/*
 * Copyright 2009- ECMWF.
 *
 * This software is licensed under the terms of the Apache Licence version 2.0
 * which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
 * In applying this licence, ECMWF does not waive the privileges and immunities
 * granted to it by virtue of its status as an intergovernmental organisation
 * nor does it submit to any jurisdiction.
 */

#include <boost/test/unit_test.hpp>

// **************************************************************************************************************
// IMPORTANT: Str:split uses StringSplitter:
//            to run these tests, please switch off Str.cpp::USE_STRINGSPLITTER
// **************************************************************************************************************
// #define STRING_SPLIT_IMPLEMENTATIONS_PERF_CHECK_ 1;

#ifdef STRING_SPLIT_IMPLEMENTATIONS_PERF_CHECK_
    #include <fstream>

    #include <boost/timer/timer.hpp>

    #include "ecflow/core/File.hpp"
    #include "ecflow/core/Str.hpp"
    #include "ecflow/core/StringSplitter.hpp"
    #include "ecflow/test/scaffold/Naming.hpp"

using namespace ecf;
#endif

BOOST_AUTO_TEST_SUITE(U_Core)

BOOST_AUTO_TEST_SUITE(T_StringSplitPerf)

#ifdef STRING_SPLIT_IMPLEMENTATIONS_PERF_CHECK_

std::vector<std::string> split_using_getline(const std::string& s, char delimiter) {
    std::vector<std::string> tokens;
    std::string token;
    std::istringstream tokenStream(s);
    while (std::getline(tokenStream, token, delimiter)) {
        tokens.push_back(token);
    }
    return tokens;
}

BOOST_AUTO_TEST_CASE(test_str_split_perf) {
    ECF_NAME_THIS_TEST();

    //   Time for istreamstream 1000000 times = 2.59404
    //   Time for std::getline 1000000 times = 1.83148
    //   Time for boost::split 1000000 times = 1.18149
    //   Time for Str::split_orig 1000000 times = 1.3015
    //   Time for make_split_iterator::split 1000000 times = 4.1821
    //   Time for std::string_view 1000000 times =  0.975816
    //   Time for std::string_view(2) 1000000 times = 0.780003

    std::string line = "This is a long string that is going to be used to test the performance of splitting with "
                       "different Implementations the fastest times wins ";
    size_t times     = 1000000;
    ECF_TEST_DBG(<< " This test will split a line " << times << " times: '" << line);

    std::string reconstructed;
    reconstructed.reserve(line.size());

    { // istreamstream    https://www.fluentcpp.com/2017/04/21/how-to-split-a-string-in-c/
        boost::timer::cpu_timer timer; // measures CPU, replace with cpu_timer with boost > 1.51, measures cpu & elapsed
        for (size_t i = 0; i < times; i++) {
            std::istringstream iss(line);
            std::vector<std::string> result((std::istream_iterator<std::string>(iss)),
                                            std::istream_iterator<std::string>());
            reconstructed.clear();
            for (const std::string& s : result) {
                reconstructed += s;
                reconstructed += " ";
            }
        }
        ECF_TEST_DBG(<< " Time for istreamstream " << times
                     << "                 times = " << timer.format(3, Str::cpu_timer_format()));
        BOOST_CHECK_MESSAGE(line == reconstructed, "\n'" << line << "'\n'" << reconstructed << "'");
    }

    { // split using std::get_line    https://www.fluentcpp.com/2017/04/21/how-to-split-a-string-in-c/
        boost::timer::cpu_timer timer; // measures CPU, replace with cpu_timer with boost > 1.51, measures cpu & elapsed
        for (size_t i = 0; i < times; i++) {
            std::vector<std::string> result = split_using_getline(line, ' ');
            reconstructed.clear();
            for (const std::string& s : result) {
                reconstructed += s;
                reconstructed += " ";
            }
        }
        ECF_TEST_DBG(<< " Time for std::getline " << times
                     << "                  times = " << timer.format(3, Str::cpu_timer_format()));
        BOOST_CHECK_MESSAGE(line == reconstructed, "\n'" << line << "'\n'" << reconstructed << "'");
    }

