feat: the extension picks a Discord source's posters from who posts in the channel, stored by id (#4488)

On a Discord channel page the Add panel lists who posted in the newest 200
messages, the creator the server is named for (or owned by) ticked. On a
channel FabledCurator already follows, the chip opens the same list with Save
and Open artist. The list is kept as user ids, so a rename never quietly stops
it matching; the name each was picked under rides beside it for display, and
the Subscriptions dialog shows it.

- DiscordClient.recent_posters + rank_posters (owner / name-matches-server;
  bots never suggested; it suggests, the operator ticks).
- GET/POST /api/extension/discord/posters; quick-add takes discord_authors.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

backend/app/api/extension.py

@@ -19,8 +19,10 @@ from ..models import AppSetting
 from ..services.extension_service import (
     ExtensionService,
     InvalidUrlError,
+    PosterLookupError,
     UnknownArtistError,
     UnknownPlatformError,
+    UnknownSourceError,
 )
 from ..services.source_service import KNOWN_PLATFORMS
 from ._responses import error_response as _bad
@@ -121,6 +123,10 @@ async def quick_add_source():
     # Patreon is canon: adding a Patreon source to an existing artist can take
     # the creator's Patreon display name (name only; the slug never moves).
     use_platform_name = body.get("use_platform_name") is True
+    # #4488: a Discord add can carry the posters picked in the panel.
+    discord_authors = body.get("discord_authors")
+    if discord_authors is not None and not _valid_authors(discord_authors):
+        return _bad("invalid_body", detail="discord_authors must be a list of {id, name}")
 
     from .credentials import _get_crypto
 
@@ -133,6 +139,7 @@ async def quick_add_source():
             result = await ExtensionService(session, _get_crypto()).quick_add_source(
                 url, artist_id=artist_id, artist_name=artist_name,
                 use_platform_name=use_platform_name,
+                discord_authors=discord_authors,
             )
         except UnknownArtistError as exc:
             return _bad("not_found", detail=str(exc), status=404)
@@ -147,6 +154,59 @@ async def quick_add_source():
     return jsonify(result), (201 if result["created_source"] else 200)
 
 
+def _valid_authors(value) -> bool:
+    """[{id, name}]: the id is what the list keys on, the name only shows it."""
+    return isinstance(value, list) and all(
+        isinstance(a, dict) and isinstance(a.get("id"), str | int)
+        and not isinstance(a.get("id"), bool)
+        and (a.get("name") is None or isinstance(a.get("name"), str))
+        for a in value
+    )
+
+
+@extension_bp.route("/discord/posters", methods=["GET"])
+async def discord_posters():
+    """Who posts in the Discord channel `url` shows, lately, with the likely
+    creator marked (#4488). Reads the channel with the stored token; writes
+    nothing."""
+    url = (request.args.get("url") or "").strip()
+    if not url:
+        return _bad("invalid_body", detail="url query parameter is required")
+    from .credentials import _get_crypto
+
+    async with get_session() as session:
+        if not await _ext_key_required(session):
+            return _bad("unauthorized", status=401)
+        try:
+            result = await ExtensionService(session, _get_crypto()).discord_posters(url)
+        except (InvalidUrlError, UnknownPlatformError) as exc:
+            return _bad("invalid_url", detail=str(exc))
+        except PosterLookupError as exc:
+            return _bad("posters_unavailable", detail=str(exc), status=409)
+    return jsonify(result)
+
+
+@extension_bp.route("/discord/posters", methods=["POST"])
+async def set_discord_posters():
+    """Set the poster list of the source following `url`'s channel."""
+    body = await request.get_json(silent=True)
+    if not isinstance(body, dict) or not isinstance(body.get("url"), str):
+        return _bad("invalid_body", detail="url is required")
+    authors = body.get("authors")
+    if not _valid_authors(authors):
+        return _bad("invalid_body", detail="authors must be a list of {id, name}")
+    async with get_session() as session:
+        if not await _ext_key_required(session):
+            return _bad("unauthorized", status=401)
+        try:
+            result = await ExtensionService(session).set_discord_posters(body["url"], authors)
+        except (InvalidUrlError, UnknownPlatformError, PosterLookupError) as exc:
+            return _bad("invalid_url", detail=str(exc))
+        except UnknownSourceError as exc:
+            return _bad("not_found", detail=str(exc), status=404)
+    return jsonify(result)
+
+
 def _read_manifest_sync() -> dict | None:
     """All the filesystem-touching work for /api/extension/manifest,
     in a sync helper so the async route can dispatch it via

backend/app/services/discord_client.py

@@ -75,6 +75,9 @@ _THREADS_BATCH = 25
 # it is honoured when present; 60s is the fallback and the cap.
 _MAX_429_RETRIES = 4
 _429_WAIT_SECONDS = 60.0
+# How far back the poster picker looks: two pages. Enough to see who posts in
+# a channel, few enough to answer while the operator waits (#4488).
+_POSTER_SCAN = 200
 
