first commit

2021-09-03 09:52:42 +00:00
commit eef066b179
11 changed files with 477 additions and 0 deletions
--- a/handlers/handlers.go
+++ b/handlers/handlers.go
@ -0,0 +1,166 @@
+package handlers
+
+import (
+	"crypto/sha256"
+	"crypto/subtle"
+	"encoding/json"
+	"errors"
+	"io/ioutil"
+	"net/http"
+	"os"
+
+	"github.com/HelloWorld/goProductAPI/entity"
+	"github.com/gorilla/mux"
+)
+
+// GetProductsHandler is used to get data inside the products defined on our product catalog
+func GetProductsHandler() http.HandlerFunc {
+	return func(rw http.ResponseWriter, r *http.Request) {
+		data, err := entity.GetProducts()
+		if err != nil {
+			rw.WriteHeader(http.StatusInternalServerError)
+			return
+		}
+		// Write the body with JSON data
+		rw.Header().Add("content-type", "application/json")
+		rw.WriteHeader(http.StatusFound)
+		rw.Write(data)
+	}
+}
+
+// GetProductHandler is used to get data inside the products defined on our product catalog
+func GetProductHandler() http.HandlerFunc {
+	return func(rw http.ResponseWriter, r *http.Request) {
+		// Read product ID
+		productID := mux.Vars(r)["id"]
+		product, err := entity.GetProduct(productID)
+		if err != nil {
+			rw.WriteHeader(http.StatusInternalServerError)
+			return
+		}
+		responseData, err := json.Marshal(product)
+		if err != nil {
+			// Check if it is No product error or any other error
+			if errors.Is(err, entity.ErrNoProduct) {
+				// Write Header if no related product found.
+				rw.WriteHeader(http.StatusNoContent)
+			} else {
+				rw.WriteHeader(http.StatusInternalServerError)
+			}
+			return
+		}
+		// Write body with found product
+		rw.Header().Add("content-type", "application/json")
+		rw.WriteHeader(http.StatusFound)
+		rw.Write(responseData)
+	}
+}
+
+// CreateProductHandler is used to create a new product and add to our product store.
+func CreateProductHandler() http.HandlerFunc {
+	return func(rw http.ResponseWriter, r *http.Request) {
+		// Read incoming JSON from request body
+		data, err := ioutil.ReadAll(r.Body)
+		// If no body is associated return with StatusBadRequest
+		if err != nil {
+			rw.WriteHeader(http.StatusBadRequest)
+			return
+		}
+		// Check if data is proper JSON (data validation)
+		var product entity.Product
+		err = json.Unmarshal(data, &product)
+		if err != nil {
+			rw.WriteHeader(http.StatusExpectationFailed)
+			rw.Write([]byte("Invalid Data Format"))
+			return
+		}
+		err = entity.AddProduct(product)
+		if err != nil {
+			rw.WriteHeader(http.StatusInternalServerError)
+			return
+		}
+		// return after writing Body
+		rw.WriteHeader(http.StatusCreated)
+		rw.Write([]byte("Added New Product"))
+	}
+}
+
+// DeleteProductHandler deletes the product with given ID.
+func DeleteProductHandler() http.HandlerFunc {
+	return func(rw http.ResponseWriter, r *http.Request) {
+		// Read product ID
+		productID := mux.Vars(r)["id"]
+		err := entity.DeleteProduct(productID)
+		if err != nil {
+			// Check if it is No product error or any other error
+			if errors.Is(err, entity.ErrNoProduct) {
+				// Write Header if no related product found.
+				rw.WriteHeader(http.StatusNoContent)
+			} else {
+				rw.WriteHeader(http.StatusInternalServerError)
+			}
+			return
+		}
+		// Write Header with Accepted Status (done operation)
+		rw.WriteHeader(http.StatusAccepted)
+	}
+}
+
+// UpdateProductHandler updates the product with given ID.
+func UpdateProductHandler() http.HandlerFunc {
+	return func(rw http.ResponseWriter, r *http.Request) {
+		// Read product ID
+		productID := mux.Vars(r)["id"]
+		err := entity.DeleteProduct(productID)
+		if err != nil {
+			if errors.Is(err, entity.ErrNoProduct) {
+				rw.WriteHeader(http.StatusNoContent)
+			} else {
+				rw.WriteHeader(http.StatusInternalServerError)
+			}
+			return
+		}
+		// Read incoming JSON from request body
+		data, err := ioutil.ReadAll(r.Body)
+		// If no body is associated return with StatusBadRequest
+		if err != nil {
+			rw.WriteHeader(http.StatusBadRequest)
+			return
+		}
+		// Check if data is proper JSON (data validation)
+		var product entity.Product
+		err = json.Unmarshal(data, &product)
+		if err != nil {
+			rw.WriteHeader(http.StatusExpectationFailed)
+			rw.Write([]byte("Invalid Data Format"))
+			return
+		}
+		// Addproduct with the requested body
+		err = entity.AddProduct(product)
+		if err != nil {
+			rw.WriteHeader(http.StatusInternalServerError)
+			return
+		}
+		// Write Header if no related product found.
+		rw.WriteHeader(http.StatusAccepted)
+	}
+}
+
+func AuthHandler(h http.Handler) http.HandlerFunc {
+	return func(rw http.ResponseWriter, r *http.Request) {
+		user, pass, ok := r.BasicAuth()
+		if ok {
+			username := sha256.Sum256([]byte(os.Getenv("USER_NAME")))
+			password := sha256.Sum256([]byte(os.Getenv("USER_PASS")))
+			userHash := sha256.Sum256([]byte(user))
+			passHash := sha256.Sum256([]byte(pass))
+			validUser := subtle.ConstantTimeCompare(userHash[:],username[:]) == 1
+			validPass := subtle.ConstantTimeCompare(passHash[:],password[:]) == 1
+			if validPass && validUser{
+			    h.ServeHTTP(rw,r)
+				return
+			}
+		}
+		http.Error(rw, "No/Invalid Credentials", http.StatusUnauthorized)
+	}
+}