#include <iostream>
#include <random>
#include <cmath>

#include <IO/WriteBufferFromFileDescriptor.h>
#include <IO/WriteHelpers.h>
#include <IO/ReadBufferFromFile.h>
#include <Common/HashTable/Hash.h>

#include "MarkovModel.h"


/** Generate infinite stream of pseudo-random data
 *   like 'hits' table in Yandex.Metrica (with structure as it was in 2013)
  *  and output it in TabSeparated format.
  */

using namespace DB;


struct Models
{
    MarkovModel Title;
    MarkovModel URL;
    MarkovModel SearchPhrase;

    static void read(MarkovModel & model, const String & path)
    {
        ReadBufferFromFile in(path);
        model.read(in);
    }

    Models()
    {
        read(Title, "Title.model");
        read(URL, "URL.model");
        read(SearchPhrase, "SearchPhrase.model");
    }
};


struct Generator
{
    WriteBufferFromFileDescriptor out;
    std::mt19937_64 random;
    std::mt19937_64 random_with_seed;
    Models models;

//    UInt64 WatchID = random();
    String Title;
    String URL;
/*    String Referer;
    String FlashMinor2;
    String UserAgentMinor;
    String MobilePhoneModel;
    String Params;*/
    String SearchPhrase;
/*    String PageCharset;
    String OriginalURL;
    String BrowserLanguage;
    String BrowserCountry;
    String SocialNetwork;
    String SocialAction;
    String SocialSourcePage;
    String ParamCurrency;
    String OpenstatServiceName;
    String OpenstatCampaignID;
    String OpenstatAdID;
    String OpenstatSourceID;
    String UTMSource;
    String UTMMedium;
    String UTMCampaign;
    String UTMContent;
    String UTMTerm;
    String FromTag;*/

    Generator() : out(STDOUT_FILENO) {}

    /** Choosing of distributions parameters sometimes resembles real data, but quite arbitary.
      */

    void generateRow()
    {
//        auto gen_random64 = [&]{ return random(); };

        /// Unique identifier of event.
/*        WatchID += std::uniform_int_distribution<UInt64>(0, 10000000000)(random);
        writeText(WatchID, out);
        writeChar('\t', out);

        bool JavaEnable = std::bernoulli_distribution(0.6)(random);
        writeText(JavaEnable, out);
        writeChar('\t', out);*/

        LocalDateTime EventTime;
        EventTime.year(2013);
        EventTime.month(7);
        EventTime.day(std::discrete_distribution<>({
            0, 0, 13, 30, 0, 14, 42, 5, 6, 31, 17, 0, 0, 0, 0, 23, 10, 0, 0, 0, 19, 24, 8, 7, 0, 0, 8, 2, 15, 12, 7, 29})(random));
        EventTime.hour(std::discrete_distribution<>({
            13, 7, 4, 3, 2, 3, 4, 6, 10, 16, 20, 23, 24, 23, 18, 19, 19, 19, 14, 15, 14, 13, 17, 17})(random));
        EventTime.minute(std::uniform_int_distribution<UInt8>(0, 59)(random));
        EventTime.second(std::uniform_int_distribution<UInt8>(0, 59)(random));

        UInt64 UserID = hash(4, powerLaw(5000, 1.1));
        UserID = UserID / 10000000000ULL * 10000000000ULL + static_cast<time_t>(EventTime) + UserID % 1000000;

        random_with_seed.seed(powerLaw(5000, 1.1));
        auto get_random_with_seed = [&]{ return random_with_seed(); };

        Title.resize(10000);
        Title.resize(models.Title.generate(&Title[0], Title.size(), get_random_with_seed));
        writeText(Title, out);
        writeChar('\t', out);

/*        bool GoodEvent = 1;
        writeText(GoodEvent, out);
        writeChar('\t', out);*/

        writeText(EventTime, out);
        writeChar('\t', out);

        LocalDate EventDate = EventTime.toDate();
        writeText(EventDate, out);
        writeChar('\t', out);

        UInt32 CounterID = hash(1, powerLaw(20, 1.1)) % 10000000;
        writeText(CounterID, out);
        writeChar('\t', out);

/*        UInt32 ClientIP = hash(2, powerLaw(5000, 1.1));
        writeText(ClientIP, out);
        writeChar('\t', out);

        UInt32 RegionID = hash(3, powerLaw(15, 1.1)) % 5000;
        writeText(RegionID, out);
        writeChar('\t', out);
*/
        writeText(UserID, out);
        writeChar('\t', out);

/*        bool CounterClass = (hash(5, CounterID) % 100) < 25;
        writeText(CounterClass, out);
        writeChar('\t', out);