 # https://discord.com/developers/docs/resources/message#message-object-message-types
 # DEFAULT, REPLY, CHAT_INPUT_COMMAND — the ones that carry user content.
@@ -204,6 +207,55 @@ def has_visual_attachment(message: dict) -> bool:
     )
 
 
+_SQUASH = re.compile(r"[\W_]+", re.UNICODE)
+# Words a server name wraps around its creator's: "Todding's Server",
+# "The Official Todding Discord".
+_SERVER_WORDS = frozenset({"server", "discord", "the", "official", "community", "s"})
+
+
+def _squash(text: str | None) -> str:
+    return _SQUASH.sub("", (text or "").lower())
+
+
+def _server_tokens(server_name: str | None) -> list[str]:
+    name = (server_name or "").lower().replace("'s", " ").replace("\u2019s", " ")
+    words = [w for w in _SQUASH.split(name) if w and w not in _SERVER_WORDS]
+    tokens = [w for w in words if len(w) >= 3]
+    joined = "".join(words)
+    if len(joined) >= 3 and joined not in tokens:
+        tokens.append(joined)
+    return tokens
+
+
+def rank_posters(server_name: str | None, owner_id, posters: list[dict]) -> list[dict]:
+    """Mark who is probably the creator a server is named for, and order the
+    list for picking: suggested first, then by images posted, then messages.
+
+    Two signals, each a reason the picker shows beside the name:
+      - they own the server;
+      - their username or display name matches the server's name, once
+        "'s Server", "Official", "Discord" and punctuation are taken off
+        ("Todding's Server" and "todding").
+    Neither signal alone is proof, which is why this suggests and never
+    decides: the operator ticks the list. Bots are never suggested."""
+    tokens = _server_tokens(server_name)
+    owner = str(owner_id) if owner_id else None
+    ranked = []
+    for p in posters:
+        reasons = []
+        if owner and p.get("id") == owner:
+            reasons.append("owns the server")
+        names = [n for n in (_squash(p.get("username")), _squash(p.get("global_name"))) if len(n) >= 3]
+        if any(t in n or n in t for t in tokens for n in names):
+            reasons.append("name matches the server")
+        ranked.append({**p, "reasons": reasons, "suggested": False})
+    best = max((len(r["reasons"]) for r in ranked if not r.get("bot")), default=0)
+    for r in ranked:
+        r["suggested"] = best > 0 and not r.get("bot") and len(r["reasons"]) == best
+    ranked.sort(key=lambda r: (not r["suggested"], -r.get("images", 0), -r.get("messages", 0)))
+    return ranked
+
+
 @dataclass
 class MediaItem:
     """One file of a Discord message. `filename`/`extension` are gallery-dl's
@@ -611,6 +663,61 @@ class DiscordClient:
                 pass
         return out
 
+    def recent_posters(
+        self, server_id: str | None, channel_id: str, *, max_messages: int = _POSTER_SCAN,
+    ) -> dict:
+        """Who has posted lately in a channel, for picking a source's poster
+        list (#4488): the newest `max_messages` messages, tallied per author.
+        Deliberately shallow — it answers "who posts here", not "who ever did".
+        Every poster comes back with their stable id, which is what the list
+        stores: a username can change on a whim, an id can't."""
+        server: dict = {}
+        if server_id:
+            try:
+                server = self._get(f"/guilds/{server_id}") or {}
+            except DiscordAPIError:
+                server = {}
+        tally: dict[str, dict] = {}
+        before = None
+        seen = 0
+        while seen < max_messages:
+            page = self._get(
+                f"/channels/{channel_id}/messages",
+                {"limit": min(_MESSAGES_BATCH, max_messages - seen), "before": before},
+            )
+            if not isinstance(page, list) or not page:
+                break
+            for message in page:
+                seen += 1
+                if message.get("type") not in MESSAGE_TYPES:
+                    continue
+                author = message.get("author") or {}
+                aid = str(author.get("id") or "")
+                if not aid:
+                    continue
+                row = tally.setdefault(aid, {
+                    "id": aid,
+                    "username": author.get("username"),
+                    "global_name": author.get("global_name"),
+                    "bot": bool(author.get("bot")),
+                    "messages": 0,
+                    "images": 0,
+                })
+                row["messages"] += 1
+                if has_visual_attachment(message):
+                    row["images"] += 1
+            if len(page) < _MESSAGES_BATCH:
+                break
+            before = str(page[-1]["id"])
+        return {
+            "server": server.get("name") or None,
+            "owner_id": str(server["owner_id"]) if server.get("owner_id") else None,
+            "scanned": seen,
+            "posters": rank_posters(
+                server.get("name"), server.get("owner_id"), list(tally.values()),
+            ),
+        }
+
     def verify_auth(self, url: str) -> tuple[bool | None, str]:
         """Is the token valid, and can it see what the source names?"""
         try:

