Merge pull request 'Discord: channel list and presence without the main bot (#225 S5, fixes #251)' (#262) from feat/225-s5-channels into main

drb-c2-core/app/internal/discord_rest.py

@@ -655,3 +655,100 @@ async def guild_snapshot(token_doc: dict, guild_id: str, *, refresh: bool = Fals
                                  error=f"check failed ({type(e).__name__})")
 
     return await access_cache.get_or_load(key, _load, lambda s: ttl_for(s.status), refresh=refresh)
+
+
+# ---------------------------------------------------------------------------
+# Voice-channel directory from a radio bot's view (server-26#225 S5)
+# ---------------------------------------------------------------------------
+
+DIRECTORY_MAX_CHANNELS = 200    # same cap as PUT /discord/guilds/{id}/directory
+_DIRECTORY_NAME_MAX = 100
+VOICE_CHANNEL = 2
+CATEGORY_CHANNEL = 4
+
+
+def _int_or(value: Any, default: int = 0) -> int:
+    try:
+        return int(value)
+    except (TypeError, ValueError):
+        return default
+
+
+def directory_from_snapshot(snap: Optional[GuildSnapshot]) -> Optional[dict]:
+    """A server's name and voice channels as one radio bot's snapshot sees
+    them, in the shape the DRB server bot pushes (``PUT
+    /discord/guilds/{id}/directory``): ``{name, voice_channels: [{channel_id,
+    name, category, position}]}``, in Discord's sidebar order (channels with
+    no category first, then each category by position; channels by position,
+    then id). None unless the snapshot is OK.
+
+    Every voice channel in the list is kept, including any this bot can't
+    View, exactly like the server bot's gateway list: whether a bot may join
+    is the permission check's answer (discord_streams.evaluate_access), and
+    the picker shows it per channel. Stage channels are not voice channels
+    here either."""
+    if snap is None or snap.status != OK or not isinstance(snap.channels, list):
+        return None
+    chans = [c for c in snap.channels if isinstance(c, dict) and c.get("id") is not None]
+    cats = {str(c["id"]): c for c in chans if c.get("type") == CATEGORY_CHANNEL}
+
+    def parent(c: dict) -> Optional[dict]:
+        return cats.get(str(c.get("parent_id") or ""))
+
+    def order(c: dict) -> tuple:
+        p = parent(c)
+        top = (0, 0, 0) if p is None else (1, _int_or(p.get("position")), _int_or(p.get("id")))
+        return (*top, _int_or(c.get("position")), _int_or(c.get("id")))
+
+    out: list[dict] = []
+    for c in sorted((c for c in chans if c.get("type") == VOICE_CHANNEL), key=order)[:DIRECTORY_MAX_CHANNELS]:
+        p = parent(c)
+        category = str(p.get("name") or "")[:_DIRECTORY_NAME_MAX] if p else ""
+        out.append({
+            "channel_id": str(c["id"]),
+            "name": str(c.get("name") or "")[:_DIRECTORY_NAME_MAX],
+            "category": category or None,
+            "position": len(out),
+        })
+    name = snap.guild.get("name") if isinstance(snap.guild, dict) else None
+    return {"name": str(name)[:_DIRECTORY_NAME_MAX] if name else None, "voice_channels": out}
+
+
+@dataclass
+class DirectoryResult:
+    """``guild_directory``'s answer. ``status``: OK (``name`` and
+    ``voice_channels`` from ``token_id``'s snapshot), NOT_MEMBER (every bot
+    asked turned out not to be in the server, or its token is invalid) or
+    UNKNOWN (no usable answer — keep what is stored)."""
+    guild_id: str
+    status: str
+    name: Optional[str] = None
+    voice_channels: Optional[list] = None
+    token_id: Optional[str] = None
+    fetched_at: Optional[float] = None
+
+
+async def guild_directory(token_docs: list[dict], guild_id: str, *, refresh: bool = False,
+                          max_bots: int = 3) -> DirectoryResult:
+    """The voice-channel list of one server, read from the first of
+    ``token_docs`` (radio bots believed to be in it, best first) whose cached
+    snapshot is OK. It is the same snapshot the permission check reads, so
+    listing channels costs no extra Discord request. At most ``max_bots``
+    bots are asked, one after another. Never raises for a Discord failure.
+
+    The caller decides which server and which bots: this never looks a
+    server up by itself, so it can't discover one (a server DRB doesn't
+    already know is never listed from a radio bot's membership)."""
+    guild_id = str(guild_id)
+    statuses: list[str] = []
+    for doc in token_docs[:max(1, max_bots)]:
+        snap = await guild_snapshot(doc, guild_id, refresh=refresh)
+        statuses.append(snap.status)
+        d = directory_from_snapshot(snap)
+        if d is not None:
+            return DirectoryResult(guild_id=guild_id, status=OK, name=d["name"],
+                                   voice_channels=d["voice_channels"], token_id=snap.token_id,
+                                   fetched_at=snap.fetched_at)
+    if statuses and all(s in (NOT_MEMBER, INVALID) for s in statuses):
+        return DirectoryResult(guild_id=guild_id, status=NOT_MEMBER)
+    return DirectoryResult(guild_id=guild_id, status=UNKNOWN)

drb-c2-core/app/internal/discord_streams.py

@@ -53,6 +53,7 @@ A retained MQTT message therefore never stores a bot credential on the broker.
 from __future__ import annotations
 
 import asyncio
+import time
 from datetime import datetime, timezone, timedelta
 from typing import Optional
 
@@ -352,14 +353,39 @@ async def check_bots(tokens: dict[str, dict], token_ids: list[str], guild_id: st
             for t in token_ids}
 
