Create custom database type for state sets

creation

README.md

@@ -50,7 +50,7 @@ Here, implemented and some unimplemented features are listed.
 - GET /_matrix/client/r0/login
 - POST /_matrix/client/r0/login: Only with password flow.
 - POST /_matrix/client/r0/register: Only with dummy flow.
-- POST /_matrix/client/r0/createRoom: Only with optional parameters name, topic, preset and invite.
+- POST /_matrix/client/r0/createRoom: Except with option invite_3pid.
 - GET /_matrix/client/r0/joined_rooms
 - POST /_matrix/client/r0/rooms/{roomId}/invite
 - POST /_matrix/client/r0/rooms/{roomId}/join: Except with third party invite.
@@ -61,6 +61,8 @@ Here, implemented and some unimplemented features are listed.
 - PUT /_matrix/client/r0/rooms/{roomId}/state/{eventType}/{stateKey}
 - PUT /_matrix/client/r0/rooms/{roomId}/send/{eventType}/{txnId}
 - GET /_matrix/client/r0/rooms/{roomId}/messages: Except filtering.
+- GET /_matrix/client/r0/rooms/{roomId}/state
+- GET /_matrix/client/r0/rooms/{roomId}/state/{eventType}/{stateKey}
 - GET /_matrix/client/r0/directory/list/room/{roomId}
 - PUT /_matrix/client/r0/directory/list/room/{roomId}
 - GET /_matrix/client/r0/capabilities
@@ -76,7 +78,7 @@ Here, implemented and some unimplemented features are listed.
 - GET /_matrix/federation/v1/state/{roomId}
 - GET /_matrix/federation/v1/state_ids/{roomId}
 - GET /_matrix/key/v2/server/{keyId}
-- GET /_matrix/federation/v1/query/profile: Except displayname and avatar_url is not implemented.
+- GET /_matrix/federation/v1/query/profile
 
 ### Major unimplemented features
 

lib/architex/room_server.ex

@@ -6,8 +6,6 @@ defmodule Architex.RoomServer do
   The RoomServers are supervised by a DynamicSupervisor RoomServer.Supervisor.
   """
 
-  @typep t :: map()
-
   use GenServer
 
   import Ecto.Query
@@ -21,9 +19,12 @@ defmodule Architex.RoomServer do
     Account,
     Device,
     DeviceTransaction,
-    Membership
+    Membership,
+    Alias
   }
 
+  alias Architex.Types.{UserId, StateSet}
+
   alias Architex.StateResolution.Authorization
   alias ArchitexWeb.Client.Request.{CreateRoom, Kick, Ban}
 
@@ -46,8 +47,13 @@ defmodule Architex.RoomServer do
   @spec get_room_server(String.t()) :: {:error, :not_found} | DynamicSupervisor.on_start_child()
   def get_room_server(room_id) do
     # TODO: Might be wise to use a transaction here to prevent race conditions.
-    case Repo.one(from r in Room, where: r.id == ^room_id) do
-      %Room{state: serialized_state_set} = room ->
+    query =
+      Room
+      |> where([r], r.id == ^room_id)
+      |> select([:id, :forward_extremities, :state_set, :visibility])
+
+    case Repo.one(query) do
+      %Room{} = room ->
         case Registry.lookup(@registry, room_id) do
           [{pid, _}] ->
             {:ok, pid}
@@ -55,8 +61,7 @@ defmodule Architex.RoomServer do
           [] ->
             opts = [
               name: {:via, Registry, {@registry, room_id}},
-              room: room,
-              serialized_state_set: serialized_state_set
+              room: room
             ]
 
             DynamicSupervisor.start_child(@supervisor, {__MODULE__, opts})
@@ -111,9 +116,10 @@ defmodule Architex.RoomServer do
   @doc """
   Invite the a user to this room.
   """
-  @spec invite(pid(), Account.t(), String.t()) :: :ok | {:error, atom()}
-  def invite(pid, account, user_id) do
-    GenServer.call(pid, {:invite, account, user_id})
+  @spec invite(pid(), Account.t(), String.t(), String.t() | nil, String.t() | nil) ::
+          :ok | {:error, atom()}
+  def invite(pid, account, user_id, avatar_url, displayname) do
+    GenServer.call(pid, {:invite, account, user_id, avatar_url, displayname})
   end
 
   @doc """
@@ -135,25 +141,28 @@ defmodule Architex.RoomServer do
   @doc """
   Kick a user from this room.
   """
-  @spec kick(pid(), Account.t(), Kick.t()) :: :ok | {:error, atom()}
-  def kick(pid, account, request) do
-    GenServer.call(pid, {:kick, account, request})
+  @spec kick(pid(), Account.t(), Kick.t(), String.t() | nil, String.t() | nil) ::
+          :ok | {:error, atom()}
+  def kick(pid, account, request, avatar_url, displayname) do
+    GenServer.call(pid, {:kick, account, request, avatar_url, displayname})
   end
 
   @doc """
   Ban a user from this room.
   """
-  @spec ban(pid(), Account.t(), Ban.t()) :: :ok | {:error, atom()}
-  def ban(pid, account, request) do
-    GenServer.call(pid, {:ban, account, request})
+  @spec ban(pid(), Account.t(), Ban.t(), String.t() | nil, String.t() | nil) ::
+          :ok | {:error, atom()}
+  def ban(pid, account, request, avatar_url, displayname) do
+    GenServer.call(pid, {:ban, account, request, avatar_url, displayname})
   end
 
   @doc """
   Unban a user from this room.
   """
-  @spec unban(pid(), Account.t(), String.t()) :: :ok | {:error, atom()}
-  def unban(pid, account, user_id) do
-    GenServer.call(pid, {:unban, account, user_id})
+  @spec unban(pid(), Account.t(), String.t(), String.t() | nil, String.t() | nil) ::
+          :ok | {:error, atom()}
+  def unban(pid, account, user_id, avatar_url, displayname) do
+    GenServer.call(pid, {:unban, account, user_id, avatar_url, displayname})
   end
 
   @doc """
@@ -182,34 +191,50 @@ defmodule Architex.RoomServer do
     GenServer.call(pid, {:send_state_event, account, event_type, content, state_key})
   end
 
+  @doc """
+  Get the current state of a room.
+  If the requesting user is not a member of the room,
+  get the state when the user left the room.
+  If the user has never been in the room, return an error.
+  """
+  @spec get_current_state(pid(), Account.t()) :: {:ok, [Event.t()]} | :error
+  def get_current_state(pid, account) do
+    GenServer.call(pid, {:get_current_state, account})
+  end
+
+  @spec get_state_event(pid(), Account.t(), String.t(), String.t()) ::
+          {:ok, map()} | {:error, :unauthorized} | {:error, :not_found}
+  def get_state_event(pid, account, event_type, state_key) do
+    GenServer.call(pid, {:get_state_event, account, event_type, state_key})
+  end
+
   ### Implementation
 
   @impl true
   def init(opts) do
-    room = Keyword.fetch!(opts, :room)
-    serialized_state_set = Keyword.fetch!(opts, :serialized_state_set)
-    state_event_ids = Enum.map(serialized_state_set, fn [_, _, event_id] -> event_id end)
-
-    state_set =
-      Event
-      |> where([e], e.id in ^state_event_ids)
-      |> Repo.all()
-      |> Enum.into(%{}, fn %Event{type: type, state_key: state_key} = event ->
-        {{type, state_key}, event}
-      end)
-
-    {:ok, %{room: room, state_set: state_set}}
+    {:ok, %{room: Keyword.fetch!(opts, :room)}}
   end
 
