#include "WebSocketSignalSession.h"
#include "SignalServer.h"
#include "StringUtility.h"
#include <boost/json/parse.hpp>
#include <boost/json/serialize.hpp>

WebSocketSignalSession::WebSocketSignalSession(boost::asio::ip::tcp::socket &&socket) : m_ws(std::move(socket)) {
}

WebSocketSignalSession::~WebSocketSignalSession() {
    auto server = Amass::Singleton<SignalServer>::instance();
    server->leave(m_id);
}

void WebSocketSignalSession::onAccept(boost::beast::error_code ec) {
    if (ec) {
        if (ec == boost::asio::error::operation_aborted || ec == boost::beast::websocket::error::closed) return;
        std::cerr << "accept: " << ec.message() << "\n";
        return;
    }
    LOG(info) << "accept websocket target: " << m_target;
    if (m_target.find("/webrtc") == 0) {
        auto splits = Amass::StringUtility::split(m_target, "/");
        if (!splits.empty()) m_id = splits.back();
    }

    auto server = Amass::Singleton<SignalServer>::instance();
    server->join(m_id, this);

    // Read a message
    m_ws.async_read(m_buffer, boost::beast::bind_front_handler(&WebSocketSignalSession::on_read, shared_from_this()));
}

void WebSocketSignalSession::on_read(boost::beast::error_code ec, std::size_t) {
    // Handle the error, if any
    if (ec) {
        // Don't report these
        if (ec == boost::asio::error::operation_aborted || ec == boost::beast::websocket::error::closed) return;
        LOG(error) << "read: " << ec.message();
        return;
    }
    auto message = boost::beast::buffers_to_string(m_buffer.data());
    LOG(info) << message;
    auto rootObject = boost::json::parse(message);
    auto &root = rootObject.as_object();
    if (root.contains("id")) {
        if (!root.at("id").is_string()) {
            LOG(warning) << "wrong format.";
            m_ws.close(boost::beast::websocket::close_code::normal);
            return;
        }
        auto server = Amass::Singleton<SignalServer>::instance();
        auto destinationId = std::string(root["id"].as_string());
        auto destination = server->client(destinationId);
        if (destination == nullptr) {
            LOG(info) << "client " << destinationId << " not found.";
        } else {
            root["id"] = m_id;
            auto reply = std::make_shared<std::string>(boost::json::serialize(root));
            destination->send(reply);
        }
    }
    m_buffer.consume(m_buffer.size()); // Clear the buffer
    m_ws.async_read(m_buffer, boost::beast::bind_front_handler(&WebSocketSignalSession::on_read, shared_from_this()));
}

void WebSocketSignalSession::send(std::shared_ptr<std::string const> const &ss) {
    // Post our work to the strand, this ensures
    // that the members of `this` will not be
    // accessed concurrently.
    m_ws.text();
    boost::asio::post(m_ws.get_executor(),
                      boost::beast::bind_front_handler(&WebSocketSignalSession::onSend, shared_from_this(), ss));
}

void WebSocketSignalSession::onSend(std::shared_ptr<std::string const> const &ss) {
    // Always add to queue
    m_queue.push_back(ss);

    // Are we already writing?
    if (m_queue.size() > 1) return;

    // We are not currently writing, so send this immediately
    m_ws.async_write(boost::asio::buffer(*m_queue.front()),
                     boost::beast::bind_front_handler(&WebSocketSignalSession::on_write, shared_from_this()));
}

void WebSocketSignalSession::on_write(boost::beast::error_code ec, std::size_t) {
    // Handle the error, if any
    if (ec) {
        // Don't report these
        if (ec == boost::asio::error::operation_aborted || ec == boost::beast::websocket::error::closed) return;
        std::cerr << "write: " << ec.message() << "\n";
        return;
    }

    // Remove the string from the queue
    m_queue.erase(m_queue.begin());
    if (!m_queue.empty())
        m_ws.async_write(boost::asio::buffer(*m_queue.front()),
                         boost::beast::bind_front_handler(&WebSocketSignalSession::on_write, shared_from_this()));
}