feat: add product catalog and goods orders

backend/src/main/java/com/linhelp/merchant/MerchantController.java

@@ -0,0 +1,61 @@
+package com.linhelp.merchant;
+
+import com.linhelp.common.api.ApiResponse;
+import com.linhelp.common.security.AuthService;
+import com.linhelp.common.security.CurrentUser;
+import com.linhelp.common.security.RequireRole;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import javax.validation.Valid;
+import java.util.List;
+
+@RestController
+@RequestMapping("/api/admin/merchants")
+@RequireRole({"PLATFORM_ADMIN", "COMMUNITY_ADMIN"})
+public class MerchantController {
+    private final MerchantService merchantService;
+    private final AuthService authService;
+
+    public MerchantController(MerchantService merchantService, AuthService authService) {
+        this.merchantService = merchantService;
+        this.authService = authService;
+    }
+
+    @GetMapping
+    public ApiResponse<List<MerchantResponse>> list() {
+        CurrentUser user = authService.currentUser();
+        return ApiResponse.ok(merchantService.list(user.getCommunityId()));
+    }
+
+    @PostMapping
+    public ApiResponse<MerchantResponse> create(@Valid @RequestBody MerchantRequest request) {
+        CurrentUser user = authService.currentUser();
+        request.setTenantId(user.getTenantId());
+        request.setCommunityId(user.getCommunityId());
+        return ApiResponse.ok(merchantService.create(request));
+    }
+
+    @PutMapping("/{id}")
+    public ApiResponse<MerchantResponse> update(@PathVariable Long id, @Valid @RequestBody MerchantRequest request) {
+        CurrentUser user = authService.currentUser();
+        request.setTenantId(user.getTenantId());
+        request.setCommunityId(user.getCommunityId());
+        return ApiResponse.ok(merchantService.update(id, request));
+    }
+
+    @PutMapping("/{id}/enable")
+    public ApiResponse<MerchantResponse> enable(@PathVariable Long id) {
+        return ApiResponse.ok(merchantService.enable(id));
+    }
+
+    @PutMapping("/{id}/disable")
+    public ApiResponse<MerchantResponse> disable(@PathVariable Long id) {
+        return ApiResponse.ok(merchantService.disable(id));
+    }
+}

backend/src/main/java/com/linhelp/merchant/MerchantRequest.java

@@ -0,0 +1,65 @@
+package com.linhelp.merchant;
+
+import javax.validation.constraints.NotBlank;
+
+public class MerchantRequest {
+    private Long tenantId;
+    private Long communityId;
+
+    @NotBlank
+    private String name;
+
+    @NotBlank
+    private String merchantType;
+
+    private String contactName;
+    private String contactPhone;
+
+    public Long getTenantId() {
+        return tenantId;
+    }
+
+    public void setTenantId(Long tenantId) {
+        this.tenantId = tenantId;
+    }
+
+    public Long getCommunityId() {
+        return communityId;
+    }
+
+    public void setCommunityId(Long communityId) {
+        this.communityId = communityId;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getMerchantType() {
+        return merchantType;
+    }
+
+    public void setMerchantType(String merchantType) {
+        this.merchantType = merchantType;
+    }
+
+    public String getContactName() {
+        return contactName;
+    }
+
+    public void setContactName(String contactName) {
+        this.contactName = contactName;
+    }
+
+    public String getContactPhone() {
+        return contactPhone;
+    }
+
+    public void setContactPhone(String contactPhone) {
+        this.contactPhone = contactPhone;
+    }
+}

backend/src/main/java/com/linhelp/merchant/MerchantResponse.java

@@ -0,0 +1,76 @@
+package com.linhelp.merchant;
+
+public class MerchantResponse {
+    private Long id;
+    private Long tenantId;
+    private Long communityId;
+    private String name;
+    private String merchantType;
+    private String contactName;
+    private String contactPhone;
+    private String status;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public Long getTenantId() {
+        return tenantId;
+    }
+
+    public void setTenantId(Long tenantId) {
+        this.tenantId = tenantId;
+    }
+
+    public Long getCommunityId() {
+        return communityId;
+    }
+
+    public void setCommunityId(Long communityId) {
+        this.communityId = communityId;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getMerchantType() {
+        return merchantType;
+    }
+
+    public void setMerchantType(String merchantType) {
+        this.merchantType = merchantType;
+    }
+
+    public String getContactName() {
+        return contactName;
+    }
+
+    public void setContactName(String contactName) {
+        this.contactName = contactName;
+    }
+
+    public String getContactPhone() {
+        return contactPhone;
+    }
+
+    public void setContactPhone(String contactPhone) {
+        this.contactPhone = contactPhone;
+    }
+
+    public String getStatus() {
+        return status;
+    }
+
+    public void setStatus(String status) {
+        this.status = status;
+    }
+}

backend/src/main/java/com/linhelp/merchant/MerchantService.java

@@ -0,0 +1,68 @@
+package com.linhelp.merchant;
+
+import org.springframework.stereotype.Service;
+
+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 MerchantService {
+    private final AtomicLong ids = new AtomicLong(1L);
+    private final Map<Long, MerchantResponse> merchants = new LinkedHashMap<Long, MerchantResponse>();
+
+    public synchronized MerchantResponse create(MerchantRequest request) {
+        MerchantResponse merchant = new MerchantResponse();
+        merchant.setId(ids.getAndIncrement());
+        copy(request, merchant);
+        merchant.setStatus("ENABLED");
+        merchants.put(merchant.getId(), merchant);
+        return merchant;
+    }
+
+    public synchronized List<MerchantResponse> list(Long communityId) {
+        List<MerchantResponse> result = new ArrayList<MerchantResponse>();
+        for (MerchantResponse merchant : merchants.values()) {
+            if (communityId.equals(merchant.getCommunityId())) {
+                result.add(merchant);
+            }
+        }
+        return result;
+    }
+
+    public synchronized MerchantResponse update(Long id, MerchantRequest request) {
+        MerchantResponse merchant = merchants.get(id);
+        if (merchant == null) {
+            return null;
+        }
+        copy(request, merchant);
+        return merchant;
+    }
+
+    public synchronized MerchantResponse enable(Long id) {
+        MerchantResponse merchant = merchants.get(id);
+        if (merchant != null) {
+            merchant.setStatus("ENABLED");
+        }
+        return merchant;
+    }
+
+    public synchronized MerchantResponse disable(Long id) {
+        MerchantResponse merchant = merchants.get(id);
+        if (merchant != null) {
+            merchant.setStatus("DISABLED");
+        }
+        return merchant;
+    }
+
+    private void copy(MerchantRequest request, MerchantResponse merchant) {
+        merchant.setTenantId(request.getTenantId());
+        merchant.setCommunityId(request.getCommunityId());
+        merchant.setName(request.getName());
+        merchant.setMerchantType(request.getMerchantType());
+        merchant.setContactName(request.getContactName());
+        merchant.setContactPhone(request.getContactPhone());
+    }
+}

backend/src/main/java/com/linhelp/order/CreateGoodsOrderItemRequest.java

@@ -0,0 +1,48 @@
+package com.linhelp.order;
+
+import javax.validation.constraints.Min;
+import javax.validation.constraints.NotNull;
+
+public class CreateGoodsOrderItemRequest {
+    @NotNull
+    private Long productId;
+
+    @NotNull
+    private Long skuId;
+
+    @Min(1)
+    private int quantity;
+
+    public CreateGoodsOrderItemRequest() {
+    }
+
+    public CreateGoodsOrderItemRequest(Long productId, Long skuId, int quantity) {
+        this.productId = productId;
+        this.skuId = skuId;
+        this.quantity = quantity;
+    }
+
+    public Long getProductId() {
+        return productId;
+    }
+
+    public void setProductId(Long productId) {
+        this.productId = productId;
+    }
+
+    public Long getSkuId() {
+        return skuId;
+    }
+
+    public void setSkuId(Long skuId) {
+        this.skuId = skuId;
+    }
+
+    public int getQuantity() {
+        return quantity;
+    }
+
+    public void setQuantity(int quantity) {
+        this.quantity = quantity;
+    }
+}