   @impl true
   def handle_call(
-        {:create_room, account, request},
+        {:create_room, account, %CreateRoom{room_alias_name: room_alias_name} = request},
         _from,
         %{room: %Room{id: room_id} = room} = state
       ) do
-    case Repo.transaction(create_room_insert_events(room, account, request)) do
-      {:ok, {state_set, room}} ->
-        {:reply, {:ok, room_id}, %{state | state_set: state_set, room: room}}
+    create_alias_result =
+      if room_alias_name do
+        Alias.create(room_alias_name, room_id)
+      else
+        {:ok, nil}
+      end
+
+    case create_alias_result do
+      {:ok, alias_} ->
+        events = create_room_events(room, account, request, alias_)
+
+        case Repo.transaction(process_events(room, events)) do
+          {:ok, room} ->
+            {:reply, {:ok, room_id}, %{state | room: room}}
 
           {:error, reason} ->
             {:reply, {:error, reason}, state}
@@ -217,9 +242,13 @@ defmodule Architex.RoomServer do
           _ ->
             {:reply, {:error, :unknown}, state}
         end
+
+      {:error, _} ->
+        {:reply, {:error, :alias}, state}
+    end
   end
 
-  def handle_call({:server_in_room?, domain}, _from, %{state_set: state_set} = state) do
+  def handle_call({:server_in_room?, domain}, _from, %{room: %Room{state_set: state_set}} = state) do
     result =
       Enum.any?(state_set, fn
         {{"m.room.member", user_id}, %Event{content: %{"membership" => "join"}}} ->
@@ -272,11 +301,15 @@ defmodule Architex.RoomServer do
     {:reply, {state_events, auth_chain}, state}
   end
 
-  def handle_call({:invite, account, user_id}, _from, %{room: room, state_set: state_set} = state) do
-    invite_event = Event.Invite.new(room, account, user_id)
+  def handle_call(
+        {:invite, account, user_id, avatar_url, displayname},
+        _from,
+        %{room: room} = state
+      ) do
+    invite_event = Event.Invite.new(room, account, user_id, avatar_url, displayname)
 
-    case Repo.transaction(insert_single_event(room, state_set, invite_event)) do
-      {:ok, {state_set, room, _}} -> {:reply, :ok, %{state | state_set: state_set, room: room}}
+    case Repo.transaction(process_event(room, invite_event)) do
+      {:ok, {room, _}} -> {:reply, :ok, %{state | room: room}}
       {:error, reason} -> {:reply, {:error, reason}, state}
     end
   end
@@ -284,59 +317,64 @@ defmodule Architex.RoomServer do
   def handle_call(
         {:join, account},
         _from,
-        %{room: %Room{id: room_id} = room, state_set: state_set} = state
+        %{room: %Room{id: room_id} = room} = state
       ) do
     join_event = Event.Join.new(room, account)
 
-    case Repo.transaction(insert_single_event(room, state_set, join_event)) do
-      {:ok, {state_set, room, _}} ->
-        {:reply, {:ok, room_id}, %{state | state_set: state_set, room: room}}
+    case Repo.transaction(process_event(room, join_event)) do
+      {:ok, {room, _}} ->
+        {:reply, {:ok, room_id}, %{state | room: room}}
 
       {:error, reason} ->
         {:reply, {:error, reason}, state}
     end
   end
 
-  def handle_call({:leave, account}, _from, %{room: room, state_set: state_set} = state) do
+  def handle_call({:leave, account}, _from, %{room: room} = state) do
     leave_event = Event.Leave.new(room, account)
 
-    case Repo.transaction(insert_single_event(room, state_set, leave_event)) do
-      {:ok, {state_set, room, _}} -> {:reply, :ok, %{state | state_set: state_set, room: room}}
+    case Repo.transaction(process_event(room, leave_event)) do
+      {:ok, {room, _}} -> {:reply, :ok, %{state | room: room}}
       {:error, reason} -> {:reply, {:error, reason}, state}
     end
   end
 
   def handle_call(
-        {:kick, account, %Kick{user_id: user_id, reason: reason}},
+        {:kick, account, %Kick{user_id: user_id, reason: reason}, avatar_url, displayname},
         _from,
-        %{room: room, state_set: state_set} = state
+        %{room: room} = state
       ) do
-    kick_event = Event.Kick.new(room, account, user_id, reason)
+    kick_event =
+      Event.Kick.new(room, account, to_string(user_id), avatar_url, displayname, reason)
 
-    case Repo.transaction(insert_single_event(room, state_set, kick_event)) do
-      {:ok, {state_set, room, _}} -> {:reply, :ok, %{state | state_set: state_set, room: room}}
+    case Repo.transaction(process_event(room, kick_event)) do
+      {:ok, {room, _}} -> {:reply, :ok, %{state | room: room}}
       {:error, reason} -> {:reply, {:error, reason}, state}
     end
   end
 
   def handle_call(
-        {:ban, account, %Kick{user_id: user_id, reason: reason}},
+        {:ban, account, %Ban{user_id: user_id, reason: reason}, avatar_url, displayname},
         _from,
-        %{room: room, state_set: state_set} = state
+        %{room: room} = state
       ) do
-    ban_event = Event.Ban.new(room, account, user_id, reason)
+    ban_event = Event.Ban.new(room, account, to_string(user_id), avatar_url, displayname, reason)
 
-    case Repo.transaction(insert_single_event(room, state_set, ban_event)) do
-      {:ok, {state_set, room, _}} -> {:reply, :ok, %{state | state_set: state_set, room: room}}
+    case Repo.transaction(process_event(room, ban_event)) do
+      {:ok, {room, _}} -> {:reply, :ok, %{state | room: room}}
       {:error, reason} -> {:reply, {:error, reason}, state}
     end
   end
 
-  def handle_call({:unban, account, user_id}, _from, %{room: room, state_set: state_set} = state) do
-    unban_event = Event.Unban.new(room, account, user_id)
+  def handle_call(
+        {:unban, account, user_id, avatar_url, displayname},
+        _from,
+        %{room: room} = state
+      ) do
+    unban_event = Event.Unban.new(room, account, user_id, avatar_url, displayname)
 
-    case Repo.transaction(insert_single_event(room, state_set, unban_event)) do
-      {:ok, {state_set, room, _}} -> {:reply, :ok, %{state | state_set: state_set, room: room}}
+    case Repo.transaction(process_event(room, unban_event)) do
+      {:ok, {room, _}} -> {:reply, :ok, %{state | room: room}}
       {:error, reason} -> {:reply, {:error, reason}, state}
     end
   end
@@ -344,7 +382,7 @@ defmodule Architex.RoomServer do
   def handle_call(
         {:set_visibility, account, visibility},
         _from,
-        %{room: room, state_set: state_set} = state
+        %{room: %Room{state_set: state_set} = room} = state
       ) do
     case state_set do
       %{{"m.room.create", ""} => %Event{content: %{"creator" => creator}}} ->
@@ -364,13 +402,13 @@ defmodule Architex.RoomServer do
   def handle_call(
         {:send_message_event, account, device, event_type, content, txn_id},
         _from,
-        %{room: room, state_set: state_set} = state
+        %{room: room} = state
       ) do
     message_event = Event.custom_event(room, account, event_type, content)
 
-    case Repo.transaction(insert_event_with_txn(state_set, room, device, message_event, txn_id)) do
-      {:ok, {state_set, room, event_id}} ->
-        {:reply, {:ok, event_id}, %{state | state_set: state_set, room: room}}
+    case Repo.transaction(process_event_with_txn(room, device, message_event, txn_id)) do
+      {:ok, {room, event_id}} ->
+        {:reply, {:ok, event_id}, %{state | room: room}}
 
