//----------------------------------------------------------------------------
/// @file test_sample_sort.cpp
/// @brief test sample_sort algorithm
///
/// @author Copyright (c) 2016 Francisco Jose Tapia (fjtapia@gmail.com )\n
///         Distributed under the Boost Software License, Version 1.0.\n
///         ( See accompanying file LICENSE_1_0.txt or copy at
///           http://www.boost.org/LICENSE_1_0.txt  )
/// @version 0.1
///
/// @remarks
//-----------------------------------------------------------------------------
#include <ciso646>
#include <cstdlib>
#include <ctime>
#include <algorithm>
#include <vector>
#include <random>
#include <boost/sort/sample_sort/sample_sort.hpp>
#include <boost/test/included/test_exec_monitor.hpp>
#include <boost/test/test_tools.hpp>

namespace bss = boost::sort::sample_detail;
using namespace boost::sort::common;

std::mt19937_64 my_rand(0);

void test3();
void test4();
void test5();
void test6();
void test7();
void test8();
void test9();

struct xk
{
    unsigned tail : 4;
    unsigned num : 28;
    xk ( uint32_t n =0 , uint32_t t =0): tail (t), num(n){};
    bool operator< (xk A) const { return (num < A.num); };
};
void test3()
{
    typedef typename std::vector<xk>::iterator iter_t;
    typedef std::less<xk> compare;

    std::mt19937_64 my_rand(0);

    const uint32_t NMAX = 500000;

    std::vector<xk> V1, V2, V3;
    V1.reserve(NMAX);
    for (uint32_t i = 0; i < 8; ++i)
    {
        for (uint32_t k = 0; k < NMAX; ++k)
        {
            uint32_t NM = my_rand();
            xk G;
            G.num = NM >> 3;
            G.tail = i;
            V1.push_back(G);
        };
    };
    V3 = V2 = V1;
    bss::sample_sort<iter_t, compare>(V1.begin(), V1.end());
    std::stable_sort(V2.begin(), V2.end());
    bss::sample_sort<iter_t, compare>(V3.begin(), V3.end(), 0);

    BOOST_CHECK(V1.size() == V2.size());
    for (uint32_t i = 0; i < V1.size(); ++i)
    {
        BOOST_CHECK(V1[i].num == V2[i].num and V1[i].tail == V2[i].tail);
    };

    BOOST_CHECK(V3.size() == V2.size());
    for (uint32_t i = 0; i < V3.size(); ++i)
    {
        BOOST_CHECK(V3[i].num == V2[i].num and V3[i].tail == V2[i].tail);
    };
}
;

void test4(void)
{
    typedef typename std::vector<uint64_t>::iterator iter_t;
    typedef std::less<uint64_t> compare;

    const uint32_t NElem = 500000;
    std::vector<uint64_t> V1;
    std::mt19937_64 my_rand(0);

    for (uint32_t i = 0; i < NElem; ++i)
        V1.push_back(my_rand() % NElem);

    // bss::sample_sort unsorted
    bss::sample_sort<iter_t, compare>(V1.begin(), V1.end());
    for (unsigned i = 1; i < NElem; i++)
    {
        BOOST_CHECK(V1[i - 1] <= V1[i]);
    };

    V1.clear();
    for (uint32_t i = 0; i < NElem; ++i)
        V1.push_back(i);

    // bss::sample_sort sorted
    bss::sample_sort<iter_t, compare>(V1.begin(), V1.end());
    for (unsigned i = 1; i < NElem; i++)
    {
        BOOST_CHECK(V1[i - 1] <= V1[i]);
    };

    V1.clear();
    for (uint32_t i = 0; i < NElem; ++i)
        V1.push_back(NElem - i);

    // bss::sample_sort reverse sorted
    bss::sample_sort<iter_t, compare>(V1.begin(), V1.end());
    for (unsigned i = 1; i < NElem; i++)
    {
        BOOST_CHECK(V1[i - 1] <= V1[i]);
    };

    V1.clear();
    for (uint32_t i = 0; i < NElem; ++i)
        V1.push_back(1000);

    // bss::sample_sort equals
    bss::sample_sort<iter_t, compare>(V1.begin(), V1.end());
    for (unsigned i = 1; i < NElem; i++)
    {
        BOOST_CHECK(V1[i - 1] == V1[i]);
    };
}
;

void test5(void)
{
    typedef typename std::vector<uint64_t>::iterator iter_t;
    typedef std::less<uint64_t> compare;
    const uint32_t KMax = 500000;

    std::vector<uint64_t> K, M;
    std::mt19937_64 my_rand(0);
    std::less<uint64_t> comp;

    for (uint32_t i = 0; i < KMax; ++i)
        K.push_back(my_rand());
    M = K;

