#include "Client.h"

#include "BoostLog.h"
#include <boost/json/object.hpp>
#include <boost/json/parse.hpp>
#include <boost/json/serialize.hpp>
#include <random>
#include <rtc/rtc.hpp>

class ClientPrivate {
public:
    Client *p = nullptr;
    rtc::Configuration config;
    std::shared_ptr<rtc::WebSocket> ws;
    std::unordered_map<std::string, std::shared_ptr<rtc::PeerConnection>> peerConnectionMap;
    std::unordered_map<std::string, std::shared_ptr<rtc::DataChannel>> dataChannelMap;
    std::shared_ptr<rtc::DataChannel> m_sender;
    ClientPrivate(Client *p) : p(p) {
    }
    std::shared_ptr<rtc::PeerConnection> createPeerConnection(const rtc::Configuration &config, std::weak_ptr<rtc::WebSocket> wws,
                                                              std::string id) {
        auto pc = std::make_shared<rtc::PeerConnection>(config);
        pc->onStateChange([](rtc::PeerConnection::State state) { LOG(info) << "State: " << state; });
        pc->onGatheringStateChange([](rtc::PeerConnection::GatheringState state) { LOG(info) << "Gathering State: " << state; });
        pc->onLocalDescription([wws, id](rtc::Description description) {
            boost::json::object message;
            message["id"] = id;
            message["type"] = description.typeString();
            message["description"] = std::string(description);
            if (auto ws = wws.lock()) ws->send(boost::json::serialize(message));
        });
        pc->onLocalCandidate([wws, id](rtc::Candidate candidate) {
            boost::json::object message;
            message["id"] = id;
            message["type"] = "candidate";
            message["candidate"] = std::string(candidate);
            message["mid"] = candidate.mid();
            if (auto ws = wws.lock()) ws->send(boost::json::serialize(message));
        });
        pc->onDataChannel([this, id](std::shared_ptr<rtc::DataChannel> dc) {
            LOG(info) << "DataChannel from " << id << " received with label \"" << dc->label() << "\"";

            dc->onOpen([this, wdc = std::weak_ptr(dc)]() {
                if (auto dc = wdc.lock()) dc->send("Hello from " + p->m_id);
            });

            dc->onClosed([id]() { LOG(info) << "DataChannel from " << id << " closed"; });

            dc->onMessage([this, id](auto data) {
                // data holds either std::string or rtc::binary
                if (std::holds_alternative<std::string>(data)) {
                    LOG(info) << "Message from " << id << " received: " << std::get<std::string>(data);
                    p->log(std::format("{}: {}", id, std::get<std::string>(data)));
                } else
                    LOG(info) << "Binary message from " << id << " received, size=" << std::get<rtc::binary>(data).size();
            });
            dataChannelMap.emplace(id, dc);
        });
        peerConnectionMap.emplace(id, pc);
        return pc;
    }
};

bool Client::sendMessage(const std::string &message) {
    bool ret = false;
    if (m_d->m_sender) {
        ret = m_d->m_sender->send(message);
    }
    return ret;
}

bool Client::setRemoteId(const std::string &id) {
    bool ret = false;
    if (id.empty() || !m_d->ws->isOpen()) return ret;
    if (id == m_id) {
        LOG(error) << "Invalid remote ID (This is the local ID)";
        log("Invalid remote ID (This is the local ID)");
        return ret;
    }
    LOG(info) << "Offering to " << id;
    log(std::format("Offering to {}", id));
    auto pc = m_d->createPeerConnection(m_d->config, m_d->ws, id);

