package com.tourguide.modules.user.service;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.tourguide.modules.order.domain.OrderStatus;
import com.tourguide.modules.order.entity.TourOrder;
import com.tourguide.modules.order.mapper.TourOrderMapper;
import com.tourguide.modules.user.entity.GuideAutoDisableConfig;
import com.tourguide.modules.user.entity.GuideUser;
import com.tourguide.modules.user.mapper.GuideAutoDisableConfigMapper;
import com.tourguide.modules.user.mapper.GuideRealtimeStatusMapper;
import com.tourguide.modules.user.mapper.GuideReceivingSessionMapper;
import com.tourguide.modules.user.mapper.GuideUserMapper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.math.BigDecimal;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

@Service
public class GuideAutoDisableService {
    private static final Logger log = LoggerFactory.getLogger(GuideAutoDisableService.class);
    private static final int BATCH_SIZE = 100;

    private final GuideAutoDisableConfigMapper configMapper;
    private final GuideUserMapper guideUserMapper;
    private final TourOrderMapper orderMapper;
    private final GuideRealtimeStatusMapper realtimeStatusMapper;
    private final GuideReceivingSessionMapper receivingSessionMapper;

    public GuideAutoDisableService(GuideAutoDisableConfigMapper configMapper,
                                   GuideUserMapper guideUserMapper,
                                   TourOrderMapper orderMapper,
                                   GuideRealtimeStatusMapper realtimeStatusMapper,
                                   GuideReceivingSessionMapper receivingSessionMapper) {
        this.configMapper = configMapper;
        this.guideUserMapper = guideUserMapper;
        this.orderMapper = orderMapper;
        this.realtimeStatusMapper = realtimeStatusMapper;
        this.receivingSessionMapper = receivingSessionMapper;
    }

    @Scheduled(fixedDelayString = "${tourguide.guide.auto-disable-scan-delay-millis:60000}")
    @Transactional
    public void disableEligibleGuides() {
        GuideAutoDisableConfig config = configMapper.selectById(1);
        if (!valid(config)) return;
        Long lastGuideId = null;
        do {
            List<GuideUser> candidates = selectCandidates(config, lastGuideId);
            if (candidates.isEmpty()) return;
            for (GuideUser guide : candidates) {
                disableIfEligible(guide, config);
            }
            lastGuideId = candidates.get(candidates.size() - 1).getId();
            if (candidates.size() < BATCH_SIZE) return;
        } while (true);
    }

    /** 导游移出白名单后立即复核，避免等待下一次定时扫描。 */
    @Transactional
    public void disableGuideIfEligible(Long guideId) {
        if (guideId == null) return;
        GuideAutoDisableConfig config = configMapper.selectById(1);
        if (!valid(config)) return;
        GuideUser guide = guideUserMapper.selectById(guideId);
        if (!matchesRule(guide, config)) return;
        disableIfEligible(guide, config);
    }

    private List<GuideUser> selectCandidates(GuideAutoDisableConfig config, Long lastGuideId) {
        List<GuideUser> candidates = guideUserMapper.selectList(
                new LambdaQueryWrapper<GuideUser>()
                        .eq(GuideUser::getStatus, GuideUserService.STATUS_ENABLED)
                        .and(wrapper -> wrapper.isNull(GuideUser::getAutoDisableWhitelisted)
                                .or().eq(GuideUser::getAutoDisableWhitelisted, 0))
                        .ge(GuideUser::getAcceptedOrderCount, config.getOrderThreshold())
                        .gt(GuideUser::getRating, BigDecimal.ZERO)
                        .le(GuideUser::getRating, config.getRatingThreshold())
                        .gt(lastGuideId != null, GuideUser::getId, lastGuideId)
                        .orderByAsc(GuideUser::getId)
                        .last("LIMIT " + BATCH_SIZE));
        return candidates == null ? Collections.emptyList() : candidates;
    }

    void disableIfEligible(GuideUser guide, GuideAutoDisableConfig config) {
        if (guide == null || Integer.valueOf(1).equals(guide.getAutoDisableWhitelisted())) return;
        if (hasActiveServiceOrder(guide.getId())) return;
        int updated = guideUserMapper.autoDisableIfEligible(guide.getId(),
                config.getOrderThreshold(), config.getRatingThreshold());
        if (updated != 1) return;
        realtimeStatusMapper.disableReceiving(guide.getId());
        receivingSessionMapper.stopReceivingByGuide(guide.getId());
        log.warn("Guide auto-disabled, guideId={}, acceptedOrderCount={}, rating={}",
                guide.getId(), guide.getAcceptedOrderCount(), guide.getRating());
    }

    private boolean hasActiveServiceOrder(Long guideId) {
        return orderMapper.selectCount(new LambdaQueryWrapper<TourOrder>()
                .eq(TourOrder::getGuideId, guideId)
                .in(TourOrder::getStatus, Arrays.asList(
                        OrderStatus.PENDING_MEETING.getCode(), OrderStatus.IN_SERVICE.getCode()))) > 0;
    }

    private boolean matchesRule(GuideUser guide, GuideAutoDisableConfig config) {
        return guide != null
                && Integer.valueOf(GuideUserService.STATUS_ENABLED).equals(guide.getStatus())
                && !Integer.valueOf(1).equals(guide.getAutoDisableWhitelisted())
                && guide.getAcceptedOrderCount() != null
                && guide.getAcceptedOrderCount() >= config.getOrderThreshold()
                && guide.getRating() != null
                && guide.getRating().compareTo(BigDecimal.ZERO) > 0
                && guide.getRating().compareTo(config.getRatingThreshold()) <= 0;
    }

    private boolean valid(GuideAutoDisableConfig config) {
        return config != null
                && config.getOrderThreshold() != null && config.getOrderThreshold() > 0
                && config.getRatingThreshold() != null;
    }
}