// This Source Code is in the Public Domain per: http://litesoft.org/License.txt
package org.litesoft.sql;

import org.litesoft.commonfoundation.typeutils.*;
import org.litesoft.orsup.base.*;
import org.litesoft.orsup.nonpublic.*;
import org.litesoft.orsup.selection.*;
import org.litesoft.orsup.selection.nonpublic.*;

public class SQL_OR_Helper extends SQLHelper
{
    public interface PersistingAccessorSCDprocessor
    {
        /**
         * @return true if anything Added
         */
        boolean process( StringBuilder pSB, String pPrefix, AttributeAccessorSCD pSCD );
    }

    private static PersistingAccessorSCDprocessor BUILD_ALL_SELECT_COLUMNS = new PersistingAccessorSCDprocessor()
    {
        @Override
        public boolean process( StringBuilder pSB, String pPrefix, AttributeAccessorSCD pSCD )
        {
            pSB.append( pPrefix ).append( pSCD.getColumnName() );
            return true;
        }
    };

    private static PersistingAccessorSCDprocessor BUILD_ALL_TABLE_COLUMNS = new PersistingAccessorSCDprocessor()
    {
        @Override
        public boolean process( StringBuilder pSB, String pPrefix, AttributeAccessorSCD pSCD )
        {
            pSB.append( pPrefix ).append( pSCD.getColumnName() );

            if ( pSCD.hasSearchColumn() )
            {
                pSB.append( ", " ).append( pSCD.getSearchColumnName() );
            }
            return true;
        }
    };

    protected static String processPersistingAccessorSCDs( StringBuilder pSB, String pInitialPrefix, MetaDataForPO pMetaDataForPO, PersistingAccessorSCDprocessor pProcessor )
    {
        String zPrefix = pInitialPrefix;
        for ( AttributeAccessorSCD zSCD : pMetaDataForPO.getPersistingAccessorSCDs() )
        {
            if ( pProcessor.process( pSB, zPrefix, zSCD ) )
            {
                zPrefix = ", ";
            }
        }
        return pSB.toString();
    }

    protected static String buildAllColumns( MetaDataForPO pMetaDataForPO, PersistingAccessorSCDprocessor pProcessor )
    {
        return processPersistingAccessorSCDs( new StringBuilder(), "", pMetaDataForPO, pProcessor );
    }

    protected static String buildAllSelectColumns( MetaDataForPO pMetaDataForPO )
    {
        return buildAllColumns( pMetaDataForPO, BUILD_ALL_SELECT_COLUMNS );
    }

    protected static String buildAllTableColumns( MetaDataForPO pMetaDataForPO )
    {
        return buildAllColumns( pMetaDataForPO, BUILD_ALL_TABLE_COLUMNS );
    }

    protected static String buildQuery( boolean pIncludingImmortalInactives, //
                                        MetaDataForPO pMetaDataForPO,//
                                        WhereClause pSelectionWhereClause, OrderBy pOrderBy )
    {
        return buildQuery( pIncludingImmortalInactives, pMetaDataForPO, buildAllSelectColumns( pMetaDataForPO ), pSelectionWhereClause, pOrderBy );
    }

    protected static String buildQuery( boolean pIncludingImmortalInactives, //
                                        MetaDataForPO pMetaDataForPO,//
                                        String pColumns, WhereClause pSelectionWhereClause, OrderBy pOrderBy )
    {
        return "SELECT " + pColumns + //
               " FROM " + pMetaDataForPO.getTableName() + //
               " " + toSQL( pIncludingImmortalInactives, pMetaDataForPO, pSelectionWhereClause ) + //
               " " + toSQL( pMetaDataForPO, pOrderBy );
    }

    protected static String toSQL( boolean pIncludingImmortalInactives, //
                                   MetaDataForPO pMetaDataForPO, //
                                   WhereClause pSelectionWhereClause )
    {
        if ( pIncludingImmortalInactives )
        {
            return toSQL( pSelectionWhereClause );
        }
        WhereClause wc = ExcludeImmortalInactives.augment( pMetaDataForPO, pSelectionWhereClause );
        return (wc != null) ? wc.toSQL( ExcludeImmortalInactives.INSTANCE ) : ALL_WHERECLAUSE;
    }

    protected static String toSQL( WhereClause pSelectionWhereClause )
    {
        return (pSelectionWhereClause != null) ? pSelectionWhereClause.toSQL() : ALL_WHERECLAUSE;
    }

    protected static String toSQL( MetaDataForPO pMetaDataForPO, OrderBy pOrderBy )
    {
        if ( pOrderBy != null )
        {
            return pOrderBy.toSQL();
        }
        String orderby = Strings.noEmpty( pMetaDataForPO.getDefaultOrderByAttributeName() );
        if ( orderby != null )
        {
            return BuilderMetaDataAwareOrderBy.create( pMetaDataForPO, orderby ).toSQL();
        }
        return "";
    }

    private static class ExcludeImmortalInactives implements WCtoSqlHelper
    {
        public static final ExcludeImmortalInactives INSTANCE = new ExcludeImmortalInactives();

        public static WhereClause augment( MetaDataForPO pMetaDataForPO, WhereClause pWhereClause )
        {
            if ( !pMetaDataForPO.isPotentiallyImmortallyInActive() )
            {
                return pWhereClause;
            }
            WhereClauseFactory f = WhereClauseFactory.INSTANCE;
            String inactiveAttributeName = pMetaDataForPO.getImmortalInactiveAttributeName();
            AttributeAccessorSCD scd = pMetaDataForPO.getAccessorSCDrequired( inactiveAttributeName );
            WhereClause wcAugmentation = f.not( f.isEqual( scd, Boolean.TRUE ) );
            return (pWhereClause == null) ? wcAugmentation : f.and( wcAugmentation, pWhereClause );
        }

        @Override
        public boolean preRender( WhereClause pWC, StringBuilder pSB )
        {
            return false;
        }

        @Override
        public void postRender( WhereClause pWC, StringBuilder pSB )
        {
        }

        @Override
        public boolean preRender( SingleColumnSelect pSCS, StringBuilder pSB )
        {
            SimpleFromIdentifier from = pSCS.getFromIdentifier();
            if ( from instanceof MetaDataForPO )
            {
                pSCS.LLtoSqlHelper( this, pSB, augment( (MetaDataForPO) from, pSCS.getWhereClause() ) );
                return true;
            }
            return false;
        }

        @Override
        public void postRender( SingleColumnSelect pSCS, StringBuilder pSB )
        {
        }
    }
}