/*
 * Copyright 2013 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.log.api;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.felix.ipojo.annotations.Component;
import org.apache.felix.ipojo.annotations.Provides;

@Component(name = "regex-parser-factory")
@Provides
public class RegexParserFactory implements LogParserFactory {

	@Override
	public String getName() {
		return "regex";
	}

	@Override
	public Collection<Locale> getDisplayNameLocales() {
		return Arrays.asList(Locale.ENGLISH, Locale.KOREAN, Locale.JAPANESE, Locale.CHINESE);
	}

	@Override
	public String getDisplayName(Locale locale) {
		if (locale != null && locale.equals(Locale.KOREAN))
			return "정규표현식";
		if (locale != null && locale.equals(Locale.JAPANESE))
			return "正規表現";
		if (locale != null && locale.equals(Locale.CHINESE))
			return "正则表达式";
		return "Regular Expression";
	}

	@Override
	public Collection<Locale> getDescriptionLocales() {
		return Arrays.asList(Locale.ENGLISH, Locale.KOREAN, Locale.JAPANESE, Locale.CHINESE);
	}

	@Override
	public String getDescription(Locale locale) {
		if (locale != null && locale.equals(Locale.KOREAN))
			return "정규표현식을 이용하여 로그를 파싱합니다.";
		if (locale != null && locale.equals(Locale.JAPANESE))
			return "正規表現を使ってログを解析します。";
		if (locale != null && locale.equals(Locale.CHINESE))
			return "利用正则表达式解析日志。";
		return "Parse logs using regular expression.";
	}

	@Override
	public Collection<LoggerConfigOption> getConfigOptions() {
		List<LoggerConfigOption> options = new ArrayList<LoggerConfigOption>();
		options.add(new StringConfigType("regex", t("regex", "정규표현식", "正規表現", "正则表达式"), t("regular expression with placeholder",
				"필드 이름이 포함된 정규표현식", "フィールド名を含めている正規表現", "包含字段名称的正则表达式"), true));
		options.add(new StringConfigType("field", t("field", "대상 필드", "対象フィールド", "目标字段"), t(
				"parse target field. 'line' field by default", "정규표현식을 적용할 필드, 미설정 시 기본값은 line", "正規表現を適用するフィールド。未設定の場合はline",
				"要应用正则表达式的字段, 默认值为line。"), false));
		options.add(new StringConfigType("include_original_field", t("include original field", "원본 필드 포함", "元フィールド込み", "包含原始字段"),
				t("return also original field (true or false)", "정규표현식으로 파싱된 결과 외에 원본 필드 값도 포함할지 설정합니다. true 혹은 false",
						"正規表現の結果と元のフィールドも含むか設定します。trueかfalse", "设置除通过正则表达式解析的结果之外，是否包含原始字段值。True或者false。"), false));
		return options;
	}

	private Map<Locale, String> t(String enText, String koText, String jpText, String cnText) {
		Map<Locale, String> m = new HashMap<Locale, String>();
		m.put(Locale.ENGLISH, enText);
		m.put(Locale.KOREAN, koText);
		m.put(Locale.JAPANESE, jpText);
		m.put(Locale.CHINESE, cnText);
		return m;
	}

	@Override
	public LogParser createParser(Map<String, String> config) {
		String field = config.get("field");
		List<String> names = new ArrayList<String>();

		Pattern placeholder = Pattern.compile("\\(\\?<(.*?)>");
		String regexToken = config.get("regex");

		regexToken = toNonCapturingGroup(regexToken);

		Matcher matcher = placeholder.matcher(regexToken);
		while (matcher.find())
			names.add(matcher.group(1));

		while (true) {
			matcher = placeholder.matcher(regexToken);
			if (!matcher.find())
				break;

			// suppress special meaning of $ and \
			String quoted = Matcher.quoteReplacement("(");
			regexToken = matcher.replaceFirst(quoted);
		}

		boolean includeOriginalField = false;
		String s = config.get("include_original_field");
		if (s != null)
			includeOriginalField = Boolean.parseBoolean(s);

		Pattern p = Pattern.compile(regexToken);
		return new RegexParser(field, p, names.toArray(new String[0]), includeOriginalField);
	}

	private String toNonCapturingGroup(String s) {
		StringBuilder sb = new StringBuilder();

		char last2 = ' ';
		char last = ' ';
		for (int i = 0; i < s.length(); i++) {
			char c = s.charAt(i);
			if (last2 != '\\' && last == '(' && c != '?')
				sb.append("?:");
			sb.append(c);
			last2 = last;
			last = c;
		}

		return sb.toString();
	}

}