) {
        Object lItem = objects.get(i);
        Object cv;
        
        if (this.item != null && this.item.isValueSettableInComponent(cursor))
          this.item.setValue(lItem, cursor);
        
        cv = this.value.stringValueInComponent(cursor);
        if (formValue.equals(cv)) {
          object = lItem;
          break; /* found it, 'object' locvar is filled */
        }
      }
    }
    else if (formValue != null && !isNoSelection) {
      /* an index binding? */

      if (isDebugOn) log.debug("lookup using index: " + formValue);
      
      if (formValue == null) {
        log.error("popup " + formName + ": no form value?");
      }
      else {
        int idx = Integer.parseInt(formValue);
        if (idx < 0 || idx >= objects.size()) {
          log.error("popup " + formName + " index out of range: " + idx);
          object = null;
        }
        else
          object = objects.get(idx);
      }
    }
    else {
      if (isDebugOn) {
        log.debug("no form value, value binding or selection: " + 
                       formValue);
      }
    }
    
    /* push selected value */
    
    if (this.selectedValue != null && 
        this.selectedValue.isValueSettableInComponent(cursor)) {
      this.selectedValue.setValue((isNoSelection ? null : formValue), cursor);
    }
    
    /* process selection */
    
    if (this.selection != null && 
        this.selection.isValueSettableInComponent(cursor)) {
      if (isDebugOn) log.debug("pushing popup selection: " + object);
      this.selection.setValue(object, cursor);
    }
    
    /* reset item to avoid dangling references */
    
    if (this.item != null && this.item.isValueSettableInComponent(cursor))
      this.item.setValue(null, cursor);
  }
  
  
  /* generate response */
  
  public void appendOptionsToResponse(WOResponse _r, WOContext _ctx) {
    Object  cursor          = _ctx.cursor();
    boolean escapesHTML     = true;
    boolean hasSettableItem;
    String  previousGroup   = null;
    
    if (this.escapeHTML != null)
      escapesHTML = this.escapeHTML.booleanValueInComponent(cursor);
    
    hasSettableItem = (this.item != null)
      ? this.item.isValueSettableInComponent(cursor) : false;
    
    /* determine selected object */
    
    boolean byVal = false; /* true if the 'selectedValue' binding is used */
    Object  sel   = null;
    
    if (this.selection == null) {
      if (this.selectedValue != null) {
        byVal = true;
        sel   = this.selectedValue.valueInComponent(cursor);
      }
    }
    else if (this.selectedValue != null) {
      byVal = true;
      sel   = this.selectedValue.valueInComponent(cursor);
      log.warn("both, 'selection' and 'selectedValue' bindings active.");
    }
    else
      sel = this.selection.valueInComponent(cursor);
    
    /* process noSelectionString option */
    
    String nilStr = null;
    if (this.noSelectionString != null)
      nilStr = this.noSelectionString.stringValueInComponent(cursor);
    
    if (nilStr != null) {
      if (this.itemGroup != null) {
        String group;
        
        if (hasSettableItem)
          this.item.setValue(null, cursor);
        
        group = this.itemGroup.stringValueInComponent(cursor);
        
        if (group != null) {
          _r.appendBeginTag("optgroup");
          _r.appendContentString(" label=\"");
          if (escapesHTML)
            _r.appendContentHTMLString(group);
          else
            _r.appendContentString(group);
          _r.appendContentCharacter('"');
          _r.appendBeginTagEnd();
          
          previousGroup = group;
        }
      }
      
      _r.appendBeginTag("option");
      _r.appendAttribute("value", WONoSelectionString);
      _r.appendBeginTagEnd();
      
      if (escapesHTML)
        _r.appendContentHTMLString(nilStr);
      else
        _r.appendContentString(nilStr);
      _r.appendEndTag("option");
      // FIXME (stephane) Shouldn't we set the 'selected' if
      //                  selArray/selValueArray is empty?
    }
    
    /* loop over options */
    
    boolean foundSelection = false;
    int toGo = 0;
    if (this.list != null) {
      // TBD: should we process this using the list
      List array =
        WOListWalker.listForValue(this.list.valueInComponent(cursor));
      if (array != null) toGo = array.size();
      
      for (int i = 0; i < toGo; i++) {
        Object object = array.get(i);
        
        if (hasSettableItem)
          this.item.setValue(object, cursor);
        
        /* determine value (DUP below) */
        
        Object v;
        String vs;
        if (this.value != null) {
          v  = this.value.valueInComponent(cursor);
          vs = v != null ? v.toString() : null;
        }
        else {
          vs = "" + i; /* adds the repetition index as the value! */
          v  = vs;
        }
        
        /* determine selection (compare against value or item) */
        
        boolean isSelected;
        if (sel == (byVal ? v : object)) // Note: also matches null==null
          isSelected = true;
        else if (sel == null || (byVal ? v : object) == null)
          isSelected = false;
        else
          isSelected = sel.equals(byVal ? v : object);
        
