feat(downloads): reuse unfinished filename matches

Fixes #26

src/components/AddDownloadsModal.tsx

@@ -7,12 +7,13 @@ import {
   type PendingAddRequestContext
 } from '../store/useDownloadStore';
 import { useSettingsStore } from '../store/useSettingsStore';
+import type { DownloadItem } from '../bindings/DownloadItem';
 import type { MediaPlaylistMetadata } from '../bindings/MediaPlaylistMetadata';
 import { FolderPlus, Settings, Shield, RefreshCw, FileText, HardDrive, Database, Link, ArrowRight, Play, ChevronDown, ChevronRight, Video, Film, Music, type LucideIcon } from 'lucide-react';
 import { open } from '@tauri-apps/plugin-dialog';
 import { invokeCommand as invoke } from '../ipc';
 import { DuplicateResolutionModal, DuplicateConflict } from './DuplicateResolutionModal';
-import { canonicalizeDownloadFileName, categoryForFileName } from '../utils/downloads';
+import { canonicalizeDownloadFileName, categoryForFileName, downloadFileNamesMatch, downloadMediaKindsMatch } from '../utils/downloads';
 import { fetchMediaMetadataDeduped, fetchMediaPlaylistMetadataDeduped } from '../utils/mediaMetadata';
 import {
   expandTilde,
@@ -752,6 +753,7 @@ export const AddDownloadsModal = () => {
     const store = useDownloadStore.getState();
     const newConflicts: DuplicateConflict[] = [];
     const plannedTargets: Array<{ location: string; fileName: string }> = [];
+    const reservedFilenameMatchIds = new Set<string>();
 
     for (let i = 0; i < parsedItems.length; i++) {
       const item = parsedItems[i];
@@ -784,7 +786,59 @@ export const AddDownloadsModal = () => {
           replaceAllowed: false
         });
       } else {
-        let fileExistsInStore = false;
+        const filenameCandidates: Array<{
+          download: DownloadItem;
+          sameDestination: boolean;
+        }> = [];
+        for (const download of store.downloads) {
+          if (
+            download.status === 'completed'
+            || !downloadMediaKindsMatch(download.isMedia, item.isMedia)
+            || !downloadFileNamesMatch(download.fileName, finalFile)
+          ) {
+            continue;
+          }
+          const destination = download.destination ||
+            await resolveCategoryDestination(settings, download.category);
+          filenameCandidates.push({
+            download,
+            sameDestination: downloadLocationEquals(
+              destination,
+              download.fileName,
+              itemLocation,
+              finalFile,
+              platform.os
+            )
+          });
+        }
+        filenameCandidates.sort((left, right) =>
+          Number(right.sameDestination) - Number(left.sameDestination)
+          || Number(reservedFilenameMatchIds.has(left.download.id)) - Number(reservedFilenameMatchIds.has(right.download.id))
+          || (right.download.downloadedBytes ?? 0) - (left.download.downloadedBytes ?? 0)
+          || (right.download.fraction ?? 0) - (left.download.fraction ?? 0)
+          || left.download.dateAdded.localeCompare(right.download.dateAdded)
+        );
+        const filenameMatch = filenameCandidates.find(candidate =>
+          !reservedFilenameMatchIds.has(candidate.download.id)
+        )?.download || filenameCandidates[0]?.download;
+
+        if (filenameMatch) {
+          const canReplace = !reservedFilenameMatchIds.has(filenameMatch.id)
+            && !isTransferLocked(filenameMatch.status);
+          newConflicts.push({
+            id: i.toString(),
+            fileName: finalFile,
+            reason: { type: 'file', msg: t($ => $.addDownloads.matchingDownloadFilename) },
+            resolution: canReplace ? 'replace' : 'rename',
+            replaceAllowed: canReplace,
+            existingDownloadId: filenameMatch.id
+          });
+          reservedFilenameMatchIds.add(filenameMatch.id);
+          plannedTargets.push({ location: itemLocation, fileName: finalFile });
+          continue;
+        }
+
+        let existingDownload;
         for (const download of store.downloads) {
           const destination = download.destination ||
             await resolveCategoryDestination(settings, download.category);
@@ -797,7 +851,7 @@ export const AddDownloadsModal = () => {
               platform.os
             )
           ) {
-            fileExistsInStore = true;
+            existingDownload = download;
             break;
           }
         }
@@ -811,18 +865,19 @@ export const AddDownloadsModal = () => {
           console.error("Failed to check if file exists on disk:", e);
         }
 
