//
//  httplib.h
//
//  Copyright (c) 2017 Yuji Hirose. All rights reserved.
//  The Boost Software License 1.0
//

#ifndef _CPPHTTPLIB_HTTPLIB_H_
#define _CPPHTTPLIB_HTTPLIB_H_

#ifdef _MSC_VER
#define _CRT_SECURE_NO_WARNINGS
#define _CRT_NONSTDC_NO_DEPRECATE

#ifndef SO_SYNCHRONOUS_NONALERT
#define SO_SYNCHRONOUS_NONALERT 0x20
#endif
#ifndef SO_OPENTYPE
#define SO_OPENTYPE 0x7008
#endif
#if (_MSC_VER < 1900)
#define snprintf _snprintf_s
#endif

#define S_ISREG(m)  (((m)&S_IFREG)==S_IFREG)
#define S_ISDIR(m)  (((m)&S_IFDIR)==S_IFDIR)

#include <fcntl.h>
#include <io.h>
#include <winsock2.h>
#include <ws2tcpip.h>

#undef min
#undef max

typedef SOCKET socket_t;
#else
#include <pthread.h>
#include <unistd.h>
#include <netdb.h>
#include <cstring>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/socket.h>

typedef int socket_t;
#endif

#include <fstream>
#include <functional>
#include <map>
#include <memory>
#include <regex>
#include <string>
#include <sys/stat.h>
#include <assert.h>

#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
#include <openssl/ssl.h>
#endif

namespace httplib
{

    typedef std::map<std::string, std::string>      Map;
    typedef std::multimap<std::string, std::string> MultiMap;
    typedef std::smatch                             Match;

    struct Request {
        std::string method;
        std::string path;
        MultiMap    headers;
        std::string body;
        Map         params;
        Match       matches;

        bool has_header(const char* key) const;
        std::string get_header_value(const char* key) const;
        void set_header(const char* key, const char* val);

        bool has_param(const char* key) const;
    };

    struct Response {
        int         status;
        MultiMap    headers;
        std::string body;

        bool has_header(const char* key) const;
        std::string get_header_value(const char* key) const;
        void set_header(const char* key, const char* val);

        void set_redirect(const char* url);
        void set_content(const char* s, size_t n, const char* content_type);
        void set_content(const std::string& s, const char* content_type);

        Response() : status(-1) {}
    };

    class Stream {
    public:
        virtual ~Stream() {}
        virtual int read(char* ptr, size_t size) = 0;
        virtual int write(const char* ptr, size_t size1) = 0;
        virtual int write(const char* ptr) = 0;
    };

    class SocketStream : public Stream {
    public:
        SocketStream(socket_t sock);
        virtual ~SocketStream();

        virtual int read(char* ptr, size_t size);
        virtual int write(const char* ptr, size_t size);
        virtual int write(const char* ptr);

    private:
        socket_t sock_;
    };

    class Server {
    public:
        typedef std::function<void (const Request&, Response&)> Handler;
        typedef std::function<void (const Request&, const Response&)> Logger;

        Server();
        virtual ~Server();

        void get(const char* pattern, Handler handler);
        void post(const char* pattern, Handler handler);

        bool set_base_dir(const char* path);

        void set_error_handler(Handler handler);
        void set_logger(Logger logger);

        bool listen(const char* host, int port);
        void stop();

    protected:
        void process_request(Stream& strm);

    private:
        typedef std::vector<std::pair<std::regex, Handler>> Handlers;

        bool routing(Request& req, Response& res);
        bool handle_file_request(Request& req, Response& res);
        bool dispatch_request(Request& req, Response& res, Handlers& handlers);

        bool read_request_line(Stream& strm, Request& req);

        virtual bool read_and_close_socket(socket_t sock);

        socket_t    svr_sock_;
        std::string base_dir_;
        Handlers    get_handlers_;
        Handlers    post_handlers_;
        Handler     error_handler_;
        Logger      logger_;
    };