        /* display string */
        
        String displayV = null;
        if (this.string != null)
          displayV = this.string.stringValueInComponent(cursor);
        else if (object != null)
          displayV = object.toString();
        else
          displayV = "<null>"; /* <> will get escaped below */
        
        /* grouping */
        
        String group = null;
        if (this.itemGroup != null)
          group = this.itemGroup.stringValueInComponent(cursor);
        
        if (group != null) {
          boolean groupChanged = false;
          
          if (previousGroup == null)
            groupChanged = true;
          else if (!group.equals(previousGroup)) {
            _r.appendEndTag("optgroup");
            groupChanged = true;
          }
          if (groupChanged) {
            _r.appendBeginTag("optgroup");
            _r.appendContentString(" label=\"");
            if (escapesHTML)
              _r.appendContentHTMLString(group);
            else
              _r.appendContentString(group);
            _r.appendContentCharacter('"');
            _r.appendBeginTagEnd();
            
            previousGroup = group;
          }
        }
        else if (previousGroup != null) {
          _r.appendEndTag("optgroup");
          previousGroup = null;
        }
        
        /* option tag */
        
        _r.appendBeginTag("option");
        _r.appendAttribute("value", vs);
        if (isSelected) {
          foundSelection = true;
          _r.appendAttribute("selected",
              _ctx.generateEmptyAttributes() ? null : "selected");
        }
        _r.appendBeginTagEnd();
        
        if (escapesHTML)
          _r.appendContentHTMLString(displayV);
        else
          _r.appendContentString(displayV);
        
        _r.appendEndTag("option");
      }
    }
    
    /* close optgroups */
    
    if (previousGroup != null)
      _r.appendEndTag("optgroup");
    
    /* process selections which where missing in the list */
    
    if (!foundSelection && sel != null) {
      // TBD
      String vs;
      Object object = null;
      
      if (byVal) {
        /* Note: 'selection' might be available! (comparison by value has a
         * higher priority.
         */
        if (hasSettableItem) {
          if (this.selection != null) {
            object = this.selection.valueInComponent(cursor);
            this.item.setValue(object, cursor);
          }
        }
        
        vs = sel.toString(); /* the value is what we detected */
      }
      else {
        /* This means the 'selection' binding was set, but not the
         * 'selectedValue' one. 'sel' will point to the item.
         */
        object = sel;
        if (hasSettableItem)
          this.item.setValue(object, cursor);
        
        /* determine value (DUP above) */
        
        Object v;
        if (this.value != null) {
          v  = this.value.valueInComponent(cursor);
          vs = v != null ? v.toString() : null;
        }
        else {
          vs = "" + toGo; /* repetition index as the value! */
          v  = vs;
        }
      }
      
      /* display string */
      
      String displayV = null;
      if (this.string != null)
        displayV = this.string.stringValueInComponent(cursor);
      else if (object != null)
        displayV = object.toString();
      else if (vs != null) /* just the value */
        displayV = vs;
      else
        displayV = "<null>"; /* <> will get escaped below */

      /* option tag */
      
      _r.appendBeginTag("option");
      _r.appendAttribute("value", vs);
      _r.appendAttribute("selected",
          _ctx.generateEmptyAttributes() ? null : "selected");
      _r.appendBeginTagEnd();
      
      if (escapesHTML)
        _r.appendContentHTMLString(displayV);
      else
        _r.appendContentString(displayV);
      
      _r.appendEndTag("option");
    }
    
    /* reset item */
    
    if (hasSettableItem)
      this.item.setValue(null /* reset */, cursor);
  }
  
  @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();

    /* start tag */
    
    _r.appendBeginTag("select");
    
    String lid = this.eid!=null ? this.eid.stringValueInComponent(cursor):null;
    if (lid != null) _r.appendAttribute("id", lid);

    _r.appendAttribute("name", this.elementNameInContext(_ctx));
    
    if (this.disabled != null) {
      if (this.disabled.booleanValueInComponent(cursor)) {
        _r.appendAttribute("disabled",
            _ctx.generateEmptyAttributes() ? null : "disabled");
      }
    }
    
    if (this.coreAttributes != null)
      this.coreAttributes.appendToResponse(_r, _ctx);
    this.appendExtraAttributesToResponse(_r, _ctx);
    // TODO: otherTagString
    
    _r.appendBeginTagEnd();
    
    /* content */
    
    this.appendOptionsToResponse(_r, _ctx);
    
    if (this.template != null)
      this.template.appendToResponse(_r, _ctx);
    
    /* close tag */
    
    _r.appendEndTag("select");
  }
  
  /* description */
  
  @Override
  public void appendAttributesToDescription(StringBuilder _d) {
    super.appendAttributesToDescription(_d);
    
    this.appendAssocToDescription(_d, "list", this.list);
    this.appendAssocToDescription(_d, "item", this.item);
  }  
}