-        if (fileExistsInStore || fileExistsOnDisk) {
+        if (existingDownload || fileExistsOnDisk) {
           newConflicts.push({
             id: i.toString(),
             fileName: finalFile,
             reason: {
               type: 'file',
-              msg: fileExistsInStore
+              msg: existingDownload
                 ? t($ => $.addDownloads.existingDownloadDestination)
                 : t($ => $.addDownloads.fileExistsOnDisk)
             },
             resolution: 'rename',
-            replaceAllowed: fileExistsInStore
+            replaceAllowed: Boolean(existingDownload),
+            existingDownloadId: existingDownload?.id
           });
         }
       }
@@ -859,6 +914,7 @@ export const AddDownloadsModal = () => {
         item.selected === false ? null : item
       );
       const platform = await getPlatformInfo().catch(() => ({ os: 'unknown' }));
+      let updatedCount = 0;
 
       if (resolutions) {
          for (const res of resolutions) {
@@ -941,29 +997,33 @@ export const AddDownloadsModal = () => {
                 itemsToAdd[idx] = null;
                 continue;
               }
-              let finalFile = item.isMedia
+              const finalFile = item.isMedia
                 ? mediaFileNameForSelectedFormat(item.file, item)
                 : canonicalizeDownloadFileName(item.file);
         const itemLocation = useSharedDestination
           ? finalLocation
           : destinationOverrides[idx] || await categoryLocationForFile(finalFile);
         const store = useDownloadStore.getState();
-        let existingItem;
+        let existingItem = conflict?.existingDownloadId
+          ? store.downloads.find(download => download.id === conflict.existingDownloadId)
+          : undefined;
         const currentSettings = useSettingsStore.getState();
-        for (const download of store.downloads) {
-          const destination = download.destination ||
-            await resolveCategoryDestination(currentSettings, download.category);
-          if (
-            downloadLocationEquals(
-              destination,
-              download.fileName,
-              itemLocation,
-              finalFile,
-              platform.os
-            )
-          ) {
-            existingItem = download;
-            break;
+        if (!existingItem && !conflict?.existingDownloadId) {
+          for (const download of store.downloads) {
+            const destination = download.destination ||
+              await resolveCategoryDestination(currentSettings, download.category);
+            if (
+              downloadLocationEquals(
+                destination,
+                download.fileName,
+                itemLocation,
+                finalFile,
+                platform.os
+              )
+            ) {
+              existingItem = download;
+              break;
+            }
           }
         }
 
@@ -974,11 +1034,36 @@ export const AddDownloadsModal = () => {
                  if (!existingItem) {
                    throw new Error(t($ => $.addDownloads.cannotReplace, { file: finalFile }));
                  }
-                 // Let the backend decide whether resumable sidecars still
-                 // exist after stopping the old transfer. This avoids a race
-                 // where a paused item finishes while the replacement is
-                 // being prepared.
-                 await store.removeDownload(existingItem.id, true, existingItem.status !== 'completed');
+                 const incomingMediaFormat = mediaFormatSelectorForRow(item);
+                 const mediaFormatChanged = item.isMedia
+                   && existingItem.mediaFormatSelector !== incomingMediaFormat;
+                 if (existingItem.status === 'completed' || mediaFormatChanged) {
+                   // Completed replacements must remove the old file so the
+                   // new transfer cannot be treated as an already-complete
+                   // aria2 target. Unfinished rows use the in-place path to
+                   // preserve their resumable assets and progress.
+                   await store.removeDownload(existingItem.id, true, false);
+                 } else {
+                   const contextUrl = requestContextUrlForRow(item);
+                   const replaced = await store.replaceDownload(existingItem.id, {
+                     url: item.downloadUrl,
+                     username: useAuth ? username.trim() : undefined,
+                     password: useAuth ? password.trim() : undefined,
+                     headers: headersForRow(contextUrl) || undefined,
+                     cookies: cookiesForRow(contextUrl, item.downloadUrl) || undefined,
+                     mirrors: mirrors.trim() || undefined,
+                     lastError: undefined
+                   }, pendingAction);
+                   if (!replaced) {
+                     throw new Error(t($ => $.addDownloads.backendRejectedStart));
+                   }
+
+                   // The existing row was updated in place; do not create a
+                   // second identity for the same filename.
+                   itemsToAdd[idx] = null;
+                   updatedCount += 1;
+                   continue;
+                 }
              }
          }
       }
@@ -1056,6 +1141,13 @@ export const AddDownloadsModal = () => {
             : t($ => $.addDownloads.addedMany, { count: addedCount }),
           variant: 'success'
         });
+      } else if (updatedCount > 0) {
+        addToast({
+          message: updatedCount === 1
+            ? t($ => $.addDownloads.updatedOne)
+            : t($ => $.addDownloads.updatedMany, { count: updatedCount }),
+          variant: 'success'
+        });
       }
   };
 