    class Client {
    public:
        Client(const char* host, int port);
        virtual ~Client();

        std::shared_ptr<Response> get(const char* path);
        std::shared_ptr<Response> head(const char* path);
        std::shared_ptr<Response> post(const char* path, const std::string& body, const char* content_type);
        std::shared_ptr<Response> post(const char* path, const Map& params);

        bool send(const Request& req, Response& res);

    protected:
        bool process_request(Stream& strm, const Request& req, Response& res);

    private:
        bool read_response_line(Stream& strm, Response& res);
        void add_default_headers(Request& req);

        virtual bool read_and_close_socket(socket_t sock, const Request& req, Response& res);

        const std::string host_;
        const int         port_;
    };

#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
    class SSLSocketStream : public Stream {
public:
    SSLSocketStream(SSL* ssl);
    virtual ~SSLSocketStream();

    virtual int read(char* ptr, size_t size);
    virtual int write(const char* ptr, size_t size);
    virtual int write(const char* ptr);

private:
    SSL* ssl_;
};

class SSLServer : public Server {
public:
    SSLServer(const char* cert_path, const char* private_key_path);
    virtual ~SSLServer();

private:
    virtual bool read_and_close_socket(socket_t sock);

    SSL_CTX* ctx_;
};

class SSLClient : public Client {
public:
    SSLClient(const char* host, int port);
    virtual ~SSLClient();

private:
    virtual bool read_and_close_socket(socket_t sock, const Request& req, Response& res);

    SSL_CTX* ctx_;
};
#endif

/*
 * Implementation
 */
    namespace detail {

        template <class Fn>
        void split(const char* b, const char* e, char d, Fn fn)
        {
            int i = 0;
            int beg = 0;

            while (e ? (b + i != e) : (b[i] != '\0')) {
                if (b[i] == d) {
                    fn(&b[beg], &b[i]);
                    beg = i + 1;
                }
                i++;
            }

            if (i) {
                fn(&b[beg], &b[i]);
            }
        }

        inline bool socket_gets(Stream& strm, char* buf, int bufsiz)
        {
            // TODO: buffering for better performance
            size_t i = 0;

            for (;;) {
                char byte;
                auto n = strm.read(&byte, 1);

                if (n < 1) {
                    if (i == 0) {
                        return false;
                    } else {
                        break;
                    }
                }

                buf[i++] = byte;

                if (byte == '\n') {
                    break;
                }
            }

            buf[i] = '\0';
            return true;
        }

        template <typename ...Args>
        inline void socket_printf(Stream& strm, const char* fmt, const Args& ...args)
        {
            char buf[BUFSIZ];
            auto n = snprintf(buf, BUFSIZ, fmt, args...);
            if (n > 0) {
                if (n >= BUFSIZ) {
                    // TODO: buffer size is not large enough...
                } else {
                    strm.write(buf, n);
                }
            }
        }

        inline int close_socket(socket_t sock)
        {
#ifdef _MSC_VER
            return closesocket(sock);
#else
            return close(sock);
#endif
        }

        template <typename T>
        inline bool read_and_close_socket(socket_t sock, T callback)
        {
            SocketStream strm(sock);
            auto ret = callback(strm);
            close_socket(sock);
            return ret;
        }

        inline int shutdown_socket(socket_t sock)
        {
#ifdef _MSC_VER
            return shutdown(sock, SD_BOTH);
#else
            return shutdown(sock, SHUT_RDWR);
#endif
        }

        template <typename Fn>
        socket_t create_socket(const char* host, int port, Fn fn)
        {
#ifdef _MSC_VER
            int opt = SO_SYNCHRONOUS_NONALERT;
    setsockopt(INVALID_SOCKET, SOL_SOCKET, SO_OPENTYPE, (char*)&opt, sizeof(opt));
#endif

