//------------------------------------------------------------------------------
/*
    This file is part of clio: https://github.com/XRPLF/clio
    Copyright (c) 2023, the clio developers.

    Permission to use, copy, modify, and distribute this software for any
    purpose with or without fee is hereby granted, provided that the above
    copyright notice and this permission notice appear in all copies.

    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================

#pragma once

#include <boost/asio/buffer.hpp>
#include <boost/asio/io_context.hpp>
#include <boost/asio/ip/tcp.hpp>
#include <boost/asio/ssl/context.hpp>
#include <boost/asio/ssl/error.hpp>
#include <boost/asio/ssl/stream_base.hpp>
#include <boost/asio/ssl/verify_context.hpp>
#include <boost/asio/ssl/verify_mode.hpp>
#include <boost/beast/core/buffers_to_string.hpp>
#include <boost/beast/core/error.hpp>
#include <boost/beast/core/flat_buffer.hpp>
#include <boost/beast/core/stream_traits.hpp>
#include <boost/beast/core/tcp_stream.hpp>
#include <boost/beast/http.hpp>
#include <boost/beast/http/field.hpp>
#include <boost/beast/http/message.hpp>
#include <boost/beast/http/string_body.hpp>
#include <boost/beast/http/verb.hpp>
#include <boost/beast/ssl/ssl_stream.hpp>
#include <boost/beast/version.hpp>
#include <boost/beast/websocket/rfc6455.hpp>
#include <boost/beast/websocket/stream.hpp>
#include <boost/beast/websocket/stream_base.hpp>
#include <openssl/err.h>
#include <openssl/tls1.h>

#include <optional>
#include <string>
#include <utility>
#include <vector>

namespace http = boost::beast::http;
namespace net = boost::asio;
namespace ssl = boost::asio::ssl;
using tcp = boost::asio::ip::tcp;

struct WebHeader {
    WebHeader(http::field name, std::string value) : name(name), value(std::move(value))
    {
    }
    http::field name;
    std::string value;
};

struct HttpSyncClient {
    static std::string
    syncPost(
        std::string const& host,
        std::string const& port,
        std::string const& body,
        std::vector<WebHeader> additionalHeaders = {}
    )
    {
        return syncRequest(host, port, body, std::move(additionalHeaders), http::verb::post);
    }

    static std::string
    syncGet(
        std::string const& host,
        std::string const& port,
        std::string const& body,
        std::string const& target,
        std::vector<WebHeader> additionalHeaders = {}
    )
    {
        return syncRequest(host, port, body, std::move(additionalHeaders), http::verb::get, target);
    }

private:
    static std::string
    syncRequest(
        std::string const& host,
        std::string const& port,
        std::string const& body,
        std::vector<WebHeader> additionalHeaders,
        http::verb method,
        std::string target = "/"
    )
    {
        boost::asio::io_context ioc;

        net::ip::tcp::resolver resolver(ioc);
        boost::beast::tcp_stream stream(ioc);

        auto const results = resolver.resolve(host, port);
        stream.connect(results);

        http::request<http::string_body> req{method, "/", 10};
        req.set(http::field::host, host);
        req.set(http::field::user_agent, BOOST_BEAST_VERSION_STRING);

        for (auto& header : additionalHeaders) {
            req.set(header.name, header.value);
        }

        req.target(target);
        req.body() = std::string(body);
        req.prepare_payload();
        http::write(stream, req);

        boost::beast::flat_buffer buffer;
        http::response<http::string_body> res;
        http::read(stream, buffer, res);

        boost::beast::error_code ec;
        stream.socket().shutdown(tcp::socket::shutdown_both, ec);

        return res.body();
    }
};

class WebSocketSyncClient {
    net::io_context ioc_;
    tcp::resolver resolver_{ioc_};
    boost::beast::websocket::stream<tcp::socket> ws_{ioc_};

public:
    void
    connect(std::string const& host, std::string const& port, std::vector<WebHeader> additionalHeaders = {})
    {
        auto const results = resolver_.resolve(host, port);
        auto const ep = net::connect(ws_.next_layer(), results);