        UInt8 OS = hash(6, powerLaw(10, 4)) % 100;
        writeText(OS, out);
        writeChar('\t', out);

        UInt8 UserAgent = hash(7, powerLaw(10, 4)) % 100;
        writeText(UserAgent, out);
        writeChar('\t', out);
*/
        URL.resize(10000);
        URL.resize(models.URL.generate(&URL[0], URL.size(), get_random_with_seed));
        writeText(URL, out);
        writeChar('\t', out);

        /// Referer

/*        bool Refresh = std::bernoulli_distribution(0.1)(random);
        writeText(Refresh, out);
        writeChar('\t', out);

        UInt16 RefererCategoryID = std::bernoulli_distribution(0.1)(random) ? 0 : (hash(8, powerLaw(10, 4)) % 10000);
        writeText(RefererCategoryID, out);
        writeChar('\t', out);

        UInt32 RefererRegionID = std::bernoulli_distribution(0.1)(random) ? 0 : (hash(9, powerLaw(15, 1.1)) % 5000);
        writeText(RefererRegionID, out);
        writeChar('\t', out);

        UInt16 URLCategoryID = std::bernoulli_distribution(0.1)(random) ? 0 : (hash(10, powerLaw(10, 4)) % 10000);
        writeText(URLCategoryID, out);
        writeChar('\t', out);

        UInt32 URLRegionID = std::bernoulli_distribution(0.1)(random) ? 0 : (hash(11, powerLaw(15, 1.1)) % 5000);
        writeText(URLRegionID, out);
        writeChar('\t', out);

        UInt16 ResolutionWidth;
        UInt16 ResolutionHeight;

        std::tie(ResolutionWidth, ResolutionHeight) = powerLawSampleFrom<std::pair<UInt16, UInt16>>(15, 1.1,
        {
            {1366, 768}, {1280, 1024}, {1920, 1080}, {0, 0}, {1024, 768},
            {1280, 800}, {1440, 900}, {1600, 900}, {1600, 900}, {1680, 1050},
            {768, 1024}, {1024, 600}, {1360, 768}, {1280, 720}, {1152, 864},
            {1280, 768}, {320, 480}, {1920, 1200}, {320, 568}, {1093, 614},
        });

        if (std::bernoulli_distribution(0.1)(random))
        {
            ResolutionWidth = std::bernoulli_distribution(0.1)(random)
                ? std::uniform_int_distribution<UInt16>(160, 3000)(random)
                : (std::uniform_int_distribution<UInt16>(160, 3000)(random) / 16 * 16);

            ResolutionHeight = std::bernoulli_distribution(0.1)(random)
                ? std::uniform_int_distribution<UInt16>(160, 3000)(random)
                : (ResolutionWidth / 16 * 10);
        }

        writeText(ResolutionWidth, out);
        writeChar('\t', out);

        writeText(ResolutionHeight, out);
        writeChar('\t', out);

        UInt8 ResolutionDepth = weightedSelect<UInt8>({32, 24, 0, 16, 8}, {2000000, 700000, 300000, 50000, 100});
        writeText(ResolutionDepth, out);
        writeChar('\t', out);

        UInt8 FlashMajor = weightedSelect<UInt8>({11, 0, 10, 6, 9, 8, 7, 5, 12}, {2000000, 600000, 200000, 100000, 8000, 800, 600, 20, 10});
        UInt8 FlashMinor = weightedSelect<UInt8>({7, 0, 8, 1, 6, 3, 2, 5, 4}, {1500000, 700000, 500000, 150000, 100000, 80000, 60000, 50000, 50000});

        writeText(FlashMajor, out);
        writeChar('\t', out);

        writeText(FlashMinor, out);
        writeChar('\t', out);

        FlashMinor2.clear();
        if (FlashMajor && FlashMinor)
        {
            FlashMinor2 = toString(hash(12, powerLaw(10, 4)) % 1000);
            if (std::bernoulli_distribution(0.2)(random))
            {
                FlashMinor2 += '.';
                FlashMinor2 += toString(hash(13, powerLaw(10, 4)) % 1000);
            }
        }

        writeText(FlashMinor2, out);
        writeChar('\t', out);

        UInt8 NetMajor = weightedSelect<UInt8>({0, 3, 2, 1, 4}, {3000000, 100000, 10000, 5000, 2});
        UInt8 NetMinor = weightedSelect<UInt8>({0, 5, 1}, {3000000, 200000, 5000});

        writeText(NetMajor, out);
        writeChar('\t', out);

        writeText(NetMinor, out);
        writeChar('\t', out);

        UInt16 UserAgentMajor = UserAgent ? hash(14, powerLaw(10, 4)) % 100 : 0;
        writeText(UserAgentMajor, out);
        writeChar('\t', out);