            // Get address info
            struct addrinfo hints;
            struct addrinfo *result;

            memset(&hints, 0, sizeof(struct addrinfo));
            hints.ai_family = AF_UNSPEC;
            hints.ai_socktype = SOCK_STREAM;
            hints.ai_flags = 0;
            hints.ai_protocol = 0;

            auto service = std::to_string(port);

            if (getaddrinfo(host, service.c_str(), &hints, &result)) {
                return -1;
            }

            for (auto rp = result; rp; rp = rp->ai_next) {
                // Create a socket
                auto sock = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
                if (sock == -1) {
                    continue;
                }

                // Make 'reuse address' option available
                int yes = 1;
                setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (char*)&yes, sizeof(yes));

                // bind or connect
                if (fn(sock, *rp)) {
                    freeaddrinfo(result);
                    return sock;
                }

                close_socket(sock);
            }

            freeaddrinfo(result);
            return -1;
        }

        inline socket_t create_server_socket(const char* host, int port)
        {
            return create_socket(host, port, [](socket_t sock, struct addrinfo& ai) -> socket_t {
                if (::bind(sock, ai.ai_addr, ai.ai_addrlen)) {
                    return false;
                }
                if (listen(sock, 5)) { // Listen through 5 channels
                    return false;
                }
                return true;
            });
        }

        inline socket_t create_client_socket(const char* host, int port)
        {
            return create_socket(host, port, [](socket_t sock, struct addrinfo& ai) -> socket_t {
                if (connect(sock, ai.ai_addr, ai.ai_addrlen)) {
                    return false;
                }
                return true;
            });
        }

        inline bool is_file(const std::string& s)
        {
            struct stat st;
            return stat(s.c_str(), &st) >= 0 && S_ISREG(st.st_mode);
        }

        inline bool is_dir(const std::string& s)
        {
            struct stat st;
            return stat(s.c_str(), &st) >= 0 && S_ISDIR(st.st_mode);
        }

        inline void read_file(const std::string& path, std::string& out)
        {
            std::ifstream fs(path, std::ios_base::binary);
            fs.seekg(0, std::ios_base::end);
            auto size = fs.tellg();
            fs.seekg(0);
            out.resize(static_cast<size_t>(size));
            fs.read(&out[0], size);
        }

        inline std::string file_extension(const std::string& path)
        {
            std::smatch m;
            auto pat = std::regex("\\.([a-zA-Z0-9]+)$");
            if (std::regex_search(path, m, pat)) {
                return m[1].str();
            }
            return std::string();
        }

        inline const char* content_type(const std::string& path)
        {
            auto ext = detail::file_extension(path);
            if (ext == "txt") {
                return "text/plain";
            } else if (ext == "html") {
                return "text/html";
            } else if (ext == "js") {
                return "text/javascript";
            } else if (ext == "css") {
                return "text/css";
            } else if (ext == "xml") {
                return "text/xml";
            } else if (ext == "jpeg" || ext == "jpg") {
                return "image/jpg";
            } else if (ext == "png") {
                return "image/png";
            } else if (ext == "gif") {
                return "image/gif";
            } else if (ext == "svg") {
                return "image/svg+xml";
            } else if (ext == "ico") {
                return "image/x-icon";
            } else if (ext == "json") {
                return "application/json";
            } else if (ext == "pdf") {
                return "application/pdf";
            } else if (ext == "xhtml") {
                return "application/xhtml+xml";
            }
            return nullptr;
        }

        inline const char* status_message(int status)
        {
            switch (status) {
                case 200: return "OK";
                case 400: return "Bad Request";
                case 404: return "Not Found";
                default:
                case 500: return "Internal Server Error";
            }
        }

        inline const char* get_header_value(const MultiMap& map, const char* key, const char* def)
        {
            auto it = map.find(key);
            if (it != map.end()) {
                return it->second.c_str();
            }
            return def;
        }

        inline int get_header_value_int(const MultiMap& map, const char* key, int def)
        {
            auto it = map.find(key);
            if (it != map.end()) {
                return std::stoi(it->second);
            }
            return def;
        }

        inline bool read_headers(Stream& strm, MultiMap& headers)
        {
            static std::regex re("(.+?): (.+?)\r\n");