backend/app/services/extension_service.py

@@ -23,6 +23,12 @@ log = logging.getLogger(__name__)
 
 # The probe runs while the chip is drawing; names that take longer are skipped.
 _NAME_LOOKUP_SECONDS = 6.0
+# The poster picker waits on two pages of a channel's messages (#4488).
+_POSTER_LOOKUP_SECONDS = 20.0
+
+# A source's poster list (discord_ingester.AUTHORS_KEY) holds user ids; this
+# keeps the name each id was picked under, for showing the list to a person.
+AUTHOR_LABELS_KEY = "discord_author_labels"
 
 
 class UnknownPlatformError(Exception):
@@ -37,6 +43,15 @@ class UnknownArtistError(Exception):
     """quick-add named an `artist_id` that does not exist."""
 
 
+class PosterLookupError(Exception):
+    """The Discord poster picker couldn't read the channel (no token, no
+    access, not a channel page, or Discord was slow)."""
+
+
+class UnknownSourceError(Exception):
+    """No source follows this Discord channel or its server."""
+
+
 # Mirrored byte-for-byte from extension/lib/platforms.js
 # PLATFORM_ARTIST_PATTERNS. Keep these two copies in sync by hand —
 # reviewers catch drift.
@@ -110,6 +125,7 @@ class ExtensionService:
         artist_id: int | None = None,
         artist_name: str | None = None,
         use_platform_name: bool = False,
+        discord_authors: list[dict] | None = None,
     ) -> dict:
         """Add `url` as a source. `artist_id` connects it to an existing
         artist, `artist_name` to that artist (created if new); with neither,
@@ -119,7 +135,10 @@ class ExtensionService:
         name is canon: a Patreon source added to an existing artist renames
         that artist to the creator's Patreon display name. Name only — the
         slug, and every path keyed off it, never moves (#130). Ignored on every
-        other platform, and when the name can't be read."""
+        other platform, and when the name can't be read.
+
+        `discord_authors` ([{id, name}], #4488) sets a Discord source's poster
+        list in the same step, on a new source or one already there."""
         platform, raw_slug = self._derive(url)
         url = canonical_source_url(platform, url, raw_slug)
         renamed_from = None
@@ -133,6 +152,8 @@ class ExtensionService:
             artist = (await self.session.execute(
                 select(Artist).where(Artist.id == existing.artist_id)
             )).scalar_one()
+            if platform == DISCORD and discord_authors is not None:
+                await self._apply_posters(existing, discord_authors)
             return self._shape(existing, artist, created_source=False, created_artist=False)
 
         if artist_id is not None:
@@ -154,11 +175,98 @@ class ExtensionService:
         source, created_source = await self._find_or_create_source(
             artist_id=artist.id, platform=platform, url=url,
         )
+        if platform == DISCORD and discord_authors is not None:
+            await self._apply_posters(source, discord_authors)
         shaped = self._shape(source, artist, created_source, created_artist)
         if renamed_from is not None:
             shaped["renamed_from"] = renamed_from
         return shaped
 
