feat(settings): pick and add Z-Library domains

README.md

@@ -148,8 +148,13 @@ daily downloads; a book whose file is already in the library is not downloaded
 again.
 
 Z-Library has no official API: Shelfloom uses the one its apps use, which can
-change. Its domain moves too; set `SHELFLOOM_ZLIBRARY_DOMAIN` to one that
-works from your server (`HTTPS_PROXY` is honoured if it needs a proxy).
+change. Its domain moves too: **Settings → Z-Library** lists its published
+domains together with the current list Z-Library's own API gives out, checks
+which ones answer from your server, and lets you switch domain or add a new
+one. Take new domains only from Z-Library's own
+channels: lookalike domains exist to steal account passwords.
+`SHELFLOOM_ZLIBRARY_DOMAIN` is only the starting choice (`HTTPS_PROXY` is
+honoured if the server needs a proxy).
 
 ### KOReader Sync and the web reader
 
@@ -198,7 +203,7 @@ npm run lint           # gofmt + go vet, eslint
 | `HOMEPAGE_URL` | | Foyer address for the sidebar link |
 | `SHELFLOOM_ZLIBRARY_EMAIL` | | Z-Library account email |
 | `SHELFLOOM_ZLIBRARY_PASSWORD` | | Z-Library account password |
-| `SHELFLOOM_ZLIBRARY_DOMAIN` | `z-library.ec` | Z-Library domain (or base URL) |
+| `SHELFLOOM_ZLIBRARY_DOMAIN` | `z-library.hn` | Z-Library domain until one is picked in Settings |
 | `TZ` | | Time zone stats are grouped in |
 
 Databases from the earlier Python-based releases open as they are, as long as

cmd/shelfloom/main.go

@@ -66,7 +66,7 @@ func main() {
 			ScanInterval:        seconds("SHELFLOOM_SCAN_INTERVAL", 300),
 			SerialCheckInterval: seconds("SHELFLOOM_SERIAL_CHECK_INTERVAL", 86400),
 			FoyerURL:            os.Getenv("HOMEPAGE_URL"),
-			ZLibraryDomain:      env("SHELFLOOM_ZLIBRARY_DOMAIN", "z-library.ec"),
+			ZLibraryDomain:      env("SHELFLOOM_ZLIBRARY_DOMAIN", "z-library.hn"),
 			ZLibraryEmail:       os.Getenv("SHELFLOOM_ZLIBRARY_EMAIL"),
 			ZLibraryPassword:    os.Getenv("SHELFLOOM_ZLIBRARY_PASSWORD"),
 		},

frontend/src/__tests__/ZLibraryModal.test.tsx

@@ -47,7 +47,7 @@ describe('ZLibraryModal', () => {
       if (u === '/api/zlibrary/status') {
         body = {
           enabled: true,
-          domain: 'z-library.ec',
+          domain: 'z-library.hn',
           downloads_today: 3,
           downloads_limit: 10,
           error: null,

