text: /*************************************************************************/
  /*  multiplayer_api.cpp                                                  */
  /*************************************************************************/
  /*                       This file is part of:                           */
  /*                           GODOT ENGINE                                */
  /*                      https://godotengine.org                          */
  /*************************************************************************/
  /* Copyright (c) 2007-2019 Juan Linietsky, Ariel Manzur.                 */
  /* Copyright (c) 2014-2019 Godot Engine contributors (cf. AUTHORS.md)    */
  /*                                                                       */
  /* 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 substantial 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 "multiplayer_api.h"
  
  #include "core/io/marshalls.h"
  #include "scene/main/node.h"
  
  _FORCE_INLINE_ bool _should_call_local(MultiplayerAPI::RPCMode mode, bool is_master, bool &r_skip_rpc) {
  
  	switch (mode) {
  
  		case MultiplayerAPI::RPC_MODE_DISABLED: {
  			// Do nothing.
  		} break;
  		case MultiplayerAPI::RPC_MODE_REMOTE: {
  			// Do nothing also. Remote cannot produce a local call.
  		} break;
  		case MultiplayerAPI::RPC_MODE_MASTERSYNC: {
  			if (is_master)
  				r_skip_rpc = true; // I am the master, so skip remote call.
  			FALLTHROUGH;
  		}
  		case MultiplayerAPI::RPC_MODE_REMOTESYNC:
  		case MultiplayerAPI::RPC_MODE_PUPPETSYNC: {
  			// Call it, sync always results in a local call.
  			return true;
  		} break;
  		case MultiplayerAPI::RPC_MODE_MASTER: {
  			if (is_master)
  				r_skip_rpc = true; // I am the master, so skip remote call.
  			return is_master;
  		} break;
  		case MultiplayerAPI::RPC_MODE_PUPPET: {
  			return !is_master;
  		} break;
  	}
  	return false;
  }
  
  _FORCE_INLINE_ bool _can_call_mode(Node *p_node, MultiplayerAPI::RPCMode mode, int p_remote_id) {
  	switch (mode) {
  
  		case MultiplayerAPI::RPC_MODE_DISABLED: {
  			return false;
  		} break;
  		case MultiplayerAPI::RPC_MODE_REMOTE:
  		case MultiplayerAPI::RPC_MODE_REMOTESYNC: {
  			return true;
  		} break;
  		case MultiplayerAPI::RPC_MODE_MASTERSYNC:
  		case MultiplayerAPI::RPC_MODE_MASTER: {
  			return p_node->is_network_master();
  		} break;
  		case MultiplayerAPI::RPC_MODE_PUPPETSYNC:
  		case MultiplayerAPI::RPC_MODE_PUPPET: {
  			return !p_node->is_network_master() && p_remote_id == p_node->get_network_master();
  		} break;
  	}
  
  	return false;
  }
  
  void MultiplayerAPI::poll() {
  
  	if (!network_peer.is_valid() || network_peer->get_connection_status() == NetworkedMultiplayerPeer::CONNECTION_DISCONNECTED)
  		return;
  
  	network_peer->poll();
  
  	if (!network_peer.is_valid()) // It's possible that polling might have resulted in a disconnection, so check here.
  		return;
  
  	while (network_peer->get_available_packet_count()) {
  
  		int sender = network_peer->get_packet_peer();
  		const uint8_t *packet;
  		int len;
  
  		Error err = network_peer->get_packet(&packet, len);
  		if (err != OK) {
  			ERR_PRINT("Error getting packet!");
  		}
  
  		rpc_sender_id = sender;
  		_process_packet(sender, packet, len);
  		rpc_sender_id = 0;
  
  		if (!network_peer.is_valid()) {
  			break; // It's also possible that a packet or RPC caused a disconnection, so also check here.
  		}
  	}
  }
  
  void MultiplayerAPI::clear() {
  	connected_peers.clear();
  	path_get_cache.clear();
  	path_send_cache.clear();
  	packet_cache.clear();
  	last_send_cache_id = 1;
  }
  
  void MultiplayerAPI::set_root_node(Node *p_node) {
  	root_node = p_node;
  }
  
  void MultiplayerAPI::set_network_peer(const Ref<NetworkedMultiplayerPeer> &p_peer) {
  
  	if (p_peer == network_peer) return; // Nothing to do
  
  	if (network_peer.is_valid()) {
  		network_peer->disconnect("peer_connected", this, "_add_peer");
  		network_peer->disconnect("peer_disconnected", this, "_del_peer");
  		network_peer->disconnect("connection_succeeded", this, "_connected_to_server");
  		network_peer->disconnect("connection_failed", this, "_connection_failed");
  		network_peer->disconnect("server_disconnected", this, "_server_disconnected");
  		clear();
  	}
  
  	network_peer = p_peer;
  