backend/src/main/java/com/linhelp/order/CreateGoodsOrderRequest.java

@@ -0,0 +1,94 @@
+package com.linhelp.order;
+
+import com.linhelp.common.enums.DeliveryMethod;
+
+import javax.validation.Valid;
+import javax.validation.constraints.NotEmpty;
+import javax.validation.constraints.NotNull;
+import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.List;
+
+public class CreateGoodsOrderRequest {
+    private Long tenantId;
+    private Long communityId;
+
+    @NotNull
+    private Long merchantId;
+
+    private Long addressId;
+
+    @NotNull
+    private DeliveryMethod deliveryMethod = DeliveryMethod.IMMEDIATE;
+
+    private LocalDateTime scheduledTime;
+    private String remark;
+
+    @Valid
+    @NotEmpty
+    private List<CreateGoodsOrderItemRequest> items = new ArrayList<CreateGoodsOrderItemRequest>();
+
+    public Long getTenantId() {
+        return tenantId;
+    }
+
+    public void setTenantId(Long tenantId) {
+        this.tenantId = tenantId;
+    }
+
+    public Long getCommunityId() {
+        return communityId;
+    }
+
+    public void setCommunityId(Long communityId) {
+        this.communityId = communityId;
+    }
+
+    public Long getMerchantId() {
+        return merchantId;
+    }
+
+    public void setMerchantId(Long merchantId) {
+        this.merchantId = merchantId;
+    }
+
+    public Long getAddressId() {
+        return addressId;
+    }
+
+    public void setAddressId(Long addressId) {
+        this.addressId = addressId;
+    }
+
+    public DeliveryMethod getDeliveryMethod() {
+        return deliveryMethod;
+    }
+
+    public void setDeliveryMethod(DeliveryMethod deliveryMethod) {
+        this.deliveryMethod = deliveryMethod;
+    }
+
+    public LocalDateTime getScheduledTime() {
+        return scheduledTime;
+    }
+
+    public void setScheduledTime(LocalDateTime scheduledTime) {
+        this.scheduledTime = scheduledTime;
+    }
+
+    public String getRemark() {
+        return remark;
+    }
+
+    public void setRemark(String remark) {
+        this.remark = remark;
+    }
+
+    public List<CreateGoodsOrderItemRequest> getItems() {
+        return items;
+    }
+
+    public void setItems(List<CreateGoodsOrderItemRequest> items) {
+        this.items = items;
+    }
+}

backend/src/main/java/com/linhelp/order/GoodsOrderController.java

@@ -0,0 +1,95 @@
+package com.linhelp.order;
+
+import com.linhelp.common.api.ApiResponse;
+import com.linhelp.common.enums.GoodsOrderStatus;
+import com.linhelp.common.security.AuthService;
+import com.linhelp.common.security.CurrentUser;
+import com.linhelp.common.security.RequireRole;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import javax.validation.Valid;
+import java.util.List;
+
+@RestController
+public class GoodsOrderController {
+    private final GoodsOrderService goodsOrderService;
+    private final AuthService authService;
+
+    public GoodsOrderController(GoodsOrderService goodsOrderService, AuthService authService) {
+        this.goodsOrderService = goodsOrderService;
+        this.authService = authService;
+    }
+
+    @PostMapping("/api/mini/goods-orders")
+    public ApiResponse<GoodsOrderResponse> create(@Valid @RequestBody CreateGoodsOrderRequest request) {
+        CurrentUser user = authService.currentUser();
+        request.setTenantId(user.getTenantId());
+        request.setCommunityId(user.getCommunityId());
+        return ApiResponse.ok(goodsOrderService.create(user.getUserId(), request));
+    }
+
+    @GetMapping("/api/mini/goods-orders")
+    public ApiResponse<List<GoodsOrderResponse>> listMine() {
+        CurrentUser user = authService.currentUser();
+        return ApiResponse.ok(goodsOrderService.listMine(user.getUserId()));
+    }
+
+    @GetMapping("/api/mini/goods-orders/{id}")
+    public ApiResponse<GoodsOrderResponse> miniDetail(@PathVariable Long id) {
+        return ApiResponse.ok(goodsOrderService.detail(id));
+    }
+
+    @PutMapping("/api/mini/goods-orders/{id}/cancel")
+    public ApiResponse<GoodsOrderResponse> cancel(@PathVariable Long id) {
+        return ApiResponse.ok(goodsOrderService.cancel(id));
+    }
+
+    @GetMapping("/api/admin/goods-orders")
+    @RequireRole({"PLATFORM_ADMIN", "COMMUNITY_ADMIN", "MERCHANT"})
+    public ApiResponse<List<GoodsOrderResponse>> listAdmin(@RequestParam(required = false) GoodsOrderStatus status) {
+        CurrentUser user = authService.currentUser();
+        return ApiResponse.ok(goodsOrderService.listAdmin(user.getCommunityId(), status));
+    }
+
+    @GetMapping("/api/admin/goods-orders/{id}")
+    @RequireRole({"PLATFORM_ADMIN", "COMMUNITY_ADMIN", "MERCHANT"})
+    public ApiResponse<GoodsOrderResponse> adminDetail(@PathVariable Long id) {
+        return ApiResponse.ok(goodsOrderService.detail(id));
+    }
+
+    @PutMapping("/api/admin/goods-orders/{id}/confirm")
+    @RequireRole({"PLATFORM_ADMIN", "COMMUNITY_ADMIN", "MERCHANT"})
+    public ApiResponse<GoodsOrderResponse> confirm(@PathVariable Long id) {
+        return ApiResponse.ok(goodsOrderService.confirm(id));
+    }
+
+    @PutMapping("/api/admin/goods-orders/{id}/prepared")
+    @RequireRole({"PLATFORM_ADMIN", "COMMUNITY_ADMIN", "MERCHANT"})
+    public ApiResponse<GoodsOrderResponse> markPrepared(@PathVariable Long id) {
+        return ApiResponse.ok(goodsOrderService.markPrepared(id));
+    }
+
+    @PutMapping("/api/admin/goods-orders/{id}/delivering")
+    @RequireRole({"PLATFORM_ADMIN", "COMMUNITY_ADMIN", "MERCHANT"})
+    public ApiResponse<GoodsOrderResponse> markDelivering(@PathVariable Long id) {
+        return ApiResponse.ok(goodsOrderService.markDelivering(id));
+    }
+
+    @PutMapping("/api/admin/goods-orders/{id}/complete")
+    @RequireRole({"PLATFORM_ADMIN", "COMMUNITY_ADMIN", "MERCHANT"})
+    public ApiResponse<GoodsOrderResponse> complete(@PathVariable Long id) {
+        return ApiResponse.ok(goodsOrderService.complete(id));
+    }
+
+    @PutMapping("/api/admin/goods-orders/{id}/paid")
+    @RequireRole({"PLATFORM_ADMIN", "COMMUNITY_ADMIN", "MERCHANT"})
+    public ApiResponse<GoodsOrderResponse> markPaid(@PathVariable Long id) {
+        return ApiResponse.ok(goodsOrderService.markPaid(id));
+    }
+}

backend/src/main/java/com/linhelp/order/GoodsOrderItemResponse.java

@@ -0,0 +1,85 @@
+package com.linhelp.order;
+
+public class GoodsOrderItemResponse {
+    private Long id;
+    private Long orderId;
+    private Long productId;
+    private Long skuId;
+    private String productName;
+    private String skuName;
+    private int quantity;
+    private int priceCent;
+    private int amountCent;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public Long getOrderId() {
+        return orderId;
+    }
+
+    public void setOrderId(Long orderId) {
+        this.orderId = orderId;
+    }
+
+    public Long getProductId() {
+        return productId;
+    }
+
+    public void setProductId(Long productId) {
+        this.productId = productId;
+    }
+
+    public Long getSkuId() {
+        return skuId;
+    }
+
+    public void setSkuId(Long skuId) {
+        this.skuId = skuId;
+    }
+
+    public String getProductName() {
+        return productName;
+    }
+
+    public void setProductName(String productName) {
+        this.productName = productName;
+    }
+
+    public String getSkuName() {
+        return skuName;
+    }
+
+    public void setSkuName(String skuName) {
+        this.skuName = skuName;
+    }
+
+    public int getQuantity() {
+        return quantity;
+    }
+
+    public void setQuantity(int quantity) {
+        this.quantity = quantity;
+    }
+
+    public int getPriceCent() {
+        return priceCent;
+    }
+
+    public void setPriceCent(int priceCent) {
+        this.priceCent = priceCent;
+    }
+
+    public int getAmountCent() {
+        return amountCent;
+    }
+
+    public void setAmountCent(int amountCent) {
+        this.amountCent = amountCent;
+    }
+}