src/components/DuplicateResolutionModal.tsx

@@ -10,6 +10,7 @@ export interface DuplicateConflict {
   reason: DuplicateReason;
   resolution: DuplicateResolution;
   replaceAllowed?: boolean;
+  existingDownloadId?: string;
 }
 
 interface Props {

src/i18n/catalogs/en.ts

@@ -391,9 +391,12 @@ const common = {
     addedWithFailures: '{{added}} added, {{failed}} failed. {{detail}}',
     addedOne: '1 download added',
     addedMany: '{{count}} downloads added',
+    updatedOne: '1 download updated',
+    updatedMany: '{{count}} downloads updated',
     urlAlreadyQueued: 'URL already in queue',
     destinationConflict: 'Another selected download uses this destination',
     existingDownloadDestination: 'Existing Firelink download uses this destination',
+    matchingDownloadFilename: 'An unfinished download already has this filename',
     fileExistsOnDisk: 'File exists on disk; rename or skip to avoid deleting unrelated data',
     backendRejectedStart: 'Backend rejected download start.',
     playlistNoEntries: 'Playlist contains no downloadable entries',

src/i18n/catalogs/fa.ts

@@ -391,9 +391,12 @@ const fa = {
     addedWithFailures: '{{added}} اضافه شد، {{failed}} ناموفق بود. {{detail}}',
     addedOne: '۱ دانلود اضافه شد',
     addedMany: '{{count}} دانلود اضافه شد',
+    updatedOne: '۱ دانلود به‌روزرسانی شد',
+    updatedMany: '{{count}} دانلود به‌روزرسانی شد',
     urlAlreadyQueued: 'URL در حال حاضر در صف است',
     destinationConflict: 'یک دانلود انتخاب‌شده دیگر از این مقصد استفاده می‌کند',
     existingDownloadDestination: 'دانلود Firelink موجود از این مقصد استفاده می‌کند',
+    matchingDownloadFilename: 'یک دانلود ناتمام از قبل همین نام فایل را دارد',
     fileExistsOnDisk: 'فایل در دیسک وجود دارد؛ برای جلوگیری از حذف داده‌های نامرتبط، تغییر نام دهید یا رد شوید',
     backendRejectedStart: 'شروع دانلود توسط موتور دانلود رد شد.',
     playlistNoEntries: 'لیست پخش شامل هیچ ورودی قابل دانلودی نیست',

src/i18n/catalogs/he.ts

@@ -391,9 +391,12 @@ const he = {
     addedWithFailures: '{{added}} נוספו, {{failed}} נכשלו. {{detail}}',
     addedOne: 'הורדה אחת נוספה',
     addedMany: '{{count}} הורדות נוספו',
+    updatedOne: 'הורדה אחת עודכנה',
+    updatedMany: '{{count}} הורדות עודכנו',
     urlAlreadyQueued: 'URL כבר בתור',
     destinationConflict: 'הורדה אחרת שנבחרה משתמשת ביעד זה',
     existingDownloadDestination: 'הורדת Firelink קיימת משתמשת ביעד זה',
+    matchingDownloadFilename: 'להורדה שלא הושלמה יש כבר שם קובץ זה',
     fileExistsOnDisk: 'הקובץ קיים בדיסק; שנה שם או דלג כדי למנוע מחיקת נתונים שאינם קשורים',
     backendRejectedStart: 'העורף דחה את התחלת ההורדה.',
     playlistNoEntries: 'הפלייליסט אינו מכיל רשומות הניתנות להורדה',