 
+# server-26#251: an interactive start (a person pressed Start / ran /join)
+# re-reads a bot's snapshot that says "denied" once it is this old, so a
+# permission fixed in Discord a moment ago is seen without waiting out the
+# cache. The reconciler never does (plan finding 4: no REST loop).
+RECHECK_DENIED_AFTER_SECONDS = 10.0
+
+
 async def _perm_check(*, org_id: str, guild_id: str, channel_id: str, stream_id: str,
-                      preferred_token_id: Optional[str], node_ids: set) -> Optional[dict]:
+                      preferred_token_id: Optional[str], node_ids: set,
+                      recheck_denied: bool = False) -> Optional[dict]:
     if not settings.discord_perm_check_enabled:
         return None
     tokens = {t["token_id"]: t for t in await fstore.collection_list(leases.TOKENS) if t.get("token_id")}
     ids = tokens_to_check(tokens, guild_id=guild_id, org_id=org_id, node_ids=node_ids,
                           exclude_stream_id=stream_id, preferred_token_id=preferred_token_id)
-    return await check_bots(tokens, ids, guild_id, channel_id)
+    snaps = await gather_snapshots(tokens, ids, guild_id)
+
+    def verdict(t: str) -> dict:
+        return evaluate_access(snaps[t], channel_id, bot=tokens[t].get("name") or t) if snaps.get(t) \
+            else _unanswered()
+
+    out = {t: verdict(t) for t in ids}
+    if recheck_denied:
+        now = time.time()
+        stale = [t for t in ids if out[t]["status"] == leases.PERM_DENIED
+                 and now - (getattr(snaps.get(t), "fetched_at", None) or now) >= RECHECK_DENIED_AFTER_SECONDS]
+        if stale:
+            fresh = await gather_snapshots(tokens, stale, guild_id, refresh=True)
+            for t, snap in fresh.items():
+                if snap is not None:     # not answered in time: keep the cached verdict
+                    snaps[t] = snap
+                    out[t] = verdict(t)
+    return out
 
 
 def _channel_ref(perms: Optional[dict], channel_name: Optional[str]) -> str:
@@ -484,6 +510,7 @@ async def start_stream(
     preferred_token_id: Optional[str] = None,
     max_streams: Optional[int] = None,
     stream_id: Optional[str] = None,
+    interactive: bool = False,
 ) -> dict:
     """Put ``system_id`` on a voice channel.
 
@@ -504,6 +531,12 @@ async def start_stream(
     channel first (``_perm_check``; server-26#225). Every entry point — the
     bot's /join, the web picker, the node command and the reconciler —
     comes through here, so none can hand a node a bot Discord will refuse.
+
+    ``interactive``: a person asked for this start (the routes pass True,
+    the reconciler never does). A bot whose cached check says "denied" is
+    then asked again if that answer is more than
+    ``RECHECK_DENIED_AFTER_SECONDS`` old (server-26#251), so "fix it in
+    Discord, then try again" works on the next try.
     """
     if mode not in ("persistent", "adhoc"):
         raise StreamError("bad_mode", "mode must be persistent or adhoc", status=400)
@@ -527,14 +560,14 @@ async def start_stream(
             org_id=org_id, guild_id=guild_id, channel_id=channel_id, system_id=system_id, mode=mode,
             channel_name=channel_name, guild_name=guild_name, created_by=created_by, node_id=node_id,
             preferred_token_id=preferred_token_id, max_streams=max_streams, stream_id=stream_id,
-            existing=existing,
+            existing=existing, interactive=interactive,
         )
 
 
 async def _start_locked(*, org_id: str, guild_id: str, channel_id: str, system_id: str, mode: str,
                         channel_name: Optional[str], guild_name: Optional[str], created_by: Optional[str],
                         node_id: Optional[str], preferred_token_id: Optional[str], max_streams: Optional[int],
-                        stream_id: Optional[str], existing: dict) -> dict:
+                        stream_id: Optional[str], existing: dict, interactive: bool = False) -> dict:
     already_on = False
     if stream_id:
         existing = await fstore.doc_get(STREAMS, stream_id) or existing   # re-read under the lock
@@ -612,7 +645,8 @@ async def _start_locked(*, org_id: str, guild_id: str, channel_id: str, system_i
 
     node_ids = {n["node_id"] for n in candidates}
     perms = await _perm_check(org_id=org_id, guild_id=guild_id, channel_id=channel_id, stream_id=stream_id,
-                              preferred_token_id=preferred_token_id, node_ids=node_ids)
+                              preferred_token_id=preferred_token_id, node_ids=node_ids,
+                              recheck_denied=interactive)
     if perms and any(p.get("status") == "bad_channel" for p in perms.values()):
         raise StreamError("bad_channel", f"{_channel_ref(perms, channel_name)} is not a voice channel. "
                                          "Radio can only play in a voice channel — pick one from the list.",
@@ -638,7 +672,7 @@ async def _start_locked(*, org_id: str, guild_id: str, channel_id: str, system_i
                     # Bots that just turned out to be members get checked too.
                     perms = await _perm_check(org_id=org_id, guild_id=guild_id, channel_id=channel_id,
                                               stream_id=stream_id, preferred_token_id=preferred_token_id,
-                                              node_ids=node_ids)
+                                              node_ids=node_ids, recheck_denied=interactive)
                 res = await leases.lease_for_stream(stream_id, node_id=node["node_id"], org_id=org_id,
                                                     preferred_token_id=preferred_token_id, stream_fields=fields,
                                                     soft_preferred_token_id=soft_pref, perms=perms)