Add editor Assets watcher refresh loop

editor/src/Core/EditorWorkspace.h

@@ -3,6 +3,7 @@
 #include "Commands/SceneCommands.h"
 #include "Core/IEditorContext.h"
 #include "Core/PlaySessionController.h"
+#include "Core/ProjectAssetWatcher.h"
 #include "Layout/DockLayoutController.h"
 #include "panels/ConsolePanel.h"
 #include "panels/GameViewPanel.h"
@@ -39,12 +40,14 @@ public:
         m_projectPanel->Initialize(context.GetProjectPath());
         Commands::LoadStartupScene(context);
         m_playSessionController.Attach(context);
+        m_projectAssetWatcher.Attach(context.GetProjectPath());
         m_dockLayoutController->Attach(context);
         m_panels.AttachAll();
     }
 
     void Detach(IEditorContext& context) {
         m_playSessionController.Detach(context);
+        m_projectAssetWatcher.Detach();
         Commands::SaveDirtySceneWithFallback(context, BuildFallbackScenePath(context));
 
         if (m_dockLayoutController) {
@@ -61,6 +64,7 @@ public:
     void Update(float dt) {
         ::XCEngine::Resources::ResourceManager::Get().UpdateAsyncLoads();
         if (IEditorContext* context = m_panels.GetContext()) {
+            m_projectAssetWatcher.Update(*context, dt);
             m_playSessionController.Update(*context, dt);
         }
         m_panels.UpdateAll(dt);
@@ -96,6 +100,7 @@ private:
     ProjectPanel* m_projectPanel = nullptr;
     std::unique_ptr<DockLayoutController> m_dockLayoutController;
     PlaySessionController m_playSessionController;
+    ProjectAssetWatcher m_projectAssetWatcher;
 };
 
 } // namespace Editor

editor/src/Core/ProjectAssetWatcher.cpp

@@ -0,0 +1,207 @@
+#include "Core/ProjectAssetWatcher.h"
+#include "Core/IProjectManager.h"
+
+#include <XCEngine/Core/Asset/ResourceManager.h>
+#include <XCEngine/Debug/Logger.h>
+
+#include <algorithm>
+#include <cctype>
+#include <system_error>
+
+namespace XCEngine {
+namespace Editor {
+
+namespace fs = std::filesystem;
+
+namespace {
+
+constexpr float kScanIntervalSeconds = 0.75f;
+constexpr float kDebounceWindowSeconds = 0.35f;
+
+std::string NormalizePathKey(const fs::path& path) {
+    std::string key = path.lexically_normal().generic_string();
+    std::transform(key.begin(), key.end(), key.begin(), [](unsigned char ch) {
+        return static_cast<char>(std::tolower(ch));
+    });
+    return key;
+}
+
+std::uint64_t GetFileSizeValue(const fs::path& path, bool isDirectory) {
+    if (isDirectory) {
+        return 0;
+    }
+
+    std::error_code ec;
+    const auto fileSize = fs::file_size(path, ec);
+    return ec ? 0 : static_cast<std::uint64_t>(fileSize);
+}
+
+std::uint64_t GetFileWriteTimeValue(const fs::path& path) {
+    std::error_code ec;
+    const auto writeTime = fs::last_write_time(path, ec);
+    if (ec) {
+        return 0;
+    }
+
+    return static_cast<std::uint64_t>(writeTime.time_since_epoch().count());
+}
+
+} // namespace
+
+void ProjectAssetWatcher::Attach(const std::string& projectPath) {
+    RefreshProjectBinding(projectPath);
+}
+
+void ProjectAssetWatcher::Detach() {
+    m_projectPath.clear();
+    m_assetsRoot.clear();
+    m_snapshot.clear();
+    m_pendingChanges.Clear();
+    m_scanCooldownSeconds = 0.0f;
+    m_debounceSeconds = 0.0f;
+    m_hasPendingRefresh = false;
+}
+
+void ProjectAssetWatcher::Update(IEditorContext& context, float dt) {
+    RefreshProjectBinding(context.GetProjectPath());
+    if (m_assetsRoot.empty()) {
+        return;
+    }
+
+    m_scanCooldownSeconds -= dt;
+    if (m_scanCooldownSeconds <= 0.0f) {
+        ScanForChanges();
+        m_scanCooldownSeconds = kScanIntervalSeconds;
+    }
+
+    if (!m_hasPendingRefresh) {
+        return;
+    }
+
+    m_debounceSeconds -= dt;
+    if (m_debounceSeconds <= 0.0f) {
+        FlushPendingRefresh(context);
+    }
+}
+
+void ProjectAssetWatcher::RefreshProjectBinding(const std::string& projectPath) {
+    if (projectPath == m_projectPath) {
+        return;
+    }
+
+    m_projectPath = projectPath;
+    m_assetsRoot = projectPath.empty() ? fs::path() : (fs::path(projectPath) / "Assets");
+    m_snapshot.clear();
+    m_pendingChanges.Clear();
+    m_scanCooldownSeconds = kScanIntervalSeconds;
+    m_debounceSeconds = 0.0f;
+    m_hasPendingRefresh = false;
+
+    if (!m_assetsRoot.empty()) {
+        BuildSnapshot(m_assetsRoot, m_snapshot);
+    }
+}
+
+void ProjectAssetWatcher::ScanForChanges() {
+    Snapshot currentSnapshot;
+    BuildSnapshot(m_assetsRoot, currentSnapshot);
+
+    const ChangeStats changes = DiffSnapshots(m_snapshot, currentSnapshot);
+    m_snapshot = std::move(currentSnapshot);
+    if (!changes.HasChanges()) {
+        return;
+    }
+
+    m_pendingChanges.Accumulate(changes);
+    m_hasPendingRefresh = true;
+    m_debounceSeconds = kDebounceWindowSeconds;
+}
+
+void ProjectAssetWatcher::FlushPendingRefresh(IEditorContext& context) {
+    if (!m_hasPendingRefresh) {
+        return;
+    }
+
+    Resources::ResourceManager::Get().RefreshProjectAssets();
+    context.GetProjectManager().RefreshCurrentFolder();
+
+    Debug::Logger::Get().Info(
+        Debug::LogCategory::FileSystem,
+        (std::string("[ProjectAssetWatcher] Refreshed project assets after external changes. added=") +
+         std::to_string(m_pendingChanges.added) +
+         " modified=" +
+         std::to_string(m_pendingChanges.modified) +
+         " removed=" +
+         std::to_string(m_pendingChanges.removed)).c_str());
+
+    m_pendingChanges.Clear();
+    m_debounceSeconds = 0.0f;
+    m_hasPendingRefresh = false;
+}
+
+void ProjectAssetWatcher::BuildSnapshot(const fs::path& assetsRoot, Snapshot& outSnapshot) {
+    outSnapshot.clear();
+
+    std::error_code ec;
+    if (assetsRoot.empty() || !fs::exists(assetsRoot, ec)) {
+        return;
+    }
+
+    for (fs::recursive_directory_iterator it(
+             assetsRoot,
+             fs::directory_options::skip_permission_denied,
+             ec),
+         end;
+         !ec && it != end;
+         it.increment(ec)) {
+        const fs::path entryPath = it->path();
+
+        std::error_code relativeEc;
+        const fs::path relativePath = fs::relative(entryPath, assetsRoot, relativeEc);
+        if (relativeEc || relativePath.empty()) {
+            continue;
+        }
+
+        std::error_code typeEc;
+        const bool isDirectory = it->is_directory(typeEc);
+        if (typeEc) {
+            continue;
+        }
+
+        AssetEntryState entryState;
+        entryState.isDirectory = isDirectory;
+        entryState.fileSize = GetFileSizeValue(entryPath, isDirectory);
+        entryState.writeTime = GetFileWriteTimeValue(entryPath);
+        outSnapshot.emplace(NormalizePathKey(relativePath), entryState);
+    }
+}
+
+ProjectAssetWatcher::ChangeStats ProjectAssetWatcher::DiffSnapshots(
+    const Snapshot& previousSnapshot,
+    const Snapshot& currentSnapshot) {
+    ChangeStats changes;
+
+    for (const auto& [pathKey, currentState] : currentSnapshot) {
+        const auto previousIt = previousSnapshot.find(pathKey);
+        if (previousIt == previousSnapshot.end()) {
+            ++changes.added;
+            continue;
+        }
+
+        if (!(previousIt->second == currentState)) {
+            ++changes.modified;
+        }
+    }
+
+    for (const auto& [pathKey, previousState] : previousSnapshot) {
+        (void)previousState;
+        if (currentSnapshot.find(pathKey) == currentSnapshot.end()) {
+            ++changes.removed;
+        }
+    }
+
+    return changes;
+}
+
+} // namespace Editor
+} // namespace XCEngine

