Phase 3: rooms, local only

Implements PLAN.md Phase 3: the roomserver, the room half of storage, the
Client-Server room endpoints and the admin room endpoints. A client can now
create a room, invite, join, leave, kick, ban, send messages and state,
redact, name a room with an alias and find one in the public directory.
Nothing talks to another server; every operation that would need to is
refused with a message that says so rather than a bare M_FORBIDDEN.

roomserver: one input pipeline every event goes through, whatever sent it —
validate, authorise, resolve, persist, emit. The rules are not
reimplemented here; internal/matrix is pure library code and this is what
connects it to a database and to a room's history. The Client-Server
handlers do no authorisation of their own, deliberately: whether Alice may
kick Bob is a question about the room's power levels, and the one place
that is answered correctly is the authorisation rules inside the pipeline.

A mutex per room serialises writers. Two events racing into one room would
each read the same forward extremities, both become one, and fork the room
for no reason — which would then need state resolution to put back
together. State resolution is wired in anyway for the multi-extremity
case. It is unreachable from outside in this phase, and the alternative is
a pipeline that authorises against one arbitrary branch of a fork without
saying so.

Room versions 3 to 12 all work and are each tested end to end. Version 12
earns that coverage: its room ID is the create event's own ID, its create
event carries no room_id, and the create event is excluded from every other
event's auth_events — so the state auth.Check is given is the event's
auth_events plus the create event, which that version identifies by room ID
rather than citing.

createRoom sends the spec's events in the spec's order, each authorised
against what the ones before it produced. A failure part-way leaves an
incomplete room, which is the lesser evil: the alternative is holding every
event of a new room in memory and writing them in one transaction, making
the pipeline that authorises them a special case. The one failure a second
client can cause at any time, an alias clash, takes the room row back out.

Redactions stay two decisions, as the spec keeps them. The rules let almost
any redaction into the room; whether it applies to its target is a separate
test, run inside the same transaction as the redaction itself so that a
client holding an event ID can always read the stripped event.

storage: events keyed by event ID rather than by a surrogate, since an
event ID appears in prev_events, auth_events, state snapshots and client
requests alike. Stream ordering comes from a counter row bumped inside the
write transaction, because a PostgreSQL sequence is explicitly not
transactional and a rolled-back write would leave a hole in the stream that
/sync would have to be taught to skip. State snapshots are stored per event
and deduplicated by content hash, so the table grows with state changes
rather than with traffic — and that is what makes "the state after a
forward extremity" answerable at all. The room's listing columns are
denormalised onto its row because the public directory orders every
published room by member count and pages the result, which cannot be done
by reading each room's state in turn.

Federation-disabled behaviour from PLAN.md section 3 is enforced here.
Restricted joins are the exception that works: the rule needs a signature
from the authorising user's server verified, and while federation is off
that server is always this one.

adminapi: room list and detail, purge, force-leave, and room and event
counters on the dashboard. clientapi gains its own rate-limit buckets for
createRoom and for joining, both of which write events rather than read
them.

Tested against the real event core and a real database rather than fakes:
what is under test is whether an event this server signs is one the
authorisation rules accept, and a fake of either would only prove that the
pipeline calls what the fake expects. The storage tests run against both
SQL drivers. docs/rooms.md describes the pipeline, the storage decisions
and the known gaps — chief among them that history visibility is
room-level rather than per-event, and that /sync still reports no rooms,
both of which belong with the event stream in Phase 4.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

server/internal/clientapi/clientapi.go

@@ -21,6 +21,7 @@ import (
 	"github.com/dariuszjaniak/warp/server/internal/federation"
 	"github.com/dariuszjaniak/warp/server/internal/httputil"
 	"github.com/dariuszjaniak/warp/server/internal/ratelimit"
+	"github.com/dariuszjaniak/warp/server/internal/roomserver"
 	"github.com/dariuszjaniak/warp/server/internal/settings"
 	"github.com/dariuszjaniak/warp/server/internal/userapi"
 )
@@ -30,6 +31,7 @@ type ClientAPI struct {
 	serverName    string
 	clientBaseURL string
 	users         *userapi.API
+	rooms         *roomserver.API
 	settings      *settings.Service
 	federation    *federation.Gate
 	registration  config.Registration
@@ -41,9 +43,11 @@ type ClientAPI struct {
 