  	ERR_FAIL_COND_MSG(p_peer.is_valid() && p_peer->get_connection_status() == NetworkedMultiplayerPeer::CONNECTION_DISCONNECTED, "Supplied NetworkedNetworkPeer must be connecting or connected.");
  
  	if (network_peer.is_valid()) {
  		network_peer->connect("peer_connected", this, "_add_peer");
  		network_peer->connect("peer_disconnected", this, "_del_peer");
  		network_peer->connect("connection_succeeded", this, "_connected_to_server");
  		network_peer->connect("connection_failed", this, "_connection_failed");
  		network_peer->connect("server_disconnected", this, "_server_disconnected");
  	}
  }
  
  Ref<NetworkedMultiplayerPeer> MultiplayerAPI::get_network_peer() const {
  	return network_peer;
  }
  
  void MultiplayerAPI::_process_packet(int p_from, const uint8_t *p_packet, int p_packet_len) {
  
  	ERR_FAIL_COND_MSG(root_node == NULL, "Multiplayer root node was not initialized. If you are using custom multiplayer, remember to set the root node via MultiplayerAPI.set_root_node before using it.");
  	ERR_FAIL_COND_MSG(p_packet_len < 1, "Invalid packet received. Size too small.");
  
  	uint8_t packet_type = p_packet[0];
  
  	switch (packet_type) {
  
  		case NETWORK_COMMAND_SIMPLIFY_PATH: {
  
  			_process_simplify_path(p_from, p_packet, p_packet_len);
  		} break;
  
  		case NETWORK_COMMAND_CONFIRM_PATH: {
  
  			_process_confirm_path(p_from, p_packet, p_packet_len);
  		} break;
  
  		case NETWORK_COMMAND_REMOTE_CALL:
  		case NETWORK_COMMAND_REMOTE_SET: {
  
  			ERR_FAIL_COND_MSG(p_packet_len < 6, "Invalid packet received. Size too small.");
  
  			Node *node = _process_get_node(p_from, p_packet, p_packet_len);
  
  			ERR_FAIL_COND_MSG(node == NULL, "Invalid packet received. Requested node was not found.");
  
  			// Detect cstring end.
  			int len_end = 5;
  			for (; len_end < p_packet_len; len_end++) {
  				if (p_packet[len_end] == 0) {
  					break;
  				}
  			}
  
  			ERR_FAIL_COND_MSG(len_end >= p_packet_len, "Invalid packet received. Size too small.");
  
  			StringName name = String::utf8((const char *)&p_packet[5]);
  
  			if (packet_type == NETWORK_COMMAND_REMOTE_CALL) {
  
  				_process_rpc(node, name, p_from, p_packet, p_packet_len, len_end + 1);
  
  			} else {
  
  				_process_rset(node, name, p_from, p_packet, p_packet_len, len_end + 1);
  			}
  
  		} break;
  
  		case NETWORK_COMMAND_RAW: {
  
  			_process_raw(p_from, p_packet, p_packet_len);
  		} break;
  	}
  }
  
  Node *MultiplayerAPI::_process_get_node(int p_from, const uint8_t *p_packet, int p_packet_len) {
  
  	uint32_t target = decode_uint32(&p_packet[1]);
  	Node *node = NULL;
  
  	if (target & 0x80000000) {
  		// Use full path (not cached yet).
  
  		int ofs = target & 0x7FFFFFFF;
  
  		ERR_FAIL_COND_V_MSG(ofs >= p_packet_len, NULL, "Invalid packet received. Size smaller than declared.");
  
  		String paths;
  		paths.parse_utf8((const char *)&p_packet[ofs], p_packet_len - ofs);
  
  		NodePath np = paths;
  
  		node = root_node->get_node(np);
  
  		if (!node)
  			ERR_PRINTS("Failed to get path from RPC: " + String(np) + ".");
  	} else {
  		// Use cached path.
  		int id = target;
  
  		Map<int, PathGetCache>::Element *E = path_get_cache.find(p_from);
  		ERR_FAIL_COND_V_MSG(!E, NULL, "Invalid packet received. Requests invalid peer cache.");
  
  		Map<int, PathGetCache::NodeInfo>::Element *F = E->get().nodes.find(id);
  		ERR_FAIL_COND_V_MSG(!F, NULL, "Invalid packet received. Unabled to find requested cached node.");
  
  		PathGetCache::NodeInfo *ni = &F->get();
  		// Do proper caching later.
  
  		node = root_node->get_node(ni->path);
  		if (!node)
  			ERR_PRINTS("Failed to get cached path from RPC: " + String(ni->path) + ".");
  	}
  	return node;
  }
  
  void MultiplayerAPI::_process_rpc(Node *p_node, const StringName &p_name, int p_from, const uint8_t *p_packet, int p_packet_len, int p_offset) {
  
  	ERR_FAIL_COND_MSG(p_offset >= p_packet_len, "Invalid packet received. Size too small.");
  
