添加图片预览api

bin/router.dart

@@ -5,9 +5,11 @@ import 'dart:async';
 import 'package:shelf/shelf.dart';
 import 'package:shelf_router/shelf_router.dart';
 
+import 'util/vips.dart';
 import 'domain/repositories/photo_repository.dart';
 import 'domain/repositories/album_repository.dart';
 
+final vips = Vips();
 final albumRepository = AlbumRepository(basePath: 'data');
 final photoRepository = PhotoRepository('data');
 
@@ -24,9 +26,10 @@ Router createApiV1Router() {
     ..get('/', _rootHandler)
     ..get("/album", _listAlbumHandler)
     ..get("/album/<id>", _getAlbumHandler)
-    ..get("/album/<id>/photo", _getPhotosOfAlbumHander)
+    ..get("/album/<id>/photo", _getPhotosOfAlbumHandler)
     ..get('/photo/<id>', _getPhotoHandler)
     ..get('/photo/<id>/file', _getPhotoFileHandler)
+    ..get('/photo/<id>/preview', _getPhotoPreviewHandler)
     ..get('/echo/<message>', _echoHandler);
 
   return router;
@@ -35,10 +38,10 @@ Router createApiV1Router() {
 /// 创建主路由器，将 API v1 挂载到 /api/v1 路径下
 Router createRouter() {
   final router = Router();
-  
+
   // 将 API v1 路由挂载到 /api/v1 路径下
   router.mount('/api/v1', createApiV1Router().call);
-  
+
   return router;
 }
 
@@ -79,10 +82,7 @@ Future<Response> _getAlbumHandler(Request req) async {
   if (album == null) {
     return Response.notFound('Album not found');
   }
-  return jsonResponse({
-    'id': album.id,
-    'name': album.name,
-  });
+  return jsonResponse({'id': album.id, 'name': album.name});
 }
 
 Future<Response> _getPhotoHandler(Request req) async {
@@ -127,7 +127,7 @@ Future<Response> _getPhotoFileHandler(Request req) async {
   // ✅ 修复：使用 StreamController 包装，确保在客户端断开时关闭文件流
   final streamController = StreamController<List<int>>();
   final fileStream = file.openRead();
-  
+
   // 订阅文件流，并将数据转发到响应流
   final subscription = fileStream.listen(
     streamController.add,
@@ -135,7 +135,7 @@ Future<Response> _getPhotoFileHandler(Request req) async {
     onDone: streamController.close,
     cancelOnError: true,
   );
-  
+
   // 当客户端取消订阅时（断开连接），取消文件流订阅并关闭文件
   streamController.onCancel = () {
     subscription.cancel();
@@ -151,7 +151,7 @@ Future<Response> _getPhotoFileHandler(Request req) async {
   );
 }
 
-Future<Response> _getPhotosOfAlbumHander(Request req) async {
+Future<Response> _getPhotosOfAlbumHandler(Request req) async {
   final idParam = req.params['id'];
   if (idParam == null) {
     return Response.badRequest(body: 'Missing album id');
@@ -163,3 +163,51 @@ Future<Response> _getPhotosOfAlbumHander(Request req) async {
   final photos = await photoRepository.getPhotosByAlbumId(albumId);
   return jsonResponse(photos);
 }
+
+Future<Response> _getPhotoPreviewHandler(Request req) async {
+  final idParam = req.params['id'];
+  if (idParam == null) {
+    return Response.badRequest(body: 'Missing photo id');
+  }
+  final id = int.tryParse(idParam);
+  if (id == null) {
+    return Response.badRequest(body: 'Invalid photo id: $idParam');
+  }
+
+  final photo = await photoRepository.getPhotoById(id);
+  if (photo == null) {
+    return Response.notFound('Photo not found');
+  }
+
+  final file = await vips.generatePreview(photo.filePath);
+
+  if (!await file.exists()) {
+    return Response.notFound('File not found');
+  }
+
+  // ✅ 修复：使用 StreamController 包装，确保在客户端断开时关闭文件流
+  final streamController = StreamController<List<int>>();
+  final fileStream = file.openRead();
+
+  // 订阅文件流，并将数据转发到响应流
+  final subscription = fileStream.listen(
+    streamController.add,
+    onError: streamController.addError,
+    onDone: streamController.close,
+    cancelOnError: true,
+  );
+
+  // 当客户端取消订阅时（断开连接），取消文件流订阅并关闭文件
+  streamController.onCancel = () {
+    subscription.cancel();
+    return Future.value();
+  };
+
+  return Response.ok(
+    streamController.stream,
+    headers: {
+      'Content-Type': photo.mimeType,
+      'Content-Length': file.statSync().size.toString(),
+    },
+  );
+}

bin/util/vips.dart

@@ -0,0 +1,31 @@
+import 'dart:io';
+
+import 'package:path/path.dart';
+
+class Vips {
+  String? vipsExecuteFile;
+
+  Vips({this.vipsExecuteFile});
+
+  Future<File> generatePreview(String imgPath) async {
+    final imgOut =
+        "cache/preview/" + basename(imgPath).hashCode.toString() + ".webp";
+    final outFile = File(imgOut);
+    if (outFile.existsSync()) {
+      return outFile;
+    }
+    final result = await Process.run("vips", [
+      "webpsave",
+      imgPath,
+      imgOut,
+      "--Q",
+      "80",
+      "--smart-subsample",
+      "--strip",
+    ]);
+    if (result.exitCode == 0) {
+      return outFile;
+    }
+    throw Exception("vips image transcode failed!");
+  }
+}