Message forwarding (#1247)

Author: braindigitalis

include/dpp/message.h

@@ -2011,6 +2011,24 @@ namespace cache_policy {
 };
 
 /**
+ * @brief Message Reference type
+ */
+enum DPP_EXPORT message_ref_type : uint8_t {
+	/**
+	 * A reply or crosspost
+	 */
+	mrt_default = 0,
+	/**
+	 * A forwarded message
+	 */
+	mrt_forward = 1,
+};
+
+template <typename T> struct message_snapshot {
+	std::vector<T> messages;
+};
+
+	/**
  * @brief Represents messages sent and received on Discord
  */
 struct DPP_EXPORT message : public managed, json_interface<message> {
@@ -2140,6 +2158,10 @@ struct DPP_EXPORT message : public managed, json_interface<message> {
 	 * @brief Reference to another message, e.g. a reply
 	 */
 	struct message_ref {
+		/**
+		 * @brief Message reference type, set to 1 to forward a message
+		 */
+		message_ref_type type{mrt_default};
 		/**
 		 * @brief ID of the originating message.
 		 */
@@ -2162,10 +2184,15 @@ struct DPP_EXPORT message : public managed, json_interface<message> {
 		bool fail_if_not_exists;
 	} message_reference;
 
+	/**
+	 * @brief Message snapshots for a forwarded message
+	 */
+	message_snapshot<message> message_snapshots;
+
 	/**
 	 * @brief Reference to an interaction
 	 */
-	struct message_interaction_struct{
+	struct message_interaction_struct {
 		/**
 		 * @brief ID of the interaction.
 		 */
@@ -2342,9 +2369,10 @@ struct DPP_EXPORT message : public managed, json_interface<message> {
 	 * @param _guild_id guild id to reply to (optional)
 	 * @param _channel_id channel id to reply to (optional)
 	 * @param fail_if_not_exists true if the message send should fail if these values are invalid (optional)
+	 * @param type Type of reference
 	 * @return message& reference to self
 	 */
-	message& set_reference(snowflake _message_id, snowflake _guild_id = 0, snowflake _channel_id = 0, bool fail_if_not_exists = false);
+	message& set_reference(snowflake _message_id, snowflake _guild_id = 0, snowflake _channel_id = 0, bool fail_if_not_exists = false, message_ref_type type = mrt_default);
 
 	/**
 	 * @brief Set the allowed mentions object for pings on the message

src/dpp/message.cpp

@@ -677,11 +677,12 @@ message::message(class cluster* o) : message() {
 	owner = o;
 }
 
-message& message::set_reference(snowflake _message_id, snowflake _guild_id, snowflake _channel_id, bool fail_if_not_exists) {
+message& message::set_reference(snowflake _message_id, snowflake _guild_id, snowflake _channel_id, bool fail_if_not_exists, message_ref_type type) {
 	message_reference.channel_id = _channel_id;
 	message_reference.guild_id = _guild_id;
 	message_reference.message_id = _message_id;
 	message_reference.fail_if_not_exists = fail_if_not_exists;
+	message_reference.type = type;
 	return *this;
 }
 
@@ -1119,6 +1120,7 @@ json message::to_json(bool with_id, bool is_interaction_response) const {
 	/* Populate message reference */
 	if (message_reference.channel_id || message_reference.guild_id || message_reference.message_id) {
 		j["message_reference"] = json::object();
+		j["message_reference"]["type"] = static_cast<uint32_t>(message_reference.type);
 		if (message_reference.channel_id) {
 			j["message_reference"]["channel_id"] = std::to_string(message_reference.channel_id);
 		}
@@ -1408,10 +1410,17 @@ message& message::fill_from_json(json* d, cache_policy_t cp) {
 	}
 	if (d->find("message_reference") != d->end()) {
 		json& mr = (*d)["message_reference"];
+		message_reference.type = static_cast<message_ref_type>(int8_not_null(&mr, "type"));
 		message_reference.channel_id = snowflake_not_null(&mr, "channel_id");
 		message_reference.guild_id = snowflake_not_null(&mr, "guild_id");
 		message_reference.message_id = snowflake_not_null(&mr, "message_id");
 		message_reference.fail_if_not_exists = bool_not_null(&mr, "fail_if_not_exists");
+
+		if (message_reference.type == mrt_forward) {
+			for (auto& e : (*d)["message_snapshots"]) {
+				message_snapshots.messages.emplace_back(message().fill_from_json(&(e["message"]), cp));
+			}
+		}
 	}
 	if (auto it = d->find("poll"); it != d->end()) {
 		from_json(*it, attached_poll.emplace());