            const auto BUFSIZ_HEADER = 2048;
            char buf[BUFSIZ_HEADER];

            for (;;) {
                if (!socket_gets(strm, buf, BUFSIZ_HEADER)) {
                    return false;
                }
                if (!strcmp(buf, "\r\n")) {
                    break;
                }
                std::cmatch m;
                if (std::regex_match(buf, m, re)) {
                    auto key = std::string(m[1]);
                    auto val = std::string(m[2]);
                    headers.insert(std::make_pair(key, val));
                }
            }

            return true;
        }

        template <typename T>
        bool read_content(Stream& strm, T& x)
        {
            auto len = get_header_value_int(x.headers, "Content-Length", 0);
            if (len) {
                x.body.assign(len, 0);
                auto r = 0;
                while (r < len){
                    auto r_incr = strm.read(&x.body[r], len - r);
                    if (r_incr <= 0) {
                        return false;
                    }
                    r += r_incr;
                }
            }
            return true;
        }

        template <typename T>
        inline void write_headers(Stream& strm, const T& res)
        {
            strm.write("Connection: close\r\n");

            for (const auto& x: res.headers) {
                if (x.first != "Content-Type" && x.first != "Content-Length") {
                    socket_printf(strm, "%s: %s\r\n", x.first.c_str(), x.second.c_str());
                }
            }

            auto t = get_header_value(res.headers, "Content-Type", "text/plain");
            socket_printf(strm, "Content-Type: %s\r\n", t);
            socket_printf(strm, "Content-Length: %ld\r\n", res.body.size());
            strm.write("\r\n");
        }

        inline void write_response(Stream& strm, const Request& req, const Response& res)
        {
            socket_printf(strm, "HTTP/1.0 %d %s\r\n", res.status, status_message(res.status));

            write_headers(strm, res);

            if (!res.body.empty() && req.method != "HEAD") {
                strm.write(res.body.c_str(), res.body.size());
            }
        }

        inline std::string encode_url(const std::string& s)
        {
            std::string result;

            for (auto i = 0; s[i]; i++) {
                switch (s[i]) {
                    case ' ':  result += "+"; break;
                    case '\'': result += "%27"; break;
                    case ',':  result += "%2C"; break;
                    case ':':  result += "%3A"; break;
                    case ';':  result += "%3B"; break;
                    default:
                        if (s[i] < 0) {
                            result += '%';
                            char hex[4];
                            size_t len = snprintf(hex, sizeof(hex), "%02X", (unsigned char)s[i]);
                            assert(len == 2);
                            result.append(hex, len);
                        } else {
                            result += s[i];
                        }
                        break;
                }
            }

            return result;
        }

        inline bool is_hex(char c, int& v)
        {
            if (0x20 <= c && isdigit(c)) {
                v = c - '0';
                return true;
            } else if ('A' <= c && c <= 'F') {
                v = c - 'A' + 10;
                return true;
            } else if ('a' <= c && c <= 'f') {
                v = c - 'a' + 10;
                return true;
            }
            return false;
        }

        inline int from_hex_to_i(const std::string& s, int i, int cnt, int& val)
        {
            val = 0;
            for (; s[i] && cnt; i++, cnt--) {
                int v = 0;
                if (is_hex(s[i], v)) {
                    val = val * 16 + v;
                } else {
                    break;
                }
            }
            return --i;
        }

