/* Function pointer type for keyspace event notifications with subkeys from modules. */
typedef void (*RedisModuleNotificationWithSubkeysFunc)(
    RedisModuleCtx *ctx, int type, const char *event,
    RedisModuleString *key, RedisModuleString **subkeys, int count);

/* Subscribe to keyspace notifications with subkey information.
 *
 * This is the extended version of RM_SubscribeToKeyspaceEvents. When subkeys
 * are available, the `subkeys` array and `count` are passed to the callback.
 * `subkeys` contains only the names of affected subkeys (values are not included),
 * and `count` is the number of elements. The array may contain duplicates when
 * the same subkey appears more than once in a command (e.g. HSET key f1 v1 f1 v2
 * produces subkeys=["f1","f1"], count=2). When no subkeys are present, `subkeys`
 * will be NULL and `count` will be 0. Whether events without subkeys are delivered
 * depends on the `flags` parameter (see below).
 *
 * `types` is a bit mask of event types the module is interested in
 * (using the same REDISMODULE_NOTIFY_* flags as RM_SubscribeToKeyspaceEvents).
 *
 * `flags` controls delivery filtering:
 *  - REDISMODULE_NOTIFY_FLAG_NONE: The callback is invoked for all matching
 *    events regardless of whether subkeys are present, so a separate
 *    RM_SubscribeToKeyspaceEvents registration can be omitted.
 *  - REDISMODULE_NOTIFY_FLAG_SUBKEYS_REQUIRED: The callback is only invoked
 *    when subkeys are not empty. Events without subkey information (e.g. SET,
 *    EXPIRE, DEL) are skipped.
 *
 * The callback signature is:
 *   void callback(RedisModuleCtx *ctx, int type, const char *event,
 *                 RedisModuleString *key, RedisModuleString **subkeys, int count);
 *
 * The subkeys array and its contents are only valid during the callback.
 * The underlying objects may be stack-allocated or temporary, so
 * RM_RetainString must NOT be used on them. To keep a subkey beyond
 * the callback (e.g. in a RM_AddPostNotificationJob callback), use
 * RM_HoldString (which handles static objects by copying) or
 * RM_CreateStringFromString to make a deep copy before returning.
 */
int RM_SubscribeToKeyspaceEventsWithSubkeys(RedisModuleCtx *ctx, int types, int flags, RedisModuleNotificationWithSubkeysFunc callback);

/* Unregister a module's callback from keyspace notifications with subkeys
 * for specific event types.
 *
 * This function removes a previously registered subscription identified by
 * the event mask, delivery flags, and the callback function.
 *
 * Parameters:
 *  - ctx: The RedisModuleCtx associated with the calling module.
 *  - types: The event mask representing the notification types to unsubscribe from.
 *  - flags: The delivery flags that were used during registration.
 *  - callback: The callback function pointer that was originally registered.
 *
 * Returns:
 *  - REDISMODULE_OK on successful removal of the subscription.
 *  - REDISMODULE_ERR if no matching subscription was found. */ 
int RM_UnsubscribeFromKeyspaceEventsWithSubkeys(
    RedisModuleCtx *ctx, int types, int flags,
    RedisModuleNotificationWithSubkeysFunc cb);

/* Like RM_NotifyKeyspaceEvent, but also triggers subkey-level notifications
 * when subkeys are provided. Both key-level (keyspace/keyevent) and
 * subkey-level (subkeyspace/subkeyevent/subkeyspaceitem/subkeyspaceevent)
 * channels are published to, depending on the server configuration.
 *
 * This is the extended version of RM_NotifyKeyspaceEvent and can actually
 * replace it. When called with subkeys=NULL and count=0, it behaves
 * identically to RM_NotifyKeyspaceEvent. */
int RM_NotifyKeyspaceEventWithSubkeys(
    RedisModuleCtx *ctx, int type, const char *event,
    RedisModuleString *key, RedisModuleString **subkeys, int count);