       {:error, reason} ->
         {:reply, {:error, reason}, state}
@@ -380,23 +418,76 @@ defmodule Architex.RoomServer do
   def handle_call(
         {:send_state_event, account, event_type, content, state_key},
         _from,
-        %{room: room, state_set: state_set} = state
+        %{room: room} = state
       ) do
     state_event = Event.custom_state_event(room, account, event_type, content, state_key)
 
-    case Repo.transaction(insert_single_event(room, state_set, state_event)) do
-      {:ok, {state_set, room, %Event{id: event_id}}} ->
-        {:reply, {:ok, event_id}, %{state | state_set: state_set, room: room}}
+    case Repo.transaction(process_event(room, state_event)) do
+      {:ok, {room, %Event{id: event_id}}} ->
+        {:reply, {:ok, event_id}, %{state | room: room}}
 
       {:error, reason} ->
         {:reply, {:error, reason}, state}
     end
   end
 
-  @spec insert_event_with_txn(t(), Room.t(), Device.t(), %Event{}, String.t()) ::
-          (() -> {t(), Room.t(), String.t()} | {:error, atom()})
-  defp insert_event_with_txn(
-         state_set,
+  def handle_call(
+        {:get_current_state, account},
+        _from,
+        %{room: %Room{state_set: state_set}} = state
+      ) do
+    mxid = Account.get_mxid(account)
+
+    case state_set[{"m.room.member", mxid}] do
+      %Event{content: %{"membership" => "join"}} ->
+        # Get the current state of the room.
+        {:reply, {:ok, Map.values(state_set)}, state}
+
+      %Event{content: %{"membership" => "leave"}} = event ->
+        # Get the state of the room, after leaving.
+        # TODO: This does not work properly, as a user's membership can change to "leave"
+        # even after they left/are banned.
+        # I think it is best to seperately keep track when a user left, maybe in the
+        # Membership table.
+        state_set = StateResolution.resolve(event)
+        {:reply, {:ok, Map.values(state_set)}, state}
+
+      _ ->
+        {:reply, :error, state}
+    end
+  end
+
+  def handle_call(
+        {:get_state_event, account, event_type, state_key},
+        _from,
+        %{room: %Room{state_set: state_set}} = state
+      ) do
+    mxid = Account.get_mxid(account)
+
+    case state_set[{"m.room.member", mxid}] do
+      %Event{content: %{"membership" => "join"}} ->
+        case state_set[{event_type, state_key}] do
+          %Event{content: content} -> {:reply, {:ok, content}, state}
+          nil -> {:reply, {:error, :not_found}, state}
+        end
+
+      %Event{content: %{"membership" => "leave"}} = event ->
+        # TODO: See get_current_state.
+        state_set = StateResolution.resolve(event)
+
+        case state_set[{event_type, state_key}] do
+          %Event{content: content} -> {:reply, {:ok, content}, state}
+          nil -> {:reply, {:error, :not_found}, state}
+        end
+
+      _ ->
+        {:reply, {:error, :unauthorized}, state}
+    end
+  end
+
+  @spec process_event_with_txn(Room.t(), Device.t(), %Event{}, String.t()) ::
+          (() -> {Room.t(), String.t()} | {:error, atom()})
+  defp process_event_with_txn(
          room,
          %Device{nid: device_nid} = device,
          message_event,
@@ -409,98 +500,107 @@ defmodule Architex.RoomServer do
                where: dt.txn_id == ^txn_id and dt.device_nid == ^device_nid
            ) do
         %DeviceTransaction{event_id: event_id} ->
-          {state_set, room, event_id}
+          {room, event_id}
 
         nil ->
-          with {state_set, room, %Event{id: event_id}} <-
-                 insert_single_event(room, state_set, message_event).() do
+          with {room, %Event{id: event_id}} <- process_event(room, message_event).() do
             # Mark this transaction as done.
             Ecto.build_assoc(device, :device_transactions, txn_id: txn_id, event_id: event_id)
             |> Repo.insert!()
 
-            {state_set, room, event_id}
+            {room, event_id}
           end
       end
     end
   end
 
-  @spec insert_single_event(Room.t(), t(), %Event{}) ::
-          (() -> {t(), Room.t(), Event.t()} | {:error, atom()})
-  defp insert_single_event(room, state_set, event) do
+  @spec process_event(Room.t(), %Event{}) :: (() -> {Room.t(), Event.t()} | {:error, atom()})
+  defp process_event(room, event) do
     fn ->
-      case finalize_and_insert_event(event, state_set, room) do
-        {:ok, state_set, room, event} ->
-          _ = update_room_state_set(room, state_set)
-          {state_set, room, event}
-
-        {:error, reason} ->
-          Repo.rollback(reason)
+      case finalize_and_process_event(event, room) do
+        {:ok, room, event} -> {room, event}
+        {:error, reason} -> Repo.rollback(reason)
       end
     end
   end
 
-  # Get a function that inserts all events for room creation.
-  @spec create_room_insert_events(Room.t(), Account.t(), CreateRoom.t()) ::
-          (() -> {:ok, t(), Room.t()} | {:error, atom()})
-  defp create_room_insert_events(room, account, %CreateRoom{
+  @spec process_events(Room.t(), [%Event{}]) :: (() -> Room.t() | {:error, atom()})
+  defp process_events(room, events) do
+    fn ->
+      Enum.reduce_while(events, room, fn event, room ->
+        case finalize_and_process_event(event, room) do
+          {:ok, room, _} -> {:cont, room}
+          {:error, reason} -> {:halt, {:error, reason}}
+        end
+      end)
+      |> then(fn
+        {:error, reason} -> Repo.rollback(reason)
+        room -> room
+      end)
+    end
+  end
+
+  @spec create_room_events(Room.t(), Account.t(), CreateRoom.t(), Alias.t() | nil) :: [%Event{}]
+  defp create_room_events(
+         room,
+         account,
+         %CreateRoom{
            room_version: room_version,
            preset: preset,
            name: name,
            topic: topic,
            invite: invite,
-         power_level_content_override: power_level_content_override
-       }) do
+           power_level_content_override: power_level_content_override,
+           is_direct: is_direct,
+           creation_content: creation_content,
+           initial_state: initial_state
+         },
+         alias_
+       ) do
+    invite_events = room_creation_invite_events(account, invite, room, is_direct)
 
-    events =
-      ([
-         Event.CreateRoom.new(room, account, room_version),
-         Event.Join.new(room, account),
-         Event.PowerLevels.create_room_new(room, account, power_level_content_override)
-       ] ++
-         room_creation_preset(account, preset, room) ++
+    # Spec doesn't specify where to insert canonical_alias event, do it after topic event.
+    name_and_topic_events =
+      Enum.reject(
         [
           if(name, do: Event.Name.new(room, account, name)),
-           if(topic, do: Event.Topic.new(room, account, topic))
-         ] ++ room_creation_invite_events(account, invite, room))
-      |> Enum.reject(&Kernel.is_nil/1)
+          if(topic, do: Event.Topic.new(room, account, topic)),
+          if(alias_, do: Event.CanonicalAlias.new(room, account, alias_.alias))
+        ],
+        &Kernel.is_nil/1
+      )
 
-    fn ->
-      result =
-        Enum.reduce_while(events, {%{}, room}, fn event, {state_set, room} ->
-          case finalize_and_insert_event(event, state_set, room) do
-            {:ok, state_set, room, _} -> {:cont, {state_set, room}}
-            {:error, reason} -> {:halt, {:error, reason}}
-          end
+    initial_state_pairs =
+      if initial_state, do: Enum.map(initial_state, &{&1.type, &1.state_key}), else: []
+
+    initial_state_events =
+      room_creation_initial_state_events(account, initial_state, room)
+      |> Enum.reject(fn %Event{type: type, state_key: state_key} ->
+        ({type, state_key} == {"m.room.name", ""} and name) ||
+          ({type, state_key} == {"m.room.topic", ""} and topic)
       end)
 