src/i18n/catalogs/ru.ts

@@ -391,9 +391,12 @@ const ru = {
     addedWithFailures: '{{added}} добавлено, {{failed}} с ошибкой. {{detail}}',
     addedOne: 'Добавлена 1 загрузка',
     addedMany: 'Добавлено {{count}} загрузок',
+    updatedOne: 'Обновлена 1 загрузка',
+    updatedMany: 'Обновлено {{count}} загрузок',
     urlAlreadyQueued: 'URL уже в очереди',
     destinationConflict: 'Другая выбранная загрузка использует это место назначения',
     existingDownloadDestination: 'Существующая загрузка Firelink использует это место назначения',
+    matchingDownloadFilename: 'Незавершённая загрузка уже имеет это имя файла',
     fileExistsOnDisk: 'Файл существует на диске; переименуйте или пропустите, чтобы избежать удаления не связанных данных',
     backendRejectedStart: 'Бэкенд отклонил запуск загрузки.',
     playlistNoEntries: 'Плейлист не содержит доступных для загрузки записей',

src/i18n/catalogs/uk.ts

@@ -391,9 +391,12 @@ const uk = {
     addedWithFailures: '{{added}} додано, {{failed}} не вдалося. {{detail}}',
     addedOne: '1 завантаження додано',
     addedMany: '{{count}} завантажень додано',
+    updatedOne: '1 завантаження оновлено',
+    updatedMany: 'Оновлено {{count}} завантажень',
     urlAlreadyQueued: 'URL-адреса вже в черзі',
     destinationConflict: 'Інше вибране завантаження використовує це місце призначення',
     existingDownloadDestination: 'Існуюче завантаження Firelink використовує це місце призначення',
+    matchingDownloadFilename: 'Незавершене завантаження вже має це ім’я файлу',
     fileExistsOnDisk: 'Файл існує на диску; перейменуйте або пропустіть, щоб уникнути видалення незв\'язаних даних',
     backendRejectedStart: 'Бекенд відхилив початок завантаження.',
     playlistNoEntries: 'Плейлист не містить елементів для завантаження',

src/i18n/catalogs/zh-CN.ts

@@ -391,9 +391,12 @@ const zhCN = {
     addedWithFailures: '添加了 {{added}} 个，失败了 {{failed}} 个。{{detail}}',
     addedOne: '添加了 1 个下载',
     addedMany: '添加了 {{count}} 个下载',
+    updatedOne: '已更新 1 个下载',
+    updatedMany: '已更新 {{count}} 个下载',
     urlAlreadyQueued: 'URL 已在队列中',
     destinationConflict: '其他选定的下载已使用此目标路径',
     existingDownloadDestination: '现有的 Firelink 下载已使用此目标路径',
+    matchingDownloadFilename: '已有一个未完成的下载使用此文件名',
     fileExistsOnDisk: '磁盘上已存在该文件；请重命名或跳过以避免删除无关数据',
     backendRejectedStart: '后端拒绝开始下载。',
     playlistNoEntries: '播放列表不包含可下载的条目',

src/store/useDownloadStore.test.ts

@@ -124,6 +124,132 @@ describe('useDownloadStore', () => {
     expect(state.pendingAddRequestContexts['https://example.com/file.bin']?.media).toBe(false);
   });
 
