WebServerConnector.hpp

#pragma once
#include <samchon/API.hpp>

#include <samchon/protocol/ServerConnector.hpp>
#include <samchon/protocol/WebCommunicator.hpp>

#include <map>
#include <samchon/library/RWMutex.hpp>
#include <samchon/library/StringUtil.hpp>

namespace samchon
{
namespace protocol
{
    class WebServerConnector
        : public ServerConnector,
        public WebCommunicator
    {
    private:
        typedef ServerConnector super;

        static std::map<std::pair<std::string, int>, std::string> s_cookies;
        static library::RWMutex s_mtx;

    public:
        WebServerConnector(IProtocol *listener)
            : super(listener),
            WebCommunicator(false)
        {
        };
        virtual ~WebServerConnector() = default;

        virtual void connect(const std::string &ip, int port) override
        {
            connect(ip, port, "");
        };
        
        virtual void connect(const std::string &ip, int port, const std::string &path)
        {
            _Connect(ip, port);

            handshake(ip, port, path);

            listen_message();
        };

    private:
        void handshake(const std::string &ip, int port, const std::string &path)
        {
            // SEND HEADER
            // CERTIFICATION KEY
            std::string &base64_key = WebSocketUtil::generate_base64_certification_key();
            std::string &sha1_key = WebSocketUtil::encode_certification_key(base64_key);

            // COOKIE
            std::string cookie;
            {
                library::UniqueReadLock uk(s_mtx);
                auto it = s_cookies.find({ ip, port });

                if (it != s_cookies.end())
                    cookie = "Cookie: " + it->second + "\r\n";
            }

            // SEND
            std::string &query = library::StringUtil::substitute
            (
                std::string("") +
                "GET {1} HTTP/1.1\r\n" + //path
                "Host: {2}\r\n" + //ip:port
                "Upgrade: websocket\r\n" +
                "Connection: Upgrade\r\n" +
                "{3}" + // cookie
                "Sec-WebSocket-Key: {4}\r\n" + // hashed certification key
                "Sec-WebSocket-Version: 13\r\n" +
                "\r\n",

                path.empty() ? "/" : "/" + path,
                ip + ":" + std::to_string(port),
                cookie,
                base64_key
            );
            socket->write_some(boost::asio::buffer(query.data(), query.size()));

            // LISTEN HEADER
            std::array<unsigned char, 1000> byte_array;
            size_t size = socket->read_some(boost::asio::buffer(byte_array));

            WeakString wstr((const char*)byte_array.data(), size);
            std::string server_sha1 = wstr.between("Sec-WebSocket-Accept: ", "\r\n").str();

            // INSPECT VALIDITY
            if (sha1_key != server_sha1)
                throw std::domain_error("WebSocket handshaking has failed.");

            // SET-COOKIE
            if (wstr.find("Set-Cookie: ") != std::string::npos)
            {
                WeakString set_cookie = wstr.between("Set-Cookie: ", "\r\n");
                library::UniqueWriteLock uk(s_mtx);

                s_cookies[{ip, port}] = set_cookie.str();
            }
        };
    };
};
};