-      case result do
-        {:error, reason} ->
-          Repo.rollback(reason)
+    preset_events =
+      room_creation_preset(account, preset, room)
+      |> Enum.reject(&({&1.type, &1.state_key} in initial_state_pairs))
 
-        {state_set, room} ->
-          _ = update_room_state_set(room, state_set)
-          {state_set, room}
-      end
-    end
-  end
+    basic_events = [
+      Event.CreateRoom.new(room, account, room_version, creation_content),
+      Event.Join.new(room, account),
+      Event.PowerLevels.create_room_new(
+        room,
+        account,
+        power_level_content_override,
+        invite,
+        preset
+      )
+    ]
 
-  # Update the given room in the database with the given state set.
-  @spec update_room_state_set(Room.t(), t()) :: Room.t()
-  defp update_room_state_set(room, state_set) do
-    # TODO: We might as well hold state in the Room struct,
-    #       instead of the state_set state.
-    #       Create custom type for this.
-    serialized_state_set =
-      Enum.map(state_set, fn {{type, state_key}, %Event{id: event_id}} ->
-        [type, state_key, event_id]
-      end)
-
-    Repo.update!(change(room, state: serialized_state_set))
+    basic_events ++
+      preset_events ++ initial_state_events ++ name_and_topic_events ++ invite_events
   end
 
   # Get the events for room creation as dictated by the given preset.
-  # TODO: trusted_private_chat:
-  #       All invitees are given the same power level as the room creator.
   @spec room_creation_preset(Account.t(), String.t() | nil, Room.t()) :: [%Event{}]
   defp room_creation_preset(account, nil, %Room{visibility: visibility} = room) do
     preset =
@@ -528,11 +628,24 @@ defmodule Architex.RoomServer do
   end
 
   # Get the events for room creation for inviting other users.
-  @spec room_creation_invite_events(Account.t(), [String.t()] | nil, Room.t()) :: [%Event{}]
-  defp room_creation_invite_events(_, nil, _), do: []
+  @spec room_creation_invite_events(Account.t(), [UserId.t()] | nil, Room.t(), boolean() | nil) ::
+          [%Event{}]
+  defp room_creation_invite_events(_, nil, _, _), do: []
 
-  defp room_creation_invite_events(account, invite_user_ids, room) do
-    Enum.map(invite_user_ids, &Event.Invite.new(room, account, &1))
+  defp room_creation_invite_events(account, invite_user_ids, room, is_direct) do
+    Enum.map(invite_user_ids, fn user_id ->
+      {avatar_url, displayname} = UserId.try_get_user_information(user_id)
+
+      Event.Invite.new(room, account, to_string(user_id), avatar_url, displayname, is_direct)
+    end)
+  end
+
+  defp room_creation_initial_state_events(_, nil, _), do: []
+
+  defp room_creation_initial_state_events(account, initial_state, room) do
+    Enum.map(initial_state, fn %{type: type, content: content, state_key: state_key} ->
+      Event.custom_state_event(room, account, type, content, state_key)
+    end)
   end
 
   # Finalize the event struct and insert it into the room's state using state resolution.
@@ -542,12 +655,11 @@ defmodule Architex.RoomServer do
   # - Content hash
   # - Event ID
   # - Signature
-  @spec finalize_and_insert_event(%Event{}, t(), Room.t()) ::
-          {:ok, t(), Room.t(), Event.t()} | {:error, atom()}
-  defp finalize_and_insert_event(
+  @spec finalize_and_process_event(%Event{}, Room.t()) ::
+          {:ok, Room.t(), Event.t()} | {:error, atom()}
+  defp finalize_and_process_event(
          event,
-         state_set,
-         %Room{forward_extremities: forward_extremities} = room
+         %Room{forward_extremities: forward_extremities, state_set: state_set} = room
        ) do
     event =
       event
@@ -556,7 +668,7 @@ defmodule Architex.RoomServer do
       |> Map.put(:depth, get_depth(forward_extremities))
 
     case Event.post_process(event) do
-      {:ok, event} -> authenticate_and_insert_event(event, state_set, room)
+      {:ok, event} -> authenticate_and_process_event(event, room)
       _ -> {:error, :event_creation}
     end
   end
@@ -571,7 +683,7 @@ defmodule Architex.RoomServer do
   end
 
   # Get the auth events for an events.
-  @spec auth_events_for_event(%Event{}, t()) :: [Event.t()]
+  @spec auth_events_for_event(%Event{}, StateSet.t()) :: [Event.t()]
   defp auth_events_for_event(%Event{type: "m.room.create"}, _), do: []
 
   defp auth_events_for_event(
@@ -623,9 +735,9 @@ defmodule Architex.RoomServer do
   # Authenticate and insert a new event using state resolution.
   # Implements the checks as described in the
   # [Matrix docs](https://matrix.org/docs/spec/server_server/latest#checks-performed-on-receipt-of-a-pdu).
-  @spec authenticate_and_insert_event(Event.t(), t(), Room.t()) ::
-          {:ok, t(), Room.t(), Event.t()} | {:error, atom()}
-  defp authenticate_and_insert_event(event, current_state_set, room) do
+  @spec authenticate_and_process_event(Event.t(), Room.t()) ::
+          {:ok, Room.t(), Event.t()} | {:error, atom()}
+  defp authenticate_and_process_event(event, %Room{state_set: current_state_set} = room) do
     # TODO: Correctly handle soft fails.
     # Check the following things:
     # 1. TODO: Is a valid event, otherwise it is dropped.
@@ -643,8 +755,9 @@ defmodule Architex.RoomServer do
       event = Repo.insert!(event)
       state_set = StateResolution.resolve_forward_extremities(event)
       :ok = update_membership(room, state_set)
+      room = Repo.update!(change(room, state_set: state_set))
 
-      {:ok, state_set, room, event}
+      {:ok, room, event}
     else
       _ -> {:error, :authorization}
     end
@@ -655,7 +768,7 @@ defmodule Architex.RoomServer do
   # could access rooms they are not allowed to. Then again, maybe we should perform
   # the "normal" authorization flow for local users as well, and treat the Membership
   # table only as informational.
-  @spec update_membership(Room.t(), t()) :: :ok
+  @spec update_membership(Room.t(), StateSet.t()) :: :ok
   defp update_membership(%Room{id: room_id}, state_set) do
     server_name = Architex.server_name()
 

lib/architex/schema/alias.ex

@@ -6,13 +6,18 @@ defmodule Architex.Alias do
   alias Architex.{Repo, Alias, Room}
   alias Ecto.Changeset
 
+  @type t :: %__MODULE__{
+          alias: String.t(),
+          room_id: String.t()
+        }
+
   @primary_key {:alias, :string, []}
   schema "aliases" do
     belongs_to :room, Room, foreign_key: :room_id, references: :id, type: :string
   end
 
-  def create(alias, room_id) do
-    change(%Alias{}, alias: alias, room_id: room_id)
+  def create(alias_, room_id) do
+    change(%Alias{}, alias: alias_, room_id: room_id)
     |> assoc_constraint(:room)
     |> unique_constraint(:alias, name: :aliases_pkey)
     |> Repo.insert()

lib/architex/schema/event.ex

@@ -314,4 +314,15 @@ defmodule Architex.Event do
       {:ok, :crypto.hash(:sha256, json)}
     end
   end
+
+  @spec default_membership_content(String.t() | nil, String.t() | nil) :: %{
+          optional(String.t()) => String.t()
+        }
+  def default_membership_content(avatar_url, displayname) do
+    content = %{}
+    content = if avatar_url, do: Map.put(content, "avatar_url", avatar_url), else: content
+    content = if displayname, do: Map.put(content, "displayname", displayname), else: content
+
+    content
+  end
 end

lib/architex/schema/event/formatters.ex

@@ -4,33 +4,10 @@ defmodule Architex.Event.Formatters do
   """
   alias Architex.Event
 