 	// One limiter per endpoint class, so a client hammering /login cannot
 	// spend the budget of /profile.
-	limitDefault  *ratelimit.Limiter
-	limitLogin    *ratelimit.Limiter
-	limitRegister *ratelimit.Limiter
+	limitDefault    *ratelimit.Limiter
+	limitLogin      *ratelimit.Limiter
+	limitRegister   *ratelimit.Limiter
+	limitRoomCreate *ratelimit.Limiter
+	limitJoin       *ratelimit.Limiter
 }
 
 // Options configure the component.
@@ -60,6 +64,12 @@ type Options struct {
 	// Users is the userapi component.
 	Users *userapi.API
 
+	// Rooms is the roomserver component. Without it the room endpoints are
+	// not registered at all, which is what the Phase 1 and Phase 2 tests
+	// relied on and what keeps a half-wired server from offering a
+	// createRoom it cannot honour.
+	Rooms *roomserver.API
+
 	// Settings is the runtime-settings service; the registration switch is
 	// read from it on every registration attempt.
 	Settings *settings.Service
@@ -107,6 +117,7 @@ func New(opts Options) (*ClientAPI, error) {
 		serverName:    opts.ServerName,
 		clientBaseURL: opts.ClientBaseURL,
 		users:         opts.Users,
+		rooms:         opts.Rooms,
 		settings:      opts.Settings,
 		federation:    opts.Federation,
 		registration:  opts.Registration,
@@ -120,9 +131,16 @@ func New(opts Options) (*ClientAPI, error) {
 		c.limitDefault = ratelimit.New(bucket(opts.RateLimit.Default))
 		c.limitLogin = ratelimit.New(bucket(opts.RateLimit.Login))
 		c.limitRegister = ratelimit.New(bucket(opts.RateLimit.Register))
+		// Creating a room writes a dozen events and joining one writes a
+		// membership event into a room everybody in it then sees, so both
+		// get their own, tighter bucket: the default one is sized for
+		// reads.
+		c.limitRoomCreate = ratelimit.New(bucket(opts.RateLimit.RoomCreate))
+		c.limitJoin = ratelimit.New(bucket(opts.RateLimit.Join))
 	} else {
 		c.limitDefault, c.limitLogin, c.limitRegister =
 			ratelimit.Disabled(), ratelimit.Disabled(), ratelimit.Disabled()
+		c.limitRoomCreate, c.limitJoin = ratelimit.Disabled(), ratelimit.Disabled()
 	}
 	return c, nil
 }
@@ -187,6 +205,74 @@ func (c *ClientAPI) RegisterRoutes(r *httputil.Router) {
 		c.limitDefault, c.handlePutRoomAccountData)
 
