#include "util/TestWsServer.hpp"

#include "util/requests/Types.hpp"

#include <boost/asio/buffer.hpp>
#include <boost/asio/io_context.hpp>
#include <boost/asio/ip/address.hpp>
#include <boost/asio/ip/tcp.hpp>
#include <boost/asio/socket_base.hpp>
#include <boost/asio/spawn.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/role.hpp>
#include <boost/beast/core/tcp_stream.hpp>
#include <boost/beast/http/field.hpp>
#include <boost/beast/http/message.hpp>
#include <boost/beast/http/string_body.hpp>
#include <boost/beast/websocket/error.hpp>
#include <boost/beast/websocket/rfc6455.hpp>
#include <boost/beast/websocket/stream.hpp>
#include <boost/beast/websocket/stream_base.hpp>
#include <gtest/gtest.h>

#include <algorithm>
#include <expected>
#include <functional>
#include <iterator>
#include <optional>
#include <string>
#include <string_view>
#include <utility>
#include <vector>

namespace asio = boost::asio;
namespace websocket = boost::beast::websocket;

TestWsConnection::TestWsConnection(
    websocket::stream<boost::beast::tcp_stream> wsStream,
    std::vector<util::requests::HttpHeader> headers
)
    : ws_(std::move(wsStream)), headers_(std::move(headers))
{
}

TestWsConnection::TestWsConnection(TestWsConnection&& other)
    : ws_(std::move(other.ws_)), headers_(std::move(other.headers_))
{
}

std::optional<std::string>
TestWsConnection::send(std::string const& message, boost::asio::yield_context yield)
{
    boost::beast::error_code errorCode;
    ws_.async_write(asio::buffer(message), yield[errorCode]);
    if (errorCode)
        return errorCode.message();
    return std::nullopt;
}

void
TestWsConnection::sendPing(
    boost::beast::websocket::ping_data const& data,
    boost::asio::yield_context yield
)
{
    boost::beast::error_code errorCode;
    ws_.async_ping(data, yield[errorCode]);
    [&]() { ASSERT_FALSE(errorCode) << errorCode.message(); }();
}

std::optional<std::string>
TestWsConnection::receive(boost::asio::yield_context yield)
{
    boost::beast::error_code errorCode;
    boost::beast::flat_buffer buffer;

    ws_.async_read(buffer, yield[errorCode]);
    if (errorCode == websocket::error::closed)
        return std::nullopt;

    [&]() { ASSERT_FALSE(errorCode) << errorCode.message(); }();
    return boost::beast::buffers_to_string(buffer.data());
}

std::optional<std::string>
TestWsConnection::close(boost::asio::yield_context yield)
{
    boost::beast::error_code errorCode;
    ws_.async_close(websocket::close_code::normal, yield[errorCode]);
    if (errorCode)
        return errorCode.message();
    return std::nullopt;
}

std::vector<util::requests::HttpHeader> const&
TestWsConnection::headers() const
{
    return headers_;
}

void
TestWsConnection::setControlFrameCallback(
    std::function<void(boost::beast::websocket::frame_type, std::string_view)> callback
)
{
    ws_.control_callback(std::move(callback));
}

void
TestWsConnection::resetControlFrameCallback()
{
    ws_.control_callback();
}

TestWsServer::TestWsServer(asio::io_context& context, std::string const& host) : acceptor_(context)
{
    auto endpoint = asio::ip::tcp::endpoint(boost::asio::ip::make_address(host), 0);
    acceptor_.open(endpoint.protocol());
    acceptor_.set_option(asio::socket_base::reuse_address(true));
    acceptor_.bind(endpoint);
}

std::string
TestWsServer::port() const
{
    return std::to_string(this->acceptor_.local_endpoint().port());
}

std::expected<TestWsConnection, util::requests::RequestError>
TestWsServer::acceptConnection(asio::yield_context yield)
{
    acceptor_.listen(asio::socket_base::max_listen_connections);

    boost::beast::error_code errorCode;
    asio::ip::tcp::socket socket(acceptor_.get_executor());
    acceptor_.async_accept(socket, yield[errorCode]);
    if (errorCode)
        return std::unexpected{util::requests::RequestError{"Accept error", errorCode}};

    boost::beast::flat_buffer buffer;
    boost::beast::http::request<boost::beast::http::string_body> request;
    boost::beast::http::async_read(socket, buffer, request, yield[errorCode]);
    if (errorCode)
        return std::unexpected{util::requests::RequestError{"Read error", errorCode}};
    std::vector<util::requests::HttpHeader> headers;
    std::ranges::transform(request, std::back_inserter(headers), [](auto const& header) {
        if (header.name() == boost::beast::http::field::unknown)
            return util::requests::HttpHeader{header.name_string(), header.value()};

        return util::requests::HttpHeader{header.name(), header.value()};
    });
    if (not boost::beast::websocket::is_upgrade(request))
        return std::unexpected{util::requests::RequestError{"Not a websocket request"}};

    boost::beast::websocket::stream<boost::beast::tcp_stream> ws(std::move(socket));
    ws.set_option(websocket::stream_base::timeout::suggested(boost::beast::role_type::server));
    ws.async_accept(request, yield[errorCode]);
    if (errorCode)
        return std::unexpected{util::requests::RequestError{"Handshake error", errorCode}};

    return TestWsConnection(std::move(ws), std::move(headers));
}

void
TestWsServer::acceptConnectionAndDropIt(asio::yield_context yield)
{
    acceptConnectionWithoutHandshake(yield);
}

boost::asio::ip::tcp::socket
TestWsServer::acceptConnectionWithoutHandshake(boost::asio::yield_context yield)
{
    acceptor_.listen(asio::socket_base::max_listen_connections);
    boost::beast::error_code errorCode;
    asio::ip::tcp::socket socket(acceptor_.get_executor());
    acceptor_.async_accept(socket, yield[errorCode]);
    [&]() { ASSERT_FALSE(errorCode) << errorCode.message(); }();
    return socket;
}