리펙토링: 전체 구조 검토, 개선

CLAUDE.md

@@ -15,7 +15,7 @@ There are no tests or linting configured.
 
 ## Architecture
 
-This is a macOS Electron desktop app for batch-renaming photo files. It follows strict Electron security practices: `contextIsolation: true`, `nodeIntegration: false`.
+This is a macOS Electron desktop app for batch-renaming and moving photo files. It follows strict Electron security practices: `contextIsolation: true`, `nodeIntegration: false`.
 
 **Process boundary:** All filesystem access lives exclusively in `src/main/` (main process). The renderer never touches `fs` directly.
 
@@ -27,20 +27,27 @@ src/
 │   ├── index.js          # Main process entry point; creates BrowserWindow, calls registerAll()
 │   └── ipc/
 │       ├── index.js      # registerAll(mainWindow) — delegates to folder and files modules
-│       ├── folder.js     # select-folder, reveal-folder
-│       └── files.js      # list-images, read-image, rename-files
+│       ├── folder.js     # select-folder, list-directories, get/set-last-folder,
+│       │                 # get/set-preview-on, get-home-dir, reveal-folder
+│       └── files.js      # list-images, read-image, rename-files,
+│                         # check-files-exist, move-files
 ├── preload/
 │   └── index.js          # Bridges IPC to window.api via contextBridge (isolated context)
 └── renderer/
-    ├── index.html        # App shell (dark theme, CSS variables in :root)
+    ├── index.html        # App shell; dark theme, CSS variables in :root, modal HTML
     ├── style.css         # All CSS
-    ├── renderer.js       # Main renderer logic; imports state and handlers
     ├── state.js          # Shared mutable state: files[], currentFolder, selectedIdxs, sortMode
+    ├── renderer.js       # Entry point: init, loadFolder, sortFiles, keyboard shortcuts, startup
+    ├── ui.js             # showLoading, hideLoading, setStatus, showToast
+    ├── grid.js           # renderGrid, createCard, card UI update functions, showEmptyGrid
+    ├── rename.js         # doRename + rename-conflict modal
+    ├── move.js           # handleFolderDrop + move modals + _doMoveFiles
     └── handlers/
-        ├── drag-drop.js  # Card drag-and-drop reorder (single and multi-card)
-        ├── selection.js  # Rubber-band selection, Shift-click, Cmd+click
-        ├── pinch-zoom.js # Trackpad pinch to resize thumbnails (CSS --thumb-size, 150–400px)
-        └── image-preview.js # Hover preview overlay
+        ├── drag-drop.js      # Card reorder (single/multi) + drag-to-folder in sidebar
+        ├── file-explorer.js  # Sidebar directory tree (lazy-load, expand/collapse)
+        ├── selection.js      # Rubber-band, Shift-click, Cmd+click, resetAnchor
+        ├── pinch-zoom.js     # Ctrl+scroll to resize thumbnails (CSS --thumb-size, 150–400px)
+        └── image-preview.js  # Hover preview overlay with circular loading indicator
 ```
 
 ### IPC surface
@@ -50,9 +57,15 @@ Defined in `src/main/ipc/`, bridged via `src/preload/index.js` as `window.api`:
 | Channel | Direction | Description |
 |---|---|---|
 | `select-folder` | invoke | Opens native folder picker, returns path or null |
-| `list-images` | invoke | Reads directory, returns `{name, path, mtime, size}[]` filtered to image extensions, sorted by filename |
+| `list-images` | invoke | Reads directory, returns `{name, path, mtime}[]` filtered to image extensions, sorted by filename |
 | `read-image` | invoke | Reads file, returns base64 data URL for display |
-| `rename-files({folderPath, files, prefix, digits})` | invoke | Two-phase rename: temp names first, then final names to avoid collisions |
