/**
 * Copyright (c) 2018 Cornell University.
 *
 * Author: Ted Yin <tederminant@gmail.com>
 *
 * 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 <cstdio>
#include <string>
#include <functional>

#include "salticidae/msg.h"
#include "salticidae/event.h"
#include "salticidae/network.h"
#include "salticidae/stream.h"

using salticidae::NetAddr;
using salticidae::DataStream;
using salticidae::MsgNetwork;
using salticidae::htole;
using salticidae::letoh;
using std::placeholders::_1;
using std::placeholders::_2;

/** Hello Message. */
struct MsgHello {
    static const uint8_t opcode = 0x0;
    DataStream serialized;
    std::string name;
    std::string text;
    /** Defines how to serialize the msg. */
    MsgHello(const std::string &name,
            const std::string &text) {
        serialized << htole((uint32_t)name.length());
        serialized << name << text;
    }
    /** Defines how to parse the msg. */
    MsgHello(DataStream &&s) {
        uint32_t len;
        s >> len;
        len = letoh(len);
        name = std::string((const char *)s.get_data_inplace(len), len);
        len = s.size();
        text = std::string((const char *)s.get_data_inplace(len), len);
    }
};

/** Acknowledgement Message. */
struct MsgAck {
    static const uint8_t opcode = 0x1;
    DataStream serialized;
    MsgAck() {}
    MsgAck(DataStream &&s) {}
};

const uint8_t MsgHello::opcode;
const uint8_t MsgAck::opcode;

using MsgNetworkByteOp = MsgNetwork<uint8_t>;

struct MyNet: public MsgNetworkByteOp {
    const std::string name;
    const salticidae::uint256_t peer_footprint;
    const NetAddr peer;

    MyNet(const salticidae::EventContext &ec,
            const std::string &name,
            const std::string &peer_footprint_hex,
            const NetAddr &peer):
            MsgNetwork<uint8_t>(ec, MsgNetwork::Config(
                ConnPool::Config()
                    .enable_tls(true)
                    .tls_cert_file(name + ".pem")
                    .tls_key_file(name + ".pem")
            )),
            name(name),
            peer_footprint(salticidae::from_hex(peer_footprint_hex)),
            peer(peer) {
        /* message handler could be a bound method */
        reg_handler(
            salticidae::generic_bind(&MyNet::on_receive_hello, this, _1, _2));

        reg_conn_handler([this](const ConnPool::conn_t &conn, bool connected) {
            bool res = true;
            if (connected)
            {
                auto cert_der = salticidae::get_hash(conn->get_peer_cert()->get_der());
                res = peer_footprint == cert_der;
                if (conn->get_mode() == ConnPool::Conn::ACTIVE)
                {
                    printf("[%s] Connected, sending hello.\n",
                            this->name.c_str());
                    /* send the first message through this connection */
                    send_msg(MsgHello(this->name, "Hello there!"),
                            salticidae::static_pointer_cast<Conn>(conn));
                }
                else
                {
                    printf("[%s] Accepted, waiting for greetings.\n"
                           "The peer certificate footprint is %s (%s).\n",
                            this->name.c_str(), salticidae::get_hex(cert_der).c_str(),
                            res ? "ok" : "fail");
                }
            }
            else
            {
                printf("[%s] Disconnected, retrying.\n", this->name.c_str());
                /* try to reconnect to the same address */
                connect(conn->get_addr(), false);
            }
            return res;
        });
    }

    void on_receive_hello(MsgHello &&msg, const MyNet::conn_t &conn) {
        printf("[%s] %s says %s\n",
                name.c_str(),
                msg.name.c_str(), msg.text.c_str());
        /* send acknowledgement */
        send_msg(MsgAck(), conn);
    }
};


void on_receive_ack(MsgAck &&msg, const MyNet::conn_t &conn) {
    auto net = static_cast<MyNet *>(conn->get_net());
    printf("[%s] the peer knows\n", net->name.c_str());
}

int main() {
    salticidae::EventContext ec;
    NetAddr alice_addr("127.0.0.1:12345");
    NetAddr bob_addr("127.0.0.1:12346");

    /* test two nodes in the same main loop */
    MyNet alice(ec, "alice", "ed5a9a8c7429dcb235a88244bc69d43d16b35008ce49736b27aaa3042a674043", bob_addr);
    MyNet bob(ec, "bob", "ef3bea4e72f4d0e85da7643545312e2ff6dded5e176560bdffb1e53b1cef4896", alice_addr);

    /* message handler could be a normal function */
    alice.reg_handler(on_receive_ack);
    bob.reg_handler(on_receive_ack);

    /* start all threads */
    alice.start();
    bob.start();

    /* accept incoming connections */
    alice.listen(alice_addr);
    bob.listen(bob_addr);

    /* try to connect once */
    alice.connect(bob_addr);
    bob.connect(alice_addr);

    /* the main loop can be shutdown by ctrl-c or kill */
    auto shutdown = [&](int) {ec.stop();};
    salticidae::SigEvent ev_sigint(ec, shutdown);
    salticidae::SigEvent ev_sigterm(ec, shutdown);
    ev_sigint.add(SIGINT);
    ev_sigterm.add(SIGTERM);

    /* enter the main loop */
    ec.dispatch();
    return 0;
}