  	// Check that remote can call the RPC on this node.
  	RPCMode rpc_mode = RPC_MODE_DISABLED;
  	const Map<StringName, RPCMode>::Element *E = p_node->get_node_rpc_mode(p_name);
  	if (E) {
  		rpc_mode = E->get();
  	} else if (p_node->get_script_instance()) {
  		rpc_mode = p_node->get_script_instance()->get_rpc_mode(p_name);
  	}
  
  	bool can_call = _can_call_mode(p_node, rpc_mode, p_from);
  	ERR_FAIL_COND_MSG(!can_call, "RPC '" + String(p_name) + "' is not allowed on node " + p_node->get_path() + " from: " + itos(p_from) + ". Mode is " + itos((int)rpc_mode) + ", master is " + itos(p_node->get_network_master()) + ".");
  
  	int argc = p_packet[p_offset];
  	Vector<Variant> args;
  	Vector<const Variant *> argp;
  	args.resize(argc);
  	argp.resize(argc);
  
  	p_offset++;
  
  	for (int i = 0; i < argc; i++) {
  
  		ERR_FAIL_COND_MSG(p_offset >= p_packet_len, "Invalid packet received. Size too small.");
  
  		int vlen;
  		Error err = decode_variant(args.write[i], &p_packet[p_offset], p_packet_len - p_offset, &vlen, allow_object_decoding || network_peer->is_object_decoding_allowed());
  		ERR_FAIL_COND_MSG(err != OK, "Invalid packet received. Unable to decode RPC argument.");
  
  		argp.write[i] = &args[i];
  		p_offset += vlen;
  	}
  
  	Variant::CallError ce;
  
  	p_node->call(p_name, (const Variant **)argp.ptr(), argc, ce);
  	if (ce.error != Variant::CallError::CALL_OK) {
  		String error = Variant::get_call_error_text(p_node, p_name, (const Variant **)argp.ptr(), argc, ce);
  		error = "RPC - " + error;
  		ERR_PRINTS(error);
  	}
  }
  
  void MultiplayerAPI::_process_rset(Node *p_node, const StringName &p_name, int p_from, const uint8_t *p_packet, int p_packet_len, int p_offset) {
  
  	ERR_FAIL_COND_MSG(p_offset >= p_packet_len, "Invalid packet received. Size too small.");
  
  	// Check that remote can call the RSET on this node.
  	RPCMode rset_mode = RPC_MODE_DISABLED;
  	const Map<StringName, RPCMode>::Element *E = p_node->get_node_rset_mode(p_name);
  	if (E) {
  		rset_mode = E->get();
  	} else if (p_node->get_script_instance()) {
  		rset_mode = p_node->get_script_instance()->get_rset_mode(p_name);
  	}
  
  	bool can_call = _can_call_mode(p_node, rset_mode, p_from);
  	ERR_FAIL_COND_MSG(!can_call, "RSET '" + String(p_name) + "' is not allowed on node " + p_node->get_path() + " from: " + itos(p_from) + ". Mode is " + itos((int)rset_mode) + ", master is " + itos(p_node->get_network_master()) + ".");
  
  	Variant value;
  	Error err = decode_variant(value, &p_packet[p_offset], p_packet_len - p_offset, NULL, allow_object_decoding || network_peer->is_object_decoding_allowed());
  
  	ERR_FAIL_COND_MSG(err != OK, "Invalid packet received. Unable to decode RSET value.");
  
  	bool valid;
  
  	p_node->set(p_name, value, &valid);
  	if (!valid) {
  		String error = "Error setting remote property '" + String(p_name) + "', not found in object of type " + p_node->get_class() + ".";
  		ERR_PRINTS(error);
  	}
  }
  
  void MultiplayerAPI::_process_simplify_path(int p_from, const uint8_t *p_packet, int p_packet_len) {
  
  	ERR_FAIL_COND_MSG(p_packet_len < 5, "Invalid packet received. Size too small.");
  	int id = decode_uint32(&p_packet[1]);
  
  	String paths;
  	paths.parse_utf8((const char *)&p_packet[5], p_packet_len - 5);
  
  	NodePath path = paths;
  
  	if (!path_get_cache.has(p_from)) {
  		path_get_cache[p_from] = PathGetCache();
  	}
  
  	PathGetCache::NodeInfo ni;
  	ni.path = path;
  	ni.instance = 0;
  
  	path_get_cache[p_from].nodes[id] = ni;
  
  	// Encode path to send ack.
  	CharString pname = String(path).utf8();
  	int len = encode_cstring(pname.get_data(), NULL);
  
  	Vector<uint8_t> packet;
  
  	packet.resize(1 + len);
  	packet.write[0] = NETWORK_COMMAND_CONFIRM_PATH;
  	encode_cstring(pname.get_data(), &packet.write[1]);
  
  	network_peer->set_transfer_mode(NetworkedMultiplayerPeer::TRANSFER_MODE_RELIABLE);
  	network_peer->set_target_peer(p_from);
  	network_peer->put_packet(packet.ptr(), packet.size());
  }
  
  void MultiplayerAPI::_process_confirm_path(int p_from, const uint8_t *p_packet, int p_packet_len) {
  