editor/src/Core/ProjectAssetWatcher.h

@@ -0,0 +1,72 @@
+#pragma once
+
+#include "Core/IEditorContext.h"
+
+#include <cstdint>
+#include <filesystem>
+#include <string>
+#include <unordered_map>
+
+namespace XCEngine {
+namespace Editor {
+
+class ProjectAssetWatcher {
+public:
+    void Attach(const std::string& projectPath);
+    void Detach();
+    void Update(IEditorContext& context, float dt);
+
+private:
+    struct AssetEntryState {
+        bool isDirectory = false;
+        std::uint64_t fileSize = 0;
+        std::uint64_t writeTime = 0;
+
+        bool operator==(const AssetEntryState& other) const {
+            return isDirectory == other.isDirectory &&
+                   fileSize == other.fileSize &&
+                   writeTime == other.writeTime;
+        }
+    };
+
+    struct ChangeStats {
+        std::uint32_t added = 0;
+        std::uint32_t modified = 0;
+        std::uint32_t removed = 0;
+
+        bool HasChanges() const {
+            return added > 0 || modified > 0 || removed > 0;
+        }
+
+        void Clear() {
+            added = 0;
+            modified = 0;
+            removed = 0;
+        }
+
+        void Accumulate(const ChangeStats& other) {
+            added += other.added;
+            modified += other.modified;
+            removed += other.removed;
+        }
+    };
+
+    using Snapshot = std::unordered_map<std::string, AssetEntryState>;
+
+    void RefreshProjectBinding(const std::string& projectPath);
+    void ScanForChanges();
+    void FlushPendingRefresh(IEditorContext& context);
+    static void BuildSnapshot(const std::filesystem::path& assetsRoot, Snapshot& outSnapshot);
+    static ChangeStats DiffSnapshots(const Snapshot& previousSnapshot, const Snapshot& currentSnapshot);
+
+    std::string m_projectPath;
+    std::filesystem::path m_assetsRoot;
+    Snapshot m_snapshot;
+    ChangeStats m_pendingChanges;
+    float m_scanCooldownSeconds = 0.0f;
+    float m_debounceSeconds = 0.0f;
+    bool m_hasPendingRefresh = false;
+};
+
+} // namespace Editor
+} // namespace XCEngine