baiyue-firstleg/warehouse-overseas-service/src/main/java/com/baiyue/warehouse/service/WarehousePalletTransitionService.java

package com.baiyue.warehouse.service;

import com.baomidou.mybatisplus.core.toolkit.IdWorker;
import com.baiyue.common.core.api.ResultCode;
import com.baiyue.common.core.exception.BizException;
import com.baiyue.warehouse.dto.PalletTransitionRequests;
import com.baiyue.warehouse.dto.PalletTransitionResponse;
import com.baiyue.warehouse.entity.WarehousePalletEntity;
import com.baiyue.warehouse.entity.WarehousePalletOperationEntity;
import com.baiyue.warehouse.mapper.WarehousePalletTransitionMapper;
import jakarta.annotation.Resource;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.time.LocalDateTime;
import java.util.HexFormat;
import java.util.Set;

@Service
public class WarehousePalletTransitionService {
    private static final Set<String> MUTABLE_STATUSES = Set.of("IDLE", "OCCUPIED");
    @Resource private WarehousePalletTransitionMapper mapper;

    @Transactional
    public PalletTransitionResponse apply(long palletId, PalletTransitionRequests.Apply request) {
        String key = request.operationKey().trim();
        String status = request.targetStatus().trim().toUpperCase();
        if (!MUTABLE_STATUSES.contains(status)) {
            throw new BizException(ResultCode.BAD_REQUEST, "托盘作业状态只允许 IDLE 或 OCCUPIED");
        }
        String requestHash = hash(request.warehouseId() + "|" + palletId + "|" + request.expectedVersion()
            + "|" + status + "|" + request.targetLocationId());
        WarehousePalletOperationEntity existing = mapper.findOperation(key);
        if (existing != null) return replay(existing, requestHash);

        WarehousePalletEntity pallet = mapper.lockPublicPallet(request.warehouseId(), palletId);
        if (pallet == null) throw new BizException(ResultCode.NOT_FOUND, "当前冻结仓内托盘不存在");
        int version = pallet.getVersion() == null ? 0 : pallet.getVersion();
        if (version != request.expectedVersion()) {
            throw new BizException(ResultCode.CONFLICT, "托盘版本已变化，请重新扫码");
        }
        if (mapper.countActiveLocation(request.warehouseId(), request.targetLocationId()) != 1) {
            throw new BizException(ResultCode.CONFLICT, "目标库位无效或已停用");
        }
        if (pallet.getLocationId() == null) {
            throw new BizException(ResultCode.CONFLICT, "托盘没有有效库位，不能执行库内作业");
        }
        if (mapper.transition(request.warehouseId(), palletId, status, request.targetLocationId(), version) != 1) {
            throw new BizException(ResultCode.CONFLICT, "托盘版本已变化，请重新扫码");
        }
        WarehousePalletOperationEntity operation = new WarehousePalletOperationEntity();
        operation.setId(IdWorker.getId()); operation.setOperationKey(key); operation.setRequestHash(requestHash);
        operation.setWarehouseId(request.warehouseId()); operation.setPalletId(palletId);
        operation.setPalletCode(pallet.getPalletCode()); operation.setBeforeStatus(pallet.getStatus());
        operation.setAfterStatus(status); operation.setBeforeLocationId(pallet.getLocationId());
        operation.setAfterLocationId(request.targetLocationId()); operation.setBeforeVersion(version);
        operation.setAfterVersion(version + 1); operation.setOperationStatus("APPLIED");
        operation.setReason(trim(request.reason())); operation.setCreatedAt(LocalDateTime.now());
        operation.setUpdatedAt(operation.getCreatedAt()); mapper.insert(operation);
        return response(operation, false);
    }

    @Transactional
    public PalletTransitionResponse compensate(long palletId, String operationKey,
                                                PalletTransitionRequests.Compensate request) {
        WarehousePalletOperationEntity operation = mapper.lockOperation(operationKey);
        if (operation == null || !Long.valueOf(palletId).equals(operation.getPalletId())
            || !Long.valueOf(request.warehouseId()).equals(operation.getWarehouseId())) {
            throw new BizException(ResultCode.NOT_FOUND, "托盘状态变更记录不存在");
        }
        if ("COMPENSATED".equals(operation.getOperationStatus())) return response(operation, true);
        if (!"APPLIED".equals(operation.getOperationStatus())) {
            throw new BizException(ResultCode.CONFLICT, "托盘状态变更不可补偿");
        }
        if (mapper.transition(request.warehouseId(), palletId, operation.getBeforeStatus(),
            operation.getBeforeLocationId(), operation.getAfterVersion()) != 1) {
            throw new BizException(ResultCode.CONFLICT, "托盘已被后续作业修改，自动补偿失败");
        }
        operation.setOperationStatus("COMPENSATED"); operation.setUpdatedAt(LocalDateTime.now());
        mapper.updateById(operation);
        return response(operation, false);
    }

    private PalletTransitionResponse replay(WarehousePalletOperationEntity operation, String hash) {
        if (!hash.equals(operation.getRequestHash())) {
            throw new BizException(ResultCode.CONFLICT, "操作幂等键已被不同托盘请求使用");
        }
        return response(operation, true);
    }
    private static PalletTransitionResponse response(WarehousePalletOperationEntity value, boolean replayed) {
        return new PalletTransitionResponse(value.getOperationKey(), value.getPalletId(), value.getPalletCode(),
            value.getWarehouseId(), value.getBeforeStatus(), value.getAfterStatus(), value.getBeforeLocationId(),
            value.getAfterLocationId(), value.getBeforeVersion(), value.getAfterVersion(),
            value.getOperationStatus(), replayed);
    }
    private static String hash(String value) {
        try {
            return HexFormat.of().formatHex(MessageDigest.getInstance("SHA-256")
                .digest(value.getBytes(StandardCharsets.UTF_8)));
        } catch (NoSuchAlgorithmException exception) { throw new IllegalStateException(exception); }
    }
    private static String trim(String value) { return value == null || value.isBlank() ? null : value.trim(); }
}