  	ERR_FAIL_COND_MSG(p_packet_len < 2, "Invalid packet received. Size too small.");
  
  	String paths;
  	paths.parse_utf8((const char *)&p_packet[1], p_packet_len - 1);
  
  	NodePath path = paths;
  
  	PathSentCache *psc = path_send_cache.getptr(path);
  	ERR_FAIL_COND_MSG(!psc, "Invalid packet received. Tries to confirm a path which was not found in cache.");
  
  	Map<int, bool>::Element *E = psc->confirmed_peers.find(p_from);
  	ERR_FAIL_COND_MSG(!E, "Invalid packet received. Source peer was not found in cache for the given path.");
  	E->get() = true;
  }
  
  bool MultiplayerAPI::_send_confirm_path(NodePath p_path, PathSentCache *psc, int p_target) {
  	bool has_all_peers = true;
  	List<int> peers_to_add; // If one is missing, take note to add it.
  
  	for (Set<int>::Element *E = connected_peers.front(); E; E = E->next()) {
  
  		if (p_target < 0 && E->get() == -p_target)
  			continue; // Continue, excluded.
  
  		if (p_target > 0 && E->get() != p_target)
  			continue; // Continue, not for this peer.
  
  		Map<int, bool>::Element *F = psc->confirmed_peers.find(E->get());
  
  		if (!F || !F->get()) {
  			// Path was not cached, or was cached but is unconfirmed.
  			if (!F) {
  				// Not cached at all, take note.
  				peers_to_add.push_back(E->get());
  			}
  
  			has_all_peers = false;
  		}
  	}
  
  	// Those that need to be added, send a message for this.
  
  	for (List<int>::Element *E = peers_to_add.front(); E; E = E->next()) {
  
  		// Encode function name.
  		CharString pname = String(p_path).utf8();
  		int len = encode_cstring(pname.get_data(), NULL);
  
  		Vector<uint8_t> packet;
  
  		packet.resize(1 + 4 + len);
  		packet.write[0] = NETWORK_COMMAND_SIMPLIFY_PATH;
  		encode_uint32(psc->id, &packet.write[1]);
  		encode_cstring(pname.get_data(), &packet.write[5]);
  
  		network_peer->set_target_peer(E->get()); // To all of you.
  		network_peer->set_transfer_mode(NetworkedMultiplayerPeer::TRANSFER_MODE_RELIABLE);
  		network_peer->put_packet(packet.ptr(), packet.size());
  
  		psc->confirmed_peers.insert(E->get(), false); // Insert into confirmed, but as false since it was not confirmed.
  	}
  
  	return has_all_peers;
  }
  
  void MultiplayerAPI::_send_rpc(Node *p_from, int p_to, bool p_unreliable, bool p_set, const StringName &p_name, const Variant **p_arg, int p_argcount) {
  
  	ERR_FAIL_COND_MSG(network_peer.is_null(), "Attempt to remote call/set when networking is not active in SceneTree.");
  
  	ERR_FAIL_COND_MSG(network_peer->get_connection_status() == NetworkedMultiplayerPeer::CONNECTION_CONNECTING, "Attempt to remote call/set when networking is not connected yet in SceneTree.");
  
  	ERR_FAIL_COND_MSG(network_peer->get_connection_status() == NetworkedMultiplayerPeer::CONNECTION_DISCONNECTED, "Attempt to remote call/set when networking is disconnected.");
  
  	ERR_FAIL_COND_MSG(p_argcount > 255, "Too many arguments >255.");
  
  	if (p_to != 0 && !connected_peers.has(ABS(p_to))) {
  		ERR_FAIL_COND_MSG(p_to == network_peer->get_unique_id(), "Attempt to remote call/set yourself! unique ID: " + itos(network_peer->get_unique_id()) + ".");
  
  		ERR_FAIL_MSG("Attempt to remote call unexisting ID: " + itos(p_to) + ".");
  	}
  
  	NodePath from_path = (root_node->get_path()).rel_path_to(p_from->get_path());
  	ERR_FAIL_COND_MSG(from_path.is_empty(), "Unable to send RPC. Relative path is empty. THIS IS LIKELY A BUG IN THE ENGINE!");
  
  	// See if the path is cached.
  	PathSentCache *psc = path_send_cache.getptr(from_path);
  	if (!psc) {
  		// Path is not cached, create.
  		path_send_cache[from_path] = PathSentCache();
  		psc = path_send_cache.getptr(from_path);
  		psc->id = last_send_cache_id++;
  	}
  
  	// Create base packet, lots of hardcode because it must be tight.
  
  	int ofs = 0;
  
  #define MAKE_ROOM(m_amount) \
  	if (packet_cache.size() < m_amount) packet_cache.resize(m_amount);
  
