initial commit

cmd/handlers/handlers.go

@@ -0,0 +1,109 @@
+package handlers
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+
+	"gitlab.com/developerdurp/logger"
+)
+
+type BasicMessage struct {
+	Message string `json:"message"`
+}
+
+type StandardMessage struct {
+	Message interface{}
+	Status  int `json:"status"`
+}
+
+type StandardError struct {
+	Message     string   `json:"message"`
+	Status      int      `json:"status"`
+	Description []string `json:"description"`
+}
+
+func (e StandardError) Error() string {
+	return fmt.Sprintf("Api error: %d", e.Status)
+}
+
+type Response interface {
+	SendResponse(w http.ResponseWriter)
+	Test(http.Handler)
+}
+
+func (message *StandardMessage) SendReponse(w http.ResponseWriter) {
+	setHeader(&w, message.Status)
+
+	// Write the message to the response body.
+	err := json.NewEncoder(w).Encode(message.Message)
+	if err != nil {
+		logger.LogError("Failed to Encode")
+	}
+}
+
+func (message *StandardError) SendReponse(w http.ResponseWriter) {
+	setHeader(&w, message.Status)
+
+	// Write the message to the response body.
+	err := json.NewEncoder(w).Encode(message)
+	if err != nil {
+		logger.LogError("Failed to Encode")
+	}
+}
+
+// NewFailureResponse returns a new instance of StandardError with the given message, status code and description.
+func NewFailureResponse(message string, status int, description []string) StandardError {
+	return StandardError{
+		Message:     message,
+		Status:      status,
+		Description: description,
+	}
+}
+
+// NewMessageResponse returns a new instance of StandardMessage with the given message and status code.
+func NewMessageResponse(message interface{}, status int) *StandardMessage {
+	return &StandardMessage{
+		Message: message,
+		Status:  status,
+	}
+}
+
+// NewBasicResponse returns a new basic instance of StandardMessage with the message of OK and Status OK.
+func NewBasicResponse() *StandardMessage {
+	return &StandardMessage{
+		Message: BasicMessage{
+			Message: "OK",
+		},
+		Status: http.StatusOK,
+	}
+}
+
+// SetHeader sets the HTTP response headers for a JSON response.
+func setHeader(w *http.ResponseWriter, statusCode int) {
+	(*w).WriteHeader(statusCode)
+	(*w).Header().Set("Content-Type", "application/json")
+}
+
+type APIFunc func(w http.ResponseWriter, r *http.Request) (*StandardMessage, error)
+
+func Make(handler APIFunc) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		resp, err := handler(w, r)
+		if err != nil {
+			var apiErr StandardError
+			if errors.As(err, &apiErr) {
+				apiErr.SendReponse(w)
+				return
+			}
+			resp := NewFailureResponse(
+				"Internal Server Error",
+				http.StatusInternalServerError,
+				[]string{err.Error()},
+			)
+			resp.SendReponse(w)
+		}
+		resp.SendReponse(w)
+	}
+}