package com.solution.rule.handler;


import cn.hutool.core.collection.CollUtil;
import com.solution.common.constant.ExceptionConstants;
import com.solution.rule.domain.RuleParam;
import org.springframework.stereotype.Component;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.util.List;

/**
 * 封装规则处理链
 */
@Component
public class RuleChainHandler {

    @Resource
    private List<AbstractRuleChainHandler> chainHandlers;

    private AbstractRuleChainHandler firstHandler;

    /**
     * 组装处理链
     */
    @PostConstruct
    private void constructChain(){
        if (CollUtil.isEmpty(chainHandlers)) {
            throw new RuntimeException(ExceptionConstants.NOT_FOUND_CARRIAGE_CHAIN_HANDLER);
        }
        this.firstHandler = chainHandlers.get(0);
        for (int i = 0; i < chainHandlers.size(); i++) {
            if(i == (chainHandlers.size() - 1)){
                chainHandlers.get(i).setNextHandler(null);
            }else {
                chainHandlers.get(i).setNextHandler(chainHandlers.get(i + 1));
            }
        }

    }

    public RuleParam findRuleParam(RuleParam ruleParam){
        return firstHandler.doHandler(ruleParam);
    }

}