[ADD/WIP] Basic means to view a room event.

Cytoplasm

@@ -1 +1 @@
-Subproject commit 346b912a0633cceac10780b8a103f6c89b5ba89f
+Subproject commit 9108fef7018010e6b49a111856ca0553333804f8

src/Room.c

@@ -2054,3 +2054,43 @@ RoomContainsUser(Room *room, char *user)
 
     return ret;
 }
+HashMap *
+RoomEventClientify(HashMap *pdu)
+{
+    HashMap *event;
+    if (!pdu)
+    {
+        return NULL;
+    }
+
+    event = HashMapCreate();
+#define CopyField(field, req)   do { \
+                                    JsonValue *f = HashMapGet(pdu, field);\
+                                    if (!f && req) \
+                                    { \
+                                        goto failure; \
+                                    } \
+                                    HashMapSet( \
+                                        event, \
+                                        field, JsonValueDuplicate(f) \
+                                    ); \
+                                } \
+                                while(0)
+
+    CopyField("content", true);
+    CopyField("event_id", true);
+    CopyField("origin_server_ts", true);
+    CopyField("room_id", true);
+    CopyField("sender", true);
+    CopyField("type", true);
+
+    CopyField("state_key",false);
+    CopyField("unsigned", false);
+    
+    return event;
+
+failure:
+    JsonFree(event);
+    return NULL;
+#undef CopyField
+}

src/Routes.c

@@ -142,8 +142,9 @@ RouterBuild(void)
 
     R("/_matrix/client/v3/user/(.*)/filter", RouteFilter);
     R("/_matrix/client/v3/user/(.*)/filter/(.*)", RouteFilter);
-    R("/_matrix/client/v3/rooms/(.*)/send/(.*)/(.*)", RouteSendEvent);
 
+    R("/_matrix/client/v3/rooms/(.*)/send/(.*)/(.*)", RouteSendEvent);
+    R("/_matrix/client/v3/rooms/(.*)/event/(.*)", RouteFetchEvent);
     R("/_matrix/client/v3/createRoom", RouteCreateRoom);
 
     R("/_matrix/client/v3/directory/room/(.*)", RouteAliasDirectory);

src/Routes/RouteFetchEvent.c

@@ -0,0 +1,144 @@
+/*
+ * Copyright (C) 2022-2024 Jordan Bancino <@jordan:bancino.net> with
+ * other valuable contributors. See CONTRIBUTORS.txt for the full list.
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#include <Routes.h>
+
+
+#include <Cytoplasm/HashMap.h>
+#include <Cytoplasm/Memory.h>
+#include <Cytoplasm/Json.h>
+#include <Cytoplasm/Str.h>
+
+#include <User.h>
+#include <Room.h>
+#include <string.h>
+
+#include <Schema/Filter.h>
+
+static char *
+GetServerName(Db * db)
+{
+    char *name;
+
+    Config config;
+
+    ConfigLock(db, &config);
+    if (!config.ok)
+    {
+        return NULL;
+    }
+
+    name = StrDuplicate(config.serverName);
+
+    ConfigUnlock(&config);
+
+    return name;
+}
+
+ROUTE_IMPL(RouteFetchEvent, path, argp)
+{
+    RouteArgs *args = argp;
+    Db *db = args->matrixArgs->db;
+
+    HashMap *event = NULL;
+    HashMap *response = NULL;
+
+    User *user = NULL;
+    char *token = NULL;
+    CommonID *id = NULL;
+
+    char *roomId = ArrayGet(path, 0);
+    char *eventId= ArrayGet(path, 1);
+    char *sender = NULL, *serverName = NULL;
+
+    Room *room = NULL;
+
+    char *err;
+
+    if (!roomId || !eventId)
+    {
+        /* Should be impossible */
+        HttpResponseStatus(args->context, HTTP_INTERNAL_SERVER_ERROR);
+        return MatrixErrorCreate(M_UNKNOWN, NULL);
+    }
+    if (HttpRequestMethodGet(args->context) != HTTP_GET)
+    {
+        err = "Unknown request method.";
+        HttpResponseStatus(args->context, HTTP_BAD_REQUEST);
+        response = MatrixErrorCreate(M_UNRECOGNIZED, err);
+        goto finish;
+    }
+
+    serverName = GetServerName(db);
+    if (!serverName)
+    {
+        HttpResponseStatus(args->context, HTTP_INTERNAL_SERVER_ERROR);
+        response = MatrixErrorCreate(M_UNKNOWN, NULL);
+        goto finish;
+    }
+
+    response = MatrixGetAccessToken(args->context, &token);
+    if (response)
+    {
+        goto finish;
+    }
+
+    user = UserAuthenticate(db, token);
+    if (!user)
+    {
+        HttpResponseStatus(args->context, HTTP_UNAUTHORIZED);
+        response = MatrixErrorCreate(M_UNKNOWN_TOKEN, NULL);
+        goto finish;
+    }
+    id = UserIdParse(UserGetName(user), serverName);
+    id->sigil = '@';
+    sender = ParserRecomposeCommonID(*id);
+    
+    /* TODO: Better auth(as in check m.room.history_visibility) */
+    room = RoomLock(db, roomId);
+    if (!RoomContainsUser(room, sender))
+    {
+        err = "User is not in the room.";
+        HttpResponseStatus(args->context, HTTP_UNAUTHORIZED);
+        response = MatrixErrorCreate(M_FORBIDDEN, err);
+        goto finish;
+    }
+    event = RoomEventFetch(room, eventId);
+
+    response = RoomEventClientify(event);
+    JsonFree(event);
+finish:
+    UserIdFree(id);
+    if (sender)
+    {
+        Free(sender);
+    }
+    if (serverName)
+    {
+        Free(serverName);
+    }
+    RoomUnlock(room);
+    UserUnlock(user);
+    return response;
+}

src/include/Room.h

@@ -158,6 +158,12 @@ extern void RoomSendInvite(User *, bool, char *, Room *);
  */
 extern HashMap * RoomEventFetch(Room *, char *);
 
+/**
+ * Strips all the fields not required in a 
+ * Matrix ClientEvent from a PDU object.
+ */
+extern HashMap * RoomEventClientify(HashMap *);
+
 /**
  * Verifies whenever an event(as a PDUv1) is 
  * authorised by a room.

src/include/Routes.h

@@ -101,6 +101,7 @@ ROUTE(RoutePrivileges);
 
 ROUTE(RouteCreateRoom);
 ROUTE(RouteSendEvent);
+ROUTE(RouteFetchEvent);
 
 ROUTE(RouteAliasDirectory);
 ROUTE(RouteRoomAliases);