+    # -- Discord poster picker (#4488) ------------------------------------------
+
+    def _discord_page(self, url: str) -> tuple[str, str]:
+        platform, raw_slug = self._derive(url)
+        if platform != DISCORD:
+            raise InvalidUrlError("not a Discord page")
+        server_id, _, channel_id = raw_slug.partition("/")
+        if not channel_id:
+            raise PosterLookupError("Open a channel to see who posts in it.")
+        return server_id, channel_id
+
+    async def _source_for_page(self, server_id: str, channel_id: str) -> Source | None:
+        """The source this channel's posts land on: the channel's own, else a
+        whole-server source that walks it."""
+        base = f"https://discord.com/channels/{server_id}"
+        return (
+            await self._existing_source(DISCORD, f"{base}/{channel_id}")
+            or await self._existing_source(DISCORD, base)
+        )
+
+    async def discord_posters(self, url: str) -> dict:
+        """Who posts in the channel `url` shows, newest `_POSTER_SCAN`
+        messages deep, with the likely creator marked — and, when a source
+        already follows it, the poster list that source has now."""
+        server_id, channel_id = self._discord_page(url)
+        import asyncio
+
+        from .credential_service import CredentialService
+        from .discord_client import DiscordAPIError, DiscordClient
+        token = None
+        if self._crypto is not None:
+            token = await CredentialService(self.session, self._crypto).get_token(DISCORD)
+        if not token:
+            raise PosterLookupError("No Discord token is saved in FabledCurator.")
+        client = DiscordClient(token, max_retries=0)
+        loop = asyncio.get_running_loop()
+        try:
+            found = await asyncio.wait_for(
+                loop.run_in_executor(None, client.recent_posters, server_id, channel_id),
+                timeout=_POSTER_LOOKUP_SECONDS,
+            )
+        except TimeoutError as exc:
+            raise PosterLookupError("Discord took too long to answer; try again.") from exc
+        except DiscordAPIError as exc:
+            raise PosterLookupError(f"Couldn't read this channel: {exc}") from exc
+        source = await self._source_for_page(server_id, channel_id)
+        co = (source.config_overrides or {}) if source is not None else {}
+        from .discord_ingester import AUTHORS_KEY
+        return {
+            **found,
+            "source_id": source.id if source is not None else None,
+            "selected": list(co.get(AUTHORS_KEY) or []),
+            # So someone on the list who hasn't posted lately still shows by
+            # name, and can be unticked.
+            "selected_labels": dict(co.get(AUTHOR_LABELS_KEY) or {}),
+        }
+
+    async def set_discord_posters(self, url: str, authors: list[dict]) -> dict:
+        """Store the picked posters on the source that follows `url`'s channel."""
+        server_id, channel_id = self._discord_page(url)
+        source = await self._source_for_page(server_id, channel_id)
+        if source is None:
+            raise UnknownSourceError("No source follows this channel yet.")
+        return await self._apply_posters(source, authors)
+
+    async def _apply_posters(self, source: Source, authors: list[dict]) -> dict:
+        """Ids are what the list keys on — a username can change on a whim,
+        an id can't — and the name each was picked under rides beside it for
+        showing the list to a person. An empty pick clears the list, which
+        takes everyone's posts again."""
+        from .discord_ingester import AUTHORS_KEY
+        picked = [a for a in authors if str(a.get("id") or "").strip()]
+        co = dict(source.config_overrides or {})
+        if picked:
+            co[AUTHORS_KEY] = [str(a["id"]).strip() for a in picked]
+            co[AUTHOR_LABELS_KEY] = {
+                str(a["id"]).strip(): str(a.get("name") or a["id"]) for a in picked
+            }
+        else:
+            co.pop(AUTHORS_KEY, None)
+            co.pop(AUTHOR_LABELS_KEY, None)
+        source.config_overrides = co or None
+        await self.session.commit()
+        return {"source_id": source.id, "discord_authors": co.get(AUTHORS_KEY, [])}
+
     async def _adopt_patreon_name(self, artist, raw_slug: str, url: str) -> str | None:
         """Rename `artist` to the Patreon display name; the old name when it
         changed, else None. Unreadable name → no rename, never the handle."""

extension/background/background.js

@@ -276,11 +276,26 @@ browser.runtime.onMessage.addListener(async (msg) => {
           artistId: msg.artistId ?? null,
           artistName: msg.artistName ?? null,
           usePlatformName: msg.usePlatformName === true,
+          discordAuthors: Array.isArray(msg.discordAuthors) ? msg.discordAuthors : null,
         });
       } catch (e) {
         return { error: e.message };
       }
 
