/*************************************************************************/
/*  packet_peer_udp.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)    */
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/*************************************************************************/

#include "packet_peer_udp.h"

#include "core/io/ip.h"

void PacketPeerUDP::set_blocking_mode(bool p_enable) {

	blocking = p_enable;
}

String PacketPeerUDP::_get_packet_ip() const {

	return get_packet_address();
}

Error PacketPeerUDP::_set_dest_address(const String &p_address, int p_port) {

	IP_Address ip;
	if (p_address.is_valid_ip_address()) {
		ip = p_address;
	} else {
		ip = IP::get_singleton()->resolve_hostname(p_address);
		if (!ip.is_valid())
			return ERR_CANT_RESOLVE;
	}

	set_dest_address(ip, p_port);
	return OK;
}

int PacketPeerUDP::get_available_packet_count() const {

	// TODO we should deprecate this, and expose poll instead!
	Error err = const_cast<PacketPeerUDP *>(this)->_poll();
	if (err != OK)
		return -1;

	return queue_count;
}

Error PacketPeerUDP::get_packet(const uint8_t **r_buffer, int &r_buffer_size) {

	Error err = _poll();
	if (err != OK)
		return err;
	if (queue_count == 0)
		return ERR_UNAVAILABLE;

	uint32_t size = 0;
	uint8_t ipv6[16];
	rb.read(ipv6, 16, true);
	packet_ip.set_ipv6(ipv6);
	rb.read((uint8_t *)&packet_port, 4, true);
	rb.read((uint8_t *)&size, 4, true);
	rb.read(packet_buffer, size, true);
	--queue_count;
	*r_buffer = packet_buffer;
	r_buffer_size = size;
	return OK;
}

Error PacketPeerUDP::put_packet(const uint8_t *p_buffer, int p_buffer_size) {

	ERR_FAIL_COND_V(!_sock.is_valid(), ERR_UNAVAILABLE);
	ERR_FAIL_COND_V(!peer_addr.is_valid(), ERR_UNCONFIGURED);

	Error err;
	int sent = -1;

	if (!_sock->is_open()) {
		IP::Type ip_type = peer_addr.is_ipv4() ? IP::TYPE_IPV4 : IP::TYPE_IPV6;
		err = _sock->open(NetSocket::TYPE_UDP, ip_type);
		ERR_FAIL_COND_V(err != OK, err);
		_sock->set_blocking_enabled(false);
	}

	do {
		err = _sock->sendto(p_buffer, p_buffer_size, sent, peer_addr, peer_port);
		if (err != OK) {
			if (err != ERR_BUSY)
				return FAILED;
			else if (!blocking)
				return ERR_BUSY;
			// Keep trying to send full packet
			continue;
		}
		return OK;

	} while (sent != p_buffer_size);

	return OK;
}

int PacketPeerUDP::get_max_packet_size() const {

	return 512; // uhm maybe not
}

Error PacketPeerUDP::listen(int p_port, const IP_Address &p_bind_address, int p_recv_buffer_size) {

	ERR_FAIL_COND_V(!_sock.is_valid(), ERR_UNAVAILABLE);
	ERR_FAIL_COND_V(_sock->is_open(), ERR_ALREADY_IN_USE);
	ERR_FAIL_COND_V(!p_bind_address.is_valid() && !p_bind_address.is_wildcard(), ERR_INVALID_PARAMETER);

	Error err;
	IP::Type ip_type = IP::TYPE_ANY;

	if (p_bind_address.is_valid())
		ip_type = p_bind_address.is_ipv4() ? IP::TYPE_IPV4 : IP::TYPE_IPV6;

	err = _sock->open(NetSocket::TYPE_UDP, ip_type);

	if (err != OK)
		return ERR_CANT_CREATE;

	_sock->set_blocking_enabled(false);
	_sock->set_reuse_address_enabled(true);
	err = _sock->bind(p_bind_address, p_port);

	if (err != OK) {
		_sock->close();
		return err;
	}
	rb.resize(nearest_shift(p_recv_buffer_size));
	return OK;
}

void PacketPeerUDP::close() {

	if (_sock.is_valid())
		_sock->close();
	rb.resize(16);
	queue_count = 0;
}

Error PacketPeerUDP::wait() {

	ERR_FAIL_COND_V(!_sock.is_valid(), ERR_UNAVAILABLE);
	return _sock->poll(NetSocket::POLL_TYPE_IN, -1);
}

Error PacketPeerUDP::_poll() {

	ERR_FAIL_COND_V(!_sock.is_valid(), ERR_UNAVAILABLE);

	if (!_sock->is_open()) {
		return FAILED;
	}

	Error err;
	int read;
	IP_Address ip;
	uint16_t port;

	while (true) {
		err = _sock->recvfrom(recv_buffer, sizeof(recv_buffer), read, ip, port);

		if (err != OK) {
			if (err == ERR_BUSY)
				break;
			return FAILED;
		}

		if (rb.space_left() < read + 24) {
#ifdef TOOLS_ENABLED
			WARN_PRINTS("Buffer full, dropping packets!");
#endif
			continue;
		}

		uint32_t port32 = port;
		rb.write(ip.get_ipv6(), 16);
		rb.write((uint8_t *)&port32, 4);
		rb.write((uint8_t *)&read, 4);
		rb.write(recv_buffer, read);
		++queue_count;
	}

	return OK;
}
bool PacketPeerUDP::is_listening() const {

	return _sock.is_valid() && _sock->is_open();
}

IP_Address PacketPeerUDP::get_packet_address() const {

	return packet_ip;
}

int PacketPeerUDP::get_packet_port() const {

	return packet_port;
}

void PacketPeerUDP::set_dest_address(const IP_Address &p_address, int p_port) {

	peer_addr = p_address;
	peer_port = p_port;
}

void PacketPeerUDP::_bind_methods() {

	ClassDB::bind_method(D_METHOD("listen", "port", "bind_address", "recv_buf_size"), &PacketPeerUDP::listen, DEFVAL("*"), DEFVAL(65536));
	ClassDB::bind_method(D_METHOD("close"), &PacketPeerUDP::close);
	ClassDB::bind_method(D_METHOD("wait"), &PacketPeerUDP::wait);
	ClassDB::bind_method(D_METHOD("is_listening"), &PacketPeerUDP::is_listening);
	ClassDB::bind_method(D_METHOD("get_packet_ip"), &PacketPeerUDP::_get_packet_ip);
	ClassDB::bind_method(D_METHOD("get_packet_port"), &PacketPeerUDP::get_packet_port);
	ClassDB::bind_method(D_METHOD("set_dest_address", "host", "port"), &PacketPeerUDP::_set_dest_address);
}

PacketPeerUDP::PacketPeerUDP() :
		packet_port(0),
		queue_count(0),
		peer_port(0),
		blocking(true),
		_sock(Ref<NetSocket>(NetSocket::create())) {
	rb.resize(16);
}

PacketPeerUDP::~PacketPeerUDP() {

	close();
}
