Move project save target planning to app core

src/app_core/document_canvas.h

@@ -96,6 +96,13 @@ struct DocumentCanvasPpiExportResult {
     std::vector<std::byte> bytes;
 };
 
+struct DocumentCanvasProjectSaveTargetPlan {
+    std::string target_path;
+    std::string file_name;
+    std::string temporary_path;
+    std::string timelapse_path;
+};
+
 class DocumentCanvasClearServices {
 public:
     virtual ~DocumentCanvasClearServices() = default;
@@ -299,6 +306,50 @@ export_document_canvas_save_snapshot_to_ppi(const DocumentCanvasSnapshotResult&
     });
 }
 
+[[nodiscard]] inline pp::foundation::Result<DocumentCanvasProjectSaveTargetPlan>
+plan_document_canvas_project_save_target(
+    std::string_view data_directory,
+    std::string_view target_path)
+{
+    if (data_directory.empty()) {
+        return pp::foundation::Result<DocumentCanvasProjectSaveTargetPlan>::failure(
+            pp::foundation::Status::invalid_argument("project save data directory must not be empty"));
+    }
+    if (target_path.empty()) {
+        return pp::foundation::Result<DocumentCanvasProjectSaveTargetPlan>::failure(
+            pp::foundation::Status::invalid_argument("project save target path must not be empty"));
+    }
+
+    const auto basename_start = target_path.find_last_of("/\\");
+    const auto file_name_start = basename_start == std::string_view::npos ? 0U : basename_start + 1U;
+    auto file_name = target_path.substr(file_name_start);
+    if (file_name.empty()) {
+        return pp::foundation::Result<DocumentCanvasProjectSaveTargetPlan>::failure(
+            pp::foundation::Status::invalid_argument("project save target file name must not be empty"));
+    }
+
+    constexpr std::string_view ppi_extension = ".ppi";
+    if (file_name.size() > ppi_extension.size()
+        && file_name.substr(file_name.size() - ppi_extension.size()) == ppi_extension) {
+        file_name.remove_suffix(ppi_extension.size());
+    }
+
+    DocumentCanvasProjectSaveTargetPlan plan;
+    plan.target_path = std::string(target_path);
+    plan.file_name = std::string(file_name);
+    plan.temporary_path.reserve(data_directory.size() + plan.file_name.size() + 10U);
+    plan.temporary_path += data_directory;
+    plan.temporary_path += "/";
+    plan.temporary_path += plan.file_name;
+    plan.temporary_path += ".tmp.ppi";
+    plan.timelapse_path.reserve(data_directory.size() + plan.file_name.size() + 6U);
+    plan.timelapse_path += data_directory;
+    plan.timelapse_path += "/";
+    plan.timelapse_path += plan.file_name;
+    plan.timelapse_path += ".pptl";
+    return pp::foundation::Result<DocumentCanvasProjectSaveTargetPlan>::success(std::move(plan));
+}
+
 [[nodiscard]] inline pp::foundation::Result<DocumentCanvasClearPlan> plan_document_canvas_clear(
     bool has_canvas,
     float r = 0.0F,