+    case 'DISCORD_POSTERS':
+      try {
+        return await api.getDiscordPosters(msg.url);
+      } catch (e) {
+        return { error: e.message };
+      }
+
+    case 'SET_DISCORD_POSTERS':
+      try {
+        return await api.setDiscordPosters(msg.url, msg.authors || []);
+      } catch (e) {
+        return { error: e.message };
+      }
+
     case 'SEARCH_ARTISTS':
       try {
         return { artists: await api.searchArtists(msg.q || '') };

extension/content/content-script.css

@@ -100,3 +100,7 @@
 /* The panel's own [hidden] — its rows are display:flex, which beats the UA's. */
 .fc-panel [hidden] { display: none !important; }
 .fc-panel__rename { margin-top: 8px; font-size: 13px; }
+/* Poster picker (#4488): who posts in the channel, the likely creator ticked. */
+.fc-panel__posters { max-height: 220px; overflow-y: auto; }
+.fc-panel__poster { flex-wrap: wrap; }
+.fc-panel__poster-meta { flex-basis: 100%; padding-left: 21px; font-size: 11px; color: rgb(170, 166, 156); }

extension/content/content-script.js

@@ -81,6 +81,13 @@
     const probe = currentProbe;
 
     if (probe?.state === 'source_match') {
+      // A followed Discord channel opens its poster list (#4488); the artist
+      // page is one click further, in that panel.
+      if (probe.platform === 'discord' && probe.discord?.channel_id) {
+        if (document.getElementById('fc-add-panel')) closePanel();
+        else openPostersPanel(btn, probe);
+        return;
+      }
       await openArtist(btn, probe.artist?.slug);
       return;
     }
@@ -158,6 +165,120 @@
     document.getElementById('fc-add-panel')?.remove();
   }
 
+  // ---- Poster picker (#4488) ----
+  // Who posted in this channel lately, read by FabledCurator with its Discord
+  // token, the creator the server is named for (or owned by) ticked. The
+  // source keeps their ids: a username can change on a whim, an id can't, so
+  // the list never quietly stops matching. Names are other people's text —
+  // createElement only.
+
+  function posterSection() {
+    const list = el('div', { class: 'fc-panel__posters' }, [
+      el('div', { class: 'fc-panel__hint', text: 'Reading who posts here…' }),
+    ]);
+    const node = el('div', {}, [
+      el('div', { class: 'fc-panel__label', text: 'Only posts by' }),
+      list,
+    ]);
+    const state = { data: null, picked: new Set() };
+
+    function render() {
+      const posters = withSelected(state.data);
+      if (!posters.length) {
+        list.replaceChildren(el('div', { class: 'fc-panel__hint', text: 'No one has posted here lately.' }));
+        return;
+      }
+      const rows = posters.map((p) => {
+        const id = String(p.id);
+        const box = el('input', { type: 'checkbox', checked: state.picked.has(id) });
+        box.addEventListener('change', () => {
+          if (box.checked) state.picked.add(id);
+          else state.picked.delete(id);
+          hint.textContent = pickHint();
+        });
+        const bits = [`${p.images} image${p.images === 1 ? '' : 's'}`, `${p.messages} message${p.messages === 1 ? '' : 's'}`];
+        if (p.reasons?.length) bits.unshift(p.reasons.join(', '));
+        return el('label', { class: 'fc-panel__radio fc-panel__poster' }, [
+          box,
+          el('span', { text: posterLabel(p) }),
+          el('span', { class: 'fc-panel__poster-meta', text: bits.join(' · ') }),
+        ]);
+      });
+      const hint = el('div', { class: 'fc-panel__hint', text: pickHint() });
+      list.replaceChildren(...rows, hint);
+    }
+
+    function pickHint() {
+      return state.picked.size
+        ? 'Only the ticked people’s posts are taken.'
+        : 'Nothing ticked: everyone’s posts are taken.';
+    }
+
+    async function load() {
+      let r;
+      try {
+        r = await browser.runtime.sendMessage({ type: 'DISCORD_POSTERS', url: window.location.href });
+      } catch (e) {
+        r = { error: e.message };
+      }
+      if (r?.error) {
+        list.replaceChildren(el('div', { class: 'fc-panel__hint', text: `Couldn’t list posters — ${r.error}` }));
+        return;
+      }
+      state.data = r;
+      state.picked = initialPosterPick(r);
+      render();
+    }
+
+    // null until the list has loaded: an add made before then leaves the
+    // source's list as it is instead of clearing it.
+    const request = () => (state.data ? postersRequest(state.data.posters, state.picked) : null);
+    return { node, load, request };
+  }
+
+  function openPostersPanel(btn, probe) {
+    closePanel();
+    const d = probe.discord || {};
+    const posters = posterSection();
+    const saveBtn = el('button', { class: 'fc-panel__btn fc-panel__btn--primary', text: 'Save' });
+    const artistBtn = el('button', { class: 'fc-panel__btn', text: `Open ${probe.artist?.name || 'artist'}` });
+    const cancelBtn = el('button', { class: 'fc-panel__btn', text: 'Close' });
+    const panel = el('div', { id: 'fc-add-panel', class: 'fc-panel' }, [
+      el('div', { class: 'fc-panel__title', text: 'Discord source' }),
+      el('div', { class: 'fc-panel__sub', text: d.channel_id ? channelLabel(d) : serverLabel(d) }),
+      posters.node,
+      el('div', { class: 'fc-panel__actions' }, [artistBtn, cancelBtn, saveBtn]),
+    ]);
+    panel.addEventListener('keydown', (e) => {
+      e.stopPropagation();
+      if (e.key === 'Escape') closePanel();
+    });
+    cancelBtn.addEventListener('click', closePanel);
+    artistBtn.addEventListener('click', () => { closePanel(); openArtist(btn, probe.artist?.slug); });
+    saveBtn.addEventListener('click', async () => {
+      const authors = posters.request();
+      if (!authors) return;
+      saveBtn.disabled = true;
+      try {
+        const r = await browser.runtime.sendMessage({
+          type: 'SET_DISCORD_POSTERS', url: window.location.href, authors,
+        });
+        if (r?.error) {
+          showToast(`Error: ${r.error}`, 'error');
+          return;
+        }
+        showToast(authors.length ? `Only posts by ${authors.map((a) => a.name || a.id).join(', ')}` : 'Taking everyone’s posts', 'success');
+        closePanel();
+      } catch (e) {
+        showToast(`Error: ${e.message}`, 'error');
+      } finally {
+        saveBtn.disabled = false;
+      }
+    });
+    document.body.appendChild(panel);
+    posters.load();
+  }
+
   async function openAddPanel(btn, probe) {
     closePanel();
     const platformName = PLATFORMS[probe.platform]?.name || probe.platform;
@@ -184,6 +305,8 @@
     const d = probe.discord || {};
     const discord = probe.platform === 'discord';
     const choice = panelDefaults(probe, window.location.href);
+    // #4488: on a channel page, pick whose posts the new source takes.
+    const posters = discord && d.channel_id ? posterSection() : null;
 