+  it('replaces a paused download URL in place and preserves its progress', async () => {
+    useDownloadStore.setState({
+      downloads: [{
+        id: 'replace-in-place',
+        url: 'https://expired.example/file.bin',
+        fileName: 'file.bin',
+        status: 'paused',
+        category: 'Other',
+        dateAdded: '2026-07-15T00:00:00.000Z',
+        downloadedBytes: 1024,
+        totalBytes: 4096,
+        fraction: 0.25
+      }] as any[]
+    });
+    vi.mocked(ipc.invokeCommand).mockResolvedValue(undefined as never);
+
+    const replaced = await useDownloadStore.getState().replaceDownload(
+      'replace-in-place',
+      { url: 'https://fresh.example/file.bin', lastError: undefined },
+      { type: 'add-to-queue', queueId: 'main' }
+    );
+
+    expect(replaced).toBe(true);
+    expect(useDownloadStore.getState().downloads).toEqual([expect.objectContaining({
+      id: 'replace-in-place',
+      url: 'https://fresh.example/file.bin',
+      status: 'paused',
+      downloadedBytes: 1024,
+      totalBytes: 4096,
+      fraction: 0.25
+    })]);
+    expect(ipc.invokeCommand).not.toHaveBeenCalledWith('remove_download', expect.anything());
+  });
+
+  it('resumes a replaced paused download without creating a second row', async () => {
+    useDownloadStore.setState({
+      downloads: [{
+        id: 'replace-and-resume',
+        url: 'https://expired.example/file.bin',
+        fileName: 'file.bin',
+        status: 'paused',
+        category: 'Other',
+        dateAdded: '',
+        destination: '/tmp',
+        downloadedBytes: 2048,
+        totalBytes: 4096
+      }] as any[]
+    });
+    vi.mocked(ipc.invokeCommand).mockImplementation(async (command: string) => {
+      if (command === 'resume_download') return false;
+      if (command === 'enqueue_download') {
+        return { id: 'replace-and-resume', filename: 'file.bin' };
+      }
+      if (command === 'get_pending_order') return [];
+      return undefined;
+    });
+
+    const replaced = await useDownloadStore.getState().replaceDownload(
+      'replace-and-resume',
+      { url: 'https://fresh.example/file.bin' },
+      { type: 'start-now' }
+    );
+
+    expect(replaced).toBe(true);
+    expect(useDownloadStore.getState().downloads).toHaveLength(1);
+    expect(useDownloadStore.getState().downloads[0]).toMatchObject({
+      id: 'replace-and-resume',
+      url: 'https://fresh.example/file.bin',
+      downloadedBytes: 2048,
+      totalBytes: 4096,
+      hasBeenDispatched: true
+    });
+    expect(ipc.invokeCommand).not.toHaveBeenCalledWith('remove_download', expect.anything());
+  });
+
+  it('serializes a replacement and a concurrent pause as one lifecycle operation', async () => {
+    useDownloadStore.setState({
+      downloads: [{
+        id: 'replace-pause-race',
+        url: 'https://expired.example/file.bin',
+        fileName: 'file.bin',
+        status: 'paused',
+        category: 'Other',
+        dateAdded: ''
+      }] as any[]
+    });
+
+    let releaseResume!: () => void;
+    let signalResumeStarted!: () => void;
+    const resumeStarted = new Promise<void>(resolve => {
+      signalResumeStarted = resolve;
+    });
+    const resumeGate = new Promise<void>(resolve => {
+      releaseResume = resolve;
+    });
+    vi.mocked(ipc.invokeCommand).mockImplementation(async (command: string) => {
+      if (command === 'resume_download') {
+        signalResumeStarted();
+        await resumeGate;
+        return true;
+      }
+      return undefined;
+    });
+
+    const replacing = useDownloadStore.getState().replaceDownload(
+      'replace-pause-race',
+      { url: 'https://fresh.example/file.bin' },
+      { type: 'start-now' }
+    );
+    await resumeStarted;
+
+    const pausing = useDownloadStore.getState().pauseDownload('replace-pause-race');
+    await Promise.resolve();
+    expect(ipc.invokeCommand).not.toHaveBeenCalledWith('pause_download', { id: 'replace-pause-race' });
+
+    releaseResume();
+    await replacing;
+    await pausing;
+
+    expect(ipc.invokeCommand).toHaveBeenCalledWith('pause_download', { id: 'replace-pause-race' });
+    expect(useDownloadStore.getState().downloads[0]).toMatchObject({
+      url: 'https://fresh.example/file.bin',
+      status: 'paused'
+    });
+  });
+
   it('rejects empty and duplicate queue names', () => {
     useDownloadStore.setState({
       queues: [

src/store/useDownloadStore.ts

@@ -676,6 +676,7 @@ interface DownloadState {
   closeDeleteModal: () => void;
   setSelectedPropertiesDownloadId: (id: string | null) => void;
   addDownload: (item: DownloadDraft, action: AddDownloadAction) => Promise<boolean>;
+  replaceDownload: (id: string, updates: Partial<DownloadItem>, action: AddDownloadAction) => Promise<boolean>;
   updateDownload: (id: string, updates: Partial<DownloadItem>) => void;
   removeDownload: (id: string, deleteFile?: boolean, preserveResumable?: boolean) => Promise<void>;
   pauseDownload: (id: string) => Promise<void>;
@@ -694,7 +695,115 @@ interface DownloadState {
   
