From 6f045083a2ea3fe17d99b5643c46d38daedc4a1a Mon Sep 17 00:00:00 2001
From: LDA <lda@ari.lt>
Date: Sat, 20 Jul 2024 17:45:12 +0200
Subject: [PATCH] [ADD/WIP] Dot-separated fetching, respect 'rooms'

That should get me to filter events, senders, and other things
---
 src/Matrix.c           | 68 ++++++++++++++++++++++++++++++++++++++++++
 src/Routes/RouteSync.c | 16 +++++++++-
 src/include/Matrix.h   | 11 ++++++-
 3 files changed, 93 insertions(+), 2 deletions(-)

diff --git a/src/Matrix.c b/src/Matrix.c
index 7186461..a2fac3f 100644
--- a/src/Matrix.c
+++ b/src/Matrix.c
@@ -360,3 +360,71 @@ MatrixClientWellKnown(char *base, char *identity)
 
     return response;
 }
+
+JsonValue *
+MatrixGetJSON(HashMap *json, char *string)
+{
+    JsonValue *retVal;
+    HashMap *currentObj;
+    char *field, *fieldTemp;
+    size_t i, length;
+
+    if (!json || !string)
+    {
+        return NULL;
+    }
+
+    currentObj = json;
+    retVal = NULL;
+    length = strlen(string);
+    field = NULL;
+
+#define Append(ch)  do \
+    { \
+        char chb[2] = { ch, 0 }; \
+        fieldTemp = field; \
+        field = StrConcat(2, field, chb); \
+        Free(fieldTemp); \
+    } while (0)
+
+    /* We include the 0-terminator as a valid separator. */
+    for (i = 0; i < length + 1; i++)
+    {
+        char currentChar = string[i];
+        char escape;
+        if (currentChar == '\\' && (escape = string[i+1]))
+        {
+            if (escape != '.' && escape != '\\')
+            {
+                Append('\\');
+            }
+            Append(escape);
+            i++;
+            continue;
+        }
+        else if (currentChar == '.' || currentChar == '\0')
+        {
+            if (!field || !currentObj)
+            {
+                Free(field);
+                return NULL;
+            }
+
+            retVal = HashMapGet(currentObj, field);
+            currentObj = JsonValueAsObject(retVal);
+
+            Free(field);
+            field = NULL;
+            continue;
+        }
+        Append(currentChar);
+    }
+#undef Append
+
+    if (field)
+    {
+        /* This is weird. */
+        Free(field);
+    }
+    return retVal;
+}
diff --git a/src/Routes/RouteSync.c b/src/Routes/RouteSync.c
index 72414a3..3f8a2c0 100644
--- a/src/Routes/RouteSync.c
+++ b/src/Routes/RouteSync.c
@@ -59,6 +59,7 @@ StripStateEventSync(HashMap *pdu)
     return ret;
 }
 
+/* Verify whenever a room is filtered out by a filter given in. */
 static bool
 IsRoomFiltered(Filter *filter, char *roomID)
 {
@@ -77,7 +78,20 @@ IsRoomFiltered(Filter *filter, char *roomID)
             return true;
         }
     }
-    /* TODO: Consider rooms */
+
+    count = ArraySize(filter->room.rooms);
+    if (count)
+    {
+        for (i = 0; i < count; i++)
+        {
+            char *room = ArrayGet(filter->room.rooms, i);
+            if (StrEquals(roomID, room))
+            {
+                return false;
+            }
+        }
+        return true;
+    }
     return false;
 }
 
diff --git a/src/include/Matrix.h b/src/include/Matrix.h
index 2b18fcb..a8b7011 100644
--- a/src/include/Matrix.h
+++ b/src/include/Matrix.h
@@ -39,8 +39,9 @@
 
 #include <Cytoplasm/HttpServer.h>
 #include <Cytoplasm/HttpRouter.h>
-#include <Cytoplasm/Log.h>
 #include <Cytoplasm/HashMap.h>
+#include <Cytoplasm/Json.h>
+#include <Cytoplasm/Log.h>
 
 #include <Config.h>
 #include <Cytoplasm/Db.h>
@@ -154,4 +155,12 @@ extern HashMap * MatrixRateLimit(HttpServerContext *, Db *);
  */
 extern HashMap * MatrixClientWellKnown(char *, char *);
 
+/**
+ * Decodes a dot-separated path (as defined by the Specification) and 
+ * tries to retrieve it from a JSON object hashmap, failing with NULL 
+ * if it cannot be found, like Cytoplasm's
+ * .Fn JsonGet .
+ */
+extern JsonValue * MatrixGetJSON(HashMap *, char *);
+
 #endif