     const scopeRow = (value, label, disabled) => {
       const input = el('input', {
@@ -234,6 +357,7 @@
       el('div', { class: 'fc-panel__label', text: 'Artist' }),
       el('div', { class: 'fc-panel__combo' }, [nameInput, results]),
       renameRow,
+      ...(posters ? [posters.node] : []),
       hint,
       el('div', { class: 'fc-panel__actions' }, [cancelBtn, addBtn]),
     ]);
@@ -392,6 +516,8 @@
     addBtn.addEventListener('click', async () => {
       const req = addRequest(choice);
       if (!req) return;
+      const authors = posters?.request();
+      if (authors) req.discordAuthors = authors;
       const btn = document.getElementById('fc-add-source-btn');
       addBtn.disabled = true;
       const ok = await add(btn || addBtn, req);
@@ -402,6 +528,7 @@
     document.body.appendChild(panel);
     refresh();
     nameInput.focus();
+    posters?.load();
     nameInput.select();
     // Search what the field opens with — the server's name, usually — so an
     // artist it already matches is picked before the operator types anything.

extension/lib/api.js

@@ -106,8 +106,11 @@ class FabledCuratorAPI {
   // artist from the URL. A Discord channel always sends one.
   // usePlatformName: a Patreon source joining an existing artist renames it
   // to the Patreon display name (Patreon is canon; name only, never the slug).
-  quickAddSource(url, { artistId = null, artistName = null, usePlatformName = false } = {}) {
+  // discordAuthors ([{id, name}], #4488): a Discord source's poster list, set
+  // in the same step.
+  quickAddSource(url, { artistId = null, artistName = null, usePlatformName = false, discordAuthors = null } = {}) {
     const body = { url };
+    if (discordAuthors) body.discord_authors = discordAuthors;
     if (artistId != null) body.artist_id = artistId;
     else if (artistName) body.artist_name = artistName;
     if (usePlatformName) body.use_platform_name = true;
@@ -123,6 +126,15 @@ class FabledCuratorAPI {
     const qs = new URLSearchParams(params).toString();
     return this.request('GET', `/extension/probe?${qs}`);
   }
+  // #4488: who posts in the Discord channel `url` shows, lately, with the
+  // likely creator marked; and setting the list on the source that follows it.
+  getDiscordPosters(url) {
+    const qs = new URLSearchParams({ url }).toString();
+    return this.request('GET', `/extension/discord/posters?${qs}`);
+  }
+  setDiscordPosters(url, authors) {
+    return this.request('POST', '/extension/discord/posters', { url, authors });
+  }
   // Latest published extension version on this instance — drives the in-app
   // update prompt. Public endpoint (no key needed, but request() sends it
   // harmlessly). Returns {version, xpi_url, latest_url, sha256}.