        inline size_t to_utf8(int code, char* buff)
        {
            if (code < 0x0080) {
                buff[0] = (code & 0x7F);
                return 1;
            } else if (code < 0x0800) {
                buff[0] = (0xC0 | ((code >> 6) & 0x1F));
                buff[1] = (0x80 | (code & 0x3F));
                return 2;
            } else if (code < 0xD800) {
                buff[0] = (0xE0 | ((code >> 12) & 0xF));
                buff[1] = (0x80 | ((code >> 6) & 0x3F));
                buff[2] = (0x80 | (code & 0x3F));
                return 3;
            } else if (code < 0xE000)  { // D800 - DFFF is invalid...
                return 0;
            } else if (code < 0x10000) {
                buff[0] = (0xE0 | ((code >> 12) & 0xF));
                buff[1] = (0x80 | ((code >> 6) & 0x3F));
                buff[2] = (0x80 | (code & 0x3F));
                return 3;
            } else if (code < 0x110000) {
                buff[0] = (0xF0 | ((code >> 18) & 0x7));
                buff[1] = (0x80 | ((code >> 12) & 0x3F));
                buff[2] = (0x80 | ((code >> 6) & 0x3F));
                buff[3] = (0x80 | (code & 0x3F));
                return 4;
            }

            // NOTREACHED
            return 0;
        }

        inline std::string decode_url(const std::string& s)
        {
            std::string result;

            for (int i = 0; s[i]; i++) {
                if (s[i] == '%') {
                    i++;
                    assert(s[i]);

                    if (s[i] == '%') {
                        result += s[i];
                    } else if (s[i] == 'u') {
                        // Unicode
                        i++;
                        assert(s[i]);

                        int val = 0;
                        i = from_hex_to_i(s, i, 4, val);

                        char buff[4];
                        size_t len = to_utf8(val, buff);

                        if (len > 0) {
                            result.append(buff, len);
                        }
                    } else {
                        // HEX
                        int val = 0;
                        i = from_hex_to_i(s, i, 2, val);
                        result += val;
                    }
                } else if (s[i] == '+') {
                    result += ' ';
                } else {
                    result += s[i];
                }
            }

            return result;
        }

        inline void write_request(Stream& strm, const Request& req)
        {
            auto path = encode_url(req.path);
            socket_printf(strm, "%s %s HTTP/1.0\r\n", req.method.c_str(), path.c_str());

            write_headers(strm, req);

            if (!req.body.empty()) {
                if (req.has_header("application/x-www-form-urlencoded")) {
                    auto str = encode_url(req.body);
                    strm.write(str.c_str(), str.size());
                } else {
                    strm.write(req.body.c_str(), req.body.size());
                }
            }
        }

        inline void parse_query_text(const std::string& s, Map& params)
        {
            split(&s[0], &s[s.size()], '&', [&](const char* b, const char* e) {
                std::string key;
                std::string val;
                split(b, e, '=', [&](const char* b, const char* e) {
                    if (key.empty()) {
                        key.assign(b, e);
                    } else {
                        val.assign(b, e);
                    }
                });
                params[key] = detail::decode_url(val);
            });
        }

#ifdef _MSC_VER
        class WSInit {
public:
    WSInit() {
        WSADATA wsaData;
        WSAStartup(0x0002, &wsaData);
    }

    ~WSInit() {
        WSACleanup();
    }
};

static WSInit wsinit_;
#endif

    } // namespace detail

// Request implementation
    inline bool Request::has_header(const char* key) const
    {
        return headers.find(key) != headers.end();
    }

    inline std::string Request::get_header_value(const char* key) const
    {
        return detail::get_header_value(headers, key, "");
    }

    inline void Request::set_header(const char* key, const char* val)
    {
        headers.insert(std::make_pair(key, val));
    }

    inline bool Request::has_param(const char* key) const
    {
        return params.find(key) != params.end();
    }

// Response implementation
    inline bool Response::has_header(const char* key) const
    {
        return headers.find(key) != headers.end();
    }

    inline std::string Response::get_header_value(const char* key) const
    {
        return detail::get_header_value(headers, key, "");
    }

    inline void Response::set_header(const char* key, const char* val)
    {
        headers.insert(std::make_pair(key, val));
    }

    inline void Response::set_redirect(const char* url)
    {
        set_header("Location", url);
        status = 302;
    }

    inline void Response::set_content(const char* s, size_t n, const char* content_type)
    {
        body.assign(s, n);
        set_header("Content-Type", content_type);
    }

    inline void Response::set_content(const std::string& s, const char* content_type)
    {
        body = s;
        set_header("Content-Type", content_type);
    }