 }
 
-export const useDownloadStore = create<DownloadState>((set, get) => ({
+export const useDownloadStore = create<DownloadState>((set, get) => {
+  const applyPropertiesInternal = async (id: string, updates: Partial<DownloadItem>): Promise<void> => {
+    await waitForPendingStartupResume();
+    const wasDispatching = await invalidateAndWaitForDispatch(id);
+    const state = get();
+    const item = state.downloads.find(d => d.id === id);
+    if (!item) return;
+
+    if (item.status === 'downloading' || item.status === 'processing' || item.status === 'retrying') {
+      throw new Error(i18n.t($ => $.downloadTable.transferActive));
+    }
+
+    if (item.status === 'ready' || item.status === 'staged' || item.status === 'completed' || item.status === 'failed') {
+      state.updateDownload(id, updates);
+      return;
+    }
+
+    // Queued or Paused
+    const isRegistered = state.backendRegisteredIds.has(id);
+
+    if (item.status === 'queued') {
+      if (isRegistered) {
+        await invoke('detach_download_for_reconfigure', { id });
+        state.unregisterBackendIds([id]);
+        set(current => ({ pendingOrder: current.pendingOrder.filter(value => value !== id) }));
+      }
+      state.updateDownload(id, updates);
+      if (isRegistered || wasDispatching) {
+        const dispatched = await dispatchItemInternal(id);
+        if (dispatched) {
+          state.updateDownload(id, { hasBeenDispatched: true });
+        } else {
+          state.removeFromQueue(id);
+        }
+      }
+    } else if (item.status === 'paused') {
+      if (isRegistered) {
+        try {
+          await invoke('detach_download_for_reconfigure', { id });
+        } catch (e) {
+          console.error("Failed to detach for reconfigure:", e);
+          throw e; // Preserve old properties if detach fails
+        }
+        state.unregisterBackendIds([id]);
+      }
+      state.updateDownload(id, updates);
+    }
+  };
+
+  const resumeDownloadInternal = async (id: string): Promise<boolean> => {
+    await waitForPendingStartupResume();
+    const targetItem = get().downloads.find(d => d.id === id);
+    if (!targetItem) return false;
+
+    setDownloadControlIntent(id, 'resume');
+    try {
+      if (targetItem.status === 'ready' || targetItem.status === 'staged') {
+        get().updateDownload(id, { status: 'queued', hasBeenDispatched: true });
+        if (await dispatchItemInternal(id)) {
+          return true;
+        }
+        get().updateDownload(id, { status: targetItem.status });
+        clearDownloadControlIntent(id, 'resume');
+        return false;
+      }
+
+      const prevStatus = targetItem.status;
+      const queueItems = get().downloads.filter(d =>
+        (d.queueId || MAIN_QUEUE_ID) === (targetItem.queueId || MAIN_QUEUE_ID)
+      );
+      const maxPos = queueItems.reduce((max, d) => Math.max(max, d.queuePosition ?? 0), -1);
+
+      get().updateDownload(id, {
+        status: 'queued',
+        speed: '-',
+        eta: '-',
+        queuePosition: maxPos + 1,
+        lastTry: new Date().toISOString()
+      });
+
+      const resumedExisting = await invoke('resume_download', { id });
+
+      let dispatchSucceeded = resumedExisting;
+      if (!dispatchSucceeded) {
+        get().unregisterBackendIds([id]);
+        // A terminal aria2 gid is intentionally re-enqueued as a new
+        // lifecycle. Advance and cancel the old generation before dispatching
+        // so QueueManager does not reject the legitimate user retry as stale.
+        await invalidateAndWaitForDispatch(id);
+        dispatchSucceeded = await dispatchItemInternal(id);
+      }
+
+      if (dispatchSucceeded) {
+        return true;
+      } else {
+        console.error("Failed to re-enqueue for resume");
+        get().updateDownload(id, { status: prevStatus });
+        clearDownloadControlIntent(id, 'resume');
+        return false;
+      }
+    } catch (e) {
+      console.error("Failed to resume download:", e);
+      get().updateDownload(id, { status: targetItem.status });
+      clearDownloadControlIntent(id, 'resume');
+      return false;
+    }
+  };
+
+  return {
   downloads: [],
   queues: [{ id: MAIN_QUEUE_ID, name: 'Main Queue', isMain: true }],
   pendingOrder: [],
@@ -951,53 +1060,30 @@ export const useDownloadStore = create<DownloadState>((set, get) => ({
     }
     return false;
   },
-  applyProperties: (id, updates) => runDownloadLifecycleOperation(id, 'properties', async () => {
-    await waitForPendingStartupResume();
-    const wasDispatching = await invalidateAndWaitForDispatch(id);
-    const state = get();
-    const item = state.downloads.find(d => d.id === id);
-    if (!item) return;
-
-    if (item.status === 'downloading' || item.status === 'processing' || item.status === 'retrying') {
-      throw new Error(i18n.t($ => $.downloadTable.transferActive));
-    }
-
-    if (item.status === 'ready' || item.status === 'staged' || item.status === 'completed' || item.status === 'failed') {