extension/lib/chip.js

@@ -144,3 +144,49 @@ function inlineCompletion(typed, results) {
   if (!t) return null;
   return (results || []).find((a) => a.name.length > t.length && a.name.toLowerCase().startsWith(t)) || null;
 }
+
+// ---- Discord poster picker (#4488) ----
+// /api/extension/discord/posters lists who posted in the channel lately, with
+// the creator the server is named for (or owned by) marked `suggested`. The
+// picker ticks posters; the source keeps their ids, since a username can
+// change on a whim and an id can't.
+
+/** "Todding (@todding)" — the display name, then the handle when it differs. */
+function posterLabel(p) {
+  const shown = p?.global_name || p?.username || p?.id || '';
+  const handle = p?.username && p.username !== shown ? ` (@${p.username})` : '';
+  return `${shown}${handle}`;
+}
+
+/** What the picker starts with: the source's current list when it has one,
+ *  else the suggested creator(s). A set of ids. */
+function initialPosterPick(data) {
+  const current = (data?.selected || []).map(String);
+  if (current.length) return new Set(current);
+  return new Set((data?.posters || []).filter((p) => p.suggested).map((p) => String(p.id)));
+}
+
+/** The checklist's rows: who posted lately, then anyone already on the
+ *  source's list who hasn't — by the name they were picked under — so they
+ *  can still be unticked. */
+function withSelected(data) {
+  const posters = [...(data?.posters || [])];
+  const shown = new Set(posters.map((p) => String(p.id)));
+  const labels = data?.selected_labels || {};
+  for (const id of (data?.selected || []).map(String)) {
+    if (shown.has(id)) continue;
+    posters.push({ id, global_name: labels[id] || null, username: null,
+      messages: 0, images: 0, reasons: ['on the list, not posting lately'] });
+  }
+  return posters;
+}
+
+/** The picked posters as the API takes them: [{id, name}], in list order.
+ *  An id already on the source but no longer posting lately is kept. */
+function postersRequest(posters, picked) {
+  const byId = new Map((posters || []).map((p) => [String(p.id), p]));
+  return [...picked].map((id) => ({
+    id,
+    name: byId.has(id) ? (byId.get(id).global_name || byId.get(id).username || id) : null,
+  }));
+}

extension/test/chip.spec.js

@@ -198,3 +198,46 @@ describe('Add panel on Patreon and SubscribeStar', () => {
     expect(c.artistName).toBe('Tamada')
   })
 })
+
+const { posterLabel, initialPosterPick, postersRequest, withSelected } = loadLib('chip.js', [
+  'posterLabel', 'initialPosterPick', 'postersRequest', 'withSelected',
+])
+
+describe('the poster checklist rows', () => {
+  it('adds someone on the list who has not posted lately, by their saved name', () => {
+    const rows = withSelected({
+      posters: [{ id: '7', username: 'todding', global_name: 'Todding' }],
+      selected: ['7', '42'],
+      selected_labels: { 42: 'Old Name' },
+    })
+    expect(rows.map((r) => r.id)).toEqual(['7', '42'])
+    expect(posterLabel(rows[1])).toBe('Old Name')
+    expect(rows[1].reasons).toEqual(['on the list, not posting lately'])
+  })
+})
+
+describe('the Discord poster picker (#4488)', () => {
+  const posters = [
+    { id: '7', username: 'todding', global_name: 'Todding', suggested: true },
+    { id: '8', username: 'jakeboii', global_name: 'Jake Boii', suggested: false },
+    { id: '9', username: 'plain', global_name: null, suggested: false },
+  ]
+
+  it('labels a poster by display name, then handle', () => {
+    expect(posterLabel(posters[0])).toBe('Todding (@todding)')
+    expect(posterLabel(posters[2])).toBe('plain')
+  })
+
+  it('starts from the source list when it has one, else the suggestion', () => {
+    expect([...initialPosterPick({ posters, selected: [] })]).toEqual(['7'])
+    expect([...initialPosterPick({ posters, selected: ['8'] })]).toEqual(['8'])
+    expect([...initialPosterPick({ posters: [] })]).toEqual([])
+  })
+
+  it('sends ids with the names they were picked under, keeping unknown ids', () => {
+    expect(postersRequest(posters, new Set(['7', '42']))).toEqual([
+      { id: '7', name: 'Todding' },
+      { id: '42', name: null },
+    ])
+  })
+})