    { // BOOST SPLIT
        std::vector<std::string> result;
        boost::timer::cpu_timer timer; // measures CPU, replace with cpu_timer with boost > 1.51, measures cpu & elapsed
        for (size_t i = 0; i < times; i++) {
            result.clear();
            // boost::algorithm::split(result, line, boost::is_any_of(" \t"),boost::algorithm::token_compress_on);
            boost::split(result, line, [](char c) { return c == ' '; });

            reconstructed.clear();
            for (const std::string& s : result) {
                reconstructed += s;
                reconstructed += " ";
            }
        }
        ECF_TEST_DBG(<< " Time for boost::split " << times
                     << "                  times = " << timer.format(3, Str::cpu_timer_format()));
        // BOOST_CHECK_MESSAGE(line==reconstructed,"\n'" << line << "'\n'" << reconstructed << "'"); // add extra space
    }

    { // Str::split_orig
        std::vector<std::string> result;
        boost::timer::cpu_timer timer;
        for (size_t i = 0; i < times; i++) {
            result.clear();
            Str::split_orig(line, result);

            reconstructed.clear();
            for (const std::string& s : result) {
                reconstructed += s;
                reconstructed += " ";
            }
        }
        ECF_TEST_DBG(<< " Time for Str::split_orig " << times
                     << "               times = " << timer.format(3, Str::cpu_timer_format()));
        BOOST_CHECK_MESSAGE(line == reconstructed, " error");
    }
    { // Str::split_orig1
        std::vector<std::string> result;
        boost::timer::cpu_timer timer;
        for (size_t i = 0; i < times; i++) {
            result.clear();
            Str::split_orig1(line, result);

            reconstructed.clear();
            for (const std::string& s : result) {
                reconstructed += s;
                reconstructed += " ";
            }
        }
        ECF_TEST_DBG(<< " Time for Str::split_orig1 " << times
                     << "              times = " << timer.format(3, Str::cpu_timer_format()));
        BOOST_CHECK_MESSAGE(line == reconstructed, " error");
    }
    { // Str::split_using_string_view2
        std::vector<std::string> result;
        boost::timer::cpu_timer timer;
        for (size_t i = 0; i < times; i++) {
            result.clear();
            Str::split_using_string_view2(line, result);

            reconstructed.clear();
            for (const std::string& s : result) {
                reconstructed += s;
                reconstructed += " ";
            }
        }
        ECF_TEST_DBG(<< " Time for Str::split_using_string_view2 " << times
                     << " times = " << timer.format(3, Str::cpu_timer_format()));
        BOOST_CHECK_MESSAGE(line == reconstructed, " error");
    }
    { // Str::split_using_string_view
        std::vector<std::string> result;
        boost::timer::cpu_timer timer;
        for (size_t i = 0; i < times; i++) {
            result.clear();
            Str::split_using_string_view(line, result);

            reconstructed.clear();
            for (const std::string& s : result) {
                reconstructed += s;
                reconstructed += " ";
            }
        }
        ECF_TEST_DBG(<< " Time for Str::split_using_string_view " << times
                     << "  times = " << timer.format(3, Str::cpu_timer_format()));
        BOOST_CHECK_MESSAGE(line == reconstructed, " error");
    }

    { // boost::make_split_iterator
        boost::timer::cpu_timer timer;
        for (size_t i = 0; i < times; i++) {

            auto tokens = Str::make_split_iterator(line);

            std::stringstream ss;
            for (; !tokens.eof(); ++tokens) {
                boost::iterator_range<std::string::const_iterator> range = *tokens;
                ss << range << " ";
            }
            reconstructed = ss.str();
        }
        ECF_TEST_DBG(<< " Time for make_split_iterator::split " << times
                     << "    times = " << timer.format(3, Str::cpu_timer_format()));
    }

    { // std::string_view
        boost::timer::cpu_timer timer;
        for (size_t i = 0; i < times; i++) {
            StringSplitter string_splitter(line);

            reconstructed.clear();
            while (!string_splitter.finished()) {
                std::string_view sv = string_splitter.next();
                reconstructed += std::string(sv.begin(), sv.end());
                reconstructed += " ";
            }
        }
        ECF_TEST_DBG(<< " Time for std::string_view " << times
                     << "            times = " << timer.format(3, Str::cpu_timer_format()));
        BOOST_CHECK_MESSAGE(line == reconstructed, "\n'" << line << "'\n'" << reconstructed << "'");
    }

    { // std::string_view
        boost::timer::cpu_timer timer;
        std::vector<std::string_view> result;
        for (size_t i = 0; i < times; i++) {

            result.clear();
            StringSplitter::split2(line, result);

            reconstructed.clear();
            for (const auto& s : result) {
                reconstructed += std::string(s.begin(), s.end());
                reconstructed += " ";
            }
        }
        ECF_TEST_DBG(<< " Time for std::string_view(2) " << times
                     << "         times = " << timer.format(3, Str::cpu_timer_format()));
        BOOST_CHECK_MESSAGE(line == reconstructed, "\n'" << line << "'\n'" << reconstructed << "'");
    }
}

