/*
 * Copyright 2014 Eediom Inc.
 * 
 * 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 org.araqne.logdb.query.parser;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.StringTokenizer;

import org.araqne.logdb.AbstractQueryCommandParser;
import org.araqne.logdb.QueryCommand;
import org.araqne.logdb.QueryContext;
import org.araqne.logdb.QueryErrorMessage;
import org.araqne.logdb.QueryParseException;
import org.araqne.logdb.query.command.ToJson;

public class ToJsonParser extends AbstractQueryCommandParser {

	public ToJsonParser() {
		setDescriptions("Convert specified fields to json string.", "주어진 필드 값들을 json 포맷의 텍스트로 변환합니다.");
		setOptions("output", OPTIONAL, "Specify output field name. Default value is '_json'",
				"json 포맷으로 변환한 결과물이 저장될 필드를 지정합니다. 지정하지 않을 경우 _json 필드에 저장합니다.");
	}

	@Override
	public String getCommandName() {
		return "tojson";
	}

	@Override
	public Map<String, QueryErrorMessage> getErrorMessages() {
		Map<String, QueryErrorMessage> m = new HashMap<String, QueryErrorMessage>();
		m.put("22300", new QueryErrorMessage("missing-field", "필드가 없습니다."));
		return m;
	}

	@Override
	public QueryCommand parse(QueryContext context, String commandString) {
		if (commandString.trim().endsWith(","))
			// throw new QueryParseException("missing-field",
			// commandString.length());
			throw new QueryParseException("22300", getCommandName().length() + 1, commandString.length() - 1, null);

		ParseResult r = QueryTokenizer.parseOptions(context, commandString, getCommandName().length(), Arrays.asList("output"),
				getFunctionRegistry());
		@SuppressWarnings("unchecked")
		Map<String, String> options = (Map<String, String>) r.value;

		String output = options.get("output");
		if (output == null)
			output = "_json";

		QueryTokens tokens = QueryTokenizer.tokenize(commandString.substring(r.next));

		List<String> fields = new ArrayList<String>();

		List<QueryToken> queryFields = tokens.subtokens(0, tokens.size());
		for (QueryToken token : queryFields) {
			if (!token.token.contains(",")) {
				fields.add(token.token.trim());
				continue;
			}

			StringTokenizer tok = new StringTokenizer(token.token, ",");
			while (tok.hasMoreTokens())
				fields.add(tok.nextToken().trim());
		}

		return new ToJson(fields, output);
	}

}