  	// Encode type.
  	MAKE_ROOM(1);
  	packet_cache.write[0] = p_set ? NETWORK_COMMAND_REMOTE_SET : NETWORK_COMMAND_REMOTE_CALL;
  	ofs += 1;
  
  	// Encode ID.
  	MAKE_ROOM(ofs + 4);
  	encode_uint32(psc->id, &(packet_cache.write[ofs]));
  	ofs += 4;
  
  	// Encode function name.
  	CharString name = String(p_name).utf8();
  	int len = encode_cstring(name.get_data(), NULL);
  	MAKE_ROOM(ofs + len);
  	encode_cstring(name.get_data(), &(packet_cache.write[ofs]));
  	ofs += len;
  
  	if (p_set) {
  		// Set argument.
  		Error err = encode_variant(*p_arg[0], NULL, len, allow_object_decoding || network_peer->is_object_decoding_allowed());
  		ERR_FAIL_COND_MSG(err != OK, "Unable to encode RSET value. THIS IS LIKELY A BUG IN THE ENGINE!");
  		MAKE_ROOM(ofs + len);
  		encode_variant(*p_arg[0], &(packet_cache.write[ofs]), len, allow_object_decoding || network_peer->is_object_decoding_allowed());
  		ofs += len;
  
  	} else {
  		// Call arguments.
  		MAKE_ROOM(ofs + 1);
  		packet_cache.write[ofs] = p_argcount;
  		ofs += 1;
  		for (int i = 0; i < p_argcount; i++) {
  			Error err = encode_variant(*p_arg[i], NULL, len, allow_object_decoding || network_peer->is_object_decoding_allowed());
  			ERR_FAIL_COND_MSG(err != OK, "Unable to encode RPC argument. THIS IS LIKELY A BUG IN THE ENGINE!");
  			MAKE_ROOM(ofs + len);
  			encode_variant(*p_arg[i], &(packet_cache.write[ofs]), len, allow_object_decoding || network_peer->is_object_decoding_allowed());
  			ofs += len;
  		}
  	}
  
  	// See if all peers have cached path (is so, call can be fast).
  	bool has_all_peers = _send_confirm_path(from_path, psc, p_to);
  
  	// Take chance and set transfer mode, since all send methods will use it.
  	network_peer->set_transfer_mode(p_unreliable ? NetworkedMultiplayerPeer::TRANSFER_MODE_UNRELIABLE : NetworkedMultiplayerPeer::TRANSFER_MODE_RELIABLE);
  
  	if (has_all_peers) {
  
  		// They all have verified paths, so send fast.
  		network_peer->set_target_peer(p_to); // To all of you.
  		network_peer->put_packet(packet_cache.ptr(), ofs); // A message with love.
  	} else {
  		// Not all verified path, so send one by one.
  
  		// Append path at the end, since we will need it for some packets.
  		CharString pname = String(from_path).utf8();
  		int path_len = encode_cstring(pname.get_data(), NULL);
  		MAKE_ROOM(ofs + path_len);
  		encode_cstring(pname.get_data(), &(packet_cache.write[ofs]));
  
  		for (Set<int>::Element *E = connected_peers.front(); E; E = E->next()) {
  
  			if (p_to < 0 && E->get() == -p_to)
  				continue; // Continue, excluded.
  
  			if (p_to > 0 && E->get() != p_to)
  				continue; // Continue, not for this peer.
  
  			Map<int, bool>::Element *F = psc->confirmed_peers.find(E->get());
  			ERR_CONTINUE(!F); // Should never happen.
  
  			network_peer->set_target_peer(E->get()); // To this one specifically.
  
  			if (F->get()) {
  				// This one confirmed path, so use id.
  				encode_uint32(psc->id, &(packet_cache.write[1]));
  				network_peer->put_packet(packet_cache.ptr(), ofs);
  			} else {
  				// This one did not confirm path yet, so use entire path (sorry!).
  				encode_uint32(0x80000000 | ofs, &(packet_cache.write[1])); // Offset to path and flag.
  				network_peer->put_packet(packet_cache.ptr(), ofs + path_len);
  			}
  		}
  	}
  }
  
  void MultiplayerAPI::_add_peer(int p_id) {
  	connected_peers.insert(p_id);
  	path_get_cache.insert(p_id, PathGetCache());
  	emit_signal("network_peer_connected", p_id);
  }
  
  void MultiplayerAPI::_del_peer(int p_id) {
  	connected_peers.erase(p_id);
  	path_get_cache.erase(p_id); // I no longer need your cache, sorry.
  	emit_signal("network_peer_disconnected", p_id);
  }
  
  void MultiplayerAPI::_connected_to_server() {
  
  	emit_signal("connected_to_server");
  }
  
  void MultiplayerAPI::_connection_failed() {
  
  	emit_signal("connection_failed");
  }
  
  void MultiplayerAPI::_server_disconnected() {
  
  	emit_signal("server_disconnected");
  }
  
  void MultiplayerAPI::rpcp(Node *p_node, int p_peer_id, bool p_unreliable, const StringName &p_method, const Variant **p_arg, int p_argcount) {
  
