/*
 * This file is part of the Flowee project
 * Copyright (C) 2016, 2019-2021 Tom Zander <tom@flowee.org>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#ifndef FLOWEE_NETWORKMANAGER_H
#define FLOWEE_NETWORKMANAGER_H

#include <utils/streaming/ConstBuffer.h>
#include "NetworkConnection.h"

#include <string>
#include <cstdint>
#include <vector>
#include <map>

#include <boost/asio/io_context.hpp>
#include <boost/asio/ip/tcp.hpp>

class NetworkManagerPrivate;
class NetworkServiceBase;

/**
 * The NetworkManager is the main entry-point of this library.
 *
 * Creating a NetworkManager allows you to manage your connections and their message-flows.
 */
class NetworkManager
{
public:
    NetworkManager(boost::asio::io_context &context);
    ~NetworkManager();

    enum ConnectionEnum {
        AutoCreate,
        OnlyExisting    ///< If no existing connection is found, an invalid one is returned.
    };

    /**
     * Find a connection based on explicit data from the remote argument.
     * @param remote the datastructure with all the details of a remote used in the connection.
     *      The announcePort and the ipAddress are required to be filled.
     * @param connect Indicate what to do when the connection doesn't exist yet.
     */
    NetworkConnection connection(const EndPoint &remote, ConnectionEnum connect = AutoCreate);

    std::list<NetworkConnection> connectionsFrom(boost::asio::ip::address ipAddress);

    /**
     * Return the endpoint for a known connection.
     * If the connection is unknown, an invalid endpoint will be returned.
     */
    EndPoint endPoint(int remoteId) const;

    /**
     * Punish a node that misbehaves (for instance if it breaks your protocol).
     * A node that gathers a total of 1000 points is banned for 24 hours,
     * every hour 100 points are subtracted from a each node's punishment-score.
     * @see Message.remote
     * @see NetworkManager::punishNode()
     */
    void punishNode(int remoteId, int punishment);

    /**
     * Listen for incoming connections.
     * Adds a callback that will be called when a new connection comes in.
     *
     * New connections can be vetted in this callback and you need to call NetworkConnection::accept() on
     * the new connection in your callback handler method.
     */
    void bind(const boost::asio::ip::tcp::endpoint &endpoint, const std::function<void(NetworkConnection&)> &callback);

    /**
     * Listen for incoming connections.
     *
     * This is an overload without the callback, new connections are always accepted.
     */
    void bind(const boost::asio::ip::tcp::endpoint &endpoint);

    /**
     * Listen for incoming connections on an ssl/tls connection.
     * Adds a callback that will be called when a new connection comes in.
     *
     * New connections can be vetted in this callback and you need to call NetworkConnection::accept() on
     * the new connection in your callback handler method.
     *
     * For the certificates you can use an iteration of this:
     * # private key
     * openssl genrsa -out privkey.pem 4096
     * # Create a certificate signing request using your new key
     * openssl req -new -key privkey.pem -out certreq.csr
     * # Self-sign your CSR with your own private key:
     * openssl x509 -req -days 3650 -in certreq.csr -signkey privkey.pem -out newcert.pem
     *
     * We need a DH temp file.
     * openssl dhparam -outform PEM -out DiffieHellman.pem 4096
     *
     * This method takes the actual contents of those files, not the filenames.
     *
     *
     * @param endpoint the interface and port to bind to.
     * @param certificateChain newcert.pem contents
     * @param privateKey privkey.pem contents
     * @param dhTemp the DiffieHellman file contents, may be empty.
     * @param callback the place to vet new connections, calling accept() on the connection.
     */
    void bindSsl(const boost::asio::ip::tcp::endpoint &endpoint,
        const Streaming::ConstBuffer &certificateChain, const Streaming::ConstBuffer &privateKey, const Streaming::ConstBuffer &dhTemp,
        const std::function<void(NetworkConnection&)> &callback);

    void addService(NetworkServiceBase *service);
    void removeService(NetworkServiceBase *service);

    /**
     * @brief setMessageIdLookup allows one to set the p2p legacy mappings for messageIds.
     * This maps from the messageId (Api::P2p::MessageIds) to the string version that is sent on the wire.
     * /see NetworkConnection::setMessageHeaderLegacy()
     */
    void setMessageIdLookup(const std::map<int,std::string> &table);

    /**
     * Set the network Id (sometimes called magic) that is used for legacy p2p messages in the message-header.
     * WARNING: the length is hardcoded to be 4 chars.
     */
    void setLegacyNetworkId(const std::vector<uint8_t> &magic);

    std::weak_ptr<NetworkManagerPrivate> priv(); ///< \internal

private:
    std::shared_ptr<NetworkManagerPrivate> d;
};

#include <Logger.h>

inline Log::Item operator<<(Log::Item item, const boost::asio::ip::tcp::endpoint &ep) {
    if (item.isEnabled()) {
        const bool old = item.useSpace();
        item.nospace() << '[' << ep.address().to_string() << ":" << ep.port() << "]";
        if (old)
            return item.space();
    }
    return item;
}
inline Log::SilentItem operator<<(Log::SilentItem item, const boost::asio::ip::tcp::endpoint&) { return item; }

#endif