Plan save-version targets in app core

src/app_core/document_session.h

@@ -2,6 +2,8 @@
 
 #include "foundation/result.h"
 
+#include <cctype>
+#include <cstdio>
 #include <string>
 #include <string_view>
 #include <utility>
@@ -50,6 +52,11 @@ struct DocumentFileTarget {
     std::string path;
 };
 
+struct DocumentVersionTarget {
+    std::string name;
+    std::string path;
+};
+
 [[nodiscard]] constexpr ProjectOpenDecision plan_project_open(bool has_unsaved_changes) noexcept
 {
     return has_unsaved_changes
@@ -142,4 +149,82 @@ struct DocumentFileTarget {
         : DocumentFileWriteDecision::save_now;
 }
 
+[[nodiscard]] inline bool has_legacy_two_character_version_suffix(std::string_view document_name) noexcept
+{
+    const auto dot = document_name.rfind('.');
+    if (dot == std::string_view::npos || dot + 3 != document_name.size()) {
+        return false;
+    }
+
+    const auto is_word = [](char ch) noexcept {
+        return std::isalnum(static_cast<unsigned char>(ch)) != 0 || ch == '_';
+    };
+    return is_word(document_name[dot + 1]) && is_word(document_name[dot + 2]);
+}
+
+[[nodiscard]] inline int legacy_version_number(std::string_view suffix) noexcept
+{
+    int value = 0;
+    for (const char ch : suffix) {
+        if (ch < '0' || ch > '9') {
+            break;
+        }
+
+        value = value * 10 + (ch - '0');
+    }
+    return value;
+}
+
+[[nodiscard]] inline std::string make_legacy_version_name(std::string_view base_name, int version)
+{
+    char suffix[4] {};
+    std::snprintf(suffix, sizeof(suffix), ".%02d", version);
+    std::string name;
+    name.reserve(base_name.size() + 3);
+    name += base_name;
+    name += suffix;
+    return name;
+}
+
+template <typename ExistsPredicate>
+[[nodiscard]] pp::foundation::Result<DocumentVersionTarget> find_next_document_version_target(
+    std::string_view directory,
+    std::string_view document_name,
+    ExistsPredicate&& exists)
+{
+    if (directory.empty()) {
+        return pp::foundation::Result<DocumentVersionTarget>::failure(
+            pp::foundation::Status::invalid_argument("directory must not be empty"));
+    }
+
+    if (document_name.empty()) {
+        return pp::foundation::Result<DocumentVersionTarget>::failure(
+            pp::foundation::Status::invalid_argument("document name must not be empty"));
+    }
+
+    int current = 0;
+    std::string_view base = document_name;
+    if (has_legacy_two_character_version_suffix(document_name)) {
+        const auto dot = document_name.rfind('.');
+        base = document_name.substr(0, dot);
+        current = legacy_version_number(document_name.substr(dot + 1));
+    }
+
+    for (int version = current + 1; version < 99; ++version) {
+        DocumentVersionTarget target;
+        target.name = make_legacy_version_name(base, version);
+        target.path.reserve(directory.size() + target.name.size() + 5);
+        target.path += directory;
+        target.path += "/";
+        target.path += target.name;
+        target.path += ".ppi";
+        if (!exists(target.path)) {
+            return pp::foundation::Result<DocumentVersionTarget>::success(std::move(target));
+        }
+    }
+
+    return pp::foundation::Result<DocumentVersionTarget>::failure(
+        pp::foundation::Status::out_of_range("no available document version target"));
+}
+
 }

src/app_dialogs.cpp

@@ -292,30 +292,19 @@ void App::dialog_save_ver()
         return;
     }
 
-    int current = 0;
-    std::string next = doc_name + ".01";
-    std::string base = doc_name;
-
-    std::regex r(R"((.*)\.(\w{2})$)");
-    std::smatch m;
-    if (std::regex_search(doc_name, m, r))
-    {
-        base = m[1].str();
-        current = atoi(m[2].str().c_str());
+    const auto target = pp::app::find_next_document_version_target(
+        doc_dir,
+        doc_name,
+        [](const std::string& path) {
+            return Asset::exist(path);
+        });
+    if (!target) {
+        message_box("Saving Error", target.status().message);
+        return;
     }
 
-    for (int i = current + 1; i < 99; i++)
-    {
-        static char tmp_name[256];
-        sprintf(tmp_name, "%s.%02d", base.c_str(), i);
-        next = tmp_name;
-        if (Asset::exist(doc_dir + "/" + next + ".ppi"))
-            continue;
-        break;
-    }
-
-    doc_name = next;
-    doc_path = doc_dir + "/" + next + ".ppi";
+    doc_name = target.value().name;
+    doc_path = target.value().path;
     canvas->m_canvas->m_unsaved = true;
     title_update();
     canvas->m_canvas->project_save(doc_path);