        UserAgentMinor.clear();
        if (UserAgentMajor)
        {
            UserAgentMinor = toString(hash(15, powerLaw(10, 4)) % 100);
            if (UserAgentMinor.size() == 1 && std::bernoulli_distribution(0.1)(random))
                UserAgentMinor += 'a' + std::uniform_int_distribution<UInt8>(0, 25)(random);
        }
        writeText(UserAgentMinor, out);
        writeChar('\t', out);

        bool CookieEnable = std::bernoulli_distribution(0.999)(random);
        writeText(CookieEnable, out);
        writeChar('\t', out);

        bool JavascriptEnable = std::bernoulli_distribution(0.95)(random);
        writeText(JavascriptEnable, out);
        writeChar('\t', out);

        bool IsMobile = std::bernoulli_distribution(0.15)(random);
        writeText(IsMobile, out);
        writeChar('\t', out);

        UInt8 MobilePhone = IsMobile ? hash(16, powerLaw(10, 4)) % 100 : 0;
        writeText(MobilePhone, out);
        writeChar('\t', out);
*/
/*        MobilePhoneModel.resize(100);
        MobilePhoneModel.resize(models.MobilePhoneModel.generate(&MobilePhoneModel[0], MobilePhoneModel.size(), gen_random64));
        writeText(MobilePhoneModel, out);
        writeChar('\t', out);

        Params.resize(10000);
        Params.resize(models.Params.generate(&Params[0], Params.size(), gen_random64));
        writeText(Params, out);
        writeChar('\t', out);

        UInt32 IPNetworkID = hash(17, powerLaw(15, 1.1)) % 5000;
        writeText(IPNetworkID, out);
        writeChar('\t', out);

        Int8 TraficSourceID = weightedSelect<Int8>(
            {-1, 0, 1, 2, 3, 4, 5, 6, 7, 8}, {2000000, 300000, 200000, 600000, 50000, 700, 30000, 40000, 500, 2500});
        writeText(TraficSourceID, out);
        writeChar('\t', out);

        UInt16 SearchEngineID = TraficSourceID == 2
            ? hash(18, powerLaw(10, 4)) % 100
            : (TraficSourceID == 3
                ? (std::bernoulli_distribution(0.5)(random)
                    ? hash(19, powerLaw(10, 4)) % 10
                    : 0)
                : 0);

        if (!SearchEngineID)
            SearchPhrase.clear();
        else
        {*/
            SearchPhrase.resize(1000);
            SearchPhrase.resize(models.SearchPhrase.generate(&SearchPhrase[0], SearchPhrase.size(), get_random_with_seed));
//        }
        writeText(SearchPhrase, out);
 /*       writeChar('\t', out);

        UInt8 AdvEngineID = weightedSelect<UInt8>(
            {0, 2, 12, 17, 18, 27, 34, 36}, {3000000, 30000, 3000, 30000, 1, 100, 40, 30});
        writeText(AdvEngineID, out);
        writeChar('\t', out);

        bool IsArtificial = std::bernoulli_distribution(0.07)(random);
        writeText(IsArtificial, out);
        writeChar('\t', out);

        UInt16 WindowClientWidth = std::max(3000, ResolutionWidth - hash(20, UserID) % 100);
        UInt16 WindowClientHeight = std::max(3000, ResolutionHeight - hash(21, UserID) % 100);

        writeText(WindowClientWidth, out);
        writeChar('\t', out);

        writeText(WindowClientHeight, out);*/
        writeChar('\n', out);
    }

    UInt64 powerLawImpl(double scale, double alpha, double unit_random_value)
    {
        return scale * std::pow(unit_random_value, -1.0 / alpha) - scale;
    }

    UInt64 powerLaw(double scale, double alpha)
    {
        return powerLawImpl(scale, alpha, std::uniform_real_distribution<double>(0, 1)(random));
    }

    template <typename T>
    T powerLawSampleFrom(double scale, double alpha, std::initializer_list<T> set)
    {
        return set.begin()[powerLaw(scale, alpha) % set.size()];
    }

    template <typename T>
    T weightedSelect(std::initializer_list<T> items, std::initializer_list<double> weights)
    {
        return items.begin()[std::discrete_distribution<>(weights)(random)];
    }

    static UInt64 hash(unsigned seed, UInt64 x)
    {
        return intHash64(x + seed * 0xDEADBEEF);
    }
};


int main(int argc, char ** argv)
try
{
    Generator generator;
    while (true)
        generator.generateRow();

    return 0;
}
catch (...)
{
    /// Broken pipe, when piped to 'head', by example.
    if (errno != EPIPE)
    {
        std::cerr << getCurrentExceptionMessage(true) << '\n';
        throw;
    }
}