backend/src/main/java/com/linhelp/order/GoodsOrderResponse.java

@@ -0,0 +1,174 @@
+package com.linhelp.order;
+
+import com.linhelp.common.enums.DeliveryMethod;
+import com.linhelp.common.enums.GoodsOrderStatus;
+import com.linhelp.common.enums.OfflinePayStatus;
+
+import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.List;
+
+public class GoodsOrderResponse {
+    private Long id;
+    private String orderNo;
+    private Long tenantId;
+    private Long communityId;
+    private Long userId;
+    private Long merchantId;
+    private Long addressId;
+    private DeliveryMethod deliveryMethod;
+    private GoodsOrderStatus status;
+    private OfflinePayStatus offlinePayStatus;
+    private LocalDateTime scheduledTime;
+    private String remark;
+    private int totalAmountCent;
+    private int deliveryFeeCent;
+    private int payableAmountCent;
+    private List<GoodsOrderItemResponse> items = new ArrayList<GoodsOrderItemResponse>();
+    private LocalDateTime createdAt;
+    private LocalDateTime updatedAt;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getOrderNo() {
+        return orderNo;
+    }
+
+    public void setOrderNo(String orderNo) {
+        this.orderNo = orderNo;
+    }
+
+    public Long getTenantId() {
+        return tenantId;
+    }
+
+    public void setTenantId(Long tenantId) {
+        this.tenantId = tenantId;
+    }
+
+    public Long getCommunityId() {
+        return communityId;
+    }
+
+    public void setCommunityId(Long communityId) {
+        this.communityId = communityId;
+    }
+
+    public Long getUserId() {
+        return userId;
+    }
+
+    public void setUserId(Long userId) {
+        this.userId = userId;
+    }
+
+    public Long getMerchantId() {
+        return merchantId;
+    }
+
+    public void setMerchantId(Long merchantId) {
+        this.merchantId = merchantId;
+    }
+
+    public Long getAddressId() {
+        return addressId;
+    }
+
+    public void setAddressId(Long addressId) {
+        this.addressId = addressId;
+    }
+
+    public DeliveryMethod getDeliveryMethod() {
+        return deliveryMethod;
+    }
+
+    public void setDeliveryMethod(DeliveryMethod deliveryMethod) {
+        this.deliveryMethod = deliveryMethod;
+    }
+
+    public GoodsOrderStatus getStatus() {
+        return status;
+    }
+
+    public void setStatus(GoodsOrderStatus status) {
+        this.status = status;
+    }
+
+    public OfflinePayStatus getOfflinePayStatus() {
+        return offlinePayStatus;
+    }
+
+    public void setOfflinePayStatus(OfflinePayStatus offlinePayStatus) {
+        this.offlinePayStatus = offlinePayStatus;
+    }
+
+    public LocalDateTime getScheduledTime() {
+        return scheduledTime;
+    }
+
+    public void setScheduledTime(LocalDateTime scheduledTime) {
+        this.scheduledTime = scheduledTime;
+    }
+
+    public String getRemark() {
+        return remark;
+    }
+
+    public void setRemark(String remark) {
+        this.remark = remark;
+    }
+
+    public int getTotalAmountCent() {
+        return totalAmountCent;
+    }
+
+    public void setTotalAmountCent(int totalAmountCent) {
+        this.totalAmountCent = totalAmountCent;
+    }
+
+    public int getDeliveryFeeCent() {
+        return deliveryFeeCent;
+    }
+
+    public void setDeliveryFeeCent(int deliveryFeeCent) {
+        this.deliveryFeeCent = deliveryFeeCent;
+    }
+
+    public int getPayableAmountCent() {
+        return payableAmountCent;
+    }
+
+    public void setPayableAmountCent(int payableAmountCent) {
+        this.payableAmountCent = payableAmountCent;
+    }
+
+    public List<GoodsOrderItemResponse> getItems() {
+        return items;
+    }
+
+    public void setItems(List<GoodsOrderItemResponse> items) {
+        this.items = items;
+    }
+
+    public LocalDateTime getCreatedAt() {
+        return createdAt;
+    }
+
+    public void setCreatedAt(LocalDateTime createdAt) {
+        this.createdAt = createdAt;
+    }
+
+    public LocalDateTime getUpdatedAt() {
+        return updatedAt;
+    }
+
+    public void setUpdatedAt(LocalDateTime updatedAt) {
+        this.updatedAt = updatedAt;
+    }
+}

