feat(lib): add grpc service for prices in product service server prot…

…obuff definition #139

lib/rpc/product/product.proto

@@ -10,6 +10,12 @@ message Product {
   uint64 ean = 3;
 }
 
+message Price {
+  uint64 userId = 1;
+  uint64 productId = 2;
+  float price = 3;
+}
+
 service ProductService {
   // create method for adding a new product
   rpc CreateProduct(CreateProductRequest) returns (CreateProductResponse);
@@ -27,6 +33,26 @@ service ProductService {
   rpc DeleteProduct(DeleteProductRequest) returns (DeleteProductResponse);
 }
 
+service PriceService {
+  // create method for adding a new price
+  rpc CreatePrice(CreatePriceRequest) returns (CreatePriceResponse);
+
+  // read method for finding a price by ids
+  rpc FindPrice(FindPriceRequest) returns (FindPriceResponse);
+
+  // read method for finding all products
+  rpc FindAllPrices(FindAllPricesRequest) returns (FindAllPricesResponse);
+
+  // read method for finding all products from a specific user/vendor
+  rpc FindAllPricesFromUser(FindAllPricesFromUserRequest) returns (FindAllPricesFromUserResponse);
+
+  // update method for updating a price
+  rpc UpdatePrice(UpdatePriceRequest) returns (UpdatePriceResponse);
+
+  // delete method to get rid of a price
+  rpc DeletePrice(DeletePriceRequest) returns (DeletePriceResponse);
+}
+
 // Request- and Response-Messages for CreateProduct
 message CreateProductRequest {
   Product product = 1;
@@ -68,4 +94,58 @@ message DeleteProductRequest {
 }
 
 message DeleteProductResponse {
+}
+
+// Request- and Response-Messages for CreatePrice
+message CreatePriceRequest {
+  Price price = 1;
+}
+
+message CreatePriceResponse {
+  Price price = 1;
+}
+
+// Request- and Response-Messages for FindPrice
+message FindPriceRequest {
+  uint64 userId = 1;
+  uint64 productId = 2;
+}
+
+message FindPriceResponse {
+  Price price = 1;
+}
+
+// Request- and Response-Messages for FindAllPrices
+message FindAllPricesRequest {
+}
+
+message FindAllPricesResponse {
+  repeated Price price = 1;
+}
+
+// Request- and Response-Messages for FindAllPricesFromUser
+message FindAllPricesFromUserRequest {
+  uint64 userId = 1;
+}
+
+message FindAllPricesFromUserResponse {
+  repeated Price price = 1;
+}
+
+// Request- and Response-Messages for UpdateProduct
+message UpdatePriceRequest {
+  Price price = 1;
+}
+
+message UpdatePriceResponse {
+  Price price = 1;
+}
+
+// Request- and Response-Messages for DeleteProduct
+message DeletePriceRequest {
+  uint64 userId = 1;
+  uint64 productId = 2;
+}
+
+message DeletePriceResponse {
 }