package com.linhelp.groupbuy;

import com.linhelp.common.enums.DeliveryMethod;
import com.linhelp.common.enums.GroupBuyOrderStatus;
import com.linhelp.common.enums.OfflinePayStatus;
import com.linhelp.common.exception.BizException;
import org.springframework.stereotype.Service;

import java.time.LocalDateTime;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.atomic.AtomicLong;

@Service
public class GroupBuyOrderService {
    private final GroupBuyService groupBuyService;
    private final AtomicLong ids = new AtomicLong(1L);
    private final Map<Long, GroupBuyOrderResponse> orders = new LinkedHashMap<Long, GroupBuyOrderResponse>();

    public GroupBuyOrderService(GroupBuyService groupBuyService) {
        this.groupBuyService = groupBuyService;
    }

    public synchronized GroupBuyOrderResponse create(Long userId, GroupBuyOrderRequest request) {
        if (request.getDeliveryMethod() != DeliveryMethod.SELF_PICKUP && request.getAddressId() == null) {
            throw new BizException("配送地址不能为空");
        }
        GroupBuyResponse groupBuy = groupBuyService.reserveForOrder(request.getGroupBuyId(), request.getQuantity());
        Long orderId = ids.getAndIncrement();
        GroupBuyOrderResponse order = new GroupBuyOrderResponse();
        order.setId(orderId);
        order.setOrderNo("GB" + String.format("%08d", orderId));
        order.setTenantId(request.getTenantId());
        order.setCommunityId(request.getCommunityId());
        order.setUserId(userId);
        order.setGroupBuyId(groupBuy.getId());
        order.setGroupBuyTitle(groupBuy.getTitle());
        order.setCoverUrl(groupBuy.getCoverUrl());
        order.setAddressId(request.getAddressId());
        order.setQuantity(request.getQuantity());
        order.setPriceCent(groupBuy.getPriceCent());
        order.setAmountCent(groupBuy.getPriceCent() * request.getQuantity());
        order.setDeliveryMethod(request.getDeliveryMethod());
        order.setStatus(GroupBuyOrderStatus.PENDING_CONFIRM);
        order.setOfflinePayStatus(OfflinePayStatus.UNPAID);
        order.setRemark(request.getRemark());
        order.setCreatedAt(LocalDateTime.now());
        order.setUpdatedAt(order.getCreatedAt());
        orders.put(order.getId(), order);
        return copy(order);
    }

    public synchronized GroupBuyOrderResponse detail(Long id) {
        return copy(require(id));
    }

    public synchronized List<GroupBuyOrderResponse> listMine(Long userId) {
        List<GroupBuyOrderResponse> result = new ArrayList<GroupBuyOrderResponse>();
        for (GroupBuyOrderResponse order : orders.values()) {
            if (userId.equals(order.getUserId())) {
                result.add(copy(order));
            }
        }
        return result;
    }

    public synchronized List<GroupBuyOrderResponse> listByGroupBuy(Long groupBuyId) {
        List<GroupBuyOrderResponse> result = new ArrayList<GroupBuyOrderResponse>();
        for (GroupBuyOrderResponse order : orders.values()) {
            if (groupBuyId.equals(order.getGroupBuyId())) {
                result.add(copy(order));
            }
        }
        return result;
    }

    public synchronized GroupBuyOrderResponse confirm(Long id) {
        GroupBuyOrderResponse order = require(id);
        move(order, GroupBuyOrderStatus.PENDING_CONFIRM, GroupBuyOrderStatus.CONFIRMED);
        return copy(order);
    }

    public synchronized GroupBuyOrderResponse markReady(Long id) {
        GroupBuyOrderResponse order = require(id);
        GroupBuyOrderStatus target = DeliveryMethod.SELF_PICKUP.equals(order.getDeliveryMethod())
                ? GroupBuyOrderStatus.PENDING_PICKUP
                : GroupBuyOrderStatus.PENDING_DELIVERY;
        move(order, GroupBuyOrderStatus.CONFIRMED, target);
        return copy(order);
    }

    public synchronized GroupBuyOrderResponse markDelivering(Long id) {
        GroupBuyOrderResponse order = require(id);
        move(order, GroupBuyOrderStatus.PENDING_DELIVERY, GroupBuyOrderStatus.DELIVERING);
        return copy(order);
    }

    public synchronized GroupBuyOrderResponse complete(Long id) {
        GroupBuyOrderResponse order = require(id);
        if (order.getStatus() != GroupBuyOrderStatus.PENDING_PICKUP && order.getStatus() != GroupBuyOrderStatus.DELIVERING) {
            throw new BizException("订单状态不允许操作");
        }
        order.setStatus(GroupBuyOrderStatus.COMPLETED);
        order.setUpdatedAt(LocalDateTime.now());
        return copy(order);
    }

    public synchronized GroupBuyOrderResponse cancel(Long id) {
        GroupBuyOrderResponse order = require(id);
        if (order.getStatus() == GroupBuyOrderStatus.COMPLETED) {
            throw new BizException("订单状态不允许操作");
        }
        order.setStatus(GroupBuyOrderStatus.CANCELED);
        order.setUpdatedAt(LocalDateTime.now());
        return copy(order);
    }

    private void move(GroupBuyOrderResponse order, GroupBuyOrderStatus expected, GroupBuyOrderStatus target) {
        if (order.getStatus() != expected) {
            throw new BizException("订单状态不允许操作");
        }
        order.setStatus(target);
        order.setUpdatedAt(LocalDateTime.now());
    }

    private GroupBuyOrderResponse require(Long id) {
        GroupBuyOrderResponse order = orders.get(id);
        if (order == null) {
            throw new BizException(404, "团购订单不存在");
        }
        return order;
    }

    private GroupBuyOrderResponse copy(GroupBuyOrderResponse source) {
        GroupBuyOrderResponse target = new GroupBuyOrderResponse();
        target.setId(source.getId());
        target.setOrderNo(source.getOrderNo());
        target.setTenantId(source.getTenantId());
        target.setCommunityId(source.getCommunityId());
        target.setUserId(source.getUserId());
        target.setGroupBuyId(source.getGroupBuyId());
        target.setGroupBuyTitle(source.getGroupBuyTitle());
        target.setCoverUrl(source.getCoverUrl());
        target.setAddressId(source.getAddressId());
        target.setQuantity(source.getQuantity());
        target.setPriceCent(source.getPriceCent());
        target.setAmountCent(source.getAmountCent());
        target.setDeliveryMethod(source.getDeliveryMethod());
        target.setStatus(source.getStatus());
        target.setOfflinePayStatus(source.getOfflinePayStatus());
        target.setRemark(source.getRemark());
        target.setCreatedAt(source.getCreatedAt());
        target.setUpdatedAt(source.getUpdatedAt());
        return target;
    }
}