#include <grpc/impl/codegen/port_platform.h>
#ifdef GRPC_TSAN_ENABLED
#undef GRPC_TSAN_ENABLED
#endif
#ifdef GRPC_ASAN_ENABLED
#undef GRPC_ASAN_ENABLED
#endif

#include <backend/BackendFactory.h>
#include <config/Config.h>
#include <etl/ReportingETL.h>
#include <log/Logger.h>
#include <webserver/Listener.h>

#include <boost/asio/dispatch.hpp>
#include <boost/asio/strand.hpp>
#include <boost/beast/websocket.hpp>
#include <boost/date_time/posix_time/posix_time_types.hpp>
#include <boost/filesystem/path.hpp>
#include <boost/json.hpp>
#include <boost/program_options.hpp>

#include <algorithm>
#include <cstdlib>
#include <fstream>
#include <functional>
#include <iostream>
#include <main/Build.h>
#include <memory>
#include <sstream>
#include <string>
#include <thread>
#include <vector>

using namespace clio;
namespace po = boost::program_options;

/**
 * @brief Parse command line and return path to configuration file
 *
 * @param argc
 * @param argv
 * @return std::string Path to configuration file
 */
std::string
parseCli(int argc, char* argv[])
{
    static constexpr char defaultConfigPath[] = "/etc/opt/clio/config.json";

    // clang-format off
    po::options_description description("Options");
    description.add_options()
        ("help,h", "print help message and exit")
        ("version,v", "print version and exit")
        ("conf,c", po::value<std::string>()->default_value(defaultConfigPath), "configuration file")
    ;
    // clang-format on
    po::positional_options_description positional;
    positional.add("conf", 1);

    po::variables_map parsed;
    po::store(
        po::command_line_parser(argc, argv)
            .options(description)
            .positional(positional)
            .run(),
        parsed);
    po::notify(parsed);

    if (parsed.count("version"))
    {
        std::cout << Build::getClioFullVersionString() << '\n';
        std::exit(EXIT_SUCCESS);
    }

    if (parsed.count("help"))
    {
        std::cout << "Clio server " << Build::getClioFullVersionString()
                  << "\n\n"
                  << description;
        std::exit(EXIT_SUCCESS);
    }

    return parsed["conf"].as<std::string>();
}

/**
 * @brief Parse certificates from configuration file
 *
 * @param config The configuration
 * @return std::optional<ssl::context> SSL context if certificates were parsed
 */
std::optional<ssl::context>
parseCerts(Config const& config)
{
    if (!config.contains("ssl_cert_file") || !config.contains("ssl_key_file"))
        return {};

    auto certFilename = config.value<std::string>("ssl_cert_file");
    auto keyFilename = config.value<std::string>("ssl_key_file");

    std::ifstream readCert(certFilename, std::ios::in | std::ios::binary);
    if (!readCert)
        return {};

    std::stringstream contents;
    contents << readCert.rdbuf();
    std::string cert = contents.str();

    std::ifstream readKey(keyFilename, std::ios::in | std::ios::binary);
    if (!readKey)
        return {};

    contents.str("");
    contents << readKey.rdbuf();
    readKey.close();
    std::string key = contents.str();

    ssl::context ctx{ssl::context::tlsv12};

    ctx.set_options(
        boost::asio::ssl::context::default_workarounds |
        boost::asio::ssl::context::no_sslv2);

    ctx.use_certificate_chain(boost::asio::buffer(cert.data(), cert.size()));

    ctx.use_private_key(
        boost::asio::buffer(key.data(), key.size()),
        boost::asio::ssl::context::file_format::pem);

    return ctx;
}

/**
 * @brief Start context threads
 *
 * @param ioc Context
 * @param numThreads Number of worker threads to start
 */
void
start(boost::asio::io_context& ioc, std::uint32_t numThreads)
{
    std::vector<std::thread> v;
    v.reserve(numThreads - 1);
    for (auto i = numThreads - 1; i > 0; --i)
        v.emplace_back([&ioc] { ioc.run(); });

    ioc.run();
}

int
main(int argc, char* argv[])
try
{
    auto const configPath = parseCli(argc, argv);
    auto const config = ConfigReader::open(configPath);
    if (!config)
    {
        std::cerr << "Couldnt parse config '" << configPath << "'."
                  << std::endl;
        return EXIT_FAILURE;
    }

    LogService::init(config);
    LogService::info() << "Clio version: " << Build::getClioFullVersionString();

    auto ctx = parseCerts(config);
    auto ctxRef = ctx
        ? std::optional<std::reference_wrapper<ssl::context>>{ctx.value()}
        : std::nullopt;

    auto const threads = config.valueOr("io_threads", 2);
    if (threads <= 0)
    {
        LogService::fatal() << "io_threads is less than 0";
        return EXIT_FAILURE;
    }
    LogService::info() << "Number of io threads = " << threads;

    // IO context to handle all incoming requests, as well as other things
    // This is not the only io context in the application
    boost::asio::io_context ioc{threads};

    // Rate limiter, to prevent abuse
    DOSGuard dosGuard{config, ioc};

    // Interface to the database
    std::shared_ptr<BackendInterface> backend{
        Backend::make_Backend(ioc, config)};

    // Manages clients subscribed to streams
    std::shared_ptr<SubscriptionManager> subscriptions{
        SubscriptionManager::make_SubscriptionManager(config, backend)};

    // Tracks which ledgers have been validated by the
    // network
    std::shared_ptr<NetworkValidatedLedgers> ledgers{
        NetworkValidatedLedgers::make_ValidatedLedgers()};

    // Handles the connection to one or more rippled nodes.
    // ETL uses the balancer to extract data.
    // The server uses the balancer to forward RPCs to a rippled node.
    // The balancer itself publishes to streams (transactions_proposed and
    // accounts_proposed)
    auto balancer = ETLLoadBalancer::make_ETLLoadBalancer(
        config, ioc, backend, subscriptions, ledgers);

    // ETL is responsible for writing and publishing to streams. In read-only
    // mode, ETL only publishes
    auto etl = ReportingETL::make_ReportingETL(
        config, ioc, backend, subscriptions, balancer, ledgers);

    // The server handles incoming RPCs
    auto httpServer = Server::make_HttpServer(
        config, ioc, ctxRef, backend, subscriptions, balancer, etl, dosGuard);

    // Blocks until stopped.
    // When stopped, shared_ptrs fall out of scope
    // Calls destructors on all resources, and destructs in order
    start(ioc, threads);

    return EXIT_SUCCESS;
}
catch (std::exception const& e)
{
    LogService::fatal() << "Exit on exception: " << e.what();
}