frontend/src/components/subscriptions/SourceFormDialog.vue

@@ -52,6 +52,9 @@
               placeholder="Todding" hint="Comma-separated. Empty takes everyone's."
               persistent-hint class="mt-2"
             />
+            <div v-if="platform === 'discord' && authorNames.length" class="text-caption mt-2">
+              {{ authorNames.join(', ') }}
+            </div>
             <p class="text-caption mt-2" style="opacity: 0.75">
               More per-platform fields land here over time. Use Advanced JSON for everything else.
             </p>
@@ -112,6 +115,15 @@ const structuredAuthors = ref('')
 const otherConfig = ref({})
 const STRUCTURED_KEYS = ['videos', 'since', 'discord_authors']
 
+// The extension's poster picker stores ids (#4488) and the name each was
+// picked under, so a list of numbers still says who it means.
+const authorNames = computed(() => {
+  const labels = otherConfig.value.discord_author_labels || {}
+  return splitAuthors(structuredAuthors.value)
+    .map(a => (labels[a] ? `${labels[a]} (${a})` : null))
+    .filter(Boolean)
+})
+
 function splitAuthors(txt) {
   return (txt || '').split(',').map(s => s.trim()).filter(Boolean)
 }

tests/test_discord_client.py

@@ -424,3 +424,60 @@ def test_the_adapter_authenticates_with_the_token_and_keys_by_identity(tmp_path)
         _msg(9, attachments=[{"id": "300", "url": "https://cdn/a/1.png"}])
     )
     assert _ledger_key(media) == "9:300"
+
+
+# -- the poster picker (#4488) -------------------------------------------------
+
+def _person(pid, username, global_name=None, **extra):
+    return {"id": pid, "username": username, "global_name": global_name,
+            "messages": 1, "images": 0, **extra}
+
+
+def test_the_creator_a_server_is_named_for_is_suggested():
+    ranked = dc.rank_posters("Todding's Server", "99", [
+        _person("8", "jakeboii", "Jake Boii", images=3),
+        _person("7", "todding", "Todding", images=1),
+    ])
+    assert ranked[0]["id"] == "7" and ranked[0]["suggested"] is True
+    assert ranked[0]["reasons"] == ["name matches the server"]
+    assert ranked[1]["suggested"] is False
+
+
+def test_owning_the_server_and_matching_its_name_outranks_either_alone():
+    ranked = dc.rank_posters("The Official Todding Discord", "7", [
+        _person("5", "toddingfan"),
+        _person("7", "t0dd", "Todding"),
+    ])
+    assert [r["id"] for r in ranked if r["suggested"]] == ["7"]
+    assert ranked[0]["reasons"] == ["owns the server", "name matches the server"]
+
+
+def test_no_signal_suggests_no_one_and_bots_never():
+    assert not any(r["suggested"] for r in dc.rank_posters("Art Club", None, [
+        _person("1", "alice"), _person("2", "bob"),
+    ]))
+    ranked = dc.rank_posters("Todding's Server", None, [_person("3", "toddingbot", bot=True)])
+    assert ranked[0]["suggested"] is False
+
+
+def test_recent_posters_tallies_a_shallow_window_by_id():
+    creator = {"id": "7", "username": "todding", "global_name": "Todding"}
+    other = {"id": "8", "username": "jakeboii", "global_name": "Jake Boii"}
+    art = [{"url": "https://cdn/a/1.png"}]
+    page = [_msg(i, author=creator, attachments=art) for i in range(300, 240, -1)]
+    page += [_msg(i, author=other) for i in range(240, 200, -1)]
+    routes = {
+        "/guilds/1": _ok({"id": "1", "name": "Todding's Server", "owner_id": "7"}),
+        ("/channels/2/messages", None): _ok(page),
+        ("/channels/2/messages", "201"): _ok([_msg(150, author=other)]),
+    }
+    client = _client(routes)
+    got = client.recent_posters("1", "2", max_messages=150)
+    assert got["server"] == "Todding's Server" and got["owner_id"] == "7"
+    assert got["scanned"] == 101
+    first = got["posters"][0]
+    assert (first["id"], first["messages"], first["images"], first["suggested"]) == ("7", 60, 60, True)
+    assert got["posters"][1]["messages"] == 41
+    # It asked for no more than the window: 100, then the 50 left of 150.
+    limits = [p.get("limit") for e, p in client._session.calls if e.endswith("/messages")]
+    assert limits == [100, 50]