  	ERR_FAIL_COND_MSG(!network_peer.is_valid(), "Trying to call an RPC while no network peer is active.");
  	ERR_FAIL_COND_MSG(!p_node->is_inside_tree(), "Trying to call an RPC on a node which is not inside SceneTree.");
  	ERR_FAIL_COND_MSG(network_peer->get_connection_status() != NetworkedMultiplayerPeer::CONNECTION_CONNECTED, "Trying to call an RPC via a network peer which is not connected.");
  
  	int node_id = network_peer->get_unique_id();
  	bool skip_rpc = node_id == p_peer_id;
  	bool call_local_native = false;
  	bool call_local_script = false;
  	bool is_master = p_node->is_network_master();
  
  	if (p_peer_id == 0 || p_peer_id == node_id || (p_peer_id < 0 && p_peer_id != -node_id)) {
  		// Check that send mode can use local call.
  
  		const Map<StringName, RPCMode>::Element *E = p_node->get_node_rpc_mode(p_method);
  		if (E) {
  			call_local_native = _should_call_local(E->get(), is_master, skip_rpc);
  		}
  
  		if (call_local_native) {
  			// Done below.
  		} else if (p_node->get_script_instance()) {
  			// Attempt with script.
  			RPCMode rpc_mode = p_node->get_script_instance()->get_rpc_mode(p_method);
  			call_local_script = _should_call_local(rpc_mode, is_master, skip_rpc);
  		}
  	}
  
  	if (!skip_rpc) {
  		_send_rpc(p_node, p_peer_id, p_unreliable, false, p_method, p_arg, p_argcount);
  	}
  
  	if (call_local_native) {
  		int temp_id = rpc_sender_id;
  		rpc_sender_id = get_network_unique_id();
  		Variant::CallError ce;
  		p_node->call(p_method, p_arg, p_argcount, ce);
  		rpc_sender_id = temp_id;
  		if (ce.error != Variant::CallError::CALL_OK) {
  			String error = Variant::get_call_error_text(p_node, p_method, p_arg, p_argcount, ce);
  			error = "rpc() aborted in local call:  - " + error + ".";
  			ERR_PRINTS(error);
  			return;
  		}
  	}
  
  	if (call_local_script) {
  		int temp_id = rpc_sender_id;
  		rpc_sender_id = get_network_unique_id();
  		Variant::CallError ce;
  		ce.error = Variant::CallError::CALL_OK;
  		p_node->get_script_instance()->call(p_method, p_arg, p_argcount, ce);
  		rpc_sender_id = temp_id;
  		if (ce.error != Variant::CallError::CALL_OK) {
  			String error = Variant::get_call_error_text(p_node, p_method, p_arg, p_argcount, ce);
  			error = "rpc() aborted in script local call:  - " + error + ".";
  			ERR_PRINTS(error);
  			return;
  		}
  	}
  
  	ERR_FAIL_COND_MSG(skip_rpc && !(call_local_native || call_local_script), "RPC '" + p_method + "' on yourself is not allowed by selected mode.");
  }
  
  void MultiplayerAPI::rsetp(Node *p_node, int p_peer_id, bool p_unreliable, const StringName &p_property, const Variant &p_value) {
  
  	ERR_FAIL_COND_MSG(!network_peer.is_valid(), "Trying to RSET while no network peer is active.");
  	ERR_FAIL_COND_MSG(!p_node->is_inside_tree(), "Trying to RSET on a node which is not inside SceneTree.");
  	ERR_FAIL_COND_MSG(network_peer->get_connection_status() != NetworkedMultiplayerPeer::CONNECTION_CONNECTED, "Trying to send an RSET via a network peer which is not connected.");
  
  	int node_id = network_peer->get_unique_id();
  	bool is_master = p_node->is_network_master();
  	bool skip_rset = node_id == p_peer_id;
  	bool set_local = false;
  
  	if (p_peer_id == 0 || p_peer_id == node_id || (p_peer_id < 0 && p_peer_id != -node_id)) {
  		// Check that send mode can use local call.
  		const Map<StringName, RPCMode>::Element *E = p_node->get_node_rset_mode(p_property);
  		if (E) {
  
  			set_local = _should_call_local(E->get(), is_master, skip_rset);
  		}
  
  		if (set_local) {
  			bool valid;
  			int temp_id = rpc_sender_id;
  
  			rpc_sender_id = get_network_unique_id();
  			p_node->set(p_property, p_value, &valid);
  			rpc_sender_id = temp_id;
  
  			if (!valid) {
  				String error = "rset() aborted in local set, property not found:  - " + String(p_property) + ".";
  				ERR_PRINTS(error);
  				return;
  			}
  		} else if (p_node->get_script_instance()) {
  			// Attempt with script.
  			RPCMode rpc_mode = p_node->get_script_instance()->get_rset_mode(p_property);
  