frontend/src/__tests__/ZLibrarySettings.test.tsx

@@ -0,0 +1,153 @@
+import { fireEvent, render, screen, waitFor } from '@testing-library/react'
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+import ZLibrarySettings from '../components/settings/ZLibrarySettings'
+
+describe('ZLibrarySettings', () => {
+  let fetchSpy: {
+    mockRestore: () => void
+    mock: { calls: [RequestInfo | URL, RequestInit | undefined][] }
+  }
+  let state: {
+    selected: string
+    default: string
+    enabled: boolean
+    domains: { domain: string; source: 'official' | 'zlibrary' | 'custom' }[]
+    fetched_from: string | null
+    fetched_at: number | null
+  }
+
+  beforeEach(() => {
+    state = {
+      selected: 'z-library.hn',
+      default: 'z-library.hn',
+      enabled: true,
+      domains: [
+        { domain: 'z-library.sk', source: 'official' },
+        { domain: 'z-library.hn', source: 'official' },
+      ],
+      fetched_from: null,
+      fetched_at: null,
+    }
+    fetchSpy = vi.spyOn(globalThis, 'fetch').mockImplementation((url, opts) => {
+      const u = url.toString()
+      const method = (opts?.method ?? 'GET').toUpperCase()
+      const sent = opts?.body ? JSON.parse(opts.body as string) : {}
+      let body: unknown = state
+      let status = 200
+      if (u.startsWith('/api/zlibrary/domains/check?')) {
+        const d = new URL(u, 'http://x').searchParams.get('domain')!
+        body =
+          d === 'z-library.sk'
+            ? { domain: d, ok: false, ms: 0, error: 'behind a bot check' }
+            : { domain: d, ok: true, ms: 420, error: null }
+      } else if (u === '/api/zlibrary/domains/refresh') {
+        state = {
+          ...state,
+          domains: [
+            ...state.domains,
+            { domain: 'articles.sk', source: 'zlibrary' },
+          ],
+          fetched_from: 'z-library.hn',
+          fetched_at: 1791700000,
+        }
+        body = state
+      } else if (u === '/api/zlibrary/domain' && method === 'PUT') {
+        state = { ...state, selected: sent.domain }
+        body = state
+      } else if (u === '/api/zlibrary/domains' && method === 'POST') {
+        status = 201
+        state = {
+          ...state,
+          domains: [
+            ...state.domains,
+            { domain: sent.domain, source: 'custom' },
+          ],
+        }
+        body = state
+      } else if (
+        u.startsWith('/api/zlibrary/domains/') &&
+        method === 'DELETE'
+      ) {
+        state = {
+          ...state,
+          domains: state.domains.filter((d) => d.source !== 'custom'),
+        }
+        body = state
+      }
+      return Promise.resolve({
+        ok: true,
+        status,
+        json: async () => body,
+      }) as Promise<Response>
+    }) as unknown as typeof fetchSpy
+  })
+
+  afterEach(() => {
+    fetchSpy.mockRestore()
+  })
+
+  it('checks every domain and shows which one is in use', async () => {
+    render(<ZLibrarySettings />)
+    expect(
+      (await screen.findAllByText('Works · 420 ms')).length
+    ).toBeGreaterThan(0)
+    expect(screen.getByText('behind a bot check')).toBeInTheDocument()
+    expect(
+      screen.getByRole('radio', { name: 'Use z-library.hn' })
+    ).toHaveAttribute('aria-checked', 'true')
+  })
+
+  it('adds Z-Library’s own domain list and checks the new ones', async () => {
+    render(<ZLibrarySettings />)
+    expect(await screen.findByText('articles.sk')).toBeInTheDocument()
+    expect(screen.getByText('FROM Z-LIBRARY')).toBeInTheDocument()
+    expect(screen.getByTestId('zlibrary-fetched')).toHaveTextContent(
+      'from z-library.hn'
+    )
+    await waitFor(() =>
+      expect(
+        fetchSpy.mock.calls.some(([u]) =>
+          u.toString().includes('check?domain=articles.sk')
+        )
+      ).toBe(true)
+    )
+  })
+
+  it('switches, adds and removes domains', async () => {
+    render(<ZLibrarySettings />)
+    fireEvent.click(
+      await screen.findByRole('radio', { name: 'Use z-library.sk' })
+    )
+    await waitFor(() =>
+      expect(
+        screen.getByRole('radio', { name: 'Use z-library.sk' })
+      ).toHaveAttribute('aria-checked', 'true')
+    )
+
+    fireEvent.change(screen.getByLabelText('New domain'), {
+      target: { value: 'libb.example' },
+    })
+    fireEvent.click(screen.getByRole('button', { name: 'Add' }))
+    expect(await screen.findByText('libb.example')).toBeInTheDocument()
+    await waitFor(() =>
+      expect(
+        fetchSpy.mock.calls.some(([u]) =>
+          u.toString().includes('check?domain=libb.example')
+        )
+      ).toBe(true)
+    )
+
+    fireEvent.click(screen.getByRole('button', { name: 'Remove libb.example' }))
+    await waitFor(() =>
+      expect(screen.queryByText('libb.example')).not.toBeInTheDocument()
+    )
+  })
+
+  it('says how to turn Z-Library on when no account is set', async () => {
+    state.enabled = false
+    render(<ZLibrarySettings />)
+    expect(
+      await screen.findByText(/Z-Library is off until an account is set/)
+    ).toBeInTheDocument()
+  })
+})

frontend/src/components/library/ZLibraryModal.tsx

@@ -278,6 +278,14 @@ export default function ZLibraryModal({ onClose, onAdded }: Props) {
             {error && (
               <p className="text-xs text-red-400 border border-red-400/20 bg-red-400/5 px-3 py-2 normal-case">
                 {error}
+                {/domain|reach/i.test(error) && (
+                  <>
+                    {' '}
+                    <Link to="/settings" className="font-semibold underline">
+                      Change domain in Settings
+                    </Link>
+                  </>
+                )}
               </p>
             )}
             {notice && (