gvSIG data provider for Sqlite

package org.gvsig.spatialite.dal.expressionbuilderformatter;

import java.text.MessageFormat;

import java.util.List;

import org.apache.commons.lang3.StringUtils;

import static org.gvsig.expressionevaluator.ExpressionBuilder.FUNCTION_ST_ENVELOPE;

import static org.gvsig.expressionevaluator.ExpressionBuilder.FUNCTION_ST_INTERSECTS;

import org.gvsig.expressionevaluator.ExpressionBuilder.Function;

import org.gvsig.expressionevaluator.ExpressionBuilder.Value;

import org.gvsig.expressionevaluator.ExpressionBuilder.Variable;

import org.gvsig.expressionevaluator.Formatter;

import org.gvsig.fmap.dal.SQLBuilder;

import org.gvsig.fmap.dal.feature.FeatureAttributeDescriptor;

import org.gvsig.fmap.dal.feature.FeatureType;

import org.gvsig.fmap.dal.store.jdbc.JDBCStoreParameters;

import org.gvsig.fmap.dal.store.jdbc2.OperationsFactory.TableReference;

import org.gvsig.fmap.dal.store.jdbc2.spi.JDBCSQLBuilderBase;

/**

 *

 * @author jjdelcerro

 */

class ST_Intersects implements Formatter<Value> {

    private final Formatter<Value> formatter;

    private final SQLBuilder builder;

    private String column;

    private String table;

    public ST_Intersects(SQLBuilder builder, Formatter<Value> formatter) {

        this.builder = builder;

        this.formatter = formatter;

    }

    @Override

    public boolean canApply(Value value) {

        if (value instanceof Function) {

            return StringUtils.equalsIgnoreCase(FUNCTION_ST_INTERSECTS, ((Function) value).name());

        }

        return false;

    }

    @Override

    public String format(Value function) {

        String r ;

        List<Value> parameters = ((Function) function).parameters();

        Value geom1 = parameters.get(0);

        Value geom2 = parameters.get(1);

        if( this.useSpatialIndex(geom1, geom2) ) {

            r = MessageFormat.format(

                "(ST_Intersects({0},{1}) AND ROWID IN ( SELECT ROWID FROM SpatialIndex WHERE f_table_name = ''{2}'' AND f_geometry_column = ''{3}'' AND search_frame = \"{2}\".\"{3}\"))",

                    geom1.toString(this.formatter),

                    geom2.toString(this.formatter),

                    this.table,

                    this.column

            );

        } else {

            r = MessageFormat.format(

                "(ST_Intersects({0},{1}))",

                    geom1.toString(this.formatter),

                    geom2.toString(this.formatter)

            );

        }

        return r;

    }

    private boolean useSpatialIndex(Value... values) {

        for (Value value : values) {

            if( value instanceof Variable ) {

                if( useSpatialIndex((Variable)value) ) {

                    return true;

                }

            } 

            // Tambien comprobamos si el argumento es la funcion 

            // ST_Envelope sobre un campo geometria, si es asi tambien usaremos el 

            // indice espacial, cubriendo el caso de que se use algo como:

            //   ST_Intersects(x, ST_Envelope("geom"))

            if( value instanceof Function ) {

                if( ((Function) value).name().equalsIgnoreCase(FUNCTION_ST_ENVELOPE) ) {

                    Value value2 = ((Function) value).parameters().get(0);

                    if( value2 instanceof Variable ) {

                        if( useSpatialIndex((Variable)value2) ) {

                            return true;

                        }

                    } 

                }

            }

        }

        return false;

    }    

    private boolean useSpatialIndex(Variable var) {

        // Usaremos indice espacial si podemos tener acceso al nombre del 

        // campo y la tabla.

        this.column = var.name();

        TableReference theTable = (TableReference) var.getProperty(

                JDBCSQLBuilderBase.PROP_TABLE

        );

        if( theTable!=null ) {

            this.table = theTable.getTable();

        }

        FeatureType type = (FeatureType) var.getProperty(

                JDBCSQLBuilderBase.PROP_FEATURE_TYPE

        );

        if( type != null ) {

            FeatureAttributeDescriptor attrdesc = type.getAttributeDescriptor(var.name());

            if( attrdesc != null ) {

                this.column = attrdesc.getName();

            }

            if( this.table == null ) {

                try {

                    JDBCStoreParameters jdbcparams = (JDBCStoreParameters) type

                            .getStore().getParameters();

                    this.table = jdbcparams.getTable();

                } catch(Exception ex) {

                }

            }

        }

        if( this.table == null || this.column == null ) {

            this.table = null;

            this.column = null;

            return false;

        }

        return true;

    }

}