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/*
 * Copyright 2018 Anton Straka
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package sk.antons.json.parse;

import java.util.ArrayList;
import java.util.List;
import sk.antons.json.literal.JsonLiteral;
import sk.antons.json.literal.impl.JsonLiteralImpl;
import sk.antons.json.match.Match;
import sk.antons.json.match.PathMatcher;
import sk.antons.json.parse.traversal.JsonContentHandler;
import sk.antons.json.parse.traversal.StopTraverse;
import sk.antons.json.parse.traversal.TraversalParser;
import sk.antons.json.source.JsonSource;

/**
 * Json parser, which finds only literal values.
 * It does not build all json data tree. Simple traverse that data tree and 
 * finds specified literal values.
 * @author antons
 */
public class LiteralParser {
    
    /**
     * First literal with mathed path.
     * @param source json source
     * @param matcher mather to identify resulted literal
     * @return first matched literal from json.
     */
    public static JsonLiteral first(JsonSource source, PathMatcher matcher) {
        Handler handler = new Handler(matcher, true);
        TraversalParser.instance(source, handler).parse();
        List literals = handler.literals();
        if(literals.isEmpty()) return null;
        return literals.get(0);
    }
    
    /**
     * All literals with mathed path.
     * @param source json source
     * @param matcher mather to identify resulted literals
     * @return all matched literals from json.
     */
    public static List all(JsonSource source, PathMatcher matcher) {
        Handler handler = new Handler(matcher, false);
        TraversalParser.instance(source, handler).parse();
        List literals = handler.literals();
        return literals;
    }
    
    /**
     * First literal with mathed path converted to string.
     * @param source json source
     * @param matcher mather to identify resulted literal
     * @return first matched literal from json converted to string.
     */
    public static String firstAsString(JsonSource source, PathMatcher matcher) {
        JsonLiteral literal = first(source, matcher);
        if(literal == null) return null;
        return literal.stringValue();
    }
    
    /**
     * All literals with mathed path converted to string.
     * @param source json source
     * @param matcher mather to identify resulted literals
     * @return all matched literals from json converted to string.
     */
    public static List allAsString(JsonSource source, PathMatcher matcher) {
        List literals = all(source, matcher);
        List values = new ArrayList();
        for(JsonLiteral literal : literals) {
            values.add(literal.stringValue());
        }
        return values;
    } 

    private static class Handler implements JsonContentHandler {
        private PathMatcher matcher = null;
        List path = new ArrayList();
        List