package com.zxyj.service;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.zxyj.entity.GuideInviteCode;
import com.zxyj.mapper.GuideInviteCodeMapper;
import org.springframework.stereotype.Service;

import java.util.Date;
import java.util.UUID;

/**
 * 指导师邀请码服务
 */
@Service
public class GuideInviteCodeService extends ServiceImpl<GuideInviteCodeMapper, GuideInviteCode> {

    /**
     * 生成邀请码
     */
    public GuideInviteCode generateInviteCode(Long guideId, Integer maxUseCount, Integer expireDays) {
        GuideInviteCode inviteCode = new GuideInviteCode();
        inviteCode.setGuideId(guideId);
        inviteCode.setCode(generateCode());
        inviteCode.setStatus("active");
        inviteCode.setUseCount(0);
        inviteCode.setMaxUseCount(maxUseCount != null ? maxUseCount : 1);
        
        if (expireDays != null && expireDays > 0) {
            Date expireAt = new Date();
            expireAt.setTime(expireAt.getTime() + expireDays * 24 * 60 * 60 * 1000L);
            inviteCode.setExpireAt(expireAt);
        }
        
        this.save(inviteCode);
        return inviteCode;
    }

    /**
     * 验证邀请码
     */
    public GuideInviteCode validateInviteCode(String code) {
        LambdaQueryWrapper<GuideInviteCode> wrapper = new LambdaQueryWrapper<>();
        wrapper.eq(GuideInviteCode::getCode, code)
               .eq(GuideInviteCode::getStatus, "active");
        
        GuideInviteCode inviteCode = this.getOne(wrapper);
        
        if (inviteCode == null) {
            return null;
        }
        
        // 检查是否过期
        if (inviteCode.getExpireAt() != null && inviteCode.getExpireAt().before(new Date())) {
            inviteCode.setStatus("expired");
            this.updateById(inviteCode);
            return null;
        }
        
        // 检查使用次数
        if (inviteCode.getUseCount() >= inviteCode.getMaxUseCount()) {
            inviteCode.setStatus("used");
            this.updateById(inviteCode);
            return null;
        }
        
        return inviteCode;
    }

    /**
     * 使用邀请码
     */
    public boolean useInviteCode(String code, Long userId) {
        GuideInviteCode inviteCode = validateInviteCode(code);
        
        if (inviteCode == null) {
            return false;
        }
        
        inviteCode.setUsedByUserId(userId);
        inviteCode.setUsedAt(new Date());
        inviteCode.setUseCount(inviteCode.getUseCount() + 1);
        
        // 如果达到最大使用次数，标记为已使用
        if (inviteCode.getUseCount() >= inviteCode.getMaxUseCount()) {
            inviteCode.setStatus("used");
        }
        
        return this.updateById(inviteCode);
    }

    /**
     * 获取指导师的邀请码列表
     */
    public java.util.List<GuideInviteCode> getGuideInviteCodes(Long guideId) {
        LambdaQueryWrapper<GuideInviteCode> wrapper = new LambdaQueryWrapper<>();
        wrapper.eq(GuideInviteCode::getGuideId, guideId)
               .orderByDesc(GuideInviteCode::getCreatedAt);
        
        return this.list(wrapper);
    }

    /**
     * 生成随机邀请码
     */
    private String generateCode() {
        return UUID.randomUUID().toString().replace("-", "").substring(0, 8).toUpperCase();
    }
}