package org.litesoft.GWT.client.pavsupport;

import java.util.*;

import org.litesoft.GWT.client.pavsupport.internal.*;
import org.litesoft.GWT.client.util.*;
import org.litesoft.core.typeutils.*;
import org.litesoft.core.util.*;
import org.litesoft.logger.*;

import com.google.gwt.place.shared.*;

/**
 * Supporting class that implements PlaceHistoryMapper which expects PlaceTokenizer(s) and Place(s) that implement HasPlaceId,
 * otherwise Class Name magic is used (See PlaceIdExtractor).
 */
public class PlaceRegistry implements PlaceHistoryMapper
{
    private static final Logger LOGGER = LoggerFactory.getLogger( PlaceRegistry.class );

    private static final PlaceTokenizerMap PLACE_TOKENIZER_MAP = new PlaceTokenizerMap();
    private static IdTokenizer<Place> sDefaultTokenizer;
    private static Place sDefaultPlace;

    public static void add( PlaceTokenizer<? extends Place>... pTokenizers )
    {
        if ( pTokenizers != null )
        {
            for ( PlaceTokenizer<? extends Place> zTokenizer : pTokenizers )
            {
                if ( zTokenizer != null )
                {
                    PLACE_TOKENIZER_MAP.addTokenizer( zTokenizer );
                }
            }
        }
    }

    public static void setDefaultTokenizer( PlaceTokenizer<? extends Place> pDefaultTokenizer )
    {
        if ( pDefaultTokenizer != null )
        {
            PlaceTokenizer<Place> zTokenizer = UtilsCommon.cast( pDefaultTokenizer );
            if ( null != (sDefaultTokenizer = ProxyIdTokenizer.forceToIdTokenizer( PLACE_TOKENIZER_MAP.addTokenizer( zTokenizer ), zTokenizer )) )
            {
                sDefaultPlace = sDefaultTokenizer.getPlace( null );
            }
        }
    }

    public static Place getDefaultPlace()
    {
        return sDefaultPlace;
    }

    private MessageUserSinkAccessor mMessageUserSinkAccessor;

    public PlaceRegistry( MessageUserSinkAccessor pMessageUserSinkAccessor )
    {
        mMessageUserSinkAccessor = (pMessageUserSinkAccessor != null) ? pMessageUserSinkAccessor : DefaultMessageUserSink.FACTORY;
    }

    /**
     * Convert the full Token (URL Fragment) to a Place
     *
     * @param pToken the full URL Fragment
     *
     * @return a Place, generated by one of the Registered Tokenizers, or the Default if not found, or NULL if no Default!
     */
    @Override
    public Place getPlace( String pToken )
    {
        PlaceIdAndData zIdAndData = PlaceIdAndData.fromString( pToken );
        if ( zIdAndData != null )
        {
            String zPlaceId = zIdAndData.getPlaceId();
            PlaceTokenizer<? extends Place> zTokenizer = PLACE_TOKENIZER_MAP.getTokenizer( zPlaceId );
            if ( zTokenizer == null )
            {
                mMessageUserSinkAccessor.getMessageUserSink().setErrorMessage( "Unable to determine 'view' from: " + zPlaceId );
            }
            else
            {
                Place zPlace;

                try
                {
                    if ( null != (zPlace = zTokenizer.getPlace( zIdAndData.getData() )) )
                    {
                        return zPlace;
                    }
                }
                catch ( RuntimeException e )
                {
                    String zMessage = "Unable to create 'view' from: ";
                    LOGGER.warn.log( e, zMessage, pToken );
                    mMessageUserSinkAccessor.getMessageUserSink().setErrorMessage( zMessage + zPlaceId );
                    return sDefaultPlace;
                }
                if ( zPlace == null )
                {
                    String zMessage = "No 'view' from: ";
                    LOGGER.warn.log( zMessage, pToken );
                    mMessageUserSinkAccessor.getMessageUserSink().setErrorMessage( zMessage + zPlaceId );
                }
            }
        }
        return sDefaultPlace;
    }

