package com.qxueyou.scc.exercise.service.impl.parser;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.commons.lang3.StringUtils;

import com.qxueyou.scc.exercise.service.impl.Node;
import com.qxueyou.scc.exercise.service.impl.ParseResult;
import com.qxueyou.scc.exercise.service.impl.Parser;
import com.qxueyou.scc.exercise.service.impl.node.Item;

public class ItemAnswerParser extends Parser {
	
	/**
	 * 参考答案[带括号]
	 */
	private static final String answerWithBracketsStr = "\\([ABCDEFGHIJKLMNOabcdefghijklmno√╳×TFtf]+\\)";
	
	/**
	 * 参考答案
	 */
	private static final String answerStr = "[ABCDEFGHIJKLMNOabcdefghijklmno√╳×TFtf]+";
	
	/**
	 * 参考答案模式[带括号]
	 */
	private static final Pattern answerWithBrackets = Pattern.compile(answerWithBracketsStr);
	
	/**
	 * 参考答案模式
	 */
	private static final Pattern answer = Pattern.compile(answerStr);

	@Override
	public ParseResult parse(Node node, String str) {
		return parseAnswer((Item)node,str);
	}
	
	/**
	 * 解析 Item 参考答案
	 * 1.解析出类似  *** ( ab ) 这样的参考答案
	 * 2.将类似参考答案 ( ab ) 替换成 ( )
	 * @param item
	 * @param str
	 * @return
	 */
	private ParseResult parseAnswer(Item item, String str) {
		
		//习题选项
		Matcher answerBracketsMatch = answerWithBrackets.matcher(str);
		
		//返回
		if(!answerBracketsMatch.find() || answerBracketsMatch.start()==0){
			return new ParseResult(false,ParseResult.STEP_CUR,null);
		}
		
		Matcher answerMatch = null;
		
		answerBracketsMatch.reset();
		if(answerBracketsMatch.find()){
			
			String answerBrackets = answerBracketsMatch.group();
			answerMatch = answer.matcher(answerBrackets);
			answerMatch.find();
			
			String answer = answerMatch.group();
			
			item.setAnswer(dealAnswer(answer.toUpperCase()));
			item.setTitle(item.getTitle().replaceAll(answerWithBracketsStr, "( )"));
		}
		
		//20150907修改：本来返回true，没有解析到一个类型，抛到上层
		return new ParseResult(false,ParseResult.STEP_PRE,null);
		
	}
	
	/**
	 * 处理answer
	 * @param answer
	 * @return
	 */
	private String dealAnswer(String answer){
		if(StringUtils.equalsIgnoreCase("√",answer)||StringUtils.equalsIgnoreCase("√",answer)||StringUtils.equalsIgnoreCase("T",answer)){
			return "True";
		}
		if(StringUtils.equalsIgnoreCase("×",answer)||StringUtils.equalsIgnoreCase("╳",answer)||StringUtils.equalsIgnoreCase("F",answer)){
			return "False";
		}
		return answer;
	}
}