backend/src/main/java/com/linhelp/order/GoodsOrderService.java

@@ -0,0 +1,257 @@
+package com.linhelp.order;
+
+import com.linhelp.common.enums.DeliveryMethod;
+import com.linhelp.common.enums.GoodsOrderStatus;
+import com.linhelp.common.enums.OfflinePayStatus;
+import com.linhelp.common.exception.BizException;
+import com.linhelp.product.ProductService;
+import com.linhelp.product.ProductSkuResponse;
+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 GoodsOrderService {
+    private final ProductService productService;
+    private final AtomicLong orderIds = new AtomicLong(1L);
+    private final AtomicLong itemIds = new AtomicLong(1L);
+    private final Map<Long, GoodsOrderResponse> orders = new LinkedHashMap<Long, GoodsOrderResponse>();
+
+    public GoodsOrderService(ProductService productService) {
+        this.productService = productService;
+    }
+
+    public synchronized GoodsOrderResponse create(Long userId, CreateGoodsOrderRequest request) {
+        if (request.getItems() == null || request.getItems().isEmpty()) {
+            throw new BizException("订单商品不能为空");
+        }
+        if (request.getDeliveryMethod() != DeliveryMethod.SELF_PICKUP && request.getAddressId() == null) {
+            throw new BizException("配送地址不能为空");
+        }
+
+        Map<Long, Integer> skuQuantities = collectSkuQuantities(request);
+        Map<Long, ProductSkuResponse> skuSnapshots = loadAndCheckStock(skuQuantities);
+        for (Map.Entry<Long, Integer> entry : skuQuantities.entrySet()) {
+            productService.deductStock(entry.getKey(), entry.getValue());
+        }
+
+        Long orderId = orderIds.getAndIncrement();
+        GoodsOrderResponse order = new GoodsOrderResponse();
+        order.setId(orderId);
+        order.setOrderNo("GO" + String.format("%08d", orderId));
+        order.setTenantId(request.getTenantId());
+        order.setCommunityId(request.getCommunityId());
+        order.setUserId(userId);
+        order.setMerchantId(request.getMerchantId());
+        order.setAddressId(request.getAddressId());
+        order.setDeliveryMethod(request.getDeliveryMethod());
+        order.setStatus(GoodsOrderStatus.PENDING_CONFIRM);
+        order.setOfflinePayStatus(OfflinePayStatus.UNPAID);
+        order.setScheduledTime(request.getScheduledTime());
+        order.setRemark(request.getRemark());
+        order.setItems(buildItems(orderId, request, skuSnapshots));
+        order.setTotalAmountCent(sumAmount(order.getItems()));
+        order.setDeliveryFeeCent(resolveDeliveryFee(request.getDeliveryMethod()));
+        order.setPayableAmountCent(order.getTotalAmountCent() + order.getDeliveryFeeCent());
+        order.setCreatedAt(LocalDateTime.now());
+        order.setUpdatedAt(order.getCreatedAt());
+        orders.put(order.getId(), order);
+        return copyOrder(order);
+    }
+
+    public synchronized GoodsOrderResponse detail(Long id) {
+        return copyOrder(requireOrder(id));
+    }
+
+    public synchronized List<GoodsOrderResponse> listMine(Long userId) {
+        List<GoodsOrderResponse> result = new ArrayList<GoodsOrderResponse>();
+        for (GoodsOrderResponse order : orders.values()) {
+            if (userId.equals(order.getUserId())) {
+                result.add(copyOrder(order));
+            }
+        }
+        return result;
+    }
+
+    public synchronized List<GoodsOrderResponse> listAdmin(Long communityId, GoodsOrderStatus status) {
+        List<GoodsOrderResponse> result = new ArrayList<GoodsOrderResponse>();
+        for (GoodsOrderResponse order : orders.values()) {
+            if (!communityId.equals(order.getCommunityId())) {
+                continue;
+            }
+            if (status != null && status != order.getStatus()) {
+                continue;
+            }
+            result.add(copyOrder(order));
+        }
+        return result;
+    }
+
+    public synchronized GoodsOrderResponse confirm(Long id) {
+        GoodsOrderResponse order = requireOrder(id);
+        move(order, GoodsOrderStatus.PREPARING);
+        return copyOrder(order);
+    }
+
+    public synchronized GoodsOrderResponse markPrepared(Long id) {
+        GoodsOrderResponse order = requireOrder(id);
+        GoodsOrderStatus target = DeliveryMethod.SELF_PICKUP.equals(order.getDeliveryMethod())
+                ? GoodsOrderStatus.PENDING_PICKUP
+                : GoodsOrderStatus.PENDING_DELIVERY;
+        move(order, target);
+        return copyOrder(order);
+    }
+
+    public synchronized GoodsOrderResponse markDelivering(Long id) {
+        GoodsOrderResponse order = requireOrder(id);
+        move(order, GoodsOrderStatus.DELIVERING);
+        return copyOrder(order);
+    }
+
+    public synchronized GoodsOrderResponse complete(Long id) {
+        GoodsOrderResponse order = requireOrder(id);
+        move(order, GoodsOrderStatus.COMPLETED);
+        return copyOrder(order);
+    }
+
+    public synchronized GoodsOrderResponse cancel(Long id) {
+        GoodsOrderResponse order = requireOrder(id);
+        move(order, GoodsOrderStatus.CANCELED);
+        return copyOrder(order);
+    }
+
+    public synchronized GoodsOrderResponse markPaid(Long id) {
+        GoodsOrderResponse order = requireOrder(id);
+        order.setOfflinePayStatus(OfflinePayStatus.PAID);
+        order.setUpdatedAt(LocalDateTime.now());
+        return copyOrder(order);
+    }
+
+    private Map<Long, Integer> collectSkuQuantities(CreateGoodsOrderRequest request) {
+        Map<Long, Integer> skuQuantities = new LinkedHashMap<Long, Integer>();
+        for (CreateGoodsOrderItemRequest item : request.getItems()) {
+            if (item.getSkuId() == null || item.getProductId() == null) {
+                throw new BizException("订单商品信息不完整");
+            }
+            if (item.getQuantity() <= 0) {
+                throw new BizException("购买数量必须大于0");
+            }
+            Integer existing = skuQuantities.get(item.getSkuId());
+            skuQuantities.put(item.getSkuId(), (existing == null ? 0 : existing) + item.getQuantity());
+        }
+        return skuQuantities;
+    }
+
+    private Map<Long, ProductSkuResponse> loadAndCheckStock(Map<Long, Integer> skuQuantities) {
+        Map<Long, ProductSkuResponse> snapshots = new LinkedHashMap<Long, ProductSkuResponse>();
+        for (Map.Entry<Long, Integer> entry : skuQuantities.entrySet()) {
+            ProductSkuResponse sku = productService.getSku(entry.getKey());
+            if (!sku.isEnabled()) {
+                throw new BizException("商品规格已下架");
+            }
+            if (sku.getStock() < entry.getValue()) {
+                throw new BizException("库存不足");
+            }
+            snapshots.put(entry.getKey(), sku);
+        }
+        return snapshots;
+    }
+
+    private List<GoodsOrderItemResponse> buildItems(Long orderId,
+                                                    CreateGoodsOrderRequest request,
+                                                    Map<Long, ProductSkuResponse> skuSnapshots) {
+        List<GoodsOrderItemResponse> items = new ArrayList<GoodsOrderItemResponse>();
+        for (CreateGoodsOrderItemRequest itemRequest : request.getItems()) {
+            ProductSkuResponse sku = skuSnapshots.get(itemRequest.getSkuId());
+            GoodsOrderItemResponse item = new GoodsOrderItemResponse();
+            item.setId(itemIds.getAndIncrement());
+            item.setOrderId(orderId);
+            item.setProductId(itemRequest.getProductId());
+            item.setSkuId(itemRequest.getSkuId());
+            item.setProductName(sku.getProductName());
+            item.setSkuName(sku.getSkuName());
+            item.setQuantity(itemRequest.getQuantity());
+            item.setPriceCent(sku.getPriceCent());
+            item.setAmountCent(sku.getPriceCent() * itemRequest.getQuantity());
+            items.add(item);
+        }
+        return items;
+    }
+
+    private int sumAmount(List<GoodsOrderItemResponse> items) {
+        int sum = 0;
+        for (GoodsOrderItemResponse item : items) {
+            sum += item.getAmountCent();
+        }
+        return sum;
+    }
+
+    private int resolveDeliveryFee(DeliveryMethod method) {
+        if (DeliveryMethod.SELF_PICKUP.equals(method)) {
+            return 0;
+        }
+        return 300;
+    }
+
+    private void move(GoodsOrderResponse order, GoodsOrderStatus target) {
+        if (!order.getStatus().canMoveTo(target)) {
+            throw new BizException("订单状态不允许操作");
+        }
+        order.setStatus(target);
+        order.setUpdatedAt(LocalDateTime.now());
+    }
+
+    private GoodsOrderResponse requireOrder(Long id) {
+        GoodsOrderResponse order = orders.get(id);
+        if (order == null) {
+            throw new BizException(404, "订单不存在");
+        }
+        return order;
+    }
+
+    private GoodsOrderResponse copyOrder(GoodsOrderResponse source) {
+        GoodsOrderResponse target = new GoodsOrderResponse();
+        target.setId(source.getId());
+        target.setOrderNo(source.getOrderNo());
+        target.setTenantId(source.getTenantId());
+        target.setCommunityId(source.getCommunityId());
+        target.setUserId(source.getUserId());
+        target.setMerchantId(source.getMerchantId());
+        target.setAddressId(source.getAddressId());
+        target.setDeliveryMethod(source.getDeliveryMethod());
+        target.setStatus(source.getStatus());
+        target.setOfflinePayStatus(source.getOfflinePayStatus());
+        target.setScheduledTime(source.getScheduledTime());
+        target.setRemark(source.getRemark());
+        target.setTotalAmountCent(source.getTotalAmountCent());
+        target.setDeliveryFeeCent(source.getDeliveryFeeCent());
+        target.setPayableAmountCent(source.getPayableAmountCent());
+        target.setCreatedAt(source.getCreatedAt());
+        target.setUpdatedAt(source.getUpdatedAt());
+        target.setItems(copyItems(source.getItems()));
+        return target;
+    }
+
+    private List<GoodsOrderItemResponse> copyItems(List<GoodsOrderItemResponse> sourceItems) {
+        List<GoodsOrderItemResponse> items = new ArrayList<GoodsOrderItemResponse>();
+        for (GoodsOrderItemResponse source : sourceItems) {
+            GoodsOrderItemResponse target = new GoodsOrderItemResponse();
+            target.setId(source.getId());
+            target.setOrderId(source.getOrderId());
+            target.setProductId(source.getProductId());
+            target.setSkuId(source.getSkuId());
+            target.setProductName(source.getProductName());
+            target.setSkuName(source.getSkuName());
+            target.setQuantity(source.getQuantity());
+            target.setPriceCent(source.getPriceCent());
+            target.setAmountCent(source.getAmountCent());
+            items.add(target);
+        }
+        return items;
+    }
+}

