KeywordFilterGenerator.java

/**
 * Copyright (c) Codice Foundation
 * <p/>
 * This is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser
 * General Public License as published by the Free Software Foundation, either version 3 of the
 * License, or any later version.
 * <p/>
 * 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
 * Lesser General Public License for more details. A copy of the GNU Lesser General Public License
 * is distributed along with this program and can be found at
 * <http://www.gnu.org/licenses/lgpl.html>.
 */
package org.codice.ddf.endpoints;

import org.opengis.filter.Filter;

import ddf.catalog.data.Metacard;
import ddf.catalog.filter.FilterBuilder;

public class KeywordFilterGenerator {
    // TODO refactor this from helper class
    private final FilterBuilder filterBuilder;

    public KeywordFilterGenerator(FilterBuilder filterBuilder) {
        this.filterBuilder = filterBuilder;
    }

    public Filter getFilterFromASTNode(ASTNode astNode, String xpathSelector)
            throws IllegalStateException {
        if (astNode == null) {
            throw new IllegalStateException("Unable to generate Filter from null ASTNode.");
        }

        if (filterBuilder == null) {
            throw new IllegalStateException("Unable to generate Filter using null FilterBuilder.");
        }

        if (astNode.isKeyword()) {
            if (xpathSelector != null && !xpathSelector.isEmpty()) {
                return filterBuilder.xpath(xpathSelector).is().like().text(astNode.getKeyword());
            } else {
                return filterBuilder.attribute(Metacard.ANY_TEXT).is().like()
                        .text(astNode.getKeyword());
            }
        }

        // it's an operator
        if (astNode.isOperator()) {
            switch (astNode.getOperator()) {
            case AND:
                return filterBuilder.allOf(getFilterFromASTNode(astNode.left()),
                        getFilterFromASTNode(astNode.right()));
            case OR:
                return filterBuilder.anyOf(getFilterFromASTNode(astNode.left()),
                        getFilterFromASTNode(astNode.right()));
            case NOT: // since NOT really means AND NOT
                return filterBuilder.allOf(getFilterFromASTNode(astNode.left()),
                        filterBuilder.not(getFilterFromASTNode(astNode.right())));
            default:
                throw new IllegalStateException(
                        "Unable to generate Filter from invalid OperatorASTNode.");
            }
        }

        throw new IllegalStateException(
                "Unable to generate Filter from ASTNode. Found invalid ASTNode in the tree!");
    }

    public Filter getFilterFromASTNode(ASTNode astNode) throws IllegalStateException {
        return getFilterFromASTNode(astNode, null);
    }
}