/*
 * Copyright 2005 by Oracle USA
 * 500 Oracle Parkway, Redwood Shores, California, 94065, U.S.A.
 * All rights reserved.
 */
package javax.ide.wizard.spi;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.logging.Level;
import java.util.Map;

import javax.ide.extension.ElementContext;
import javax.ide.extension.ElementEndContext;
import javax.ide.extension.ElementName;
import javax.ide.extension.ElementStartContext;
import javax.ide.extension.ElementVisitor;
import javax.ide.extension.ExtensionHook;
import javax.ide.extension.I18NStringVisitor;
import javax.ide.extension.IconVisitor;
import javax.ide.extension.spi.ExtensionVisitor;
import javax.ide.util.IconDescription;
import javax.ide.util.MetaClass;

/**
 * Wizard information gathered from processing the <b>wizard-hook</b>
 * section of an extension deployment descriptor. The information recorded 
 * here describes a new wizard and is generally given to the 
 * {@link javax.ide.wizard.WizardManager} for registration.
 */
public final class WizardHook extends ExtensionHook
{
  public static final ElementName ELEMENT = new ElementName( MANIFEST_XMLNS, 
    "wizard-hook" );
    
  private static final ElementName WIZARDS = new ElementName( MANIFEST_XMLNS, 
    "wizards" );
  private static final ElementName WIZARD = new ElementName( MANIFEST_XMLNS, 
    "wizard" );
  private static final ElementName WIZARD_CATEGORY = new ElementName( MANIFEST_XMLNS, 
    "wizard-category" );    
  private static final ElementName LABEL = new ElementName(
    MANIFEST_XMLNS, "label" );
  private static final ElementName ICONPATH = new ElementName(
    MANIFEST_XMLNS, "iconpath" );
  private static final ElementName TOOLTIP = new ElementName(
    MANIFEST_XMLNS, "tooltip" );
    
  private static final String KEY_WIZARD_INFO = "wizardInfo";
  private static final String KEY_CATEGORY = "wizardCategory";
    
  private ElementVisitor _wizardsVisitor = new WizardsVisitor();
  private ElementVisitor _wizardVisitor = new WizardVisitor();
  private ElementVisitor _labelVisitor = new LabelVisitor();
  private ElementVisitor _iconpathVisitor = new IconPathVisitor();
  private ElementVisitor _tooltipVisitor = new ToolTipVisitor();
  private ElementVisitor _wizardCategoryVisitor = new WizardCategoryVisitor();

  private final Map _wizardsByClass = new HashMap();
  private final Map _categoriesById = new HashMap();
  // Map from WizardCategory => List<WizardCategory | WizardInfo>
  private final Map _categoryChildren = new HashMap();
  
  public WizardInfo getWizardInfo( String className )
  {
    final WizardInfo info = (WizardInfo)_wizardsByClass.get( className );
    
    if ( info == null )
    {
      throw new IllegalArgumentException( "Unknown wizard class " + className );
    }
    
    return info;
  }
  
  /**
   * Get the children of the specified category. 
   * 
   * @param category the category to get children of. This may be 
   *    WizardCategory.NONE to get root items.
   * @return a collection of either WizardCategory or WizardInfo instances.
   */
  public Collection getChildren( WizardCategory category )
  {
    if ( category == null )
    {
      throw new NullPointerException( "Null category" );
    }
    return Collections.unmodifiableCollection( getCategoryChildren( category ) );
  }
  
  private Collection getCategoryChildren(WizardCategory parent)
  {
    Collection children = (Collection)_categoryChildren.get( parent );
    if ( children == null )
    {
      children = new ArrayList();
      _categoryChildren.put( parent, children );
    }
    return children;
  }  
  
  public Collection /*<String>*/ getAllWizardClasses()
  {
    return Collections.unmodifiableCollection( _wizardsByClass.keySet() );
  }
  
  public void start( ElementStartContext context )
  {
    context.registerChildVisitor( WIZARDS, _wizardsVisitor );
  }
  
  private static WizardInfo getWizardInfo( ElementContext context )
  {
    return (WizardInfo) context.getScopeData().get( KEY_WIZARD_INFO );
  }
  