+| `rename-files({folderPath, files, prefix, digits})` | invoke | Two-phase rename: temp names (crypto.randomUUID) first, then final names |
+| `check-files-exist(folderPath, names[])` | invoke | Returns subset of names that already exist in folderPath |
+| `move-files({targetFolder, files[]})` | invoke | Moves files; each file may have optional `newName`; handles cross-device (EXDEV) |
+| `list-directories(folderPath)` | invoke | Returns `{name, path, hasChildren}[]` subdirs, or `null` on access error |
+| `get-home-dir` | invoke | Returns `os.homedir()` |
+| `get-last-folder` / `set-last-folder` | invoke | Persists last opened folder in userData config.json |
+| `get-preview-on` / `set-preview-on` | invoke | Persists hover preview toggle state in userData config.json |
 | `reveal-folder` | invoke | Opens folder in Finder via `shell.openPath` |
 | `fullscreen-change` | push (main→renderer) | Sent on `enter-full-screen` / `leave-full-screen` window events |
 
@@ -60,14 +73,54 @@ Defined in `src/main/ipc/`, bridged via `src/preload/index.js` as `window.api`:
 
 Uses ES module imports (`type="module"`). No framework.
 
+**Dependency direction** (no cycles):
+```
+renderer.js → rename.js, move.js → grid.js → handlers/*
+                                 ↘         ↗
+                                   ui.js
+```
+
 **State** (`src/renderer/state.js`):
-- `files[]` — ordered array of file objects; order determines rename sequence
+- `files[]` — ordered array of `{name, path, mtime}`; order determines rename sequence
 - `selectedIdxs` — `Set<number>` of selected card indices
 - `currentFolder` — active directory path
 - `sortMode` — `'name'` | `'date'` | `null`
 
-**Thumbnail loading:** Uses `IntersectionObserver` with `rootMargin: '400px 0px'` — images load lazily as cards enter the viewport. DOM card elements are created immediately without `src`; the observer fills in `img.src` on entry. Drag-and-drop reorder remaps existing card elements via `card.dataset.filepath` to avoid re-fetching images.
+**Keyboard shortcuts:**
+- `O` — 폴더 열기
+- `S` — 이름 변경 실행
+- `A` — 전체 선택
 
-**Styling:** All CSS lives in `src/renderer/index.html`. Dark theme with CSS variables defined in `:root`. The macOS traffic-light buttons sit in `#titlebar` with `-webkit-app-region: drag`.
+**Card selection** (`selection.js`):
+- Click — 단독 선택 (재클릭 시 해제)
+- Shift+Click — 범위 선택
+- Cmd+Click — 개별 토글
+- Rubber-band drag — 영역 선택 (rAF throttle 적용)
+- `resetAnchor()` — 그리드 재렌더 시 Shift 기준점 초기화 (grid.js에서 호출)
+
+**Drag-and-drop** (`drag-drop.js`):
+- 그리드 내: 카드 순서 재배치 (single/multi)
+- 사이드바 폴더로: 선택된 파일들을 해당 폴더로 이동
+  - 파일명 충돌 시 rename-and-move 모달 표시
+  - 드래그 중 `.tree-row.drop-target` 클래스로 대상 폴더 하이라이트
+
+**Rename** (`rename.js`):
+- 선택된 파일만 이름 변경 (선택 없으면 전체)
+- 변경될 이름이 미선택 파일과 충돌하면 충돌 목록 모달 표시
+
+**Move** (`move.js`):
+- 충돌 없으면 즉시 이동
+- 충돌 있으면 prefix + digits 입력 모달 → 새 이름으로 이동
+- 새 이름도 충돌이면 에러 모달
+
+**Thumbnail loading:** `IntersectionObserver` with `rootMargin: '400px 0px'` — lazy load as cards enter viewport. `entry.target.isConnected` 체크로 폴더 전환 중 스탈 카드 방지. Drag reorder remaps card elements via `card.dataset.filepath` to avoid re-fetching.
+
+**Hover preview** (`image-preview.js`): 1초 지연 후 전체 크기 팝업. 썸네일 캐시 우선 사용. 상태는 config.json에 영속.
+
+**Sidebar tree** (`file-explorer.js`): Lazy-load 자식 폴더. 접근 불가 폴더는 `null` 반환 → "접근 불가" 표시. 행 클릭 시 항상 펼침, 화살표 클릭 시 토글.
+
+**Styling:** CSS는 `src/renderer/style.css`에 집중. Dark theme, CSS variables in `:root`. macOS traffic-light은 `header`의 `-webkit-app-region: drag`.
 
 **Build output:** `electron-builder` targets DMG for arm64 and x64. The app icon must be at `assets/icon.icns`.
+
+**Config persistence:** `app.getPath('userData')/config.json`에 `lastFolder`, `previewOn` 저장.