  			set_local = _should_call_local(rpc_mode, is_master, skip_rset);
  
  			if (set_local) {
  				int temp_id = rpc_sender_id;
  
  				rpc_sender_id = get_network_unique_id();
  				bool valid = p_node->get_script_instance()->set(p_property, p_value);
  				rpc_sender_id = temp_id;
  
  				if (!valid) {
  					String error = "rset() aborted in local script set, property not found:  - " + String(p_property) + ".";
  					ERR_PRINTS(error);
  					return;
  				}
  			}
  		}
  	}
  
  	if (skip_rset) {
  		ERR_FAIL_COND_MSG(!set_local, "RSET for '" + p_property + "' on yourself is not allowed by selected mode.");
  		return;
  	}
  
  	const Variant *vptr = &p_value;
  
  	_send_rpc(p_node, p_peer_id, p_unreliable, true, p_property, &vptr, 1);
  }
  
  Error MultiplayerAPI::send_bytes(PoolVector<uint8_t> p_data, int p_to, NetworkedMultiplayerPeer::TransferMode p_mode) {
  
  	ERR_FAIL_COND_V_MSG(p_data.size() < 1, ERR_INVALID_DATA, "Trying to send an empty raw packet.");
  	ERR_FAIL_COND_V_MSG(!network_peer.is_valid(), ERR_UNCONFIGURED, "Trying to send a raw packet while no network peer is active.");
  	ERR_FAIL_COND_V_MSG(network_peer->get_connection_status() != NetworkedMultiplayerPeer::CONNECTION_CONNECTED, ERR_UNCONFIGURED, "Trying to send a raw packet via a network peer which is not connected.");
  
  	MAKE_ROOM(p_data.size() + 1);
  	PoolVector<uint8_t>::Read r = p_data.read();
  	packet_cache.write[0] = NETWORK_COMMAND_RAW;
  	memcpy(&packet_cache.write[1], &r[0], p_data.size());
  
  	network_peer->set_target_peer(p_to);
  	network_peer->set_transfer_mode(p_mode);
  
  	return network_peer->put_packet(packet_cache.ptr(), p_data.size() + 1);
  }
  
  void MultiplayerAPI::_process_raw(int p_from, const uint8_t *p_packet, int p_packet_len) {
  
  	ERR_FAIL_COND_MSG(p_packet_len < 2, "Invalid packet received. Size too small.");
  
  	PoolVector<uint8_t> out;
  	int len = p_packet_len - 1;
  	out.resize(len);
  	{
  		PoolVector<uint8_t>::Write w = out.write();
  		memcpy(&w[0], &p_packet[1], len);
  	}
  	emit_signal("network_peer_packet", p_from, out);
  }
  
  int MultiplayerAPI::get_network_unique_id() const {
  
  	ERR_FAIL_COND_V_MSG(!network_peer.is_valid(), 0, "No network peer is assigned. Unable to get unique network ID.");
  	return network_peer->get_unique_id();
  }
  
  bool MultiplayerAPI::is_network_server() const {
  
  	// XXX Maybe fail silently? Maybe should actually return true to make development of both local and online multiplayer easier?
  	ERR_FAIL_COND_V_MSG(!network_peer.is_valid(), false, "No network peer is assigned. I can't be a server.");
  	return network_peer->is_server();
  }
  
  void MultiplayerAPI::set_refuse_new_network_connections(bool p_refuse) {
  
  	ERR_FAIL_COND_MSG(!network_peer.is_valid(), "No network peer is assigned. Unable to set 'refuse_new_connections'.");
  	network_peer->set_refuse_new_connections(p_refuse);
  }
  
  bool MultiplayerAPI::is_refusing_new_network_connections() const {
  
  	ERR_FAIL_COND_V_MSG(!network_peer.is_valid(), false, "No network peer is assigned. Unable to get 'refuse_new_connections'.");
  	return network_peer->is_refusing_new_connections();
  }
  
  Vector<int> MultiplayerAPI::get_network_connected_peers() const {
  
  	ERR_FAIL_COND_V_MSG(!network_peer.is_valid(), Vector<int>(), "No network peer is assigned. Assume no peers are connected.");
  