  private class WizardsVisitor extends ElementVisitor
  {
    public void start( ElementStartContext context )
    {
      context.registerChildVisitor( WIZARD, _wizardVisitor );
      context.registerChildVisitor( WIZARD_CATEGORY, _wizardCategoryVisitor );
    }
  }
  
  private class WizardCategoryVisitor extends ElementVisitor
  {
    public void start( ElementStartContext context )
    {
      String id = context.getAttributeValue( "id" );
      if ( id == null || (id = id.trim()).length() == 0 )
      {
        log( context, Level.SEVERE, "Missing required 'id' attribute." );
        return;
      }
      WizardCategory parent = WizardCategory.NONE;
      String parentCategory = context.getAttributeValue( "parent-category" );
      if ( parentCategory != null )
      {
        parentCategory = parentCategory.trim();
        parent = (WizardCategory)_categoriesById.get( parentCategory );
        if ( parent == null )
        {
          log( context, Level.WARNING, "Wizard category '"+parentCategory+"' not found." );
          parent = WizardCategory.NONE;
        }
      }
      
      WizardCategory cat = new WizardCategory( parent, id );
      context.getScopeData().put( KEY_CATEGORY, cat );
      
      _categoriesById.put( id, cat );
      getCategoryChildren(parent).add( cat );
  
      context.registerChildVisitor( LABEL, new I18NStringVisitor() {
        protected void string(ElementContext context, String string)
        {
          WizardCategory c = 
            (WizardCategory) context.getScopeData().get( KEY_CATEGORY );
          c.setLabel( string );
        }
      }
      );
    }


    
    public void end( ElementEndContext context )
    {
      WizardCategory c = (WizardCategory) context.getScopeData().get( KEY_CATEGORY );
      if ( c.getLabel() == null )
      {
        log( context, Level.WARNING, "Missing label element for category." );
        c.setLabel( c.getId() );
      }
    }
  }
  
  private class WizardVisitor extends ElementVisitor
  {
    public void start( ElementStartContext context )
    {
      String className = context.getAttributeValue( "wizard-class" );
      if ( className == null || (className = className.trim()).length() == 0 )
      {
        log( context, Level.SEVERE, "Missing required 'wizard-class' attribute." );
        return;
      }
      
      String parentId = context.getAttributeValue( "category-ref" );
      WizardCategory parent = WizardCategory.NONE;
      if ( parentId != null && (parentId = parentId.trim()).length() > 0 )
      {
        parent = (WizardCategory)_categoriesById.get( parentId );
        if ( parent == null )
        {
          log( context, Level.WARNING, "Unknown category id '" + parentId + "'." );
          parent = WizardCategory.NONE;
        }
      }

      
      MetaClass clazz = new MetaClass( 
        (ClassLoader) context.getScopeData().get( ExtensionVisitor.KEY_CLASSLOADER ),
        className
      );
      WizardInfo info = new WizardInfo( clazz );
      getCategoryChildren( parent ).add( info );      
      info.setCategory( parent );
      
      context.getScopeData().put( KEY_WIZARD_INFO, info );
      context.registerChildVisitor( LABEL, _labelVisitor );
      context.registerChildVisitor( ICONPATH, _iconpathVisitor );
      context.registerChildVisitor( TOOLTIP, _tooltipVisitor );
    }
    
    public void end( ElementEndContext context )
    {
      WizardInfo wi = getWizardInfo( context );
      _wizardsByClass.put( wi.getWizardClass().getClassName(), wi );
    }
  }
  
  private class LabelVisitor extends I18NStringVisitor
  {
    protected void string( ElementContext context, String value )
    {
      getWizardInfo( context ).setLabel( value );
    }
  }
  
  private class IconPathVisitor extends IconVisitor
  {
    protected void icon( ElementContext context, IconDescription icon )
    {
      getWizardInfo( context ).setIcon( icon );
    }
  }
  
  private class ToolTipVisitor extends I18NStringVisitor
  {
    protected void string( ElementContext context, String value )
    {
      getWizardInfo( context ).setToolTip( value );
    }
  }

}