backend/src/main/java/com/linhelp/product/ProductCategoryRequest.java

@@ -0,0 +1,54 @@
+package com.linhelp.product;
+
+import javax.validation.constraints.NotBlank;
+
+public class ProductCategoryRequest {
+    private Long tenantId;
+    private Long communityId;
+
+    @NotBlank
+    private String name;
+
+    private int sortNo;
+    private boolean enabled = true;
+
+    public Long getTenantId() {
+        return tenantId;
+    }
+
+    public void setTenantId(Long tenantId) {
+        this.tenantId = tenantId;
+    }
+
+    public Long getCommunityId() {
+        return communityId;
+    }
+
+    public void setCommunityId(Long communityId) {
+        this.communityId = communityId;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public int getSortNo() {
+        return sortNo;
+    }
+
+    public void setSortNo(int sortNo) {
+        this.sortNo = sortNo;
+    }
+
+    public boolean isEnabled() {
+        return enabled;
+    }
+
+    public void setEnabled(boolean enabled) {
+        this.enabled = enabled;
+    }
+}

backend/src/main/java/com/linhelp/product/ProductCategoryResponse.java

@@ -0,0 +1,58 @@
+package com.linhelp.product;
+
+public class ProductCategoryResponse {
+    private Long id;
+    private Long tenantId;
+    private Long communityId;
+    private String name;
+    private int sortNo;
+    private boolean enabled;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public Long getTenantId() {
+        return tenantId;
+    }
+
+    public void setTenantId(Long tenantId) {
+        this.tenantId = tenantId;
+    }
+
+    public Long getCommunityId() {
+        return communityId;
+    }
+
+    public void setCommunityId(Long communityId) {
+        this.communityId = communityId;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public int getSortNo() {
+        return sortNo;
+    }
+
+    public void setSortNo(int sortNo) {
+        this.sortNo = sortNo;
+    }
+
+    public boolean isEnabled() {
+        return enabled;
+    }
+
+    public void setEnabled(boolean enabled) {
+        this.enabled = enabled;
+    }
+}

backend/src/main/java/com/linhelp/product/ProductController.java

@@ -0,0 +1,151 @@
+package com.linhelp.product;
+
+import com.linhelp.common.api.ApiResponse;
+import com.linhelp.common.security.AuthService;
+import com.linhelp.common.security.CurrentUser;
+import com.linhelp.common.security.RequireRole;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import javax.validation.Valid;
+import java.util.List;
+
+@RestController
+public class ProductController {
+    private final ProductService productService;
+    private final AuthService authService;
+
+    public ProductController(ProductService productService, AuthService authService) {
+        this.productService = productService;
+        this.authService = authService;
+    }
+
+    @GetMapping("/api/admin/product-categories")
+    @RequireRole({"PLATFORM_ADMIN", "COMMUNITY_ADMIN", "MERCHANT"})
+    public ApiResponse<List<ProductCategoryResponse>> listAdminCategories() {
+        CurrentUser user = authService.currentUser();
+        return ApiResponse.ok(productService.listCategories(user.getCommunityId(), false));
+    }
+
+    @PostMapping("/api/admin/product-categories")
+    @RequireRole({"PLATFORM_ADMIN", "COMMUNITY_ADMIN", "MERCHANT"})
+    public ApiResponse<ProductCategoryResponse> createCategory(@Valid @RequestBody ProductCategoryRequest request) {
+        CurrentUser user = authService.currentUser();
+        request.setTenantId(user.getTenantId());
+        request.setCommunityId(user.getCommunityId());
+        return ApiResponse.ok(productService.createCategory(request));
+    }
+
+    @PutMapping("/api/admin/product-categories/{id}")
+    @RequireRole({"PLATFORM_ADMIN", "COMMUNITY_ADMIN", "MERCHANT"})
+    public ApiResponse<ProductCategoryResponse> updateCategory(@PathVariable Long id, @Valid @RequestBody ProductCategoryRequest request) {
+        CurrentUser user = authService.currentUser();
+        request.setTenantId(user.getTenantId());
+        request.setCommunityId(user.getCommunityId());
+        return ApiResponse.ok(productService.updateCategory(id, request));
+    }
+
+    @PutMapping("/api/admin/product-categories/{id}/enable")
+    @RequireRole({"PLATFORM_ADMIN", "COMMUNITY_ADMIN", "MERCHANT"})
+    public ApiResponse<ProductCategoryResponse> enableCategory(@PathVariable Long id) {
+        return ApiResponse.ok(productService.enableCategory(id));
+    }
+
+    @PutMapping("/api/admin/product-categories/{id}/disable")
+    @RequireRole({"PLATFORM_ADMIN", "COMMUNITY_ADMIN", "MERCHANT"})
+    public ApiResponse<ProductCategoryResponse> disableCategory(@PathVariable Long id) {
+        return ApiResponse.ok(productService.disableCategory(id));
+    }
+
+    @GetMapping("/api/admin/products")
+    @RequireRole({"PLATFORM_ADMIN", "COMMUNITY_ADMIN", "MERCHANT"})
+    public ApiResponse<List<ProductResponse>> listAdminProducts(@RequestParam(required = false) Long merchantId,
+                                                                 @RequestParam(required = false) Long categoryId) {
+        CurrentUser user = authService.currentUser();
+        return ApiResponse.ok(productService.listAdmin(user.getCommunityId(), merchantId, categoryId));
+    }
+
+    @PostMapping("/api/admin/products")
+    @RequireRole({"PLATFORM_ADMIN", "COMMUNITY_ADMIN", "MERCHANT"})
+    public ApiResponse<ProductResponse> createProduct(@Valid @RequestBody ProductRequest request) {
+        CurrentUser user = authService.currentUser();
+        request.setTenantId(user.getTenantId());
+        request.setCommunityId(user.getCommunityId());
+        return ApiResponse.ok(productService.createProduct(request));
+    }
+
+    @PutMapping("/api/admin/products/{id}")
+    @RequireRole({"PLATFORM_ADMIN", "COMMUNITY_ADMIN", "MERCHANT"})
+    public ApiResponse<ProductResponse> updateProduct(@PathVariable Long id, @Valid @RequestBody ProductRequest request) {
+        CurrentUser user = authService.currentUser();
+        request.setTenantId(user.getTenantId());
+        request.setCommunityId(user.getCommunityId());
+        return ApiResponse.ok(productService.updateProduct(id, request));
+    }
+
+    @PutMapping("/api/admin/products/{id}/on-shelf")
+    @RequireRole({"PLATFORM_ADMIN", "COMMUNITY_ADMIN", "MERCHANT"})
+    public ApiResponse<ProductResponse> onShelf(@PathVariable Long id) {
+        return ApiResponse.ok(productService.onShelf(id));
+    }
+
+    @PutMapping("/api/admin/products/{id}/off-shelf")
+    @RequireRole({"PLATFORM_ADMIN", "COMMUNITY_ADMIN", "MERCHANT"})
+    public ApiResponse<ProductResponse> offShelf(@PathVariable Long id) {
+        return ApiResponse.ok(productService.offShelf(id));
+    }
+
+    @PostMapping("/api/admin/products/{id}/skus")
+    @RequireRole({"PLATFORM_ADMIN", "COMMUNITY_ADMIN", "MERCHANT"})
+    public ApiResponse<ProductSkuResponse> addSku(@PathVariable Long id, @Valid @RequestBody ProductSkuRequest request) {
+        CurrentUser user = authService.currentUser();
+        request.setTenantId(user.getTenantId());
+        request.setCommunityId(user.getCommunityId());
+        return ApiResponse.ok(productService.addSku(id, request));
+    }
+
+    @PutMapping("/api/admin/products/{id}/skus/{skuId}")
+    @RequireRole({"PLATFORM_ADMIN", "COMMUNITY_ADMIN", "MERCHANT"})
+    public ApiResponse<ProductSkuResponse> updateSku(@PathVariable Long id,
+                                                      @PathVariable Long skuId,
+                                                      @Valid @RequestBody ProductSkuRequest request) {
+        CurrentUser user = authService.currentUser();
+        request.setTenantId(user.getTenantId());
+        request.setCommunityId(user.getCommunityId());
+        return ApiResponse.ok(productService.updateSku(id, skuId, request));
+    }
+
+    @PutMapping("/api/admin/products/{id}/skus/{skuId}/enable")
+    @RequireRole({"PLATFORM_ADMIN", "COMMUNITY_ADMIN", "MERCHANT"})
+    public ApiResponse<ProductSkuResponse> enableSku(@PathVariable Long id, @PathVariable Long skuId) {
+        return ApiResponse.ok(productService.enableSku(id, skuId));
+    }
+
+    @PutMapping("/api/admin/products/{id}/skus/{skuId}/disable")
+    @RequireRole({"PLATFORM_ADMIN", "COMMUNITY_ADMIN", "MERCHANT"})
+    public ApiResponse<ProductSkuResponse> disableSku(@PathVariable Long id, @PathVariable Long skuId) {
+        return ApiResponse.ok(productService.disableSku(id, skuId));
+    }
+
+    @GetMapping("/api/mini/product-categories")
+    public ApiResponse<List<ProductCategoryResponse>> listMiniCategories() {
+        CurrentUser user = authService.currentUser();
+        return ApiResponse.ok(productService.listCategories(user.getCommunityId(), true));
+    }
+
+    @GetMapping("/api/mini/products")
+    public ApiResponse<List<ProductResponse>> listMiniProducts(@RequestParam(required = false) Long categoryId) {
+        CurrentUser user = authService.currentUser();
+        return ApiResponse.ok(productService.listMini(user.getCommunityId(), categoryId));
+    }
+
+    @GetMapping("/api/mini/products/{id}")
+    public ApiResponse<ProductResponse> miniProductDetail(@PathVariable Long id) {
+        return ApiResponse.ok(productService.detail(id));
+    }
+}