BOOST_AUTO_TEST_CASE(test_str_split_perf_with_file) {
    ECF_NAME_THIS_TEST();

    //   Time for istreamstream 2001774 times = 1.81123
    //   Time for std::getline 2001774 times = 2.89138
    //   Time for boost::split 2001774 times = 1.98556
    //   Time for Str::split_orig 2001774 times = 0.947959
    //   Time for boost::make_split_iterator 2001774 times = 3.921
    //   Time for std::string_view 2001774 times = 0.765805
    //   Time for std::string_view(2) 2001774 times = 0.752472

    // Now test performance of splitting with a big DEFS file
    auto ecf_test_defs_dir = ecf::environment::fetch("ECF_TEST_DEFS_DIR");
    if (!ecf_test_defs_dir) {
        ECF_TEST_DBG(<< "Igoring test, since directory defined by environment variable(ECF_TEST_DEFS_DIR) is missing");
        return;
    }
    std::string path = ecf_test_defs_dir.value() + "/vsms2.31415.def";
    if (!fs::exists(path)) {
        std::cout << "Igoring test, since file defined by environment variable(ECF_TEST_DEFS_DIR) " << path
                  << " is missing";
        return;
    }

    std::vector<std::string> file_contents;
    if (File::splitFileIntoLines(path, file_contents, true /* ignore empty lines*/)) {

        ECF_TEST_DBG(<< " This test will split each line in file " << path);

        std::vector<std::string> result;
        result.reserve(300);

        auto reconstruct_line = [](const std::vector<std::string>& result) {
            std::string reconstructed;
            for (const auto& s : result) {
                reconstructed += s;
                reconstructed += " ";
            }
        };

        { // istreamstream
            boost::timer::cpu_timer timer;
            for (size_t i = 0; i < file_contents.size(); i++) {
                std::istringstream iss(file_contents[i]);
                std::vector<std::string> result1((std::istream_iterator<std::string>(iss)),
                                                 std::istream_iterator<std::string>());
                reconstruct_line(result1);
            }
            ECF_TEST_DBG(<< " Time for istreamstream " << file_contents.size()
                         << " times = " << timer.format(3, Str::cpu_timer_format()));
        }
        { // std::getline
            boost::timer::cpu_timer timer;
            for (size_t i = 0; i < file_contents.size(); i++) {
                reconstruct_line(split_using_getline(file_contents[i], ' '));
            }
            ECF_TEST_DBG(<< " Time for std::getline " << file_contents.size()
                         << " times = " << timer.format(3, Str::cpu_timer_format()));
        }
        {
            boost::timer::cpu_timer timer;
            for (size_t i = 0; i < file_contents.size(); i++) {
                result.clear();
                // boost::algorithm::split(result,file_contents[i], boost::is_any_of("
                // \t"),boost::algorithm::token_compress_on);
                boost::split(result, file_contents[i], [](char c) { return c == ' '; });

                reconstruct_line(result);
            }
            ECF_TEST_DBG(<< " Time for boost::split " << file_contents.size()
                         << " times = " << timer.format(3, Str::cpu_timer_format()));
        }
        {
            boost::timer::cpu_timer timer;
            for (size_t i = 0; i < file_contents.size(); i++) {
                result.clear();
                Str::split_orig(file_contents[i], result);

                reconstruct_line(result);
            }
            ECF_TEST_DBG(<< " Time for Str::split_orig " << file_contents.size()
                         << " times = " << timer.format(3, Str::cpu_timer_format()));
        }
        {
            boost::timer::cpu_timer timer;
            for (size_t i = 0; i < file_contents.size(); i++) {
                result.clear();
                Str::split_orig1(file_contents[i], result);

                reconstruct_line(result);
            }
            ECF_TEST_DBG(<< " Time for Str::split_orig1 " << file_contents.size()
                         << " times = " << timer.format(3, Str::cpu_timer_format()));
        }
        {
            boost::timer::cpu_timer timer;
            for (size_t i = 0; i < file_contents.size(); i++) {
                result.clear();
                Str::split_using_string_view(file_contents[i], result);

                reconstruct_line(result);
            }
            ECF_TEST_DBG(<< " Time for Str::split_using_string_view " << file_contents.size()
                         << " times = " << timer.format(3, Str::cpu_timer_format()));
        }
        {
            boost::timer::cpu_timer timer;
            for (size_t i = 0; i < file_contents.size(); i++) {
                result.clear();
                Str::split_using_string_view2(file_contents[i], result);

