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

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

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;
import com.qxueyou.scc.exercise.service.impl.node.Option;



public class OptionParser extends Parser {
	
	/**
	 * 习题选项编号模式[带括号]
	 */
	//Pattern optNoWithBrackets = Pattern.compile("\\(?[ABCDEFabcdef]\\)?[、.．]");
	
	/**
	 * 习题选项  word自带的格式的 a.a、a)	这三种较为普遍，目前03可以解析成功，07解析失败*[\t]
	 */
	Pattern optNoWithBrackets = Pattern.compile("\\(?[ABCDEFGHIJKLMNOabcdefghijklmno]\\)?[.．、]");
	
	/**
	 * 习题选项编号模式
	 */
	Pattern optNo = Pattern.compile("[ABCDEFGHIJKLMNOabcdefghijklmno]");
	

	@Override
	public ParseResult parse(Node node, String str) {
		return parse((Option)node,str);
	}
	
	/**
	 * 解析 Item
	 * @param item
	 * @param str
	 * @return
	 */
	private ParseResult parse(Option option, String str) {
		
		//习题选项
		Matcher optNoWithBracketsMatch = optNoWithBrackets.matcher(str);
		
		//尝试调用上级解析器继续解析
		if(!matchBegin(optNoWithBracketsMatch)){
			return new ParseResult(false,ParseResult.STEP_PRE,null);
		}
		
		Matcher optNoMatch = null;
		
		int start = 0;
		Option preOpt = null;
		
		optNoWithBracketsMatch.reset();
		while(optNoWithBracketsMatch.find()){
			
			String noWithBrackets = optNoWithBracketsMatch.group();
			optNoMatch = optNo.matcher(noWithBrackets);
			optNoMatch.find();
			String no = optNoMatch.group();

			Option opt = getOpt(no.toUpperCase(),(Item)option.getParent());
			
			if(start!=optNoWithBracketsMatch.start() && preOpt!=null){
				preOpt.setContent(
						beautyContent(
								str.substring(start, optNoWithBracketsMatch.start())
								)
						);	
			}
			preOpt = opt;
			start = optNoWithBracketsMatch.end();
			
			// 在最开始匹配成功即跳出循环
			//break ;
		}
		
		preOpt.setContent(beautyContent(str.substring(start, str.length())));
		
		return new ParseResult(true,ParseResult.STEP_CUR,null);
		
	}
	
	/**
	 * 去除文本中多余字符
	 * @param content
	 * @return
	 */
	private String beautyContent(String str){
		String prefix = ".。~、、．．)";
		String content = str;
		while(content.length()>0 && prefix.contains(content.substring(0, 1))){
			content = content.substring(1);
		}
		return content;
	}
	
	/**
	 * 获取题目选项
	 * @param no
	 * @param item
	 * @return
	 */
	private Option getOpt(String no,Item item){
		Option opt = item.getOption(no);
		if(opt==null){
			
			opt = item.getOption("");
			
			if(opt==null){
				opt = new Option();
				item.addNode(opt);
				opt.setNo(no);
			}
		}
		return opt;
	}
}