-      state.updateDownload(id, updates);
-      return;
-    }
-
-    // Queued or Paused
-    const isRegistered = state.backendRegisteredIds.has(id);
-
-    if (item.status === 'queued') {
-      if (isRegistered) {
-        await invoke('detach_download_for_reconfigure', { id });
-        state.unregisterBackendIds([id]);
-        set(current => ({ pendingOrder: current.pendingOrder.filter(value => value !== id) }));
+  replaceDownload: (id, updates, action) => runDownloadLifecycleOperation(
+    id,
+    'replace',
+    async () => {
+      if (!get().downloads.some(download => download.id === id)) return false;
+      await applyPropertiesInternal(id, updates);
+      if (!get().downloads.some(download => download.id === id)) return false;
+      if (action.type === 'start-now') {
+        const resumed = await resumeDownloadInternal(id);
+        if (resumed) get().updateDownload(id, { hasBeenDispatched: true });
+        return resumed;
       }
-      state.updateDownload(id, updates);
-      if (isRegistered || wasDispatching) {
-        const dispatched = await dispatchItemInternal(id);
-        if (dispatched) {
-          state.updateDownload(id, { hasBeenDispatched: true });
-        } else {
-          state.removeFromQueue(id);
-        }
-      }
-    } else if (item.status === 'paused') {
-      if (isRegistered) {
-        try {
-          await invoke('detach_download_for_reconfigure', { id });
-        } catch (e) {
-          console.error("Failed to detach for reconfigure:", e);
-          throw e; // Preserve old properties if detach fails
-        }
-        state.unregisterBackendIds([id]);
-      }
-      state.updateDownload(id, updates);
-    }
-  }, false, preemptDispatch),
+      return true;
+    },
+    false,
+    preemptDispatch
+  ),
+  applyProperties: (id, updates) => runDownloadLifecycleOperation(
+    id,
+    'properties',
+    () => applyPropertiesInternal(id, updates),
+    false,
+    preemptDispatch
+  ),
   updateDownload: (id, updates) => {
     set((state) => ({
       downloads: state.downloads.map(d => {
@@ -1126,64 +1212,13 @@ export const useDownloadStore = create<DownloadState>((set, get) => ({
       info(`Download ${id} redownloaded (queued)`);
     }
   }, true, preemptDispatch),
-  resumeDownload: (id) => runDownloadLifecycleOperation(id, 'resume', async () => {
-    await waitForPendingStartupResume();
-    const targetItem = get().downloads.find(d => d.id === id);
-    if (!targetItem) return false;
-
-    setDownloadControlIntent(id, 'resume');
-    try {
-      if (targetItem.status === 'ready' || targetItem.status === 'staged') {
-        get().updateDownload(id, { status: 'queued', hasBeenDispatched: true });
-        if (await dispatchItemInternal(id)) {
-          return true;
-        }
-        get().updateDownload(id, { status: targetItem.status });
-        clearDownloadControlIntent(id, 'resume');
-        return false;
-      }
-
-      const prevStatus = targetItem.status;
-      const queueItems = get().downloads.filter(d => 
-        (d.queueId || MAIN_QUEUE_ID) === (targetItem.queueId || MAIN_QUEUE_ID)
-      );
-      const maxPos = queueItems.reduce((max, d) => Math.max(max, d.queuePosition ?? 0), -1);
-      
-      get().updateDownload(id, { 
-        status: 'queued', 
-        speed: '-', 
-        eta: '-',
-        queuePosition: maxPos + 1,
-        lastTry: new Date().toISOString()
-      });
-
-      const resumedExisting = await invoke('resume_download', { id });
-      
-      let dispatchSucceeded = resumedExisting;
-      if (!dispatchSucceeded) {
-        get().unregisterBackendIds([id]);
-        // A terminal aria2 gid is intentionally re-enqueued as a new
-        // lifecycle. Advance and cancel the old generation before dispatching
-        // so QueueManager does not reject the legitimate user retry as stale.
-        await invalidateAndWaitForDispatch(id);
-        dispatchSucceeded = await dispatchItemInternal(id);
-      }
-
-      if (dispatchSucceeded) {
-        return true;
-      } else {
-        console.error("Failed to re-enqueue for resume");
-        get().updateDownload(id, { status: prevStatus });
-        clearDownloadControlIntent(id, 'resume');
-        return false;
-      }
-    } catch (e) {
-      console.error("Failed to resume download:", e);
-      get().updateDownload(id, { status: targetItem.status });
-      clearDownloadControlIntent(id, 'resume');
-      return false;
-    }
-  }, true, preemptDispatch),
+  resumeDownload: (id) => runDownloadLifecycleOperation(
+    id,
+    'resume',
+    () => resumeDownloadInternal(id),
+    true,
+    preemptDispatch
+  ),
   startQueue: (queueId) => {
     const requestedGeneration = currentQueueControlGeneration(queueId);
     const previousOperation = queueStartPromises.get(queueId) ?? Promise.resolve([]);
@@ -1654,7 +1689,8 @@ export const useDownloadStore = create<DownloadState>((set, get) => ({
       throw e;
     }
   }
-}));
+  };
+});
 