-  @spec messages_response(Event.t()) :: map()
-  def messages_response(%Event{
-        content: content,
-        type: type,
-        id: event_id,
-        sender: sender,
-        origin_server_ts: origin_server_ts,
-        unsigned: unsigned,
-        room_id: room_id,
-        state_key: state_key
-      }) do
-    data = %{
-      content: content,
-      type: type,
-      event_id: event_id,
-      sender: to_string(sender),
-      origin_server_ts: origin_server_ts,
-      room_id: room_id
-    }
-
-    data = if unsigned, do: Map.put(data, :unsigned, unsigned), else: data
-    data = if state_key, do: Map.put(data, :state_key, state_key), else: data
-
-    data
-  end
-
-  def sync_response(%Event{
+  @doc """
+  Event format with keys that all formats have in common.
+  """
+  def base_client_response(%Event{
         content: content,
         type: type,
         id: event_id,
@@ -46,11 +23,37 @@ defmodule Architex.Event.Formatters do
       origin_server_ts: origin_server_ts
     }
 
-    data = if unsigned, do: Map.put(data, :unsigned, unsigned), else: data
-
-    data
+    if unsigned, do: Map.put(data, :unsigned, unsigned), else: data
   end
 
+  @doc """
+  The base event format, with room_id and state_key added.
+  Used in the client /messages response.
+  """
+  @spec messages_response(Event.t()) :: map()
+  def messages_response(%Event{room_id: room_id, state_key: state_key} = event) do
+    data =
+      base_client_response(event)
+      |> Map.put(:room_id, room_id)
+
+    if state_key, do: Map.put(data, :state_key, state_key), else: data
+  end
+
+  @doc """
+  The event format used in the client /state response.
+  TODO: prev_content
+  """
+  def state_response(event), do: messages_response(event)
+
+  @doc """
+  The base event format, used in the client /sync response.
+  """
+  @spec sync_response(Event.t()) :: map()
+  def sync_response(event), do: base_client_response(event)
+
+  @doc """
+  The PDU format used for federation.
+  """
   @spec as_pdu(Event.t()) :: map()
   def as_pdu(%Event{
         auth_events: auth_events,

lib/architex/schema/event/generators.ex

@@ -2,16 +2,21 @@ defmodule Architex.Event.Join do
   alias Architex.{Event, Account, Room}
 
   @spec new(Room.t(), Account.t()) :: %Event{}
-  def new(room, %Account{localpart: localpart} = sender) do
+  def new(
+        room,
+        %Account{localpart: localpart, avatar_url: avatar_url, displayname: displayname} = sender
+      ) do
     mxid = Architex.get_mxid(localpart)
 
+    content =
+      Event.default_membership_content(avatar_url, displayname)
+      |> Map.put("membership", "join")
+
     %Event{
       Event.new(room, sender)
       | type: "m.room.member",
         state_key: mxid,
-        content: %{
-          "membership" => "join"
-        }
+        content: content
     }
   end
 end
@@ -19,24 +24,38 @@ end
 defmodule Architex.Event.CreateRoom do
   alias Architex.{Event, Account, Room}
 
-  @spec new(Room.t(), Account.t(), String.t()) :: %Event{}
-  def new(room, %Account{localpart: localpart} = creator, room_version) do
+  @clobber_content_keys ["creator", "room_version"]
+
+  @spec new(Room.t(), Account.t(), String.t(), %{optional(String.t()) => any()} | nil) :: %Event{}
+  def new(room, %Account{localpart: localpart} = creator, room_version, creation_content) do
     mxid = Architex.get_mxid(localpart)
 
+    content = %{
+      "creator" => mxid,
+      "room_version" => room_version || Architex.default_room_version()
+    }
+
+    content =
+      if creation_content do
+        creation_content
+        |> Map.drop(@clobber_content_keys)
+        |> Map.merge(content)
+      else
+        content
+      end
+
     %Event{
       Event.new(room, creator)
       | type: "m.room.create",
         state_key: "",
-        content: %{
-          "creator" => mxid,
-          "room_version" => room_version || Architex.default_room_version()
-        }
+        content: content
     }
   end
 end
 
 defmodule Architex.Event.PowerLevels do
   alias Architex.{Event, Account, Room}
+  alias Architex.Types.UserId
   alias ArchitexWeb.Client.Request.CreateRoom
   alias ArchitexWeb.Client.Request.CreateRoom.PowerLevelContentOverride
 
@@ -50,12 +69,21 @@ defmodule Architex.Event.PowerLevels do
   @users_default 0
   @notifications_room 50
 
-  @spec create_room_new(Room.t(), Account.t(), CreateRoom.plco_t()) :: %Event{}
-  def create_room_new(room, sender, nil) do
-    create_room_new(room, sender, %PowerLevelContentOverride{})
+  @spec create_room_new(
+          Room.t(),
+          Account.t(),
+          CreateRoom.PowerLevelContentOverride.t(),
+          [UserId.t()] | nil,
+          String.t() | nil
+        ) :: %Event{}
+  def create_room_new(room, sender, nil, invite_ids, preset) do
+    create_room_new(room, sender, %PowerLevelContentOverride{}, invite_ids, preset)
   end
 
-  def create_room_new(room, %Account{localpart: localpart} = sender, %PowerLevelContentOverride{
+  def create_room_new(
+        room,
+        %Account{localpart: localpart} = sender,
+        %PowerLevelContentOverride{
           ban: ban_override,
           events: events_override,
           events_default: events_default_override,
@@ -66,10 +94,24 @@ defmodule Architex.Event.PowerLevels do
           users: users_override,
           users_default: users_default_override,
           notifications: notifications_override
-      }) do
+        },
+        invite_ids,
+        preset
+      ) do
     mxid = Architex.get_mxid(localpart)
     users = %{mxid => @creator}
     users = if users_override, do: Map.merge(users, users_override), else: users
+    creator_pl = users[mxid]
+
+    # Give each invitee the same power level as the creator.
+    # This overrides the content override, but the spec is not clear on this.
+    users =
+      if preset == "trusted_private_chat" and invite_ids do
+        invite_users_pls = Enum.into(invite_ids, %{}, &{to_string(&1), creator_pl})
+        Map.merge(users, invite_users_pls)
+      else
+        users
+      end
 
     notifications =
       case notifications_override do
@@ -180,15 +222,26 @@ end
 defmodule Architex.Event.Invite do
   alias Architex.{Event, Account, Room}
 
-  @spec new(Room.t(), Account.t(), String.t()) :: %Event{}
-  def new(room, sender, user_id) do
+  @spec new(
+          Room.t(),
+          Account.t(),
+          String.t(),
+          String.t() | nil,
+          String.t() | nil,
+          boolean() | nil
+        ) :: %Event{}
+  def new(room, sender, user_id, avatar_url, displayname, is_direct \\ nil) do
+    content =
+      Event.default_membership_content(avatar_url, displayname)
+      |> Map.put("membership", "invite")
+
+    content = if is_direct != nil, do: Map.put(content, "is_direct", is_direct), else: content
+
     %Event{
       Event.new(room, sender)
       | type: "m.room.member",
         state_key: user_id,
-        content: %{
-          "membership" => "invite"
-        }
+        content: content
     }
   end
 end
@@ -197,14 +250,16 @@ defmodule Architex.Event.Leave do
   alias Architex.{Event, Account, Room}
 