// Socket stream implementation
    inline SocketStream::SocketStream(socket_t sock): sock_(sock)
    {
    }

    inline SocketStream::~SocketStream()
    {
    }

    inline int SocketStream::read(char* ptr, size_t size)
    {
        return recv(sock_, ptr, size, 0);
    }

    inline int SocketStream::write(const char* ptr, size_t size)
    {
        return send(sock_, ptr, size, 0);
    }

    inline int SocketStream::write(const char* ptr)
    {
        return write(ptr, strlen(ptr));
    }

// HTTP server implementation
    inline Server::Server()
            : svr_sock_(-1)
    {
    }

    inline Server::~Server()
    {
    }

    inline void Server::get(const char* pattern, Handler handler)
    {
        get_handlers_.push_back(std::make_pair(std::regex(pattern), handler));
    }

    inline void Server::post(const char* pattern, Handler handler)
    {
        post_handlers_.push_back(std::make_pair(std::regex(pattern), handler));
    }

    inline bool Server::set_base_dir(const char* path)
    {
        if (detail::is_dir(path)) {
            base_dir_ = path;
            return true;
        }
        return false;
    }

    inline void Server::set_error_handler(Handler handler)
    {
        error_handler_ = handler;
    }

    inline void Server::set_logger(Logger logger)
    {
        logger_ = logger;
    }

    inline bool Server::listen(const char* host, int port)
    {
        svr_sock_ = detail::create_server_socket(host, port);
        if (svr_sock_ == -1) {
            return false;
        }

        auto ret = true;

        for (;;) {
            socket_t sock = accept(svr_sock_, NULL, NULL);

            if (sock == -1) {
                if (svr_sock_ != -1) {
                    detail::close_socket(svr_sock_);
                    ret = false;
                } else {
                    ; // The server socket was closed by user.
                }
                break;
            }

            // TODO: should be async
            read_and_close_socket(sock);
        }

        return ret;
    }

    inline void Server::stop()
    {
        detail::shutdown_socket(svr_sock_);
        detail::close_socket(svr_sock_);
        svr_sock_ = -1;
    }

    inline bool Server::read_request_line(Stream& strm, Request& req)
    {
        const auto BUFSIZ_REQUESTLINE = 2048;
        char buf[BUFSIZ_REQUESTLINE];
        if (!detail::socket_gets(strm, buf, BUFSIZ_REQUESTLINE)) {
            return false;
        }

        static std::regex re("(GET|HEAD|POST) ([^?]+)(?:\\?(.+?))? HTTP/1\\.[01]\r\n");

        std::cmatch m;
        if (std::regex_match(buf, m, re)) {
            req.method = std::string(m[1]);
            req.path = detail::decode_url(m[2]);

            // Parse query text
            auto len = std::distance(m[3].first, m[3].second);
            if (len > 0) {
                detail::parse_query_text(m[3], req.params);
            }

            return true;
        }

        return false;
    }

    inline bool Server::handle_file_request(Request& req, Response& res)
    {
        if (!base_dir_.empty()) {
            std::string path = base_dir_ + req.path;

            if (!path.empty() && path.back() == '/') {
                path += "index.html";
            }

            if (detail::is_file(path)) {
                detail::read_file(path, res.body);
                auto type = detail::content_type(path);
                if (type) {
                    res.set_header("Content-Type", type);
                }
                res.status = 200;
                return true;
            }
        }

        return false;
    }

    inline bool Server::routing(Request& req, Response& res)
    {
        if (req.method == "GET" && handle_file_request(req, res)) {
            return true;
        }

        if (req.method == "GET" || req.method == "HEAD") {
            return dispatch_request(req, res, get_handlers_);
        } else if (req.method == "POST") {
            return dispatch_request(req, res, post_handlers_);
        }
        return false;
    }