 	c.authed(r, "GET "+v3+"/sync", c.limitDefault, c.handleSync)
+
+	c.registerRoomRoutes(r)
+}
+
+// registerRoomRoutes adds the room endpoints, if there is a roomserver.
+//
+// A build without one answers them with M_UNRECOGNIZED, which is the right
+// answer: a server that cannot store a room should say it has no createRoom
+// rather than fail every call to it.
+func (c *ClientAPI) registerRoomRoutes(r *httputil.Router) {
+	if c.rooms == nil {
+		return
+	}
+
+	c.authed(r, "POST "+v3+"/createRoom", c.limitRoomCreate, c.handleCreateRoom)
+
+	// Membership. The two join endpoints differ only in what they are
+	// addressed by: /join/{roomIdOrAlias} resolves an alias first.
+	c.authed(r, "POST "+v3+"/join/{roomIDOrAlias}", c.limitJoin, c.handleJoinRoom)
+	c.authed(r, "POST "+v3+"/rooms/{roomID}/join", c.limitJoin, c.handleJoinRoomByID)
+	c.authed(r, "POST "+v3+"/rooms/{roomID}/leave", c.limitDefault, c.handleLeaveRoom)
+	c.authed(r, "POST "+v3+"/rooms/{roomID}/invite", c.limitDefault, c.handleInvite)
+	c.authed(r, "POST "+v3+"/rooms/{roomID}/kick", c.limitDefault, c.handleKick)
+	c.authed(r, "POST "+v3+"/rooms/{roomID}/ban", c.limitDefault, c.handleBan)
+	c.authed(r, "POST "+v3+"/rooms/{roomID}/unban", c.limitDefault, c.handleUnban)
+
+	// Sending. The state endpoint is registered twice, because the empty
+	// state key is both valid and the common case and arrives in two
+	// spellings: ".../state/m.room.name" and ".../state/m.room.name/".
+	// The trailing-slash form uses a multi-segment wildcard, which is the
+	// only kind Go's router matches against an empty segment — and which
+	// also means a state key a client did not escape arrives whole rather
+	// than as a 404.
+	c.authed(r, "PUT "+v3+"/rooms/{roomID}/send/{eventType}/{txnID}",
+		c.limitDefault, c.handleSendEvent)
+	c.authed(r, "PUT "+v3+"/rooms/{roomID}/state/{eventType}",
+		c.limitDefault, c.handlePutState)
+	c.authed(r, "PUT "+v3+"/rooms/{roomID}/state/{eventType}/{stateKey...}",
+		c.limitDefault, c.handlePutState)
+	c.authed(r, "PUT "+v3+"/rooms/{roomID}/redact/{eventID}/{txnID}",
+		c.limitDefault, c.handleRedact)
+
+	// Reading.
+	c.authed(r, "GET "+v3+"/rooms/{roomID}/event/{eventID}", c.limitDefault, c.handleGetEvent)
+	c.authed(r, "GET "+v3+"/rooms/{roomID}/state", c.limitDefault, c.handleGetState)
+	c.authed(r, "GET "+v3+"/rooms/{roomID}/state/{eventType}",
+		c.limitDefault, c.handleGetStateEvent)
+	c.authed(r, "GET "+v3+"/rooms/{roomID}/state/{eventType}/{stateKey...}",
+		c.limitDefault, c.handleGetStateEvent)
+	c.authed(r, "GET "+v3+"/rooms/{roomID}/members", c.limitDefault, c.handleGetMembers)
+	c.authed(r, "GET "+v3+"/rooms/{roomID}/joined_members",
+		c.limitDefault, c.handleGetJoinedMembers)
+	c.authed(r, "GET "+v3+"/joined_rooms", c.limitDefault, c.handleGetJoinedRooms)
+
+	// The directory. Resolving an alias and reading the public room list
+	// need no token: a client handed a link has to be able to follow it
+	// before it decides whether to log in.
+	c.public(r, "GET "+v3+"/directory/room/{roomAlias}", c.limitDefault, c.handleGetAlias)
+	c.authed(r, "PUT "+v3+"/directory/room/{roomAlias}", c.limitDefault, c.handlePutAlias)
+	c.authed(r, "DELETE "+v3+"/directory/room/{roomAlias}", c.limitDefault, c.handleDeleteAlias)
+	c.authed(r, "GET "+v3+"/rooms/{roomID}/aliases", c.limitDefault, c.handleGetRoomAliases)
+
+	c.public(r, "GET "+v3+"/publicRooms", c.limitDefault, c.handleGetPublicRooms)
+	c.authed(r, "POST "+v3+"/publicRooms", c.limitDefault, c.handlePostPublicRooms)
+	c.public(r, "GET "+v3+"/directory/list/room/{roomID}",
+		c.limitDefault, c.handleGetRoomVisibility)
+	c.authed(r, "PUT "+v3+"/directory/list/room/{roomID}",
+		c.limitDefault, c.handlePutRoomVisibility)
 }
 
 // public registers an endpoint that needs no access token.