   @spec new(Room.t(), Account.t()) :: %Event{}
-  def new(room, sender) do
+  def new(room, %Account{avatar_url: avatar_url, displayname: displayname} = sender) do
+    content =
+      Event.default_membership_content(avatar_url, displayname)
+      |> Map.put("membership", "leave")
+
     %Event{
       Event.new(room, sender)
       | type: "m.room.member",
         state_key: Account.get_mxid(sender),
-        content: %{
-          "membership" => "leave"
-        }
+        content: content
     }
   end
 end
@@ -212,9 +267,19 @@ end
 defmodule Architex.Event.Kick do
   alias Architex.{Event, Account, Room}
 
-  @spec new(Room.t(), Account.t(), String.t(), String.t() | nil) :: %Event{}
-  def new(room, sender, user_id, reason \\ nil) do
-    content = %{"membership" => "leave"}
+  @spec new(
+          Room.t(),
+          Account.t(),
+          String.t(),
+          String.t() | nil,
+          String.t() | nil,
+          String.t() | nil
+        ) :: %Event{}
+  def new(room, sender, user_id, avatar_url, displayname, reason \\ nil) do
+    content =
+      Event.default_membership_content(avatar_url, displayname)
+      |> Map.put("membership", "leave")
+
     content = if reason, do: Map.put(content, "reason", reason), else: content
 
     %Event{
@@ -229,9 +294,19 @@ end
 defmodule Architex.Event.Ban do
   alias Architex.{Event, Account, Room}
 
-  @spec new(Room.t(), Account.t(), String.t(), String.t() | nil) :: %Event{}
-  def new(room, sender, user_id, reason \\ nil) do
-    content = %{"membership" => "ban"}
+  @spec new(
+          Room.t(),
+          Account.t(),
+          String.t(),
+          String.t() | nil,
+          String.t() | nil,
+          String.t() | nil
+        ) :: %Event{}
+  def new(room, sender, user_id, avatar_url, displayname, reason \\ nil) do
+    content =
+      Event.default_membership_content(avatar_url, displayname)
+      |> Map.put("membership", "ban")
+
     content = if reason, do: Map.put(content, "reason", reason), else: content
 
     %Event{
@@ -245,15 +320,36 @@ end
 
 defmodule Architex.Event.Unban do
   alias Architex.{Event, Account, Room}
-  @spec new(Room.t(), Account.t(), String.t()) :: %Event{}
-  def new(room, sender, user_id) do
+
+  @spec new(Room.t(), Account.t(), String.t(), String.t() | nil, String.t() | nil) :: %Event{}
+  def new(room, sender, avatar_url, displayname, user_id) do
+    content =
+      Event.default_membership_content(avatar_url, displayname)
+      |> Map.put("membership", "leave")
+
     %Event{
       Event.new(room, sender)
       | type: "m.room.member",
         state_key: user_id,
-        content: %{
-          "membership" => "leave"
-        }
+        content: content
+    }
+  end
+end
+
+defmodule Architex.Event.CanonicalAlias do
+  alias Architex.{Event, Account, Room}
+
+  @spec new(Room.t(), Account.t(), String.t() | nil, [String.t()] | nil) :: %Event{}
+  def new(room, sender, alias_ \\ nil, alt_aliases \\ nil) do
+    content = %{}
+    content = if alias_, do: Map.put(content, "alias", alias_), else: content
+    content = if alt_aliases, do: Map.put(content, "alt_aliases", alt_aliases), else: content
+
+    %Event{
+      Event.new(room, sender)
+      | type: "m.room.canonical_alias",
+        state_key: "",
+        content: content
     }
   end
 end

lib/architex/schema/room.ex

@@ -5,18 +5,19 @@ defmodule Architex.Room do
   import Ecto.Query
 
   alias Architex.{Repo, Room, Event, Alias, RoomServer, Account}
+  alias Architex.Types.StateSet
   alias ArchitexWeb.Client.Request.{CreateRoom, Messages}
 
   @type t :: %__MODULE__{
           visibility: :public | :private,
-          state: list(list(String.t())),
+          state_set: StateSet.t(),
           forward_extremities: list(String.t())
         }
 
   @primary_key {:id, :string, []}
   schema "rooms" do
     field :visibility, Ecto.Enum, values: [:public, :private]
-    field :state, {:array, {:array, :string}}
+    field :state_set, StateSet, load_in_query: false
     field :forward_extremities, {:array, :string}
     has_many :events, Event, foreign_key: :room_id
     has_many :aliases, Alias, foreign_key: :room_id

lib/architex/types/state_set.ex

@@ -0,0 +1,45 @@
+defmodule Architex.Types.StateSet do
+  use Ecto.Type
+
+  import Ecto.Query
+
+  alias Architex.{Repo, Event}
+
+  @type t :: %{optional({String.t(), String.t()}) => Event.t()}
+
+  def type(), do: {:array, :string}
+
+  def cast(_), do: :error
+
+  def load(event_ids) when is_list(event_ids) do
+    events =
+      Event
+      |> where([e], e.id in ^event_ids)
+      |> Repo.all()
+      |> IO.inspect()
+
+    if length(events) == length(event_ids) do
+      state_set =
+        Enum.into(events, %{}, fn %Event{type: type, state_key: state_key} = event ->
+          {{type, state_key}, event}
+        end)
+
+      {:ok, state_set}
+    else
+      :error
+    end
+  end
+
+  def load(_), do: :error
+
+  def dump(state_set) when is_map(state_set) do
+    dumped =
+      Enum.map(state_set, fn {_, %Event{id: event_id}} ->
+        event_id
+      end)
+
+    {:ok, dumped}
+  end
+
+  def dump(_), do: :error
+end

lib/architex/types/user_id.ex

@@ -1,7 +1,11 @@
 defmodule Architex.Types.UserId do
   use Ecto.Type
 
+  import Ecto.Query
+
+  alias Architex.{Repo, Account}
   alias Architex.Types.UserId
+  alias ArchitexWeb.Federation.HTTPClient
 
   @type t :: %__MODULE__{
           localpart: String.t(),
@@ -53,4 +57,37 @@ defmodule Architex.Types.UserId do
 
   def dump(%UserId{} = user_id), do: {:ok, to_string(user_id)}
   def dump(_), do: :error
+
+  # TODO: Seems out of place here.
+  @spec try_get_user_information(UserId.t()) :: {String.t() | nil, String.t() | nil}
+  def try_get_user_information(%UserId{localpart: localpart, domain: domain} = user_id) do
+    if domain == Architex.server_name() do
+      # Get information about a user on this homeserver.
+      query =
+        Account
+        |> where([a], a.localpart == ^localpart)
+        |> select([a], {a.avatar_url, a.displayname})
+
+      case Repo.one(query) do
+        nil -> {nil, nil}
+        info -> info
+      end
+    else
+      # Get information about a user on another homeserver.
+      client = HTTPClient.client(domain)
+
+      case HTTPClient.query_profile(client, to_string(user_id)) do
+        {:ok, response} ->
+          avatar_url = Map.get(response, "avatar_url")
+          avatar_url = if is_binary(avatar_url), do: avatar_url
+          displayname = Map.get(response, "displayname")
+          displayname = if is_binary(displayname), do: displayname
+
+          {avatar_url, displayname}
+
+        {:error, _, _} ->
+          {nil, nil}
+      end
+    end
+  end
 end

lib/architex_web/api_schemas/client/request/ban.ex

@@ -1,14 +1,16 @@
 defmodule ArchitexWeb.Client.Request.Ban do
   use ArchitexWeb.APIRequest
 
+  alias Architex.Types.UserId
+
   @type t :: %__MODULE__{
-          user_id: String.t(),
+          user_id: UserId.t(),
           reason: String.t() | nil
         }
 