backend/src/main/java/com/linhelp/product/ProductRequest.java

@@ -0,0 +1,86 @@
+package com.linhelp.product;
+
+import javax.validation.constraints.NotBlank;
+import javax.validation.constraints.NotNull;
+
+public class ProductRequest {
+    private Long tenantId;
+    private Long communityId;
+
+    @NotNull
+    private Long merchantId;
+
+    @NotNull
+    private Long categoryId;
+
+    @NotBlank
+    private String name;
+
+    private String coverUrl;
+    private String description;
+    private String unitName = "件";
+
+    public Long getTenantId() {
+        return tenantId;
+    }
+
+    public void setTenantId(Long tenantId) {
+        this.tenantId = tenantId;
+    }
+
+    public Long getCommunityId() {
+        return communityId;
+    }
+
+    public void setCommunityId(Long communityId) {
+        this.communityId = communityId;
+    }
+
+    public Long getMerchantId() {
+        return merchantId;
+    }
+
+    public void setMerchantId(Long merchantId) {
+        this.merchantId = merchantId;
+    }
+
+    public Long getCategoryId() {
+        return categoryId;
+    }
+
+    public void setCategoryId(Long categoryId) {
+        this.categoryId = categoryId;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getCoverUrl() {
+        return coverUrl;
+    }
+
+    public void setCoverUrl(String coverUrl) {
+        this.coverUrl = coverUrl;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public void setDescription(String description) {
+        this.description = description;
+    }
+
+    public String getUnitName() {
+        return unitName;
+    }
+
+    public void setUnitName(String unitName) {
+        this.unitName = unitName;
+    }
+}

backend/src/main/java/com/linhelp/product/ProductResponse.java

@@ -0,0 +1,106 @@
+package com.linhelp.product;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class ProductResponse {
+    private Long id;
+    private Long tenantId;
+    private Long communityId;
+    private Long merchantId;
+    private Long categoryId;
+    private String name;
+    private String coverUrl;
+    private String description;
+    private String unitName;
+    private String status;
+    private List<ProductSkuResponse> skus = new ArrayList<ProductSkuResponse>();
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public Long getTenantId() {
+        return tenantId;
+    }
+
+    public void setTenantId(Long tenantId) {
+        this.tenantId = tenantId;
+    }
+
+    public Long getCommunityId() {
+        return communityId;
+    }
+
+    public void setCommunityId(Long communityId) {
+        this.communityId = communityId;
+    }
+
+    public Long getMerchantId() {
+        return merchantId;
+    }
+
+    public void setMerchantId(Long merchantId) {
+        this.merchantId = merchantId;
+    }
+
+    public Long getCategoryId() {
+        return categoryId;
+    }
+
+    public void setCategoryId(Long categoryId) {
+        this.categoryId = categoryId;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getCoverUrl() {
+        return coverUrl;
+    }
+
+    public void setCoverUrl(String coverUrl) {
+        this.coverUrl = coverUrl;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public void setDescription(String description) {
+        this.description = description;
+    }
+
+    public String getUnitName() {
+        return unitName;
+    }
+
+    public void setUnitName(String unitName) {
+        this.unitName = unitName;
+    }
+
+    public String getStatus() {
+        return status;
+    }
+
+    public void setStatus(String status) {
+        this.status = status;
+    }
+
+    public List<ProductSkuResponse> getSkus() {
+        return skus;
+    }
+
+    public void setSkus(List<ProductSkuResponse> skus) {
+        this.skus = skus;
+    }
+}

