Support download zip on web

lib/api/client.dart

@@ -209,4 +209,19 @@ class EHApi extends __EHApi {
   Future<ApiResult<Tags>> getTags(List<int> ids, {CancelToken? cancel}) {
     return _getTags(ids.join(","), cancel: cancel);
   }
+
+  String exportGalleryZipUrl(int gid,
+      {bool? jpnTitle, int? maxLength, bool? exportAd}) {
+    final uri = Uri.parse(_combineBaseUrls(_dio.options.baseUrl, baseUrl));
+    var queries = {
+      "jpn_title": jpnTitle?.toString(),
+      "max_length": maxLength?.toString(),
+      "export_ad": exportAd?.toString(),
+    };
+    queries.removeWhere((key, value) => value == null);
+    final newUri = uri
+        .resolve("export/gallery/zip/$gid")
+        .replace(queryParameters: queries);
+    return newUri.toString();
+  }
 }

lib/globals.dart

@@ -89,7 +89,7 @@ bool tryInitApi(BuildContext context) {
     if (_api != null) {
       return true;
     }
-    initApi("${Uri.base.origin}/api");
+    initApi("${Uri.base.origin}/api/");
     clearAllStates(context);
     return true;
   }

lib/platform/save_file_none.dart

@@ -4,3 +4,7 @@ void saveFileWeb(
     Uint8List data, String mimeType, String filenameWithoutExtension) {
   throw UnimplementedError();
 }
+
+void saveUriWeb(String uri) {
+  throw UnimplementedError();
+}

lib/platform/save_file_web.dart

@@ -26,3 +26,9 @@ void saveFileWeb(
   a.click();
   Url.revokeObjectUrl(url);
 }
+
+void saveUriWeb(String uri) {
+  final a = document.createElement("a") as AnchorElement;
+  a.href = uri;
+  a.click();
+}

lib/utils.dart

@@ -5,3 +5,22 @@ bool get isDesktop =>
     !kIsWeb && (Platform.isWindows || Platform.isLinux || Platform.isMacOS);
 bool get isWindows => !kIsWeb && Platform.isWindows;
 bool get isAndroid => !kIsWeb && Platform.isAndroid;
+
+String? getFilenameFromContentDisposition(String? contentDisposition) {
+  if (contentDisposition == null) {
+    return null;
+  }
+  var ind = contentDisposition.indexOf("filename=\"");
+  if (ind != -1) {
+    final filename = contentDisposition.substring(
+        ind + 10, contentDisposition.lastIndexOf("\""));
+    return Uri.decodeComponent(filename);
+  }
+  ind = contentDisposition.indexOf("filename*=UTF-8''");
+  if (ind != -1) {
+    final filename =
+        contentDisposition.substring(ind + 17, contentDisposition.length);
+    return Uri.decodeComponent(filename);
+  }
+  return null;
+}

lib/utils/download_zip.dart

@@ -1,10 +1,17 @@
 import 'package:dio/dio.dart';
 import 'package:flutter/foundation.dart';
+import 'package:path/path.dart' as path;
 import '../globals.dart';
 import '../platform/save_file.dart';
+import '../utils.dart';
 
 Future<void> downloadZip(int gid,
     {bool? jpnTitle, int? maxLength, bool? exportAd}) async {
+  if (kIsWeb) {
+    saveUriWeb(api.exportGalleryZipUrl(gid,
+        jpnTitle: jpnTitle, maxLength: maxLength, exportAd: exportAd));
+    return;
+  }
   final cancel = CancelToken();
   final re = await api.exportGalleryZip(gid,
       jpnTitle: jpnTitle,
@@ -16,12 +23,11 @@ Future<void> downloadZip(int gid,
     throw Exception("${data.statusCode} ${data.statusMessage}.");
   }
   final fileName = re.response.headers.value("content-disposition");
-  final filenameWithoutExtension = fileName?.substring(
-          fileName.indexOf("filename=\"") + 10, fileName.lastIndexOf(".")) ??
-      "$gid";
+  final filenameWithoutExtension = path.basenameWithoutExtension(
+      getFilenameFromContentDisposition(fileName) ?? "$gid");
   try {
     final f = await platformPath.openFile(
-        Uri.decodeComponent(filenameWithoutExtension), "application/zip");
+        filenameWithoutExtension, "application/zip");
     try {
       await data.stream.forEach((data) {
         f.write(data);