   @primary_key false
   embedded_schema do
-    field :user_id, :string
+    field :user_id, UserId
     field :reason, :string
   end
 

lib/architex_web/api_schemas/client/request/create_room.ex

@@ -1,18 +1,29 @@
 defmodule ArchitexWeb.Client.Request.CreateRoom do
   use ArchitexWeb.APIRequest
 
+  alias Architex.Types.UserId
+
+  defmodule PowerLevelContentOverride do
+    use Ecto.Schema
+
+    defmodule Notifications do
+      use Ecto.Schema
+
       @type t :: %__MODULE__{
-          visibility: String.t() | nil,
-          room_alias_name: String.t() | nil,
-          name: String.t() | nil,
-          topic: String.t() | nil,
-          invite: list(String.t()) | nil,
-          room_version: String.t() | nil,
-          preset: String.t() | nil,
-          power_level_content_override: plco_t() | nil
+              room: integer() | nil
             }
 
-  @type plco_t :: %__MODULE__.PowerLevelContentOverride{
+      @primary_key false
+      embedded_schema do
+        field :room, :integer
+      end
+
+      def changeset(data, params) do
+        cast(data, params, [:room])
+      end
+    end
+
+    @type t :: %__MODULE__{
             ban: integer() | nil,
             events: %{optional(String.t()) => integer()} | nil,
             events_default: integer() | nil,
@@ -22,24 +33,11 @@ defmodule ArchitexWeb.Client.Request.CreateRoom do
             state_default: integer() | nil,
             users: %{optional(String.t()) => integer()} | nil,
             users_default: integer() | nil,
-          notifications: plco_n_t() | nil
-        }
-
-  @type plco_n_t :: %__MODULE__.PowerLevelContentOverride.Notifications{
-          room: integer() | nil
+            notifications: Notifications.t() | nil
           }
 
     @primary_key false
     embedded_schema do
-    field :visibility, :string
-    field :room_alias_name, :string
-    field :name, :string
-    field :topic, :string
-    field :invite, {:array, :string}
-    field :room_version, :string
-    field :preset, :string
-
-    embeds_one :power_level_content_override, PowerLevelContentOverride, primary_key: false do
       field :ban, :integer
       field :events, {:map, :integer}
       field :events_default, :integer
@@ -50,34 +48,10 @@ defmodule ArchitexWeb.Client.Request.CreateRoom do
       field :users, {:map, :integer}
       field :users_default, :integer
 
-      embeds_one :notifications, Notifications, primary_key: false do
-        field :room, :integer
-      end
-    end
-
-    # TODO: unimplemented:
-    # creation_content, initial_state, invite_3pid, initial_state, is_direct
+      embeds_one :notifications, Notifications
     end
 
     def changeset(data, params) do
-    data
-    |> cast(params, [
-      :visibility,
-      :room_alias_name,
-      :name,
-      :topic,
-      :invite,
-      :room_version,
-      :preset
-    ])
-    |> cast_embed(:power_level_content_override,
-      with: &power_level_content_override_changeset/2,
-      required: false
-    )
-    |> validate_inclusion(:preset, ["private_chat", "public_chat", "trusted_private_chat"])
-  end
-
-  def power_level_content_override_changeset(data, params) do
       data
       |> cast(params, [
         :ban,
@@ -91,12 +65,84 @@ defmodule ArchitexWeb.Client.Request.CreateRoom do
         :users_default
       ])
       |> cast_embed(:notifications,
-      with: &power_level_content_override_notifications_changeset/2,
+        with: &Notifications.changeset/2,
         required: false
       )
     end
+  end
 
-  def power_level_content_override_notifications_changeset(data, params) do
-    cast(data, params, [:room])
+  defmodule StateEvent do
+    use Ecto.Schema
+
+    @type t :: %__MODULE__{
+            type: String.t(),
+            state_key: String.t(),
+            content: %{optional(String.t()) => any()}
+          }
+
+    @primary_key false
+    embedded_schema do
+      field :type, :string
+      field :state_key, :string, default: ""
+      field :content, :map
+    end
+
+    def changeset(data, params) do
+      data
+      |> cast(params, [:type, :state_key, :content])
+      |> validate_required([:type, :content])
+    end
+  end
+
+  @type t :: %__MODULE__{
+          visibility: String.t() | nil,
+          room_alias_name: String.t() | nil,
+          name: String.t() | nil,
+          topic: String.t() | nil,
+          invite: [UserId.t()] | nil,
+          room_version: String.t() | nil,
+          preset: String.t() | nil,
+          is_direct: boolean() | nil,
+          creation_content: %{optional(String.t()) => any()} | nil,
+          power_level_content_override: PowerLevelContentOverride.t() | nil,
+          initial_state: [StateEvent.t()] | nil
+        }
+
+  @primary_key false
+  embedded_schema do
+    # TODO: unimplemented: invite_3pid and room_alias_name
+    field :visibility, :string
+    field :room_alias_name, :string
+    field :name, :string
+    field :topic, :string
+    field :invite, {:array, UserId}
+    field :room_version, :string
+    field :preset, :string
+    field :is_direct, :boolean
+    field :creation_content, :map
+
+    embeds_many :initial_state, StateEvent
+    embeds_one :power_level_content_override, PowerLevelContentOverride
+  end
+
+  def changeset(data, params) do
+    data
+    |> cast(params, [
+      :visibility,
+      :room_alias_name,
+      :name,
+      :topic,
+      :invite,
+      :room_version,
+      :preset,
+      :is_direct,
+      :creation_content
+    ])
+    |> cast_embed(:power_level_content_override,
+      with: &PowerLevelContentOverride.changeset/2,
+      required: false
+    )
+    |> cast_embed(:initial_state, with: &StateEvent.changeset/2, required: false)
+    |> validate_inclusion(:preset, ["private_chat", "public_chat", "trusted_private_chat"])
   end
 end

lib/architex_web/api_schemas/client/request/kick.ex

@@ -1,14 +1,16 @@
 defmodule ArchitexWeb.Client.Request.Kick do
   use ArchitexWeb.APIRequest
 
+  alias Architex.Types.UserId
+
   @type t :: %__MODULE__{
-          user_id: String.t(),
+          user_id: UserId.t(),
           reason: String.t() | nil
         }
 
   @primary_key false
   embedded_schema do
-    field :user_id, :string
+    field :user_id, UserId
     field :reason, :string
   end
 

lib/architex_web/client/controllers/room_controller.ex

@@ -25,6 +25,9 @@ defmodule ArchitexWeb.Client.RoomController do
         {:error, :authorization} ->
           put_error(conn, :invalid_room_state)
 
