package com.ruoyi.app.order;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.ruoyi.common.core.domain.entity.SysDictData;
import com.ruoyi.common.exception.ServiceException;
import com.ruoyi.common.utils.DictUtils;
import com.ruoyi.common.utils.MessageUtils;
import com.ruoyi.system.domain.InfoUser;
import com.ruoyi.system.domain.PosOrder;
import com.ruoyi.system.domain.flash.FlashDeliveryOrder;
import com.ruoyi.system.mapper.flash.FlashDeliveryOrderMapper;
import com.ruoyi.system.service.IInfoUserService;
import com.ruoyi.system.service.IPosOrderService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Service;

import java.util.List;

import static com.ruoyi.system.domain.flash.FlashDeliveryStatus.ACCEPTED;
import static com.ruoyi.system.domain.flash.FlashDeliveryStatus.PICKED_UP;

/**
 * 骑手接单统一策略：在骑手级锁内检查账号资格、配送类型、进行中任务容量和急送独占。
 * 调用方必须先取得 {@link RiderDeliveryLockService} 的同一骑手锁，避免并发请求同时绕过容量检查。
 */
@Service
public class RiderDeliveryAcceptanceService {
    static final String FOOD_LIMIT_DICT = "sys_rider_food_active_order_limit";
    static final String FLASH_LIMIT_DICT = "sys_rider_flash_active_order_limit";
    static final String TOTAL_LIMIT_DICT = "sys_rider_total_active_order_limit";
    private static final String URGENT = "URGENT";
    private static final int DEFAULT_LIMIT = 1;
    private static final int MAX_LIMIT = 20;
    private static final Logger log = LoggerFactory.getLogger(RiderDeliveryAcceptanceService.class);

    private final IInfoUserService riders;
    private final IPosOrderService foodOrders;
    private final FlashDeliveryOrderMapper flashOrders;

    public RiderDeliveryAcceptanceService(IInfoUserService riders,
                                           IPosOrderService foodOrders,
                                           FlashDeliveryOrderMapper flashOrders) {
        this.riders = riders;
        this.foodOrders = foodOrders;
        this.flashOrders = flashOrders;
    }

    /** 校验骑手能否再承接一笔外卖；进行中外卖和跨类型总量均受字典上限控制。 */
    public void assertCanAcceptFood(Long riderId) {
        requireEligibleRider(riderId, "FOOD");
        ActiveTasks active = activeTasks(riderId);
        if (active.urgentFlash() > 0) throw exclusiveConflict();
        if (active.food() >= configuredLimit(FOOD_LIMIT_DICT)) {
            throw new ServiceException(MessageUtils.message("rider.accept.food.limit.reached"));
        }
        assertTotalCapacity(active);
    }

    /** 校验骑手能否承接闪送；加急闪送保持跨外卖、闪送的一对一独占。 */
    public void assertCanAcceptFlash(Long riderId, String deliveryType) {
        requireEligibleRider(riderId, "FLASH");
        ActiveTasks active = activeTasks(riderId);
        if (URGENT.equals(deliveryType)) {
            if (active.food() > 0 || active.flash() > 0) throw exclusiveConflict();
            return;
        }
        if (active.urgentFlash() > 0) throw exclusiveConflict();
        if (active.flash() >= configuredLimit(FLASH_LIMIT_DICT)) {
            throw new ServiceException(MessageUtils.message("rider.accept.flash.limit.reached"));
        }
        assertTotalCapacity(active);
    }

    /**
     * 统一账号资格口径。空配送类型仍沿用 InfoUser 的历史兼容规则，但停用、未审核和离线账号均不得接单。
     */
    private InfoUser requireEligibleRider(Long riderId, String deliveryType) {
        InfoUser rider = riderId == null ? null : riders.getById(riderId);
        if (rider == null || !"2".equals(rider.getUserType())) {
            throw new ServiceException(MessageUtils.message("rider.operation.role.required"));
        }
        if (!"1".equals(rider.getAuditStatus())) {
            throw new ServiceException(MessageUtils.message("no.user.state.no.audit"));
        }
        if (!"0".equals(rider.getStatus())) {
            throw new ServiceException(MessageUtils.message("no.user.stop"));
        }
        if (!"0".equals(rider.getOffline())) {
            throw new ServiceException(MessageUtils.message("rider.accept.offline"));
        }
        if (!rider.supportsDeliveryType(deliveryType)) {
            String key = "FOOD".equals(deliveryType)
                    ? "no.user.delivery.type.not.enabled"
                    : "flash.delivery.rider.type.not.enabled";
            throw new ServiceException(MessageUtils.message(key));
        }
        return rider;
    }

    /** 一次读取两类进行中任务，所有容量判断使用同一数据库快照口径。 */
    private ActiveTasks activeTasks(Long riderId) {
        QueryWrapper<PosOrder> foodQuery = new QueryWrapper<PosOrder>()
                .eq("qs_id", riderId)
                .in("delivery_status", 1, 2)
                .in("state", 0, 1, 2)
                .eq("after_sale_status", 0);
        QueryWrapper<FlashDeliveryOrder> flashQuery = new QueryWrapper<FlashDeliveryOrder>()
                .eq("rider_id", riderId)
                .in("status", ACCEPTED, PICKED_UP);
        QueryWrapper<FlashDeliveryOrder> urgentQuery = new QueryWrapper<FlashDeliveryOrder>()
                .eq("rider_id", riderId)
                .in("status", ACCEPTED, PICKED_UP)
                .eq("delivery_type", URGENT);
        return new ActiveTasks(safe(foodOrders.count(foodQuery)),
                safe(flashOrders.selectCount(flashQuery)), safe(flashOrders.selectCount(urgentQuery)));
    }

    private void assertTotalCapacity(ActiveTasks active) {
        if (active.food() + active.flash() >= configuredLimit(TOTAL_LIMIT_DICT)) {
            throw new ServiceException(MessageUtils.message("rider.accept.total.limit.reached"));
        }
    }

    /**
     * 容量字典只接受 1 至 20 的整数。缺失、空值、越界、解析或缓存异常一律保守回退为 1，绝不放宽为不限单。
     */
    private int configuredLimit(String dictType) {
        List<SysDictData> values;
        try {
            values = DictUtils.getDictCache(dictType);
        } catch (RuntimeException exception) {
            log.warn("Failed to read rider acceptance limit, fallback to 1, dictType={}", dictType, exception);
            return DEFAULT_LIMIT;
        }
        if (values == null || values.isEmpty()) return DEFAULT_LIMIT;
        String raw = values.get(0).getDictValue();
        if (raw == null || !raw.trim().matches("[0-9]+")) return DEFAULT_LIMIT;
        try {
            int value = Integer.parseInt(raw.trim());
            return value >= 1 && value <= MAX_LIMIT ? value : DEFAULT_LIMIT;
        } catch (NumberFormatException ignored) {
            return DEFAULT_LIMIT;
        }
    }

    private long safe(Long value) {
        return value == null ? 0L : value;
    }

    private ServiceException exclusiveConflict() {
        return new ServiceException(MessageUtils.message("flash.delivery.rider.exclusive.conflict"));
    }

    private record ActiveTasks(long food, long flash, long urgentFlash) { }
}