 let lastSavedDownloads = '';
 let isSavingDownloads = false;

src/utils/downloads.test.ts

@@ -1,6 +1,11 @@
 import { describe, expect, it } from 'vitest';
 import type { DownloadItem } from '../bindings/DownloadItem';
-import { redactDownloadForPersistence, resolveDownloadConnections } from './downloads';
+import {
+  downloadFileNamesMatch,
+  downloadMediaKindsMatch,
+  redactDownloadForPersistence,
+  resolveDownloadConnections
+} from './downloads';
 
 const item = (status: DownloadItem['status']): DownloadItem => ({
   id: 'download-1',
@@ -56,3 +61,28 @@ describe('download connection resolution', () => {
     expect(resolveDownloadConnections(Number.NaN, 8)).toBe(8);
   });
 });
+
+describe('download filename matching', () => {
+  it('matches case and path spelling while preserving the actual filename', () => {
+    expect(downloadFileNamesMatch(
+      'Media\\Example.Show.S01E01.MKV',
+      'example.show.s01e01.mkv'
+    )).toBe(true);
+  });
+
+  it('does not collapse distinct extensions or names', () => {
+    expect(downloadFileNamesMatch('example.zip', 'example.tar')).toBe(false);
+    expect(downloadFileNamesMatch('example-1.zip', 'example.zip')).toBe(false);
+  });
+
+  it('does not auto-match weak metadata fallback names', () => {
+    expect(downloadFileNamesMatch('download', 'download')).toBe(false);
+    expect(downloadFileNamesMatch('identifier', 'IDENTIFIER')).toBe(false);
+    expect(downloadFileNamesMatch('real-file.bin', 'real-file.bin')).toBe(true);
+  });
+
+  it('treats omitted media flags as ordinary downloads', () => {
+    expect(downloadMediaKindsMatch(undefined, false)).toBe(true);
+    expect(downloadMediaKindsMatch(undefined, true)).toBe(false);
+  });
+});

src/utils/downloads.ts

@@ -132,6 +132,29 @@ export const canonicalizeDownloadFileName = (fileName: string): string => {
   return sanitized && sanitized !== '.' && sanitized !== '..' ? sanitized : 'download';
 };
 
+/**
+ * Compare metadata-derived names without allowing path spelling or case to
+ * turn the same download into a second queue entry. Keep the extension and
+ * the rest of the name intact: URL query strings are not part of this value.
+ */
+export const normalizeDownloadFileNameForMatch = (fileName: string): string =>
+  canonicalizeDownloadFileName(fileName).normalize('NFKC').toLowerCase();
+
+export const downloadMediaKindsMatch = (
+  left: boolean | undefined,
+  right: boolean | undefined
+): boolean => Boolean(left) === Boolean(right);
+
+const WEAK_DOWNLOAD_FILE_NAMES = new Set(['download', 'identifier', 'view', 'uc']);
+
+export const downloadFileNamesMatch = (left: string, right: string): boolean => {
+  const normalizedLeft = normalizeDownloadFileNameForMatch(left);
+  const normalizedRight = normalizeDownloadFileNameForMatch(right);
+  return !WEAK_DOWNLOAD_FILE_NAMES.has(normalizedLeft)
+    && !WEAK_DOWNLOAD_FILE_NAMES.has(normalizedRight)
+    && normalizedLeft === normalizedRight;
+};
+
 export const isMediaUrl = (rawUrl: string): boolean => {
   try {
     const url = new URL(rawUrl);