+        {:error, :alias} ->
+          put_error(conn, :room_in_use, "The requested alias is already in use.")
+
         {:error, :unknown} ->
           put_error(conn, :unknown)
       end
@@ -60,9 +63,11 @@ defmodule ArchitexWeb.Client.RoomController do
         "room_id" => room_id,
         "user_id" => user_id
       }) do
-    with {:ok, _} <- UserId.cast(user_id),
+    with {:ok, user_id_struct} <- UserId.cast(user_id),
          {:ok, pid} <- RoomServer.get_room_server(room_id) do
-      case RoomServer.invite(pid, account, user_id) do
+      {avatar_url, displayname} = UserId.try_get_user_information(user_id_struct)
+
+      case RoomServer.invite(pid, account, user_id, avatar_url, displayname) do
         :ok ->
           conn
           |> send_resp(200, [])
@@ -132,9 +137,11 @@ defmodule ArchitexWeb.Client.RoomController do
   Action for POST /_matrix/client/r0/rooms/{roomId}/kick.
   """
   def kick(%Conn{assigns: %{account: account}} = conn, %{"room_id" => room_id} = params) do
-    with {:ok, request} <- Kick.parse(params),
+    with {:ok, %Kick{user_id: user_id} = request} <- Kick.parse(params),
          {:ok, pid} <- RoomServer.get_room_server(room_id) do
-      case RoomServer.kick(pid, account, request) do
+      {avatar_url, displayname} = UserId.try_get_user_information(user_id)
+
+      case RoomServer.kick(pid, account, request, avatar_url, displayname) do
         :ok ->
           conn
           |> send_resp(200, [])
@@ -155,9 +162,11 @@ defmodule ArchitexWeb.Client.RoomController do
   Action for POST /_matrix/client/r0/rooms/{roomId}/ban.
   """
   def ban(%Conn{assigns: %{account: account}} = conn, %{"room_id" => room_id} = params) do
-    with {:ok, request} <- Ban.parse(params),
+    with {:ok, %Ban{user_id: user_id} = request} <- Ban.parse(params),
          {:ok, pid} <- RoomServer.get_room_server(room_id) do
-      case RoomServer.ban(pid, account, request) do
+      {avatar_url, displayname} = UserId.try_get_user_information(user_id)
+
+      case RoomServer.ban(pid, account, request, avatar_url, displayname) do
         :ok ->
           conn
           |> send_resp(200, [])
@@ -181,9 +190,11 @@ defmodule ArchitexWeb.Client.RoomController do
         "room_id" => room_id,
         "user_id" => user_id
       }) do
-    case RoomServer.get_room_server(room_id) do
-      {:ok, pid} ->
-        case RoomServer.unban(pid, account, user_id) do
+    with {:ok, user_id_struct} <- UserId.cast(user_id),
+         {:ok, pid} <- RoomServer.get_room_server(room_id) do
+      {avatar_url, displayname} = UserId.try_get_user_information(user_id_struct)
+
+      case RoomServer.unban(pid, account, user_id, avatar_url, displayname) do
         :ok ->
           conn
           |> send_resp(200, [])
@@ -192,9 +203,9 @@ defmodule ArchitexWeb.Client.RoomController do
         {:error, _} ->
           put_error(conn, :unknown)
       end
-
-      {:error, :not_found} ->
-        put_error(conn, :not_found, "The given room was not found.")
+    else
+      :error -> put_error(conn, :invalid_param, "Given user ID is invalid.")
+      {:error, :not_found} -> put_error(conn, :not_found, "The given room was not found.")
     end
   end
 
@@ -300,4 +311,75 @@ defmodule ArchitexWeb.Client.RoomController do
       {:error, _} -> put_error(conn, :bad_json)
     end
   end
+
+  @doc """
+  Get the state events for the current state of a room.
+
+  Action for GET /_matrix/client/r0/rooms/{roomId}/state.
+  """
+  def get_state(%Conn{assigns: %{account: account}} = conn, %{"room_id" => room_id}) do
+    case RoomServer.get_room_server(room_id) do
+      {:ok, pid} ->
+        case RoomServer.get_current_state(pid, account) do
+          {:ok, events} ->
+            events = Enum.map(events, &Event.Formatters.state_response/1)
+
+            conn
+            |> put_status(200)
+            |> json(events)
+
+          :error ->
+            put_error(
+              conn,
+              :forbidden,
+              "You aren't a member of the room and weren't previously a member of the room."
+            )
+        end
+
+      {:error, :not_found} ->
+        put_error(conn, :not_found, "The given room was not found.")
+    end
+  end
+
+  @doc """
+  Looks up the contents of a state event in a room.
+
+  Action for GET /_matrix/client/r0/rooms/{roomId}/state/{eventType}/{stateKey}.
+  """
+  def get_state_event(conn, %{"state_key" => [state_key | _]} = params) do
+    do_get_state_event(conn, params, state_key)
+  end
+
+  def get_state_event(conn, params) do
+    do_get_state_event(conn, params, "")
+  end
+
+  defp do_get_state_event(
+         %Conn{assigns: %{account: account}} = conn,
+         %{"room_id" => room_id, "event_type" => event_type},
+         state_key
+       ) do
+    case RoomServer.get_room_server(room_id) do
+      {:ok, pid} ->
+        case RoomServer.get_state_event(pid, account, event_type, state_key) do
+          {:ok, content} ->
+            conn
+            |> put_status(200)
+            |> json(content)
+
+          {:error, :unauthorized} ->
+            put_error(
+              conn,
+              :forbidden,
+              "You aren't a member of the room and weren't previously a member of the room."
+            )
+
+          {:error, :not_found} ->
+            put_error(conn, :not_found, "The room has no state with the given type or key.")
+        end
+
+      {:error, :not_found} ->
+        put_error(conn, :not_found, "The given room was not found.")
+    end
+  end
 end

lib/architex_web/error.ex

@@ -14,6 +14,7 @@ defmodule ArchitexWeb.Error do
     unauthorized: {400, "M_UNAUTHORIZED", "The request was unauthorized."},
     invalid_param: {400, "M_INVALID_PARAM", "A request parameter was invalid."},
     missing_param: {400, "M_MISSING_PARAM", "A request parameter is missing."},
+    room_in_use: {400, "M_ROOM_IN_USE", "The room is already in use."},
     unknown_token: {401, "M_UNKNOWN_TOKEN", "Invalid access token."},
     missing_token: {401, "M_MISSING_TOKEN", "Access token required."},
     not_found: {404, "M_NOT_FOUND", "The requested resource was not found."},

lib/architex_web/federation/http_client.ex

@@ -33,6 +33,8 @@ defmodule ArchitexWeb.Federation.HTTPClient do
   """
   @spec client(String.t()) :: Tesla.Client.t()
   def client(server_name) do
+    # TODO: When implementing resolving homeservers, probably create
+    # a homeserver struct instead of using domain names directly.
     Tesla.client(
       [
         {Tesla.Middleware.Opts, [server_name: server_name]},

lib/architex_web/router.ex

@@ -61,13 +61,16 @@ defmodule ArchitexWeb.Router do
 
     scope "/r0" do
       get "/account/whoami", AccountController, :whoami
-      post "/logout", AccountController, :logout
-      post "/logout/all", AccountController, :logout_all
       post "/createRoom", RoomController, :create
       get "/joined_rooms", RoomController, :joined_rooms
       get "/capabilities", InfoController, :capabilities
       get "/sync", SyncController, :sync
 
+      scope "/logout" do
+        post "/", AccountController, :logout
+        post "/all", AccountController, :logout_all
+      end
+
       scope "/profile/:user_id" do
         put "/avatar_url", ProfileController, :set_avatar_url
         put "/displayname", ProfileController, :set_displayname
@@ -87,7 +90,15 @@ defmodule ArchitexWeb.Router do
         post "/unban", RoomController, :unban
         put "/send/:event_type/:txn_id", RoomController, :send_message_event
         get "/messages", RoomController, :messages
-        put "/state/:event_type/*state_key", RoomController, :send_state_event
+
+        scope "/state" do
+          get "/", RoomController, :get_state
+
+          scope "/:event_type/*state_key" do
+            get "/", RoomController, :get_state_event
+            put "/", RoomController, :send_state_event
+          end
+        end
       end
     end
   end

priv/repo/migrations/20210830160818_create_initial_tables.exs

@@ -14,7 +14,7 @@ defmodule Architex.Repo.Migrations.CreateInitialTables do
 
     create table(:rooms, primary_key: false) do
       add :id, :string, primary_key: true
-      add :state, {:array, {:array, :string}}, default: [], null: false
+      add :state_set, {:array, :string}, default: [], null: false
       add :forward_extremities, {:array, :string}, default: [], null: false
       add :visibility, :string, null: false, default: "public"
     end