    inline bool Server::dispatch_request(Request& req, Response& res, Handlers& handlers)
    {
        for (const auto& x: handlers) {
            const auto& pattern = x.first;
            const auto& handler = x.second;

            if (std::regex_match(req.path, req.matches, pattern)) {
                handler(req, res);
                return true;
            }
        }
        return false;
    }

    inline void Server::process_request(Stream& strm)
    {
        Request req;
        Response res;

        if (!read_request_line(strm, req) ||
            !detail::read_headers(strm, req.headers)) {
            // TODO:
            return;
        }

        if (req.method == "POST") {
            if (!detail::read_content(strm, req)) {
                // TODO:
                return;
            }
            static std::string type = "application/x-www-form-urlencoded";
            if (!req.get_header_value("Content-Type").compare(0, type.size(), type)) {
                detail::parse_query_text(req.body, req.params);
            }
        }

        if (routing(req, res)) {
            if (res.status == -1) {
                res.status = 200;
            }
        } else {
            res.status = 404;
        }
        assert(res.status != -1);

        if (400 <= res.status && error_handler_) {
            error_handler_(req, res);
        }

        detail::write_response(strm, req, res);

        if (logger_) {
            logger_(req, res);
        }
    }

    inline bool Server::read_and_close_socket(socket_t sock)
    {
        return detail::read_and_close_socket(sock, [this](Stream& strm) {
            process_request(strm);
            return true;
        });
    }

// HTTP client implementation
    inline Client::Client(const char* host, int port)
            : host_(host)
            , port_(port)
    {
    }

    inline Client::~Client()
    {
    }

    inline bool Client::read_response_line(Stream& strm, Response& res)
    {
        const auto BUFSIZ_RESPONSELINE = 2048;
        char buf[BUFSIZ_RESPONSELINE];
        if (!detail::socket_gets(strm, buf, BUFSIZ_RESPONSELINE)) {
            return false;
        }

        const static std::regex re("HTTP/1\\.[01] (\\d+?) .+\r\n");

        std::cmatch m;
        if (std::regex_match(buf, m, re)) {
            res.status = std::stoi(std::string(m[1]));
        }

        return true;
    }

    inline bool Client::send(const Request& req, Response& res)
    {
        auto sock = detail::create_client_socket(host_.c_str(), port_);
        if (sock == -1) {
            return false;
        }

        return read_and_close_socket(sock, req, res);
    }

    inline bool Client::process_request(Stream& strm, const Request& req, Response& res)
    {
        // Send request
        detail::write_request(strm, req);

        // Receive response
        if (!read_response_line(strm, res) ||
            !detail::read_headers(strm, res.headers)) {
            return false;
        }
        if (req.method != "HEAD") {
            if (!detail::read_content(strm, res)) {
                return false;
            }
        }

        return true;
    }

    inline bool Client::read_and_close_socket(socket_t sock, const Request& req, Response& res)
    {
        return detail::read_and_close_socket(sock, [&](Stream& strm) {
            return process_request(strm, req, res);
        });
    }

    inline void Client::add_default_headers(Request& req)
    {
        req.set_header("Host", host_.c_str());
        req.set_header("Accept", "*/*");
        req.set_header("User-Agent", "cpp-httplib/0.1");
    }

    inline std::shared_ptr<Response> Client::get(const char* path)
    {
        Request req;
        req.method = "GET";
        req.path = path;
        add_default_headers(req);

        auto res = std::make_shared<Response>();

        return send(req, *res) ? res : nullptr;
    }

    inline std::shared_ptr<Response> Client::head(const char* path)
    {
        Request req;
        req.method = "HEAD";
        req.path = path;
        add_default_headers(req);

        auto res = std::make_shared<Response>();

        return send(req, *res) ? res : nullptr;
    }

    inline std::shared_ptr<Response> Client::post(
            const char* path, const std::string& body, const char* content_type)
    {
        Request req;
        req.method = "POST";
        req.path = path;
        add_default_headers(req);

        req.set_header("Content-Type", content_type);
        req.body = body;