backend/src/main/java/com/linhelp/product/ProductService.java

@@ -0,0 +1,329 @@
+package com.linhelp.product;
+
+import com.linhelp.common.exception.BizException;
+import org.springframework.stereotype.Service;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicLong;
+
+@Service
+public class ProductService {
+    public static final String STATUS_ON_SHELF = "ON_SHELF";
+    public static final String STATUS_OFF_SHELF = "OFF_SHELF";
+
+    private final AtomicLong categoryIds = new AtomicLong(1L);
+    private final AtomicLong productIds = new AtomicLong(1L);
+    private final AtomicLong skuIds = new AtomicLong(1L);
+    private final Map<Long, ProductCategoryResponse> categories = new LinkedHashMap<Long, ProductCategoryResponse>();
+    private final Map<Long, ProductResponse> products = new LinkedHashMap<Long, ProductResponse>();
+    private final Map<Long, ProductSkuResponse> skus = new LinkedHashMap<Long, ProductSkuResponse>();
+
+    public synchronized ProductCategoryResponse createCategory(ProductCategoryRequest request) {
+        ProductCategoryResponse category = new ProductCategoryResponse();
+        category.setId(categoryIds.getAndIncrement());
+        category.setTenantId(request.getTenantId());
+        category.setCommunityId(request.getCommunityId());
+        category.setName(request.getName());
+        category.setSortNo(request.getSortNo());
+        category.setEnabled(request.isEnabled());
+        categories.put(category.getId(), category);
+        return copyCategory(category);
+    }
+
+    public synchronized ProductCategoryResponse updateCategory(Long id, ProductCategoryRequest request) {
+        ProductCategoryResponse category = requireCategory(id);
+        category.setName(request.getName());
+        category.setSortNo(request.getSortNo());
+        category.setEnabled(request.isEnabled());
+        if (request.getTenantId() != null) {
+            category.setTenantId(request.getTenantId());
+        }
+        if (request.getCommunityId() != null) {
+            category.setCommunityId(request.getCommunityId());
+        }
+        return copyCategory(category);
+    }
+
+    public synchronized ProductCategoryResponse enableCategory(Long id) {
+        ProductCategoryResponse category = requireCategory(id);
+        category.setEnabled(true);
+        return copyCategory(category);
+    }
+
+    public synchronized ProductCategoryResponse disableCategory(Long id) {
+        ProductCategoryResponse category = requireCategory(id);
+        category.setEnabled(false);
+        return copyCategory(category);
+    }
+
+    public synchronized List<ProductCategoryResponse> listCategories(Long communityId, boolean onlyEnabled) {
+        List<ProductCategoryResponse> result = new ArrayList<ProductCategoryResponse>();
+        for (ProductCategoryResponse category : categories.values()) {
+            if (communityId.equals(category.getCommunityId()) && (!onlyEnabled || category.isEnabled())) {
+                result.add(copyCategory(category));
+            }
+        }
+        Collections.sort(result, new Comparator<ProductCategoryResponse>() {
+            @Override
+            public int compare(ProductCategoryResponse left, ProductCategoryResponse right) {
+                return Integer.valueOf(left.getSortNo()).compareTo(right.getSortNo());
+            }
+        });
+        return result;
+    }
+
+    public synchronized ProductResponse createProduct(ProductRequest request) {
+        ProductResponse product = new ProductResponse();
+        product.setId(productIds.getAndIncrement());
+        product.setTenantId(request.getTenantId());
+        product.setCommunityId(request.getCommunityId());
+        copyProductFields(request, product);
+        product.setStatus(STATUS_OFF_SHELF);
+        products.put(product.getId(), product);
+        return copyProduct(product);
+    }
+
+    public synchronized ProductResponse updateProduct(Long id, ProductRequest request) {
+        ProductResponse product = requireProduct(id);
+        copyProductFields(request, product);
+        if (request.getTenantId() != null) {
+            product.setTenantId(request.getTenantId());
+        }
+        if (request.getCommunityId() != null) {
+            product.setCommunityId(request.getCommunityId());
+        }
+        return copyProduct(product);
+    }
+
+    public synchronized ProductResponse onShelf(Long id) {
+        ProductResponse product = requireProduct(id);
+        product.setStatus(STATUS_ON_SHELF);
+        return copyProduct(product);
+    }
+
+    public synchronized ProductResponse offShelf(Long id) {
+        ProductResponse product = requireProduct(id);
+        product.setStatus(STATUS_OFF_SHELF);
+        return copyProduct(product);
+    }
+
+    public synchronized ProductResponse detail(Long id) {
+        return copyProduct(requireProduct(id));
+    }
+
+    public synchronized List<ProductResponse> listAdmin(Long communityId, Long merchantId, Long categoryId) {
+        return listProducts(communityId, merchantId, categoryId, false);
+    }
+
+    public synchronized List<ProductResponse> listMini(Long communityId, Long categoryId) {
+        return listProducts(communityId, null, categoryId, true);
+    }
+
+    public synchronized ProductSkuResponse addSku(Long productId, ProductSkuRequest request) {
+        ProductResponse product = requireProduct(productId);
+        ProductSkuResponse sku = new ProductSkuResponse();
+        sku.setId(skuIds.getAndIncrement());
+        sku.setTenantId(request.getTenantId() == null ? product.getTenantId() : request.getTenantId());
+        sku.setCommunityId(request.getCommunityId() == null ? product.getCommunityId() : request.getCommunityId());
+        sku.setProductId(productId);
+        sku.setProductName(product.getName());
+        copySkuFields(request, sku);
+        skus.put(sku.getId(), sku);
+        return copySku(sku);
+    }
+
+    public synchronized ProductSkuResponse updateSku(Long productId, Long skuId, ProductSkuRequest request) {
+        requireProduct(productId);
+        ProductSkuResponse sku = requireSku(skuId);
+        if (!productId.equals(sku.getProductId())) {
+            throw new BizException(404, "商品规格不存在");
+        }
+        copySkuFields(request, sku);
+        if (request.getTenantId() != null) {
+            sku.setTenantId(request.getTenantId());
+        }
+        if (request.getCommunityId() != null) {
+            sku.setCommunityId(request.getCommunityId());
+        }
+        ProductResponse product = products.get(productId);
+        sku.setProductName(product.getName());
+        return copySku(sku);
+    }
+
+    public synchronized ProductSkuResponse enableSku(Long productId, Long skuId) {
+        return setSkuEnabled(productId, skuId, true);
+    }
+
+    public synchronized ProductSkuResponse disableSku(Long productId, Long skuId) {
+        return setSkuEnabled(productId, skuId, false);
+    }
+
+    public synchronized ProductSkuResponse createDemoSku(Long tenantId, Long communityId, Long productId, String skuName, int priceCent, int stock) {
+        ProductSkuResponse sku = new ProductSkuResponse();
+        sku.setId(skuIds.getAndIncrement());
+        sku.setTenantId(tenantId);
+        sku.setCommunityId(communityId);
+        sku.setProductId(productId);
+        sku.setProductName(resolveProductName(productId));
+        sku.setSkuName(skuName);
+        sku.setPriceCent(priceCent);
+        sku.setStock(stock);
+        sku.setEnabled(true);
+        skus.put(sku.getId(), sku);
+        return copySku(sku);
+    }
+
+    public synchronized ProductSkuResponse getSku(Long skuId) {
+        return copySku(requireSku(skuId));
+    }
+
+    public synchronized void deductStock(Long skuId, int quantity) {
+        if (quantity <= 0) {
+            throw new BizException("购买数量必须大于0");
+        }
+        ProductSkuResponse sku = requireSku(skuId);
+        if (!sku.isEnabled()) {
+            throw new BizException("商品规格已下架");
+        }
+        if (sku.getStock() < quantity) {
+            throw new BizException("库存不足");
+        }
+        sku.setStock(sku.getStock() - quantity);
+    }
+
+    private ProductSkuResponse setSkuEnabled(Long productId, Long skuId, boolean enabled) {
+        requireProduct(productId);
+        ProductSkuResponse sku = requireSku(skuId);
+        if (!productId.equals(sku.getProductId())) {
+            throw new BizException(404, "商品规格不存在");
+        }
+        sku.setEnabled(enabled);
+        return copySku(sku);
+    }
+
+    private List<ProductResponse> listProducts(Long communityId, Long merchantId, Long categoryId, boolean onlyOnShelf) {
+        List<ProductResponse> result = new ArrayList<ProductResponse>();
+        for (ProductResponse product : products.values()) {
+            if (!communityId.equals(product.getCommunityId())) {
+                continue;
+            }
+            if (merchantId != null && !merchantId.equals(product.getMerchantId())) {
+                continue;
+            }
+            if (categoryId != null && !categoryId.equals(product.getCategoryId())) {
+                continue;
+            }
+            if (onlyOnShelf && !STATUS_ON_SHELF.equals(product.getStatus())) {
+                continue;
+            }
+            result.add(copyProduct(product));
+        }
+        return result;
+    }
+
+    private ProductCategoryResponse requireCategory(Long id) {
+        ProductCategoryResponse category = categories.get(id);
+        if (category == null) {
+            throw new BizException(404, "商品分类不存在");
+        }
+        return category;
+    }
+
+    private ProductResponse requireProduct(Long id) {
+        ProductResponse product = products.get(id);
+        if (product == null) {
+            throw new BizException(404, "商品不存在");
+        }
+        return product;
+    }
+
+    private ProductSkuResponse requireSku(Long id) {
+        ProductSkuResponse sku = skus.get(id);
+        if (sku == null) {
+            throw new BizException(404, "商品规格不存在");
+        }
+        return sku;
+    }
+
+    private void copyProductFields(ProductRequest request, ProductResponse product) {
+        product.setMerchantId(request.getMerchantId());
+        product.setCategoryId(request.getCategoryId());
+        product.setName(request.getName());
+        product.setCoverUrl(request.getCoverUrl());
+        product.setDescription(request.getDescription());
+        product.setUnitName(request.getUnitName());
+    }
+
+    private void copySkuFields(ProductSkuRequest request, ProductSkuResponse sku) {
+        sku.setSkuName(request.getSkuName());
+        sku.setPriceCent(request.getPriceCent());
+        sku.setOriginPriceCent(request.getOriginPriceCent());
+        sku.setStock(request.getStock());
+        sku.setEnabled(request.isEnabled());
+    }
+
+    private String resolveProductName(Long productId) {
+        ProductResponse product = products.get(productId);
+        if (product == null) {
+            return "Demo Product " + productId;
+        }
+        return product.getName();
+    }
+
+    private ProductCategoryResponse copyCategory(ProductCategoryResponse source) {
+        ProductCategoryResponse target = new ProductCategoryResponse();
+        target.setId(source.getId());
+        target.setTenantId(source.getTenantId());
+        target.setCommunityId(source.getCommunityId());
+        target.setName(source.getName());
+        target.setSortNo(source.getSortNo());
+        target.setEnabled(source.isEnabled());
+        return target;
+    }
+
+    private ProductResponse copyProduct(ProductResponse source) {
+        ProductResponse target = new ProductResponse();
+        target.setId(source.getId());
+        target.setTenantId(source.getTenantId());
+        target.setCommunityId(source.getCommunityId());
+        target.setMerchantId(source.getMerchantId());
+        target.setCategoryId(source.getCategoryId());
+        target.setName(source.getName());
+        target.setCoverUrl(source.getCoverUrl());
+        target.setDescription(source.getDescription());
+        target.setUnitName(source.getUnitName());
+        target.setStatus(source.getStatus());
+        target.setSkus(listSkusByProduct(source.getId()));
+        return target;
+    }
+
+    private List<ProductSkuResponse> listSkusByProduct(Long productId) {
+        List<ProductSkuResponse> result = new ArrayList<ProductSkuResponse>();
+        for (ProductSkuResponse sku : skus.values()) {
+            if (productId.equals(sku.getProductId())) {
+                result.add(copySku(sku));
+            }
+        }
+        return result;
+    }
+
+    private ProductSkuResponse copySku(ProductSkuResponse source) {
+        ProductSkuResponse target = new ProductSkuResponse();
+        target.setId(source.getId());
+        target.setTenantId(source.getTenantId());
+        target.setCommunityId(source.getCommunityId());
+        target.setProductId(source.getProductId());
+        target.setProductName(source.getProductName());
+        target.setSkuName(source.getSkuName());
+        target.setPriceCent(source.getPriceCent());
+        target.setOriginPriceCent(source.getOriginPriceCent());
+        target.setStock(source.getStock());
+        target.setEnabled(source.isEnabled());
+        return target;
+    }
+}

