package com.xuqm.im.service;

import com.xuqm.common.exception.BusinessException;
import com.xuqm.im.entity.ImFriendRequestEntity;
import com.xuqm.im.repository.ImFriendRequestRepository;
import com.xuqm.im.repository.ImFriendRepository;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.time.LocalDateTime;
import java.util.List;
import java.util.UUID;

@Service
public class FriendRequestService {

    private final ImFriendRequestRepository requestRepository;
    private final ImFriendRepository friendRepository;

    public FriendRequestService(ImFriendRequestRepository requestRepository,
                                ImFriendRepository friendRepository) {
        this.requestRepository = requestRepository;
        this.friendRepository = friendRepository;
    }

    @Transactional
    public ImFriendRequestEntity send(String appId, String fromUserId, String toUserId, String remark) {
        return requestRepository.findByAppIdAndFromUserIdAndToUserId(appId, fromUserId, toUserId)
                .orElseGet(() -> {
                    ImFriendRequestEntity entity = new ImFriendRequestEntity();
                    entity.setId(UUID.randomUUID().toString());
                    entity.setAppId(appId);
                    entity.setFromUserId(fromUserId);
                    entity.setToUserId(toUserId);
                    entity.setRemark(remark);
                    entity.setStatus(ImFriendRequestEntity.Status.PENDING.name());
                    entity.setCreatedAt(LocalDateTime.now());
                    return requestRepository.save(entity);
                });
    }

    @Transactional
    public ImFriendRequestEntity accept(String appId, String requestId, String operatorId) {
        ImFriendRequestEntity request = getRequest(appId, requestId, operatorId);
        request.setStatus(ImFriendRequestEntity.Status.ACCEPTED.name());
        request.setReviewedAt(LocalDateTime.now());
        requestRepository.save(request);
        friendRepository
                .findByAppIdAndUserIdAndFriendId(appId, request.getFromUserId(), request.getToUserId())
                .orElseGet(() -> friendEntity(appId, request.getFromUserId(), request.getToUserId()));
        friendRepository
                .findByAppIdAndUserIdAndFriendId(appId, request.getToUserId(), request.getFromUserId())
                .orElseGet(() -> friendEntity(appId, request.getToUserId(), request.getFromUserId()));
        return request;
    }

    @Transactional
    public ImFriendRequestEntity reject(String appId, String requestId, String operatorId) {
        ImFriendRequestEntity request = getRequest(appId, requestId, operatorId);
        request.setStatus(ImFriendRequestEntity.Status.REJECTED.name());
        request.setReviewedAt(LocalDateTime.now());
        return requestRepository.save(request);
    }

    public List<ImFriendRequestEntity> incoming(String appId, String userId) {
        return requestRepository.findByAppIdAndToUserId(appId, userId);
    }

    public List<ImFriendRequestEntity> outgoing(String appId, String userId) {
        return requestRepository.findByAppIdAndFromUserId(appId, userId);
    }

    private ImFriendRequestEntity getRequest(String appId, String requestId, String operatorId) {
        ImFriendRequestEntity request = requestRepository.findById(requestId)
                .orElseThrow(() -> new BusinessException(404, "好友申请不存在"));
        if (!request.getAppId().equals(appId) || !request.getToUserId().equals(operatorId)) {
            throw new BusinessException(403, "无权操作");
        }
        return request;
    }

    private com.xuqm.im.entity.ImFriendEntity friendEntity(String appId, String userId, String friendId) {
        com.xuqm.im.entity.ImFriendEntity entity = new com.xuqm.im.entity.ImFriendEntity();
        entity.setAppId(appId);
        entity.setUserId(userId);
        entity.setFriendId(friendId);
        return friendRepository.save(entity);
    }
}