    /**
     * Convert a Place into the full Token (URL Fragment)
     *
     * @param pPlace place to convert (null ok)
     *
     * @return the full URL Fragment (null if Place was null & there was NO Default Tokenizer)
     */
    @Override
    public String getToken( Place pPlace )
    {
        if ( pPlace == null )
        {
            return null;
        }
        String zPlaceId = PlaceIdExtractor.getPlaceId( pPlace );
        if ( zPlaceId == null )
        {
            mMessageUserSinkAccessor.getMessageUserSink().setErrorMessage( "Unable to determine 'view' from class: " + pPlace.getClass().getName() );
            return null;
        }
        PlaceTokenizer<Place> zTokenizer = PLACE_TOKENIZER_MAP.getTokenizer( zPlaceId );
        if ( zTokenizer == null )
        {
            String zMessage = "No 'view' for '" + zPlaceId + "'";
            LOGGER.error.log( zMessage, ": ", pPlace.getClass().getName() );
            mMessageUserSinkAccessor.getMessageUserSink().setErrorMessage( zMessage );
            if ( null == sDefaultTokenizer )
            {
                return null;
            }
            zTokenizer = sDefaultTokenizer;
            pPlace = sDefaultPlace;
            zPlaceId = sDefaultTokenizer.getPlaceId();
        }
        String zToken = null;
        try
        {
            zToken = zTokenizer.getToken( pPlace );
        }
        catch ( RuntimeException e )
        {
            LOGGER.error.log( e, "Unable to 'tokenize' Place: ", pPlace.getClass(), " with PlaceId '", zPlaceId, "'" );
        }
        return new PlaceIdAndData( zPlaceId, zToken ).toString();
    }

    private static class ProxyIdTokenizer<T extends Place> extends IdTokenizer<T>
    {
        private PlaceTokenizer<T> mTokenizer;

        protected ProxyIdTokenizer( Object pPlaceId, PlaceTokenizer<T> pTokenizer )
        {
            super( pPlaceId );
            mTokenizer = pTokenizer;
        }

        @Override
        public T getPlace( String pToken )
        {
            return mTokenizer.getPlace( pToken );
        }

        @Override
        public String getToken( T pPlace )
        {
            return mTokenizer.getToken( pPlace );
        }

        public static <T extends Place> IdTokenizer<T> forceToIdTokenizer( String pPlaceId, PlaceTokenizer<T> pTokenizer )
        {
            return (pTokenizer instanceof IdTokenizer) ? (IdTokenizer<T>) pTokenizer : new ProxyIdTokenizer<T>( pPlaceId, pTokenizer );
        }
    }

    private static class PlaceTokenizerMap
    {
        private final Map<String, PlaceTokenizer<Place>> mPlaceIdToTokenizers = new HashMap<String, PlaceTokenizer<Place>>();

        /**
         * @param pTokenizer !null
         *
         * @return PlaceId
         */
        public String addTokenizer( PlaceTokenizer<? extends Place> pTokenizer )
        {
            PlaceTokenizer<Place> zTokenizer = UtilsCommon.cast( pTokenizer );
            String zPlaceId = PlaceIdExtractor.getPlaceId( zTokenizer );
            if ( null == zPlaceId )
            {
                throw new IllegalStateException( "Unable to determine PlaceId from Tokenizer: " + pTokenizer.getClass().getName() );
            }
            PlaceTokenizer<Place> zPreviousTokenizer = mPlaceIdToTokenizers.put( zPlaceId, zTokenizer );
            if ( (zPreviousTokenizer != null) && (zPreviousTokenizer != zTokenizer) )
            {
                throw new IllegalStateException( "Duplicate registration for PlaceId '':" + //
                                                 "\n   " + zPreviousTokenizer.getClass().getName() + //
                                                 "\n   " + pTokenizer.getClass().getName() );
            }
            return zPlaceId;
        }

        public PlaceTokenizer<Place> getTokenizer( String pPlaceId )
        {
            return mPlaceIdToTokenizers.get( pPlaceId );
        }
    }

    private static class PlaceIdAndData
    {
        private String mPlaceId, mData;

        public PlaceIdAndData( String pPlaceId, String pData )
        {
            mPlaceId = Strings.assertNotNullNotEmpty( "PlaceID", pPlaceId );
            mData = Strings.noEmpty( pData );
        }

        public String getPlaceId()
        {
            return mPlaceId;
        }

        public String getData()
        {
            return mData;
        }

        @Override
        public String toString()
        {
            return (mData == null) ? mPlaceId : mPlaceId + ':' + mData;
        }

        public static PlaceIdAndData fromString( String pURLfragment )
        {
            if ( pURLfragment != null )
            {
                if ( (pURLfragment = pURLfragment.trim()).length() != 0 )
                {
                    int at = pURLfragment.indexOf( ':' );
                    if ( at == 0 )
                    {
                        LOGGER.error.log( "Invalid URLfragment: '", pURLfragment, "'" );
                    }
                    else
                    {
                        String zData = null;
                        String zPlaceID = pURLfragment;
                        if ( at != -1 )
                        {
                            zPlaceID = pURLfragment.substring( 0, at ).trim();
                            zData = pURLfragment.substring( at + 1 );
                        }
                        return new PlaceIdAndData( zPlaceID, zData );
                    }
                }
            }
            return null;
        }
    }
}