  	Vector<int> ret;
  	for (Set<int>::Element *E = connected_peers.front(); E; E = E->next()) {
  		ret.push_back(E->get());
  	}
  
  	return ret;
  }
  
  void MultiplayerAPI::set_allow_object_decoding(bool p_enable) {
  
  	allow_object_decoding = p_enable;
  }
  
  bool MultiplayerAPI::is_object_decoding_allowed() const {
  
  	return allow_object_decoding;
  }
  
  void MultiplayerAPI::_bind_methods() {
  	ClassDB::bind_method(D_METHOD("set_root_node", "node"), &MultiplayerAPI::set_root_node);
  	ClassDB::bind_method(D_METHOD("send_bytes", "bytes", "id", "mode"), &MultiplayerAPI::send_bytes, DEFVAL(NetworkedMultiplayerPeer::TARGET_PEER_BROADCAST), DEFVAL(NetworkedMultiplayerPeer::TRANSFER_MODE_RELIABLE));
  	ClassDB::bind_method(D_METHOD("has_network_peer"), &MultiplayerAPI::has_network_peer);
  	ClassDB::bind_method(D_METHOD("get_network_peer"), &MultiplayerAPI::get_network_peer);
  	ClassDB::bind_method(D_METHOD("get_network_unique_id"), &MultiplayerAPI::get_network_unique_id);
  	ClassDB::bind_method(D_METHOD("is_network_server"), &MultiplayerAPI::is_network_server);
  	ClassDB::bind_method(D_METHOD("get_rpc_sender_id"), &MultiplayerAPI::get_rpc_sender_id);
  	ClassDB::bind_method(D_METHOD("_add_peer", "id"), &MultiplayerAPI::_add_peer);
  	ClassDB::bind_method(D_METHOD("_del_peer", "id"), &MultiplayerAPI::_del_peer);
  	ClassDB::bind_method(D_METHOD("set_network_peer", "peer"), &MultiplayerAPI::set_network_peer);
  	ClassDB::bind_method(D_METHOD("poll"), &MultiplayerAPI::poll);
  	ClassDB::bind_method(D_METHOD("clear"), &MultiplayerAPI::clear);
  
  	ClassDB::bind_method(D_METHOD("_connected_to_server"), &MultiplayerAPI::_connected_to_server);
  	ClassDB::bind_method(D_METHOD("_connection_failed"), &MultiplayerAPI::_connection_failed);
  	ClassDB::bind_method(D_METHOD("_server_disconnected"), &MultiplayerAPI::_server_disconnected);
  	ClassDB::bind_method(D_METHOD("get_network_connected_peers"), &MultiplayerAPI::get_network_connected_peers);
  	ClassDB::bind_method(D_METHOD("set_refuse_new_network_connections", "refuse"), &MultiplayerAPI::set_refuse_new_network_connections);
  	ClassDB::bind_method(D_METHOD("is_refusing_new_network_connections"), &MultiplayerAPI::is_refusing_new_network_connections);
  	ClassDB::bind_method(D_METHOD("set_allow_object_decoding", "enable"), &MultiplayerAPI::set_allow_object_decoding);
  	ClassDB::bind_method(D_METHOD("is_object_decoding_allowed"), &MultiplayerAPI::is_object_decoding_allowed);
  
  	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "allow_object_decoding"), "set_allow_object_decoding", "is_object_decoding_allowed");
  	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "refuse_new_network_connections"), "set_refuse_new_network_connections", "is_refusing_new_network_connections");
  	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "network_peer", PROPERTY_HINT_RESOURCE_TYPE, "NetworkedMultiplayerPeer", 0), "set_network_peer", "get_network_peer");
  	ADD_PROPERTY_DEFAULT("refuse_new_network_connections", false);
  
  	ADD_SIGNAL(MethodInfo("network_peer_connected", PropertyInfo(Variant::INT, "id")));
  	ADD_SIGNAL(MethodInfo("network_peer_disconnected", PropertyInfo(Variant::INT, "id")));
  	ADD_SIGNAL(MethodInfo("network_peer_packet", PropertyInfo(Variant::INT, "id"), PropertyInfo(Variant::POOL_BYTE_ARRAY, "packet")));
  	ADD_SIGNAL(MethodInfo("connected_to_server"));
  	ADD_SIGNAL(MethodInfo("connection_failed"));
  	ADD_SIGNAL(MethodInfo("server_disconnected"));
  
  	BIND_ENUM_CONSTANT(RPC_MODE_DISABLED);
  	BIND_ENUM_CONSTANT(RPC_MODE_REMOTE);
  	BIND_ENUM_CONSTANT(RPC_MODE_MASTER);
  	BIND_ENUM_CONSTANT(RPC_MODE_PUPPET);
  	BIND_ENUM_CONSTANT(RPC_MODE_SLAVE); // Deprecated.
  	BIND_ENUM_CONSTANT(RPC_MODE_REMOTESYNC);
  	BIND_ENUM_CONSTANT(RPC_MODE_SYNC); // Deprecated.
  	BIND_ENUM_CONSTANT(RPC_MODE_MASTERSYNC);
  	BIND_ENUM_CONSTANT(RPC_MODE_PUPPETSYNC);
  }
  
  MultiplayerAPI::MultiplayerAPI() :
  		allow_object_decoding(false) {
  	rpc_sender_id = 0;
  	root_node = NULL;
  	clear();
  }
  
  MultiplayerAPI::~MultiplayerAPI() {
  	clear();
  }
  