        // Update the host_ string. This will provide the value of the
        // Host HTTP header during the WebSocket handshake.
        // See https://tools.ietf.org/html/rfc7230#section-5.4
        auto const hostPort = host + ':' + std::to_string(ep.port());

        ws_.set_option(boost::beast::websocket::stream_base::decorator([additionalHeaders = std::move(additionalHeaders
                                                                        )](boost::beast::websocket::request_type& req) {
            req.set(http::field::user_agent, std::string(BOOST_BEAST_VERSION_STRING) + " websocket-client-coro");
            for (auto const& header : additionalHeaders) {
                req.set(header.name, header.value);
            }
        }));

        ws_.handshake(hostPort, "/");
    }

    void
    disconnect()
    {
        ws_.close(boost::beast::websocket::close_code::normal);
    }

    std::string
    syncPost(std::string const& body)
    {
        boost::beast::flat_buffer buffer;

        ws_.write(net::buffer(std::string(body)));
        ws_.read(buffer);

        return boost::beast::buffers_to_string(buffer.data());
    }
};

struct HttpsSyncClient {
    static bool
    verify_certificate(bool /* preverified */, boost::asio::ssl::verify_context& /* ctx */)
    {
        return true;
    }

    static std::string
    syncPost(std::string const& host, std::string const& port, std::string const& body)
    {
        net::io_context ioc;
        boost::asio::ssl::context ctx(boost::asio::ssl::context::sslv23);
        ctx.set_default_verify_paths();
        ctx.set_verify_mode(ssl::verify_none);

        tcp::resolver resolver(ioc);
        boost::beast::ssl_stream<boost::beast::tcp_stream> stream(ioc, ctx);

// We can't fix this so have to ignore
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wold-style-cast"
        if (!SSL_set_tlsext_host_name(stream.native_handle(), host.c_str()))
#pragma GCC diagnostic pop
        {
            boost::beast::error_code const ec{static_cast<int>(::ERR_get_error()), net::error::get_ssl_category()};
            throw boost::beast::system_error{ec};
        }

        auto const results = resolver.resolve(host, port);
        boost::beast::get_lowest_layer(stream).connect(results);
        stream.handshake(ssl::stream_base::client);

        http::request<http::string_body> req{http::verb::post, "/", 10};
        req.set(http::field::host, host);
        req.set(http::field::user_agent, BOOST_BEAST_VERSION_STRING);
        req.body() = std::string(body);
        req.prepare_payload();
        http::write(stream, req);

        boost::beast::flat_buffer buffer;
        http::response<http::string_body> res;
        http::read(stream, buffer, res);

        boost::beast::error_code ec;
        stream.shutdown(ec);

        return res.body();
    }
};

class WebServerSslSyncClient {
    net::io_context ioc_;
    std::optional<boost::beast::websocket::stream<boost::beast::ssl_stream<tcp::socket>>> ws_;

public:
    void
    connect(std::string const& host, std::string const& port)
    {
        boost::asio::ssl::context ctx(boost::asio::ssl::context::sslv23);
        ctx.set_default_verify_paths();
        ctx.set_verify_mode(ssl::verify_none);

        tcp::resolver resolver{ioc_};
        ws_.emplace(ioc_, ctx);

        auto const results = resolver.resolve(host, port);
        net::connect(ws_->next_layer().next_layer(), results.begin(), results.end());
        ws_->next_layer().handshake(ssl::stream_base::client);

        ws_->set_option(boost::beast::websocket::stream_base::decorator([](boost::beast::websocket::request_type& req) {
            req.set(http::field::user_agent, std::string(BOOST_BEAST_VERSION_STRING) + " websocket-client-coro");
        }));

        ws_->handshake(host, "/");
    }

    void
    disconnect()
    {
        ws_->close(boost::beast::websocket::close_code::normal);
    }

    std::string
    syncPost(std::string const& body)
    {
        boost::beast::flat_buffer buffer;
        ws_->write(net::buffer(std::string(body)));
        ws_->read(buffer);

        return boost::beast::buffers_to_string(buffer.data());
    }
};