package org.geotools.filter;


import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;

import org.geotools.Builder;
import org.geotools.factory.CommonFactoryFinder;
import org.opengis.filter.Filter;
import org.opengis.filter.FilterFactory;
import org.opengis.filter.Id;
import org.opengis.filter.identity.Identifier;

/**
 * FitlerBuilder acting as a simple wrapper around an Expression.
 *
 *
 * @source $URL$
 */
public class IdBuilder<P> implements Builder<Id> {
    protected Filter filter; // placeholder just to keep us going right now
    protected FilterFactory ff = CommonFactoryFinder.getFilterFactory2(null);
    protected P parent;
    
    protected boolean unset = false;    
    private List<Identifier> ids = new ArrayList<Identifier>();
    
    public IdBuilder(){
        reset();    
    }
    
    public IdBuilder( P parent){
        this.parent = parent;
        reset();
    }
    
    
    /**
     * Build the expression.
     */
    public Id build() {
        if( unset ) {
            return null;
        }
        return ff.id( new HashSet<Identifier>(ids));
    }

    public IdBuilder<P> fid( String fid ){
        ids.add( ff.featureId(fid));
        return this;
    }
    
    public IdBuilder<P> featureId( String fid ){
        ids.add( ff.featureId(fid));
        return this;
    }
    
    public IdBuilder<P> fid( List<String> fids ){
        for( String fid : fids ){
            ids.add( ff.featureId(fid));            
        }
        return this;
    }
    
    public P end(){
        return parent;
    }
    public IdBuilder<P> reset() {
        this.filter = org.opengis.filter.Filter.EXCLUDE;
        this.unset = false;
        return this;
    }
    
    public IdBuilder<P> reset(Id filter) {
        if( filter == null ){
            return unset();
        }
        this.ids.clear();
        this.ids.addAll( filter.getIdentifiers() );
        this.unset = false;
        return this;
    }

    public IdBuilder<P> unset() {        
        this.unset = true;
        this.ids.clear();
        return this;
    }

}