        auto res = std::make_shared<Response>();

        return send(req, *res) ? res : nullptr;
    }

    inline std::shared_ptr<Response> Client::post(
            const char* path, const Map& params)
    {
        std::string query;
        for (auto it = params.begin(); it != params.end(); ++it) {
            if (it != params.begin()) {
                query += "&";
            }
            query += it->first;
            query += "=";
            query += it->second;
        }

        return post(path, query, "application/x-www-form-urlencoded");
    }

/*
 * SSL Implementation
 */
#ifdef CPPHTTPLIB_OPENSSL_SUPPORT
    namespace detail {

template <typename U, typename T>
inline bool read_and_close_socket_ssl(socket_t sock, SSL_CTX* ctx, U SSL_connect_or_accept, T callback)
{
    auto ssl = SSL_new(ctx);

    auto bio = BIO_new_socket(sock, BIO_NOCLOSE);
    SSL_set_bio(ssl, bio, bio);

    SSL_connect_or_accept(ssl);

    SSLSocketStream strm(ssl);
    auto ret = callback(strm);

    SSL_shutdown(ssl);
    SSL_free(ssl);
    close_socket(sock);
    return ret;
}

class SSLInit {
public:
    SSLInit() {
        SSL_load_error_strings();
        SSL_library_init();
    }
};

static SSLInit sslinit_;

} // namespace detail

// SSL socket stream implementation
inline SSLSocketStream::SSLSocketStream(SSL* ssl): ssl_(ssl)
{
}

inline SSLSocketStream::~SSLSocketStream()
{
}

inline int SSLSocketStream::read(char* ptr, size_t size)
{
    return SSL_read(ssl_, ptr, size);
}

inline int SSLSocketStream::write(const char* ptr, size_t size)
{
    return SSL_write(ssl_, ptr, size);
}

inline int SSLSocketStream::write(const char* ptr)
{
    return write(ptr, strlen(ptr));
}

// SSL HTTP server implementation
inline SSLServer::SSLServer(const char* cert_path, const char* private_key_path)
{
    ctx_ = SSL_CTX_new(SSLv23_server_method());

    if (ctx_) {
        SSL_CTX_set_options(ctx_,
                            SSL_OP_ALL | SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3 |
                            SSL_OP_NO_COMPRESSION |
                            SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION);

        // auto ecdh = EC_KEY_new_by_curve_name(NID_X9_62_prime256v1);
        // SSL_CTX_set_tmp_ecdh(ctx_, ecdh);
        // EC_KEY_free(ecdh);

        if (SSL_CTX_use_certificate_file(ctx_, cert_path, SSL_FILETYPE_PEM) != 1 ||
            SSL_CTX_use_PrivateKey_file(ctx_, private_key_path, SSL_FILETYPE_PEM) != 1) {
            SSL_CTX_free(ctx_);
            ctx_ = nullptr;
        }
    }
}

inline SSLServer::~SSLServer()
{
    if (ctx_) {
        SSL_CTX_free(ctx_);
    }
}

inline bool SSLServer::read_and_close_socket(socket_t sock)
{
    return detail::read_and_close_socket_ssl(sock, ctx_, SSL_accept, [this](Stream& strm) {
        process_request(strm);
        return true;
    });
}

// SSL HTTP client implementation
inline SSLClient::SSLClient(const char* host, int port)
    : Client(host, port)
{
    ctx_ = SSL_CTX_new(SSLv23_client_method());
}

inline SSLClient::~SSLClient()
{
    if (ctx_) {
        SSL_CTX_free(ctx_);
    }
}

inline bool SSLClient::read_and_close_socket(socket_t sock, const Request& req, Response& res)
{
    return detail::read_and_close_socket_ssl(sock, ctx_, SSL_connect, [&](Stream& strm) {
        return process_request(strm, req, res);
    });
}
#endif

} // namespace httplib

#endif

// vim: et ts=4 sw=4 cin cino={1s ff=unix