From f033b881217cd617ffcbf2275e0658aa03c02bf6 Mon Sep 17 00:00:00 2001
From: Pim Kunis <pim@kunis.nl>
Date: Thu, 29 Jul 2021 22:06:02 +0200
Subject: [PATCH] Fix create room API endpoint

---
 lib/matrix_server/room.ex                     | 12 ++++++-
 lib/matrix_server/room_server.ex              | 34 +++++++------------
 .../controllers/room_controller.ex            | 21 +++++++-----
 lib/matrix_server_web/plug/error.ex           |  4 ++-
 4 files changed, 38 insertions(+), 33 deletions(-)

diff --git a/lib/matrix_server/room.ex b/lib/matrix_server/room.ex
index df5db54..c01b647 100644
--- a/lib/matrix_server/room.ex
+++ b/lib/matrix_server/room.ex
@@ -4,7 +4,7 @@ defmodule MatrixServer.Room do
   import Ecto.Changeset
   import Ecto.Query
 
-  alias MatrixServer.{Repo, Room, Event}
+  alias MatrixServer.{Repo, Room, Event, RoomServer}
   alias MatrixServerWeb.API.CreateRoom
 
   @primary_key {:id, :string, []}
@@ -39,10 +39,20 @@ defmodule MatrixServer.Room do
       ) do
     new_forward_extremities = [event_id | forward_extremities -- prev_event_ids]
 
+    # TODO: might not need to save to DB here.
     {_, [room]} =
       from(r in Room, where: r.id == ^room_id, select: r)
       |> Repo.update_all(set: [forward_extremities: new_forward_extremities])
 
     room
   end
+
+  def create(account, input) do
+    with {:ok, %Room{id: room_id}} <- Repo.insert(create_changeset(input)),
+         {:ok, pid} <- RoomServer.get_room_server(room_id) do
+      RoomServer.create_room(pid, account, input)
+    else
+      _ -> {:error, :unknown}
+    end
+  end
 end
diff --git a/lib/matrix_server/room_server.ex b/lib/matrix_server/room_server.ex
index 252528b..e0465c6 100644
--- a/lib/matrix_server/room_server.ex
+++ b/lib/matrix_server/room_server.ex
@@ -114,8 +114,9 @@ defmodule MatrixServer.RoomServer do
       end)
 
     case result do
-      {:ok, state_set} -> {:reply, :ok, %{state | state_set: state_set}}
+      {:ok, state_set} -> {:reply, {:ok, room_id}, %{state | state_set: state_set}}
       {:error, reason} -> {:reply, {:error, reason}, state}
+      _ -> {:reply, {:error, :unknown}, state}
     end
   end
 
@@ -160,28 +161,17 @@ defmodule MatrixServer.RoomServer do
     # 6. Passes authorization rules based on the current state of the room, otherwise it is "soft failed".
     event = %Event{event | prev_events: forward_extremities}
 
-    if Event.prevalidate(event) do
-      if Authorization.authorized_by_auth_events?(event) do
-        state_set = StateResolution.resolve(event, false)
-
-        if Authorization.authorized?(event, state_set) do
-          if Authorization.authorized?(event, current_state_set) do
-            # We assume here that the event is always a forward extremity.
-            room = Room.update_forward_extremities(event, room)
-            event = Repo.insert!(event)
-            state_set = StateResolution.resolve_forward_extremities(event)
-            {:ok, state_set, room}
-          else
-            {:error, :soft_failed}
-          end
-        else
-          {:error, :rejected}
-        end
-      else
-        {:error, :rejected}
-      end
+    with true <- Event.prevalidate(event),
+         true <- Authorization.authorized_by_auth_events?(event),
+         state_set <- StateResolution.resolve(event, false),
+         true <- Authorization.authorized?(event, state_set),
+         true <- Authorization.authorized?(event, current_state_set) do
+      room = Room.update_forward_extremities(event, room)
+      event = Repo.insert!(event)
+      state_set = StateResolution.resolve_forward_extremities(event)
+      {:ok, state_set, room}
     else
-      {:error, :invalid}
+      _ -> {:error, :authorization}
     end
   end
 end
diff --git a/lib/matrix_server_web/controllers/room_controller.ex b/lib/matrix_server_web/controllers/room_controller.ex
index fc00b43..1b874f7 100644
--- a/lib/matrix_server_web/controllers/room_controller.ex
+++ b/lib/matrix_server_web/controllers/room_controller.ex
@@ -4,7 +4,7 @@ defmodule MatrixServerWeb.RoomController do
   import MatrixServerWeb.Plug.Error
   import Ecto.Changeset
 
-  alias MatrixServer.{Repo, Room, RoomServer}
+  alias MatrixServer.Room
   alias MatrixServerWeb.API.{CreateRoom}
   alias Ecto.Changeset
   alias Plug.Conn
@@ -14,15 +14,18 @@ defmodule MatrixServerWeb.RoomController do
       %Changeset{valid?: true} = cs ->
         input = apply_changes(cs)
 
-        # TODO: refactor
-        # Room.create(account, input)
-        # %Room{id: room_id} = Repo.insert!(Room.create_changeset(input))
-        # {:ok, pid} = RoomServer.get_room_server(room_id)
-        # RoomServer.create_room(pid, account, input)
+        case Room.create(account, input) do
+          {:ok, room_id} ->
+            conn
+            |> put_status(200)
+            |> json(%{room_id: room_id})
 
-        conn
-        |> put_status(200)
-        |> json(%{})
+          {:error, :authorization} ->
+            put_error(conn, :invalid_room_state)
+
+          {:error, :unknown} ->
+            put_error(conn, :unknown)
+        end
 
       _ ->
         put_error(conn, :bad_json)
diff --git a/lib/matrix_server_web/plug/error.ex b/lib/matrix_server_web/plug/error.ex
index a2ff711..465232d 100644
--- a/lib/matrix_server_web/plug/error.ex
+++ b/lib/matrix_server_web/plug/error.ex
@@ -9,13 +9,15 @@ defmodule MatrixServerWeb.Plug.Error do
     forbidden: {400, "M_FORBIDDEN", "The requested action is forbidden."},
     unrecognized: {400, "M_UNRECOGNIZED", "Unrecognized request."},
     unknown: {400, "M_UNKNOWN", "An unknown error occurred."},
+    invalid_room_state:
+      {400, "M_INVALID_ROOM_STATE", "The request would result in and invalid room state."},
     unknown_token: {401, "M_UNKNOWN_TOKEN", "Invalid access token."},
     missing_token: {401, "M_MISSING_TOKEN", "Access token required."}
   }
 
   def put_error(conn, error, msg \\ nil) do
     {status, errcode, default_msg} = @error_map[error]
-    data = %{errcode: errcode, error: msg or default_msg}
+    data = %{errcode: errcode, error: msg || default_msg}
 
     conn
     |> put_status(status)