#include <log/LogUtils.h>
#include <misc/strobf.h>
#include <misc/hex.h>
#include <src/Configuration.h>
#include <arpa/inet.h>
#include <src/ShutdownHelper.h>
#include "src/InstanceHandler.h"
#include "LicenseHelper.h"

using namespace license;
using namespace std;
using namespace std::chrono;
using namespace ts;
using namespace ts::server;

LicenseHelper::LicenseHelper() {
    this->scheduled_request = system_clock::now() + seconds(rand() % 30); //Check in one minute
}

LicenseHelper::~LicenseHelper() {
    if(this->request.prepare_thread.joinable())
        this->request.prepare_thread.join();

    {
        unique_lock lock(this->request.current_lock);
        if(this->request.current) {
            auto request = move(this->request.current);
            lock.unlock();

            request->abortRequest();
	        request->callback_update_certificate = nullptr;
        }
    }
}

inline string format_time(const system_clock::time_point& time) {
    std::time_t now = system_clock::to_time_t(time);
    std::tm * ptm = std::localtime(&now);
    char buffer[128];
    const auto length = std::strftime(buffer, 128, "%a, %d.%m.%Y %H:%M:%S", ptm);
    return string(buffer, length);
}

void LicenseHelper::tick() {
    lock_guard tick_lock(this->license_tick_lock);

    bool verbose = config::license->isPremium();
    {
        lock_guard request_lock(this->request.current_lock);
        if(this->request.current) {
            auto promise = this->request.current->requestInfo();
            if(promise.state() != threads::FutureState::WORKING){
            	auto exception = this->request.current->exception();
                if(promise.state() == threads::FutureState::FAILED) {
                    this->handle_request_failed(verbose, exception ? exception->what() : strobf("unknown").c_str());
                    this->request.current = nullptr; /* connection should be already closed */
                    return;
                } else {
                    auto response = promise.waitAndGet(nullptr);
                    this->request.current = nullptr; /* connection should be already closed */

                    if(!response){
                        this->handle_request_failed(verbose, exception ? exception->what() : strobf("invalid result (null)").c_str());
                        return;
                    }
                    if(!response->license_valid || !response->properties_valid){
                        if(!response->license_valid) {
                            if(config::license->isPremium()) logCritical(strobf("Could not validate license.").c_str());
                            else logCritical(strobf("Your server has been shutdown remotely!").c_str());
                        } else if(!response->properties_valid) {
                            logCritical(strobf("Property adjustment failed!").c_str());
                        } else
                            logCritical(strobf("Your license expired!").c_str());
                        logCritical(strobf("Stopping application!").c_str());
                        ts::server::shutdownInstance();
                        return;
                    } else {
                        this->scheduled_request = this->last_request + hours(2);
                        logMessage(LOG_INSTANCE, strobf("License successfully validated! Scheduling next check at {}").c_str(), format_time(this->scheduled_request));
                        if(response->speach_reset)
                            serverInstance->resetSpeechTime();
                        serverInstance->properties()[property::SERVERINSTANCE_SPOKEN_TIME_VARIANZ] = response->speach_varianz_adjustment;

                        {
                            lock_guard lock(this->request.info_lock);
                            this->request.info = response->license;
                        }

                        this->request_fail_count = 0;
                        this->last_successful_request = system_clock::now();
                    }
                }
            }
        }
    }

    if(system_clock::now() > scheduled_request){
        this->do_request(verbose);
    }
}
void LicenseHelper::do_request(bool verbose) {
    if(verbose) {
        if(config::license && config::license->isPremium())
            logMessage(LOG_INSTANCE, strobf("Validating license").c_str());
        else
            logMessage(LOG_INSTANCE, strobf("Validating instance integrity").c_str());
    }

    this->last_request = system_clock::now();
    this->scheduled_request = this->last_request + minutes(10); /* some kind of timeout */

    {
        unique_lock lock(this->request.current_lock);
        if(this->request.current) {
            auto request = move(this->request.current);
            lock.unlock();

            if(verbose) {
                auto promise = request->requestInfo();
                if(promise.state() == threads::FutureState::WORKING) {
                    logMessage(LOG_INSTANCE, strobf("Old check timed out (10 min). Running new one!").c_str());
                }
            }
            request->abortRequest();
        }
    }

    if(this->request.prepare_thread.joinable()) /* usually the preparation should not take too long */
        this->request.prepare_thread.join();

    this->request.prepare_thread = std::thread([&]{
        sockaddr_in server_addr{};
        server_addr.sin_family = AF_INET;

#ifdef DO_LOCAL_REQUEST
        auto license_host = gethostbyname(strobf("localhost").c_str());
        server_addr.sin_addr.s_addr = ((in_addr*) license_host->h_addr)->s_addr;
#else
        auto license_host = gethostbyname(strobf("license.teaspeak.de").c_str());
        if(!license_host){
            if(verbose) logError(strobf("Could not valid license! (1)").c_str());
            return;
        }
        if(!license_host->h_addr){
            if(verbose) logError(strobf("Could not valid license! (2)").c_str());
            return;
        }
        server_addr.sin_addr.s_addr = ((in_addr*) license_host->h_addr)->s_addr;
        logger::logger(0)->debug(strobf("Requesting server {}").c_str(), inet_ntoa(server_addr.sin_addr));
        int first = server_addr.sin_addr.s_addr >> 24;
        if(first == 0 || first == 127 || first == 255) {
            if(config::license->isPremium()) {
                logError(strobf("You tried to nullroot 'license.teaspeak.de'!").c_str());
                logCritical(strobf("Could not validate license!").c_str());
                logCritical(strobf("Stopping server!").c_str());
                ts::server::shutdownInstance();
                return;
            }
            return;
        }

#endif
        server_addr.sin_port = htons(27786);


        auto license_data = serverInstance->generateLicenseData();
        auto request = make_shared<license::LicenceRequest>(license_data, server_addr);
        request->verbose = false;
	    request->callback_update_certificate = [&](const auto& update) { this->callback_certificate_update(update); };
        {
            lock_guard lock(this->request.current_lock);
            this->request.current = request;
            request->requestInfo();
        }
    });
}

void LicenseHelper::handle_request_failed(bool verbose, const std::string& error) {
    if(verbose) {
        if(config::license && config::license->isPremium())
            logError(LOG_INSTANCE, strobf("License validation failed: {}").c_str(), error);
        else
            logError(LOG_INSTANCE, strobf("Instance integrity check failed: {}").c_str(), error);
    }
    this->request_fail_count++;
    milliseconds next_request;

    if(this->request_fail_count <= 1)
        next_request = minutes(1);
    else if(this->request_fail_count <= 5)
        next_request = minutes(5);
    else if(this->request_fail_count <= 10)
        next_request = minutes(10);
    else
        next_request = minutes(30);

    this->scheduled_request = this->last_request + next_request;
    if(verbose)
        logMessage(LOG_INSTANCE, strobf("Scheduling next check at {}").c_str(), format_time(this->scheduled_request));
}

void LicenseHelper::callback_certificate_update(const license::WebCertificate &certificate) {
	serverInstance->setWebCertRoot(certificate.key, certificate.certificate, certificate.revision);
}