Initial project snapshot

backend/internal/platform/httpx/json.go

@@ -0,0 +1,45 @@
+package httpx
+
+import (
+	"encoding/json"
+	"net/http"
+)
+
+func WriteJSON(w http.ResponseWriter, status int, payload any) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(status)
+	_ = json.NewEncoder(w).Encode(payload)
+}
+
+func WriteError(w http.ResponseWriter, status int, message string) {
+	traceID := ensureTraceID(w)
+	WriteJSON(w, status, ErrorResponse{
+		Error: NewErrorMessage(status, message, nil, traceID),
+	})
+}
+
+func WriteErrorMessage(w http.ResponseWriter, status int, message any) {
+	traceID := ensureTraceID(w)
+	switch payload := message.(type) {
+	case string:
+		WriteJSON(w, status, ErrorResponse{
+			Error: NewErrorMessage(status, payload, nil, traceID),
+		})
+	case ErrorResponse:
+		payload.Error.TraceID = traceID
+		WriteJSON(w, status, payload)
+	case *ErrorResponse:
+		if payload == nil {
+			WriteJSON(w, status, ErrorResponse{
+				Error: NewErrorMessage(status, "", nil, traceID),
+			})
+			return
+		}
+		payload.Error.TraceID = traceID
+		WriteJSON(w, status, payload)
+	default:
+		WriteJSON(w, status, ErrorResponse{
+			Error: NewErrorMessage(status, "Request failed.", nil, traceID),
+		})
+	}
+}

backend/internal/platform/httpx/message.go

@@ -0,0 +1,131 @@
+package httpx
+
+import (
+	"net/http"
+	"strings"
+	"unicode"
+
+	"github.com/google/uuid"
+
+	messagecontracts "github.com/example/remote-access-platform/backend/pkg/contracts/message"
+)
+
+type ErrorResponse struct {
+	Error messagecontracts.Message `json:"error"`
+}
+
+func NewMessage(code, messageKey, fallbackMessage string, details map[string]any, traceID string) messagecontracts.Message {
+	if traceID == "" {
+		traceID = uuid.NewString()
+	}
+	if details == nil {
+		details = map[string]any{}
+	}
+	return messagecontracts.Message{
+		Code:            code,
+		MessageKey:      messageKey,
+		FallbackMessage: fallbackMessage,
+		Details:         details,
+		TraceID:         traceID,
+	}
+}
+
+func NewErrorMessage(status int, fallbackMessage string, details map[string]any, traceID string) messagecontracts.Message {
+	normalizedFallback, normalizedDetails := normalizeErrorFallback(status, fallbackMessage, details)
+	code := deriveErrorCode(status, normalizedFallback)
+	return NewMessage(code, "errors."+code, normalizedFallback, normalizedDetails, traceID)
+}
+
+func ensureTraceID(w http.ResponseWriter) string {
+	traceID := w.Header().Get("X-Trace-Id")
+	if traceID == "" {
+		traceID = uuid.NewString()
+		w.Header().Set("X-Trace-Id", traceID)
+	}
+	return traceID
+}
+
+func normalizeErrorFallback(status int, fallbackMessage string, details map[string]any) (string, map[string]any) {
+	if details == nil {
+		details = map[string]any{}
+	}
+	details["http_status"] = status
+
+	if status >= http.StatusInternalServerError {
+		return "An internal server error occurred.", details
+	}
+
+	trimmed := strings.TrimSpace(fallbackMessage)
+	switch strings.ToLower(trimmed) {
+	case "forbidden", "access denied":
+		return "Access denied.", details
+	}
+
+	if field, ok := extractRequiredField(trimmed); ok {
+		details["field"] = field
+	}
+
+	return trimmed, details
+}
+
+func deriveErrorCode(status int, fallbackMessage string) string {
+	switch strings.ToLower(strings.TrimSpace(fallbackMessage)) {
+	case "invalid credentials":
+		return "auth.invalid_credentials"
+	case "session expired. please sign in again.":
+		return "auth.session_expired"
+	case "access denied.":
+		return "common.access_denied"
+	}
+
+	statusPrefix := map[int]string{
+		http.StatusBadRequest:          "bad_request",
+		http.StatusUnauthorized:        "unauthorized",
+		http.StatusForbidden:           "forbidden",
+		http.StatusNotFound:            "not_found",
+		http.StatusConflict:            "conflict",
+		http.StatusUnprocessableEntity: "unprocessable_entity",
+		http.StatusInternalServerError: "internal_server_error",
+	}[status]
+	if statusPrefix == "" {
+		statusPrefix = "http_" + strings.ReplaceAll(http.StatusText(status), " ", "_")
+		statusPrefix = strings.ToLower(statusPrefix)
+	}
+
+	slug := slugifyMessage(fallbackMessage)
+	if slug == "" {
+		slug = "message"
+	}
+	if status >= http.StatusInternalServerError {
+		return "common." + statusPrefix
+	}
+	return statusPrefix + "." + slug
+}
+
+func slugifyMessage(input string) string {
+	var builder strings.Builder
+	lastUnderscore := false
+	for _, r := range strings.ToLower(strings.TrimSpace(input)) {
+		if unicode.IsLetter(r) || unicode.IsDigit(r) {
+			builder.WriteRune(r)
+			lastUnderscore = false
+			continue
+		}
+		if !lastUnderscore {
+			builder.WriteRune('_')
+			lastUnderscore = true
+		}
+	}
+	return strings.Trim(builder.String(), "_")
+}
+
+func extractRequiredField(message string) (string, bool) {
+	const suffix = " is required"
+	if !strings.HasSuffix(strings.ToLower(message), suffix) {
+		return "", false
+	}
+	field := strings.TrimSpace(message[:len(message)-len(suffix)])
+	field = strings.ReplaceAll(field, " ", "_")
+	field = strings.ToLower(field)
+	return field, field != ""
+}