Refactor: improve backend modularity

Backend/internal/httpx/api_project_decode.go

@@ -0,0 +1,127 @@
+// Path: Backend/internal/httpx/api_project_decode.go
+
+package httpx
+
+import (
+	"encoding/json"
+	"errors"
+	"io"
+	"net/http"
+	"strings"
+)
+
+type createProjectFolderRequest struct {
+	Name             string `json:"name"`
+	ParentFolderPath string `json:"parentFolderId"`
+}
+
+type renameProjectFolderRequest struct {
+	FolderPath string `json:"folderId"`
+	Name       string `json:"name"`
+}
+
+type deleteProjectFolderRequest struct {
+	FolderPath string `json:"folderId"`
+}
+
+// Keep the existing JSON contract for the frontend, but use clearer path-vs-stable-ID
+// names internally so the move flow is easier to reason about.
+type moveProjectFolderRequest struct {
+	FolderPath       string `json:"folderId"`
+	FolderStableID   string `json:"folderNodeId"`
+	ParentFolderPath string `json:"parentFolderId"`
+	ParentStableID   string `json:"parentNodeId"`
+	TargetIndex      int    `json:"targetIndex"`
+}
+
+type createProjectItemRequest struct {
+	Name             string `json:"name"`
+	ParentFolderPath string `json:"parentFolderId"`
+	ItemType         string `json:"itemType"`
+}
+
+type deleteProjectItemRequest struct {
+	ItemPath string `json:"itemId"`
+}
+
+type moveProjectItemRequest struct {
+	ItemPath         string `json:"itemId"`
+	ItemStableID     string `json:"itemNodeId"`
+	ParentFolderPath string `json:"parentFolderId"`
+	ParentStableID   string `json:"parentNodeId"`
+	TargetIndex      int    `json:"targetIndex"`
+}
+
+func decodeMoveProjectFolderRequest(w http.ResponseWriter, r *http.Request) (moveProjectFolderRequest, bool) {
+	var payload moveProjectFolderRequest
+	if !decodeJSONObjectBody(w, r, &payload) {
+		return payload, false
+	}
+	return payload, true
+}
+
+func decodeDeleteProjectFolderRequest(r *http.Request) deleteProjectFolderRequest {
+	return deleteProjectFolderRequest{
+		FolderPath: strings.TrimSpace(r.URL.Query().Get("folderId")),
+	}
+}
+
+func decodeDeleteProjectItemRequest(r *http.Request) deleteProjectItemRequest {
+	return deleteProjectItemRequest{
+		ItemPath: strings.TrimSpace(r.URL.Query().Get("itemId")),
+	}
+}
+
+func decodeRenameProjectFolderRequest(w http.ResponseWriter, r *http.Request) (renameProjectFolderRequest, bool) {
+	var payload renameProjectFolderRequest
+	if !decodeJSONObjectBody(w, r, &payload) {
+		return payload, false
+	}
+	return payload, true
+}
+
+func decodeProjectFolderRequest(w http.ResponseWriter, r *http.Request) (createProjectFolderRequest, bool) {
+	var payload createProjectFolderRequest
+	if !decodeJSONObjectBody(w, r, &payload) {
+		return payload, false
+	}
+	return payload, true
+}
+
+func decodeProjectItemRequest(w http.ResponseWriter, r *http.Request) (createProjectItemRequest, bool) {
+	var payload createProjectItemRequest
+	if !decodeJSONObjectBody(w, r, &payload) {
+		return payload, false
+	}
+	return payload, true
+}
+
+func decodeMoveProjectItemRequest(w http.ResponseWriter, r *http.Request) (moveProjectItemRequest, bool) {
+	var payload moveProjectItemRequest
+	if !decodeJSONObjectBody(w, r, &payload) {
+		return payload, false
+	}
+	return payload, true
+}
+
+func decodeJSONObjectBody(w http.ResponseWriter, r *http.Request, target any) bool {
+	decoder := json.NewDecoder(r.Body)
+	decoder.DisallowUnknownFields()
+
+	if err := decoder.Decode(target); err != nil {
+		if errors.Is(err, io.EOF) {
+			WriteError(w, http.StatusBadRequest, RequestIDFromContext(r.Context()), "invalid_json", "The request body is required and must be valid JSON.")
+			return false
+		}
+
+		WriteError(w, http.StatusBadRequest, RequestIDFromContext(r.Context()), "invalid_json", "The request body must be valid JSON.")
+		return false
+	}
+
+	if err := decoder.Decode(&struct{}{}); !errors.Is(err, io.EOF) {
+		WriteError(w, http.StatusBadRequest, RequestIDFromContext(r.Context()), "invalid_json", "The request body must contain a single JSON object.")
+		return false
+	}
+
+	return true
+}