    // We are the offerer, so create a data channel to initiate the process
    const std::string label = "test";
    LOG(info) << "Creating DataChannel with label \"" << label << "\"";
    log(std::format("Creating DataChannel with label \"{}\"", label));
    m_d->m_sender = pc->createDataChannel(label);
    m_d->m_sender->onOpen([this, id, wdc = std::weak_ptr(m_d->m_sender)]() {
        LOG(info) << "DataChannel from " << id << " open";
        if (auto dc = wdc.lock()) dc->send("Hello from " + m_id);
    });
    m_d->m_sender->onClosed([id]() { LOG(info) << "DataChannel from " << id << " closed"; });
    m_d->m_sender->onMessage([this, id, wdc = std::weak_ptr(m_d->m_sender)](auto data) {
        // data holds either std::string or rtc::binary
        if (std::holds_alternative<std::string>(data)) {
            LOG(info) << "Message from " << id << " received: " << std::get<std::string>(data);
            log(std::format("{}: {}", id, std::get<std::string>(data)));
        } else
            LOG(info) << "Binary message from " << id << " received, size=" << std::get<rtc::binary>(data).size();
    });
    m_d->dataChannelMap.emplace(id, m_d->m_sender);
    ret = true;
    return ret;
}

std::string Client::randomId(size_t length) {
    using std::chrono::high_resolution_clock;
    static thread_local std::mt19937 rng(static_cast<unsigned int>(high_resolution_clock::now().time_since_epoch().count()));
    static const std::string characters("0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz");
    std::string id(length, '0');
    std::uniform_int_distribution<int> uniform(0, int(characters.size() - 1));
    std::generate(id.begin(), id.end(), [&]() { return characters.at(uniform(rng)); });
    return id;
}

Client::Client() : m_d{new ClientPrivate(this)} {
    rtc::InitLogger(rtc::LogLevel::Info);
    m_d->config.iceServers.emplace_back("stun:amass.fun:5439");
    m_d->config.iceServers.emplace_back(rtc::IceServer("amass.fun", 5439, "amass", "88888888"));
    m_id = randomId(4);
    LOG(info) << "The local ID is " << m_id;
    log(std::format("The local ID is {}", m_id));

    m_d->ws = std::make_shared<rtc::WebSocket>();

    m_d->ws->onOpen([this]() {
        LOG(info) << "WebSocket connected, signaling ready";
        log("WebSocket connected, signaling ready");
    });
    m_d->ws->onError([this](std::string s) {
        LOG(error) << "WebSocket error: " << s;
        log(std::format("WebSocket error: {}", s));
    });
    m_d->ws->onClosed([]() { LOG(info) << "WebSocket closed"; });
    m_d->ws->onMessage([this](auto data) {
        if (!std::holds_alternative<std::string>(data)) return;
        auto jsonValue = boost::json::parse(std::get<std::string>(data));
        auto &json = jsonValue.as_object();
        if (!json.contains("id") || !json.contains("type")) {
            return;
        }
        auto id = static_cast<std::string>(json.at("id").as_string());
        auto type = static_cast<std::string>(json.at("type").as_string());

        std::shared_ptr<rtc::PeerConnection> pc;
        if (auto jt = m_d->peerConnectionMap.find(id); jt != m_d->peerConnectionMap.end()) {
            pc = jt->second;
        } else if (type == "offer") {
            std::cout << "Answering to " + id << std::endl;
            pc = m_d->createPeerConnection(m_d->config, m_d->ws, id);
        } else {
            return;
        }
        if (type == "offer" || type == "answer") {
            auto sdp = static_cast<std::string>(json.at("description").as_string());
            pc->setRemoteDescription(rtc::Description(sdp, type));
        } else if (type == "candidate") {
            auto sdp = static_cast<std::string>(json.at("candidate").as_string());
            auto mid = static_cast<std::string>(json.at("mid").as_string());
            pc->addRemoteCandidate(rtc::Candidate(sdp, mid));
        }
    });

    const std::string url = std::format("ws://127.0.0.1:8081/api/v1/webrtc/signal/{}", m_id);
    LOG(info) << "WebSocket URL is " << url;
    log(std::format("WebSocket URL is {}", url));
    m_d->ws->open(url);

    LOG(info) << "Waiting for signaling to be connected...";
    log("Waiting for signaling to be connected...");
}

Client::~Client() {
    LOG(info) << "Cleaning up...";
    if (m_d != nullptr) {
        delete m_d;
        m_d = nullptr;
    }
}

std::string Client::id() const {
    return m_id;
}

void Client::log(const std::string &message) {
    m_oss << message << std::endl;
}

std::string Client::log() const {
    return m_oss.str();
}