Add Filter API to validate filters and process events.

TODO.txt

@@ -34,6 +34,8 @@ Milestone: v0.4.0
 
 [ ] Refactor MatrixErrorCreate() to take a custom message.
     This will make debugging a lot easier.
+[ ] Make sure admin registration token is printed to log, not stdout.
+    Unless they are the same, of course.
 
 Milestone: v0.5.0
 -----------------

src/Filter.c

@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2022-2023 Jordan Bancino <@jordan:bancino.net>
+ *
+ * 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 <string.h>
+
+#include <HashMap.h>
+#include <Memory.h>
+#include <User.h>
+#include <Json.h>
+#include <Str.h>
+
+static HashMap *
+ValidateRoomFilter(HashMap *json)
+{
+    return NULL;
+}
+
+static HashMap *
+ValidateEventFields(Array *fields)
+{
+    return NULL;
+}
+
+static HashMap *
+ValidateEventFormat(char *fmt)
+{
+    return NULL;
+}
+
+static HashMap *
+ValidateEventFilter(HashMap *json)
+{
+    JsonValue *val;
+
+    val = HashMapGet(json, "limit");
+    if (val)
+    {
+        if (JsonValueType(val) == JSON_INTEGER)
+        {
+            long limit = JsonValueAsInteger(val);
+            if (limit <= 0 || limit > 100)
+            {
+                return MatrixErrorCreate(M_BAD_JSON);
+            }
+        }
+        else
+        {
+            return MatrixErrorCreate(M_BAD_JSON);
+        }
+    }
+
+    return NULL;
+}
+
+HashMap *
+FilterValidate(HashMap *json)
+{
+    JsonValue *val;
+    HashMap *response = NULL;
+
+#define VALIDATE(key, type, func, param) \
+    val = HashMapGet(json, key); \
+    if (val) \
+    { \
+        if (JsonValueType(val) == type) \
+        { \
+            response = func(param); \
+            if (response) \
+            { \
+                goto finish; \
+            } \
+        } \
+        else \
+        { \
+            return MatrixErrorCreate(M_BAD_JSON); \
+        } \
+    }
+
+    VALIDATE("account_data", JSON_OBJECT, ValidateEventFilter, JsonValueAsObject(val));
+    VALIDATE("event_fields", JSON_ARRAY, ValidateEventFields, JsonValueAsArray(val));
+    VALIDATE("event_format", JSON_STRING, ValidateEventFormat, JsonValueAsString(val));
+    VALIDATE("presence", JSON_OBJECT, ValidateEventFilter, JsonValueAsObject(val));
+    VALIDATE("room", JSON_OBJECT, ValidateRoomFilter, JsonValueAsObject(val));
+
+#undef VALIDATE
+
+finish:
+    return response;
+}
+

src/Routes/RouteFilter.c

@@ -23,14 +23,17 @@
  */
 #include <Routes.h>
 
-#include <string.h>
 
 #include <HashMap.h>
 #include <Memory.h>
-#include <User.h>
 #include <Json.h>
 #include <Str.h>
 
+#include <User.h>
+#include <Filter.h>
+
+#include <string.h>
+
 static char *
 GetServerName(Db *db)
 {
@@ -55,6 +58,7 @@ ROUTE_IMPL(RouteFilter, path, argp)
     RouteArgs *args = argp;
     Db *db = args->matrixArgs->db;
 
+    HashMap *request = NULL;
     HashMap *response = NULL;
 
     User *user = NULL;
@@ -101,13 +105,6 @@ ROUTE_IMPL(RouteFilter, path, argp)
         goto finish;
     }
 
-    if (!StrEquals(id->localpart, UserGetName(user)))
-    {
-        HttpResponseStatus(args->context, HTTP_UNAUTHORIZED);
-        response = MatrixErrorCreate(M_INVALID_PARAM);
-        goto finish;
-    }
-
     user = UserAuthenticate(db, token);
     if (!user)
     {
@@ -116,6 +113,13 @@ ROUTE_IMPL(RouteFilter, path, argp)
         goto finish;
     }
 
+    if (!StrEquals(id->localpart, UserGetName(user)))
+    {
+        HttpResponseStatus(args->context, HTTP_UNAUTHORIZED);
+        response = MatrixErrorCreate(M_INVALID_PARAM);
+        goto finish;
+    }
+
     if (ArraySize(path) == 2 && HttpRequestMethodGet(args->context) == HTTP_GET)
     {
         DbRef *ref = DbLock(db, 3, "filters", UserGetName(user), ArrayGet(path, 1));
@@ -132,8 +136,46 @@ ROUTE_IMPL(RouteFilter, path, argp)
     }
     else if (ArraySize(path) == 1 && HttpRequestMethodGet(args->context) == HTTP_POST)
     {
-        /* TODO */
+        DbRef *ref;
+        char *filterId;
+
+        request = JsonDecode(HttpServerStream(args->context));
+        if (!request)
+        {
+            HttpResponseStatus(args->context, HTTP_BAD_REQUEST);
+            response = MatrixErrorCreate(M_NOT_JSON);
+            goto finish;
+        }
+
+        response = FilterValidate(request);
+        if (response)
+        {
+            goto finish;
+        }
+
+        filterId = StrRandom(12);
+        if (!filterId)
+        {
+            HttpResponseStatus(args->context, HTTP_INTERNAL_SERVER_ERROR);
             response = MatrixErrorCreate(M_UNKNOWN);
+            goto finish;
+        }
+
+        ref = DbCreate(db, 3, "filters", UserGetName(user), filterId);
+        if (!ref)
+        {
+            Free(filterId);
+            HttpResponseStatus(args->context, HTTP_INTERNAL_SERVER_ERROR);
+            response = MatrixErrorCreate(M_UNKNOWN);
+            goto finish;
+        }
+
+        DbJsonSet(ref, request);
+        DbUnlock(db, ref);
+
+        response = HashMapCreate();
+        HashMapSet(response, "filter_id", JsonValueString(filterId));
+        Free(filterId);
     }
     else
     {
@@ -145,5 +187,6 @@ finish:
     Free(serverName);
     UserIdFree(id);
     UserUnlock(user);
+    JsonFree(request);
     return response;
 }

src/include/Filter.h

@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2022-2023 Jordan Bancino <@jordan:bancino.net>
+ *
+ * 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.
+ */
+#ifndef TELODENDRIA_FILTER_H
+#define TELODENDRIA_FILTER_H
+
+/***
+ * @Nm Filter
+ * @Nd Validate JSON filters and apply them to events.
+ * @Dd June 17 2023
+ *
+ * The Matrix Client-Server API defines a mechanism for defining
+ * filters and applying them to certain endpoints. This API allows
+ * those filters to be validated and applied to events.
+ */
+
+/**
+ * Validate a JSON filter as provided by a client. This function
+ * takes in a filter and returns a JSON response if a validation
+ * error occurs. If an error occurs, the response should be returned
+ * to the client. If no error occurs, then NULL will be returned and
+ * the caller may proceed with the assumption that the filter is
+ * valid.
+ */
+extern HashMap *
+FilterValidate(HashMap *);
+
+/**
+ * Apply the given JSON filter to the given event, returning a
+ * new event JSON with the filter applied, or NULL if the event
+ * is excluded totally by the rules of the filter.
+ */
+extern HashMap *
+FilterEvent(HashMap *, HashMap *);
+
+#endif /* TELODENDRIA_FILTER_H */