package org.eclipse.jst.jsf.facelet.core.internal.tagmodel;

import java.io.Serializable;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

import org.eclipse.jst.jsf.common.runtime.internal.view.model.common.ITagElement;
import org.eclipse.jst.jsf.designtime.internal.view.model.jsp.ITagResolvingStrategy;
import org.eclipse.jst.jsf.facelet.core.internal.registry.IFaceletTagResolvingStrategy.TLDWrapper;
import org.eclipse.jst.jsf.facelet.core.internal.registry.taglib.IFaceletTagRecord;
import org.eclipse.jst.jsf.facelet.core.internal.registry.taglib.faceletTaglib.FaceletTaglibTag;

/**
 * A description about a facelet tag library descriptor (facelet-taglib_1_0.dtd)
 * 
 * @author cbateman
 * 
 */
public class FaceletNamespace extends
        org.eclipse.jst.jsf.common.runtime.internal.view.model.common.Namespace
{
    /**
     * 
     */
    private static final long          serialVersionUID = 2133853120220947741L;
    /**
     * The namespace that this tag library is associated with
     */
    private final FaceletNamespaceData _data;

    /**
     * @param record
     * @param resolver
     */
    public FaceletNamespace(final IFaceletTagRecord record,
            final ITagResolvingStrategy<TLDWrapper, String> resolver)
    {
        _data = new TaglibFaceletNamespaceData(record, resolver);
    }

    @Override
    public String getDisplayName()
    {
        return _data.getDisplayName();
    }

    @Override
    public String getNSUri()
    {
        return _data.getUri();
    }

    @Override
    public Collection<? extends ITagElement> getViewElements()
    {
        return _data.getAllViewElements().values();
    }

    @Override
    public String toString()
    {
        return "Namespace: " + getNSUri() + "\n"; //$NON-NLS-1$ //$NON-NLS-2$
    }

    @Override
    public ITagElement getViewElement(final String name)
    {
        return _data.getViewElement(name);
    }

    @Override
    public boolean hasViewElements()
    {
        return _data.getNumTags() > 0;
    }

    @Override
    public boolean isInitialized()
    {
        return _data.isInitialized();
    }

    /**
     * Namespace data driven off a record.
     * 
     */
    private static class TaglibFaceletNamespaceData extends
            FaceletNamespaceData
    {
        /**
         * 
         */
        private static final long                                         serialVersionUID = -562720162853425804L;
        private transient final IFaceletTagRecord                         _record;
        private transient final ITagResolvingStrategy<TLDWrapper, String> _resolver;
        private final Map<String, ITagElement>                            _tags;

        public TaglibFaceletNamespaceData(final IFaceletTagRecord record,
                final ITagResolvingStrategy<TLDWrapper, String> resolver)
        {
            _record = record;
            _tags = new HashMap<String, ITagElement>();
            _resolver = resolver;
        }

        @Override
        public synchronized Map<String, ITagElement> getAllViewElements()
        {
            if (!isInitialized())
            {
                for (final FaceletTaglibTag tagDefn : _record.getTags())
                {
                    getViewElement(tagDefn.getTagName());
                }
            }
            return _tags;
        }

        @Override
        public synchronized ITagElement getViewElement(final String name)
        {
            final FaceletTaglibTag tagDefn = _record.getTag(name);
            if (tagDefn != null)
            {
                return getAndInitIfMissing(tagDefn);
            }
            return null;
        }

        private ITagElement getAndInitIfMissing(final FaceletTaglibTag tagDefn)
        {
            ITagElement tagElement = _tags.get(tagDefn.getTagName());
            if (tagElement == null)
            {
                tagElement = _resolver
                        .resolve(new TLDWrapper(tagDefn, getUri()));
                _tags.put(tagDefn.getTagName(), tagElement);
            }
            return tagElement;
        }

        @Override
        public synchronized boolean isInitialized()
        {
            return _tags.size() == _record.getNumTags();
        }

        @Override
        public String getDisplayName()
        {
            return _record.getURI();
        }

        @Override
        public int getNumTags()
        {
            return _record.getNumTags();
        }

        @Override
        public String getUri()
        {
            return _record.getURI();
        }
    }

    /**
     * Encapsulates all the data for a TLDNamespace. Allows the model to be
     * separated from the Namespace interface for ease of serialization and
     * controlled subclassing.
     * 
     */
    public abstract static class FaceletNamespaceData implements Serializable
    {
        /**
         * 
         */
        private static final long serialVersionUID = 1697605990460247389L;

        /**
         * @return the displayb
         */
        public abstract String getDisplayName();

        /**
         * @return the number of tags
         */
        public abstract int getNumTags();

        /**
         * @return the namespace uri
         */
        public abstract String getUri();

        /**
         * @param name
         * @return the view element for name or null if not found.
         */
        public abstract ITagElement getViewElement(final String name);

        /**
         * May be long running since it will lazily calculate all unloaded tags.
         * 
         * @return all view elements for this namespace
         */
        public abstract Map<String, ITagElement> getAllViewElements();

        /**
         * @return true if all elements have been lazily loaded
         */
        public abstract boolean isInitialized();
    }
}