/*
 * Copyright (C) 2017 Ortega Froysa, Nicolás <nortega@themusicinnoise.net>
 * Author: Ortega Froysa, Nicolás <nortega@themusicinnoise.net>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "neocomm.h"

#include "error.hpp"
#include "globals.hpp"

std::map<std::string, struct channel_info> channels;

static std::mt19937_64 rand_dev { dht::crypto::random_device{}() };
static std::uniform_int_distribution<dht::Value::Id> rand_id;

static std::map<time_t, int> sent_messages;

int NeoComm_join_channel(const char *channel_name) {
	if(not node.isRunning())
	{
		add_error("NeoComm must be initialized.");
		return 0;
	}

	const std::string s_chan_name(channel_name);
	if(s_chan_name.empty())
	{
		add_error("Chan name is empty.");
		return 0;
	}

	// if it already exists then just exit
	if(channels.find(s_chan_name) == channels.end())
		return 1;

	dht::InfoHash chan_hash(s_chan_name);
	{
		static constexpr dht::InfoHash INVALID_ID {};
		if(chan_hash == INVALID_ID)
			chan_hash = dht::InfoHash::get(s_chan_name);
	}

	channels[s_chan_name] = {
		/*.hash =*/ chan_hash,
		/*.token =*/ node.listen<dht::ImMessage>(chan_hash,
				[&](dht::ImMessage &&msg) {
					channels[s_chan_name].msgs.push_back(msg);
					return true;
				}),
		/*.msgs = */ std::vector<dht::ImMessage>()
	};

	return 1;
}

void NeoComm_leave_channel(const char *channel_name) {
	if(not node.isRunning())
		return;
	const std::string s_chan_name(channel_name);
	if(channels.find(s_chan_name) == channels.end())
		return;

	struct channel_info *channel = &channels[s_chan_name];
	channel->token.wait();
	node.cancelListen(channel->hash, channel->token.get());
	channels.erase(s_chan_name);
}

struct message *NeoComm_get_next_message(const char *channel_name) {
	const std::string s_chan_name(channel_name);
	if(channels[s_chan_name].msgs.empty())
		return NULL;
	const dht::ImMessage *new_msg = &channels[s_chan_name].msgs.front();
	struct message *msg =
		static_cast<struct message*>(malloc(sizeof(struct message)));

	*msg = {
		/*.msg =*/ new_msg->msg.c_str(),
		/*.sent =*/ new_msg->date,
		/*.from =*/ {
			/*.nick =*/ "DEFAULT", // TODO: Implement this!!!
			/*.hash =*/ new_msg->from.to_c_str()
		}
	};

	return msg;
}

time_t NeoComm_send_message(const char *channel_name, const char *message) {
	if(not node.isRunning())
	{
		add_error("NeoComm must be initialized.");
		return 0;
	}
	const dht::InfoHash chan_hash = channels[channel_name].hash;
	const time_t now =
		std::chrono::system_clock::to_time_t(std::chrono::system_clock::now());

	if(channels.find(channel_name) == channels.end())
	{
		add_error("Not connected to channel");
		return 0;
	}
	sent_messages[now] = NC_PENDING;
	node.putSigned(chan_hash,
			dht::ImMessage(rand_id(rand_dev), message, now), [&](bool sent) {
				sent_messages[now] = sent ? NC_GOOD : NC_BAD;
			});
	return now;
}

// TODO: Devise a way so that the message can be resent.
int NeoComm_check_message(const time_t token) {
	if(sent_messages.find(token) == sent_messages.end())
	{
		add_error("No message found with that token.");
		return 0;
	}
	const int status = sent_messages[token];
	sent_messages.erase(token);
	return status;
}