package org.trails.finder;

 import java.util.Map;

 import ognl.Ognl;

 import ognl.OgnlException;

 import org.apache.tapestry.IRequestCycle;

 import org.apache.tapestry.components.Block;

 import org.apache.tapestry.util.ComponentAddress;

 import org.trails.page.IEditorBlockPage;

 import org.trails.descriptor.IPropertyDescriptor;

 public class BaseBlockFinder implements BlockFinder

 {

         private Map<String, ComponentAddress> editorMap;

         private ComponentAddress defaultEditor;

         public Map<String, ComponentAddress> getEditorMap()

         {

                 return editorMap;

         }

         /**

          * This a map where the keys are ognl expressions and the values are component address.

          *

          * @param editorMap

          */

         public void setEditorMap(Map<String, ComponentAddress> editorMap)

         {

                 this.editorMap = editorMap;

         }

         /**

          * @param descriptor

          * @return The first component address in the editorMap whose key evaluates to true for descriptor. This will be used

          *         to load an editor for the descriptor. Returns default editor if no match is found.

          * @see BlockFinder#findBlockAddress(org.trails.descriptor.IPropertyDescriptor)

          */

         public ComponentAddress findBlockAddress(IPropertyDescriptor descriptor)

         {

                 ComponentAddress componentAddress = findBlockAddress(editorMap, descriptor);

                 return componentAddress != null ? componentAddress : getDefaultBlockAddress();

         }

         protected ComponentAddress findBlockAddress(Map<String, ComponentAddress> map, IPropertyDescriptor descriptor)

         {

                 for (Map.Entry<String, ComponentAddress> entry : map.entrySet())

                 {

                         try

                         {

                                 if ((Boolean) Ognl.getValue(entry.getKey(), descriptor))

                                 {

                                         return entry.getValue();

                                 }

                         } catch (OgnlException e)

                         {

                         }

                 }

                 return null;

         }

         public Block findBlock(IRequestCycle cycle, IPropertyDescriptor descriptor)

         {

                 if (cycle.getPage().getComponents().containsKey(descriptor.getName()))

                 {

                         Block block = (Block) cycle.getPage().getComponent(descriptor.getName());

                         return block;

                 } else

                 {

                         // since it came from a block container page, we need to set

                         // the model and descriptor on the container page so its visible to the

                         // block

                         ComponentAddress blockAddress = findBlockAddress(descriptor);

                         Block block = (Block) blockAddress.findComponent(cycle);

                         ((IEditorBlockPage) block.getPage()).setDescriptor(descriptor);

                         return block;

                 }

         }

         public ComponentAddress getDefaultBlockAddress()

         {

                 return defaultEditor;

         }

         public void setDefaultBlockAddress(ComponentAddress defaultEditor)

         {

                 this.defaultEditor = defaultEditor;

         }

 }