backend/src/main/java/com/linhelp/product/ProductSkuRequest.java

@@ -0,0 +1,78 @@
+package com.linhelp.product;
+
+import javax.validation.constraints.Min;
+import javax.validation.constraints.NotBlank;
+
+public class ProductSkuRequest {
+    private Long tenantId;
+    private Long communityId;
+
+    @NotBlank
+    private String skuName;
+
+    @Min(0)
+    private int priceCent;
+
+    private Integer originPriceCent;
+
+    @Min(0)
+    private int stock;
+
+    private boolean enabled = true;
+
+    public Long getTenantId() {
+        return tenantId;
+    }
+
+    public void setTenantId(Long tenantId) {
+        this.tenantId = tenantId;
+    }
+
+    public Long getCommunityId() {
+        return communityId;
+    }
+
+    public void setCommunityId(Long communityId) {
+        this.communityId = communityId;
+    }
+
+    public String getSkuName() {
+        return skuName;
+    }
+
+    public void setSkuName(String skuName) {
+        this.skuName = skuName;
+    }
+
+    public int getPriceCent() {
+        return priceCent;
+    }
+
+    public void setPriceCent(int priceCent) {
+        this.priceCent = priceCent;
+    }
+
+    public Integer getOriginPriceCent() {
+        return originPriceCent;
+    }
+
+    public void setOriginPriceCent(Integer originPriceCent) {
+        this.originPriceCent = originPriceCent;
+    }
+
+    public int getStock() {
+        return stock;
+    }
+
+    public void setStock(int stock) {
+        this.stock = stock;
+    }
+
+    public boolean isEnabled() {
+        return enabled;
+    }
+
+    public void setEnabled(boolean enabled) {
+        this.enabled = enabled;
+    }
+}

backend/src/main/java/com/linhelp/product/ProductSkuResponse.java

@@ -0,0 +1,94 @@
+package com.linhelp.product;
+
+public class ProductSkuResponse {
+    private Long id;
+    private Long tenantId;
+    private Long communityId;
+    private Long productId;
+    private String productName;
+    private String skuName;
+    private int priceCent;
+    private Integer originPriceCent;
+    private int stock;
+    private boolean enabled;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public Long getTenantId() {
+        return tenantId;
+    }
+
+    public void setTenantId(Long tenantId) {
+        this.tenantId = tenantId;
+    }
+
+    public Long getCommunityId() {
+        return communityId;
+    }
+
+    public void setCommunityId(Long communityId) {
+        this.communityId = communityId;
+    }
+
+    public Long getProductId() {
+        return productId;
+    }
+
+    public void setProductId(Long productId) {
+        this.productId = productId;
+    }
+
+    public String getProductName() {
+        return productName;
+    }
+
+    public void setProductName(String productName) {
+        this.productName = productName;
+    }
+
+    public String getSkuName() {
+        return skuName;
+    }
+
+    public void setSkuName(String skuName) {
+        this.skuName = skuName;
+    }
+
+    public int getPriceCent() {
+        return priceCent;
+    }
+
+    public void setPriceCent(int priceCent) {
+        this.priceCent = priceCent;
+    }
+
+    public Integer getOriginPriceCent() {
+        return originPriceCent;
+    }
+
+    public void setOriginPriceCent(Integer originPriceCent) {
+        this.originPriceCent = originPriceCent;
+    }
+
+    public int getStock() {
+        return stock;
+    }
+
+    public void setStock(int stock) {
+        this.stock = stock;
+    }
+
+    public boolean isEnabled() {
+        return enabled;
+    }
+
+    public void setEnabled(boolean enabled) {
+        this.enabled = enabled;
+    }
+}

backend/src/test/java/com/linhelp/order/GoodsOrderServiceTests.java

@@ -0,0 +1,53 @@
+package com.linhelp.order;
+
+import com.linhelp.common.enums.DeliveryMethod;
+import com.linhelp.common.enums.GoodsOrderStatus;
+import com.linhelp.product.ProductService;
+import com.linhelp.product.ProductSkuResponse;
+import org.junit.jupiter.api.Test;
+
+import java.util.Collections;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+class GoodsOrderServiceTests {
+
+    @Test
+    void cannotCreateGoodsOrderWhenSkuStockIsInsufficient() {
+        ProductService productService = new ProductService();
+        ProductSkuResponse sku = productService.createDemoSku(1L, 1L, 1L, "500g", 990, 2);
+        GoodsOrderService goodsOrderService = new GoodsOrderService(productService);
+
+        CreateGoodsOrderRequest request = new CreateGoodsOrderRequest();
+        request.setTenantId(1L);
+        request.setCommunityId(1L);
+        request.setMerchantId(1L);
+        request.setAddressId(1L);
+        request.setDeliveryMethod(DeliveryMethod.IMMEDIATE);
+        request.setItems(Collections.singletonList(new CreateGoodsOrderItemRequest(1L, sku.getId(), 99)));
+
+        assertThatThrownBy(() -> goodsOrderService.create(1L, request))
+                .hasMessageContaining("库存不足");
+    }
+
+    @Test
+    void selfPickupOrderMovesToPendingPickupAfterPreparing() {
+        ProductService productService = new ProductService();
+        ProductSkuResponse sku = productService.createDemoSku(1L, 1L, 1L, "500g", 990, 5);
+        GoodsOrderService goodsOrderService = new GoodsOrderService(productService);
+
+        CreateGoodsOrderRequest request = new CreateGoodsOrderRequest();
+        request.setTenantId(1L);
+        request.setCommunityId(1L);
+        request.setMerchantId(1L);
+        request.setDeliveryMethod(DeliveryMethod.SELF_PICKUP);
+        request.setItems(Collections.singletonList(new CreateGoodsOrderItemRequest(1L, sku.getId(), 1)));
+        GoodsOrderResponse order = goodsOrderService.create(1L, request);
+
+        goodsOrderService.confirm(order.getId());
+        goodsOrderService.markPrepared(order.getId());
+
+        assertThat(goodsOrderService.detail(order.getId()).getStatus()).isEqualTo(GoodsOrderStatus.PENDING_PICKUP);
+    }
+}

backend/src/test/java/com/linhelp/product/ProductInventoryTests.java

@@ -0,0 +1,18 @@
+package com.linhelp.product;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class ProductInventoryTests {
+
+    @Test
+    void deductStockReducesSkuStock() {
+        ProductService productService = new ProductService();
+        ProductSkuResponse sku = productService.createDemoSku(1L, 1L, 1L, "500g", 990, 5);
+
+        productService.deductStock(sku.getId(), 2);
+
+        assertThat(productService.getSku(sku.getId()).getStock()).isEqualTo(3);
+    }
+}