Application: gvSIG desktop

/**

 * gvSIG. Desktop Geographic Information System.

 *

 * Copyright (C) 2007-2020 gvSIG Association.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 3

 * of the License, or (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,

 * MA  02110-1301, USA.

 *

 * For any additional information, do not hesitate to contact us

 * at info AT gvsig.com, or visit our website www.gvsig.com.

 */

package org.gvsig.fmap.dal.store.jdbc2.spi.expressionbuilder.formatters;

import org.gvsig.expressionevaluator.Code;

import org.gvsig.expressionevaluator.Expression;

import org.gvsig.expressionevaluator.ExpressionBuilder;

import org.gvsig.expressionevaluator.ExpressionBuilder.Value;

import org.gvsig.expressionevaluator.Formatter;

import org.gvsig.expressionevaluator.GeometryExpressionBuilder;

import org.gvsig.fmap.dal.SQLBuilder;

import static org.gvsig.fmap.dal.SQLBuilder.PROP_FEATURE_TYPE;

import static org.gvsig.fmap.dal.SQLBuilder.PROP_JDBCHELPER;

import static org.gvsig.fmap.dal.SQLBuilder.PROP_QUERY;

import org.gvsig.fmap.dal.expressionevaluator.FeatureAttributeEmulatorExpression;

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

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

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

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

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

import org.gvsig.fmap.dal.feature.spi.SQLBuilderBase;

import org.gvsig.fmap.dal.store.jdbc2.JDBCHelper;

/**

 *

 * @author jjdelcerro

 */

public class ComputedAttribute implements Formatter<Value> {

    private final SQLBuilder sqlbuilder;

    private final Formatter<Value> formatter;

    public ComputedAttribute(SQLBuilder sqlbuilder, Formatter<Value> formatter) {

        this.sqlbuilder = sqlbuilder;

        this.formatter = formatter;

    }

    @Override

    public boolean canApply(ExpressionBuilder.Value value) {

        if( value instanceof SQLBuilder.SelectColumnBuilder ) {

            return false;

        }

        FeatureAttributeDescriptor attr = this.getFeatureAttributeDescriptor(value);

        if (attr == null) {

            return false;

        }

        if (!attr.isComputed()) {

            return false;

        }

        FeatureAttributeEmulator emulator = attr.getFeatureAttributeEmulator();

        if (!(emulator instanceof FeatureAttributeEmulatorExpression)) {

            return false;

        }

//        Expression expr = ((FeatureAttributeEmulatorExpression) emulator).getExpression();

//        return jdbcHelper.supportExpression(featureType, expr.getPhrase());

        return true;

    }

    private FeatureAttributeDescriptor getFeatureAttributeDescriptor(ExpressionBuilder.Value value) {

        if (value instanceof SQLBuilderBase.Column) {

            SQLBuilder.Column column = (SQLBuilder.Column) value;

            SQLBuilder.TableNameBuilder table = column.table();

            if( table!=null ) {

                FeatureType featureType = table.featureType();

                if (featureType != null) {

                    FeatureAttributeDescriptor attr = featureType.getAttributeDescriptor(column.name());

                    if (attr != null) {

                        return attr;

                    }

                }

            }

        }

        if (value instanceof ExpressionBuilder.Variable) {

            FeatureType featureType = (FeatureType) value.getProperty(PROP_FEATURE_TYPE);

            if (featureType == null) {

                return null;

            }

            JDBCHelper jdbcHelper = (JDBCHelper) value.getProperty(PROP_JDBCHELPER);

            if (jdbcHelper == null) {

                return null;

            }

            ExpressionBuilder.Variable variable = (ExpressionBuilder.Variable) value;

            FeatureAttributeDescriptor attr = featureType.getAttributeDescriptor(variable.name());

            if (attr != null) {

                return attr;

            }

            FeatureQuery query = (FeatureQuery) value.getProperty(PROP_QUERY);

            if (query == null) {

                return null;

            }

            FeatureExtraColumns extraColumn = query.getExtraColumn();

            if (extraColumn == null) {

                return null;

            }

            attr = extraColumn.get(variable.name());

            return attr;

        }

        return null;

    }

    @Override

    public String format(Value value) {

        Value valueExpr = this.expandedValue(value);

        return "(" + this.formatter.format(valueExpr) + ")";

    }

    public Value expandedValue(Value value) {

//        ExpressionBuilder.Variable variable = (ExpressionBuilder.Variable) value;

//        FeatureType featureType = (FeatureType) value.getProperty(PROP_FEATURE_TYPE);

//        FeatureAttributeDescriptor attr = featureType.getAttributeDescriptor(variable.name());

        FeatureAttributeDescriptor attr = getFeatureAttributeDescriptor(value);

        if (attr == null) {

            return value;

        }

        SQLBuilder.TableNameBuilder table = null;

        if (value instanceof SQLBuilderBase.Column) {

            table = ((SQLBuilder.Column) value).table();

        }

        FeatureAttributeEmulator emulator = attr.getFeatureAttributeEmulator();

        Expression expr = ((FeatureAttributeEmulatorExpression) emulator).getExpression();

        Code code = expr.getCode();

        GeometryExpressionBuilder builder = this.sqlbuilder.expression();

        Value valueExpr = setTableName(table, code.toValue(builder));

        return valueExpr;

    }

    private ExpressionBuilder.Value setTableName(SQLBuilder.TableNameBuilder table, ExpressionBuilder.Value value) {

        if( table == null ) {

            return value;

        }

        value.accept(new ExpressionBuilder.Visitor() {

            @Override

            public void visit(ExpressionBuilder.Visitable value) {

                if( value instanceof SQLBuilder.Column) {

                    SQLBuilder.Column c = (SQLBuilder.Column) value;

                    SQLBuilder.TableNameBuilder t = c.table();

                    if( t==null ) {

                        c.table(table);

                        return;

                    }

                    if( t.equals(table) ) {

                        t.setFeatureType(table.featureType());

                    }

                }

            }

        }, null);

        return value;

    }

    private ExpressionBuilder.Value replaceVariablesByColumns(SQLBuilder.TableNameBuilder table, ExpressionBuilder.Value value) {

        return value;

//        if( table == null ) {

//            return value;

//        }

//        value.accept(new ExpressionBuilder.Visitor() {

//            @Override

//            public void visit(ExpressionBuilder.Visitable value) {

//                if( value instanceof ExpressionBuilder.Variable) {

//

//                }

//            }

//        }, null);

//        return value;

    }

}