package wox.serial;

import java.lang.reflect.*;
import org.litesoft.core.typeutils.Objects;
import java.util.*;

/**
 * Version: 1.0
 * Author: Carlos R. Jaimez Gonzalez
 * Author: Simon M. Lucas
 * Site: http://woxserializer.sourceforge.net/
 *
 * Version: 1.5
 * Author: Steven M Lewis
 *
 * Version: 2.0
 * Author: George Smith
 * SVN: http://svn.xp-dev.com/svn/WOX2/
 * Note: XML form for vs 2 is more compact and therefor incompatible with vs 1
 */

public class ArrayHandler extends AbstractHandler implements WoxIsAHandler
{
    public static final String WOX_TYPE = "array";

    public static final ArrayHandler INSTANCE = new ArrayHandler();

    protected ArrayHandler()
    {
    }

    @Override
    public String[] getForReadObjectWoxTypeNames()
    {
        return new String[]{WOX_TYPE}; // Because we only support one type
    }

    @Override
    public String getWoxTypeFor( WoxHandlers pWoxHandlers, Class pType, Field pField, boolean pJustType )
    {
        return WOX_TYPE; // Because we only support one type
    }

    @Override
    public boolean willReadObjectForWoxType( String pWoxType )
    {
        return Util.areEqual( WOX_TYPE, pWoxType );
    }

    public boolean isFor( Class pType )
    {
        return pType.isArray();
    }

    @Override
    public Class getNativeTypeFor( WoxHandlers pWoxHandlers, String pWoxType )
    {
        throw new ApplicationException( "Array Handler does not support GetNativeTypeFor for any type, including: " + pWoxType );
    }

    @Override
    public Object readObject( WoxHandlers pWoxHandlers, WoxReader pWoxReader, XMLreader pReader )
    {
        XMLreader zSubtree = pReader.createSubtreeReader();
        zSubtree.readStartElement(); //position the cursor to our element

        try
        {
            String zWoxArrayType = pReader.getAttribute( Serial.ELEMENT_TYPE );

            WoxHandler zHandler = pWoxHandlers.getWoxFieldHandler( zWoxArrayType );
            if ( zHandler != null && zHandler.willFieldValueNeverHaveAnySpaces() )
            {
                Class zFieldElementType = zHandler.getNativeTypeFor( pWoxHandlers, zWoxArrayType );
                // get element's value as String. e.g. "67 87 98 87"
                String zValuesAsString = pReader.readElementText().trim();
                String[] zValues = (zValuesAsString.length() != 0) //
                                   ? splitOnSpaces( zValuesAsString ) //
                                   : EMPTY_STRING_ARRAY;
                return zHandler.createArrayFor( zFieldElementType, zValues );
            }
            Class zComponentType = commonNativeType( pWoxHandlers, zWoxArrayType );
            if ( zComponentType == null )
            {
                throw new ApplicationException( "No Native Type for Wox Type: " + zWoxArrayType );
            }
            ArrayList zList = readObjects( pWoxReader, zSubtree );
            Object zArray = Array.newInstance( zComponentType, zList.size() );
            for ( int i = 0; i < zList.size(); i++ )
            {
                Array.set( zArray, i, zList.get( i ) );
            }
            return zArray;
        }
        catch ( Exception e )
        {
            throw new ApplicationException( "ArrayList Exception is: " + e.getMessage(), e );
        }
        finally
        {
            consume( zSubtree );
        }
    }

    @Override
    public void writeObject( WoxHandlers pWoxHandlers, WoxWriter pWoxWriter, Object pObject, Field pField, XMLwriter pWriter, boolean pJustType )
    {
        pWriter.writeStartElement( Serial.OBJECT );
        pWriter.writeAttributeString( Serial.TYPE, WOX_TYPE );

        Class zElementType = pObject.getClass().getComponentType();
        WoxHandler zHandler = pWoxHandlers.getNativeHandler( zElementType );
        if ( zHandler.willFieldValueNeverHaveAnySpaces() )
        {
            //These arrays can go easily to a String with spaces separating their elements.
            writeInLineArray( pWoxHandlers, zHandler, zElementType, pObject, pWriter );
        }
        else
        {
            String zElementWoxType = commonWoxType( pWoxHandlers, zElementType, pField, pJustType );

            pWriter.writeAttributeString( Serial.ELEMENT_TYPE, zElementWoxType );

            int zLength = Array.getLength( pObject );
            if ( zLength > 0 )
            {
                pWriter.writeAttributeString( Serial.ID, pWoxWriter.createIDfor( pObject ) );

                for ( int i = 0; i < zLength; i++ )
                {
                    pWoxWriter.write( Array.get( pObject, i ), pField, pWriter, pJustType );
                }
            }
        }
        pWriter.writeEndElement();
    }


    private static void writeInLineArray( WoxHandlers pWoxHandlers, WoxHandler pHandler, Class pElementType, Object pObject, XMLwriter pWriter )
    {
        pWriter.writeAttributeString( Serial.ELEMENT_TYPE, pHandler.getWoxTypeFor( pWoxHandlers, pElementType, null, false ) );

        int zLength = Array.getLength( pObject );

        if ( zLength != 0 )
        {
            StringBuilder sb = new StringBuilder();

            sb.append( pHandler.createFieldValue( Array.get( pObject, 0 ) ) );

            for ( int i = 1; i < zLength; i++ )
            {
                sb.append( ' ' ).append( pHandler.createFieldValue( Array.get( pObject, i ) ) );
            }

            pWriter.writeElementText( sb.toString() );
        }
    }

    private static String[] splitOnSpaces( String pValues )
    {
        List<String> zValues = new ArrayList<String>();
        int zFrom = 0;
        for ( int zAt; -1 != (zAt = pValues.indexOf( ' ', zFrom )); zFrom = zAt + 1 )
        {
            zValues.add( pValues.substring( zFrom, zAt ) );
        }
        zValues.add( pValues.substring( zFrom ) );
        return zValues.toArray( new String[zValues.size()] );
    }
}