                reconstruct_line(result);
            }
            ECF_TEST_DBG(<< " Time for Str::split_using_string_view2 " << file_contents.size()
                         << " times = " << timer.format(3, Str::cpu_timer_format()));
        }
        {
            boost::timer::cpu_timer timer;
            for (size_t i = 0; i < file_contents.size(); i++) {

                std::stringstream ss;
                auto tokens = Str::make_split_iterator(file_contents[i]);

                for (; !tokens.eof(); ++tokens) {
                    auto range = *tokens;
                    ss << range << " ";
                }
                std::string reconstructed = ss.str();
            }
            ECF_TEST_DBG(<< " Time for boost::make_split_iterator " << file_contents.size()
                         << " times = " << timer.format(3, Str::cpu_timer_format()));
        }

        {
            boost::timer::cpu_timer timer;
            for (size_t i = 0; i < file_contents.size(); i++) {

                StringSplitter string_splitter(file_contents[i]);

                std::string reconstructed;
                while (!string_splitter.finished()) {
                    std::string_view sv = string_splitter.next();
                    reconstructed += std::string(sv.begin(), sv.end());
                    reconstructed += " ";
                }
            }
            ECF_TEST_DBG(<< " Time for std::string_view " << file_contents.size()
                         << " times = " << timer.format(3, Str::cpu_timer_format()));
        }

        {
            std::vector<std::string_view> result1;
            boost::timer::cpu_timer timer;
            for (size_t i = 0; i < file_contents.size(); i++) {

                StringSplitter::split2(file_contents[i], result1);

                std::string reconstructed;
                for (const auto& s : result1) {
                    reconstructed += std::string(s.begin(), s.end());
                    reconstructed += " ";
                }
                result1.clear();
            }
            ECF_TEST_DBG(<< " Time std::string_view(2) " << file_contents.size()
                         << " times = " << timer.format(3, Str::cpu_timer_format()));
        }
    }
}

BOOST_AUTO_TEST_CASE(test_str_get_token_perf) {
    ECF_NAME_THIS_TEST();

    std::vector<std::string> result;
    std::string line = "This is a long string that is going to be used to test the performance of splitting with "
                       "different Implementations the fastest times wins ";
    size_t times     = 250000;
    ECF_TEST_DBG(<< " This test will split a line " << times << " times: '" << line);

    Str::split_using_string_view(line, result);
    size_t result_size = result.size();
    std::string token;

    {
        boost::timer::cpu_timer timer;
        for (size_t i = 0; i < times; i++) {
            for (size_t r = 0; r < result_size; r++) {
                token.clear();
                (void)StringSplitter::get_token(line, r, token);
            }
        }
        ECF_TEST_DBG(<< " Time for StringSplitter::get_token " << times
                     << " times = " << timer.format(3, Str::cpu_timer_format()));
        BOOST_CHECK_MESSAGE(true, "Keep compiler happy");
    }
    {
        boost::timer::cpu_timer timer;
        for (size_t i = 0; i < times; i++) {
            for (size_t r = 0; r < result_size; r++) {
                token.clear();
                (void)Str::get_token(line, r, token);
            }
        }
        ECF_TEST_DBG(<< " Time for Str::get_token            " << times
                     << " times = " << timer.format(3, Str::cpu_timer_format()));
        BOOST_CHECK_MESSAGE(true, "Keep compiler happy");
    }
    {
        boost::timer::cpu_timer timer;
        for (size_t i = 0; i < times; i++) {
            for (size_t r = 0; r < result_size; r++) {
                token.clear();
                (void)Str::get_token2(line, r, token);
            }
        }
        ECF_TEST_DBG(<< " Time for Str::get_token2           " << times
                     << " times = " << timer.format(3, Str::cpu_timer_format()));
        BOOST_CHECK_MESSAGE(true, "Keep compiler happy");
    }
    {
        boost::timer::cpu_timer timer;
        for (size_t i = 0; i < times; i++) {
            for (size_t r = 0; r < result_size; r++) {
                token.clear();
                (void)Str::get_token3(line, r, token);
            }
        }
        ECF_TEST_DBG(<< " Time for Str::get_token3           " << times
                     << " times = " << timer.format(3, Str::cpu_timer_format()));
        BOOST_CHECK_MESSAGE(true, "Keep compiler happy");
    }
}

#endif

BOOST_AUTO_TEST_SUITE_END()

BOOST_AUTO_TEST_SUITE_END()