feat: update codex live chat workflow

src/components/previewer/CodexDiffPreviewer.tsx

@@ -1,5 +1,6 @@
 import {
   CopyOutlined,
+  DownloadOutlined,
   DownOutlined,
   FileImageOutlined,
   FileTextOutlined,
@@ -92,7 +93,7 @@ export function CodexDiffPreviewer({
 }: CodexDiffPreviewerProps) {
   const [messageApi, contextHolder] = message.useMessage();
   const [activeMode, setActiveMode] = useState<'source' | 'diff'>(files.length > 0 ? 'source' : 'diff');
-  const [expandedSourcePaths, setExpandedSourcePaths] = useState<string[]>(() => files.slice(0, 1).map((file) => file.path));
+  const [expandedSourcePath, setExpandedSourcePath] = useState<string | null>(() => files[0]?.path ?? null);
   const [expandedPreviewPath, setExpandedPreviewPath] = useState<string | null>(null);
   const statusCount = useMemo(() => buildStatusCount(files), [files]);
   const canShowSource = files.length > 0;
@@ -129,6 +130,24 @@ export function CodexDiffPreviewer({
     }
   }
 
+  function handleDownload(path: string, content: string) {
+    if (typeof document === 'undefined') {
+      messageApi.error('다운로드를 사용할 수 없습니다.');
+      return;
+    }
+
+    const fileName = path.split('/').pop() || 'preview.txt';
+    const blob = new Blob([content], { type: 'text/plain;charset=utf-8' });
+    const objectUrl = URL.createObjectURL(blob);
+    const link = document.createElement('a');
+    link.href = objectUrl;
+    link.download = fileName;
+    document.body.appendChild(link);
+    link.click();
+    document.body.removeChild(link);
+    URL.revokeObjectURL(objectUrl);
+  }
+
   function handleFullscreen(path: string) {
     setExpandedPreviewPath((currentPath) => (currentPath === path ? null : path));
   }
@@ -141,15 +160,12 @@ export function CodexDiffPreviewer({
       return;
     }
 
-    setExpandedSourcePaths((currentPaths) => {
-      const availablePaths = new Set(files.map((file) => file.path));
-      const nextPaths = currentPaths.filter((path) => availablePaths.has(path));
-
-      if (nextPaths.length > 0) {
-        return nextPaths;
+    setExpandedSourcePath((currentPath) => {
+      if (currentPath && files.some((file) => file.path === currentPath)) {
+        return currentPath;
       }
 
-      return files[0] ? [files[0].path] : [];
+      return files[0]?.path ?? null;
     });
   }, [canShowSource, diffText, files]);
 
@@ -231,15 +247,15 @@ export function CodexDiffPreviewer({
               <Button
                 size="small"
                 onClick={() => {
-                  setExpandedSourcePaths(files.map((file) => file.path));
+                  setExpandedSourcePath(files[0]?.path ?? null);
                 }}
               >
-                전체 펼치기
+                첫 문서 펼치기
               </Button>
               <Button
                 size="small"
                 onClick={() => {
-                  setExpandedSourcePaths([]);
+                  setExpandedSourcePath(null);
                 }}
               >
                 전체 접기
@@ -248,7 +264,7 @@ export function CodexDiffPreviewer({
           </div>
 
           {files.map((file) => {
-            const isExpanded = expandedSourcePaths.includes(file.path);
+            const isExpanded = expandedSourcePath === file.path;
             const isPreviewExpanded = expandedPreviewPath === file.path;
             const displayPath = file.previousPath ? `${file.previousPath} -> ${file.path}` : file.path;
 
@@ -266,11 +282,7 @@ export function CodexDiffPreviewer({
                   type="button"
                   className="codex-diff-previewer__diff-toggle"
                   onClick={() => {
-                    setExpandedSourcePaths((currentPaths) =>
-                      currentPaths.includes(file.path)
-                        ? currentPaths.filter((path) => path !== file.path)
-                        : [...currentPaths, file.path],
-                    );
+                    setExpandedSourcePath((currentPath) => (currentPath === file.path ? null : file.path));
                   }}
                 >
                   <Space align="center" size={10} className="codex-diff-previewer__diff-toggle-main">
@@ -296,6 +308,16 @@ export function CodexDiffPreviewer({
                       void handleCopy(file.content);
                     }}
                   />
+                  <Button
+                    size="small"
+                    type="text"
+                    aria-label="다운로드"
+                    icon={<DownloadOutlined />}
+                    onClick={(event) => {
+                      event.stopPropagation();
+                      handleDownload(file.path, file.content);
+                    }}
+                  />
                   <Button
                     size="small"
                     type="text"
@@ -316,6 +338,7 @@ export function CodexDiffPreviewer({
                       value={file.content}
                       language={file.language}
                       imageAlt={file.path.split('/').pop() ?? file.path}
+                      downloadFileName={file.path.split('/').pop() ?? file.path}
                       height={isPreviewExpanded ? 'calc(100vh - 120px)' : height}
                       copyable={false}
                       maximizable={false}