    // bss::sample_sort - random elements
    uint64_t *Ptr = std::get_temporary_buffer<uint64_t>(KMax).first;
    if (Ptr == nullptr) throw std::bad_alloc();
    range<uint64_t *> Rbuf(Ptr, Ptr + KMax);

    bss::sample_sort<iter_t, compare>(K.begin(), K.end(), comp,
                    std::thread::hardware_concurrency(), Rbuf);

    std::return_temporary_buffer(Ptr);

    std::stable_sort(M.begin(), M.end(), comp);
    for (unsigned i = 0; i < KMax; i++)
        BOOST_CHECK(M[i] == K[i]);
}
;

void test6(void)
{
    typedef typename std::vector<uint64_t>::iterator iter_t;
    typedef std::less<uint64_t> compare;
    std::vector<uint64_t> V;

    for (uint32_t i = 0; i < 2083333; ++i)
        V.push_back(i);
    bss::sample_sort<iter_t, compare>(V.begin(), V.end());
    for (uint32_t i = 0; i < V.size(); ++i)
    {
        BOOST_CHECK(V[i] == i);
    };
}
;

void test7(void)
{
    typedef typename std::vector<uint64_t>::iterator iter_t;
    typedef std::less<uint64_t> compare;

    const uint32_t NELEM = 416667;
    std::vector<uint64_t> A;

    for (uint32_t i = 0; i < 1000; ++i)
        A.push_back(0);
    for (uint32_t i = 0; i < NELEM; ++i)
        A.push_back(NELEM - i);
    for (uint32_t i = 0; i < 1000; ++i)
        A.push_back(0);

    bss::sample_sort<iter_t, compare>(A.begin() + 1000,
                    A.begin() + (1000 + NELEM));

    for (iter_t it = A.begin() + 1000; it != A.begin() + (1000 + NELEM); ++it)
    {
        BOOST_CHECK((*(it - 1)) <= (*it));
    };

    BOOST_CHECK (A[998] == 0 and A[999] == 0 and A[1000 + NELEM] == 0
                 and A[1001 + NELEM] == 0);

    A.clear();
    for (uint32_t i = 0; i < 1000; ++i)
        A.push_back(999999999);
    for (uint32_t i = 0; i < NELEM; ++i)
        A.push_back(NELEM - i);
    for (uint32_t i = 0; i < 1000; ++i)
        A.push_back(999999999);

    bss::sample_sort<iter_t, compare>
        (A.begin() + 1000, A.begin() + (1000 + NELEM));

    for (iter_t it = A.begin() + 1001; it != A.begin() + (1000 + NELEM); ++it)
    {
        BOOST_CHECK((*(it - 1)) <= (*it));
    };
    BOOST_CHECK (A[998] == 999999999
                 and A[999] == 999999999
                 and A[1000 + NELEM] == 999999999
                 and A[1001 + NELEM] == 999999999);

    std::vector<uint64_t> B(NELEM + 2000, 0);

    A.clear();
    for (uint32_t i = 0; i < NELEM; ++i) A.push_back(NELEM - i);

    range<uint64_t *> Rbuf(&B[1000], (&B[1000]) + NELEM);
    bss::sample_sort<iter_t, compare>
        ( A.begin(), A.end(), std::less<uint64_t>(),
          std::thread::hardware_concurrency(), Rbuf);

    for (iter_t it = A.begin() + 1; it != A.end(); ++it)
    {
        BOOST_CHECK((*(it - 1)) <= (*it));
    };
    BOOST_CHECK (B[998] == 0 and B[999] == 0 and B[1000 + NELEM] == 0
                 and B[1001 + NELEM] == 0);

    for (uint32_t i = 0; i < B.size(); ++i) B[i] = 999999999;
    A.clear();
    for (uint32_t i = 0; i < NELEM; ++i) A.push_back(NELEM - i);

    bss::sample_sort<iter_t, std::less<uint64_t> >
        (A.begin(), A.end(), std::less<uint64_t>(),
         std::thread::hardware_concurrency(), Rbuf);

    for (iter_t it = A.begin() + 1; it != A.end(); ++it)
    {
        if ((*(it - 1)) > (*it)) std::cout << "error 2\n";
    };
    BOOST_CHECK (B[998] == 999999999 and B[999] == 999999999
                 and B[1000 + NELEM] == 999999999
                 and B[1001 + NELEM] == 999999999);
}
;
void test8(void)
{
    typedef typename std::vector<uint64_t>::iterator iter_t;
    typedef std::less<uint64_t> compare;
    const uint32_t KMax = 66000;

    std::vector<uint64_t> K, M;
    std::mt19937_64 my_rand(0);
    std::less<uint64_t> comp;

    for (uint32_t i = 0; i < KMax; ++i)
        K.push_back(my_rand());
    M = K;

    bss::sample_sort<iter_t, compare>(K.begin(), K.end(), 300);

    std::stable_sort(M.begin(), M.end(), comp);
    for (unsigned i = 0; i < KMax; i++)
        BOOST_CHECK(M[i] == K[i]);
};

void test9 (void)
{
    typedef typename std::vector<xk>::iterator  iter_t;
    typedef std::less<xk>                           compare_t;
    std::mt19937 my_rand (0);
    std::vector<xk> V ;
    const uint32_t NELEM = 500000;
    V.reserve(NELEM * 10);


    for (uint32_t k =0 ; k < 10 ; ++k)
    {   for ( uint32_t i =0 ; i < NELEM ; ++i)
        {   V.emplace_back(i , k);
        };
        iter_t first = V.begin() + (k * NELEM);
        iter_t last = first + NELEM ;
        std::shuffle( first, last, my_rand);
    };
    bss::sample_sort<iter_t, compare_t>( V.begin() , V.end(), compare_t());
    for ( uint32_t i =0 ; i < ( NELEM * 10); ++i)
    {   BOOST_CHECK ( V[i].num == (i / 10) and V[i].tail == (i %10) );
    };
}


int test_main(int, char *[])
{
    test3();
    test4();
    test5();
    test6();
    test7();
    test8();
    test9();
    return 0;
};