/*
    Copyright (c) 2005-2021 Intel Corporation

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
*/

//! \file test_environment_whitebox.cpp
//! \brief Test for [internal] functionality

#if _WIN32 || _WIN64
#define _CRT_SECURE_NO_WARNINGS
#endif

#include "common/test.h"
#include "common/utils.h"
#include "common/utils_env.h"
#include "src/tbb/environment.h"

#include <string>
#include <algorithm>
#include <sstream>
#include <climits>
#include <utility>
#include <vector>

const char* environment_variable_name = "TEST_VARIABLE_NAME";

// For WIN8UI applications reading and writing the environment variables
// is prohibited due to the platform limitations
#if !__TBB_WIN8UI_SUPPORT

#if _WIN32 || _WIN64
// Environment variable length is limited by 32K on Windows
const std::size_t large_length = 32000;
#else
const std::size_t large_length = 1000000;
#endif

template <typename T>
void set_and_get_test_variable( T (*environment_variable_getter)( const char* ),
                                std::pair<std::string, T> test_case )
{
    utils::SetEnv(environment_variable_name, test_case.first.c_str());
    T result = environment_variable_getter(environment_variable_name);
    REQUIRE_MESSAGE(result == test_case.second, "Wrong Get<Type>EnvironmentVariable return value");
    utils::SetEnv(environment_variable_name, "");
}

utils::FastRandom<> rnd(12345);

struct RandomCharacterGenerator {
    char operator()() {
        return rnd.get() % 128; // 127 - the last ASCII symbol
    }
}; // struct RandomCharacterGenerator

bool alternative_env_variable_checker( const char* str, bool ) {
    bool result = false;
    for (unsigned i = 0; str[i]; ++i) {
        if (str[i] == '1') {
            // if we found more then one '1' character -> return false
            result = !result;
            if (!result) return false;
        } else if (str[i] != ' ') {
            // if we found some character other than ' ' and '1' -> return false
            return false;
        }
    }
    return result;
}

// Suitable alternative checker for GetLongEnvVariable() was not found
// So here we use the code from GetLongEnvVariable() realization
long alternative_env_variable_checker( const char* str, long ) {
    char* end;
    errno = 0;
    long result = std::strtol(str, &end, 10);

    // We have exceeded the range, value is negative or it is the end of the string
    if (errno == ERANGE || result < 0 || end == str) {
        result = -1;
    }

    for (; *end != '\0'; ++end) {
        if (!std::isspace(*end))
            result = -1;
    }
    return result;
}

template <typename T>
std::pair<std::string, T> create_random_case( std::size_t length ) {
    REQUIRE_MESSAGE(length != 0, "Requested random string cannot be empty");
    std::string rand_string(length, ' ');
    std::generate(rand_string.begin(), rand_string.end(), RandomCharacterGenerator{});

    T expected_result = alternative_env_variable_checker(rand_string.c_str(), T());

    return std::make_pair(rand_string, expected_result);
}

template <typename T>
void prepare_random_cases( std::vector<std::pair<std::string, T>>& cases ) {
    // Random cases
    std::size_t length = 10000;

    for (std::size_t i = 0; i < 10; ++i) {
        cases.push_back(create_random_case<T>((rnd.get() % length) + 1));
    }

    // Random case with large string
    cases.push_back(create_random_case<T>(large_length));
}

std::vector<std::pair<std::string, bool>> initialize_cases( bool wrong_result ) {
    std::vector<std::pair<std::string, bool>> cases;
    // Valid cases
    cases.push_back(std::make_pair("1", true));
    cases.push_back(std::make_pair(" 1 ", true));
    cases.push_back(std::make_pair("1              ", true));
    cases.push_back(std::make_pair("             1           ", true));
    cases.push_back(std::make_pair("         1", true));
    cases.push_back(std::make_pair((std::string(large_length, ' ') + '1').c_str(), true));

    // Invalid cases
    cases.push_back(std::make_pair("", wrong_result));
    cases.push_back(std::make_pair(" ", wrong_result));
    cases.push_back(std::make_pair(" 11", wrong_result));
    cases.push_back(std::make_pair("111111", wrong_result));
    cases.push_back(std::make_pair("1 1", wrong_result));
    cases.push_back(std::make_pair(" 1 abc?", wrong_result));
    cases.push_back(std::make_pair("1;", wrong_result));
    cases.push_back(std::make_pair(" d ", wrong_result));
    cases.push_back(std::make_pair("0", wrong_result));
    cases.push_back(std::make_pair("0 ", wrong_result));
    cases.push_back(std::make_pair("000000", wrong_result));
    cases.push_back(std::make_pair("01", wrong_result));
    cases.push_back(std::make_pair("00000001", wrong_result));
    cases.push_back(std::make_pair("ABCDEFG", wrong_result));
    cases.push_back(std::make_pair("2018", wrong_result));
    cases.push_back(std::make_pair("ABC_123", wrong_result));
    cases.push_back(std::make_pair("true", wrong_result));
    cases.push_back(std::make_pair(std::string(large_length, 'A').c_str(), wrong_result));

    prepare_random_cases(cases);
    return cases;
}

std::vector<std::pair<std::string, long>> initialize_cases( long wrong_result ) {
    std::vector<std::pair<std::string, long>> cases;
    std::stringstream ss;
    // Valid cases
    for (long i = 0; i < 100; ++i) {
        ss << i;
        cases.push_back(std::make_pair(ss.str().c_str(), i));
        ss.str("");

        ss << "     " << i << "     ";
        cases.push_back(std::make_pair(ss.str().c_str(), i));
        ss.str("");

        ss << i << "     ";
        cases.push_back(std::make_pair(ss.str().c_str(), i));
        ss.str("");

        ss << "     " << i;
        cases.push_back(std::make_pair(ss.str().c_str(), i));
        ss.str("");
    }

    ss << LONG_MAX;
    cases.push_back(std::make_pair(ss.str().c_str(), LONG_MAX));
    ss.str("");

    cases.push_back(std::make_pair((std::string(large_length, ' ') + '1').c_str(), 1L));

    // Invalid cases
    cases.push_back(std::make_pair("", wrong_result));
    cases.push_back(std::make_pair("  ", wrong_result));
    cases.push_back(std::make_pair("a", wrong_result));
    cases.push_back(std::make_pair("^&*", wrong_result));
    cases.push_back(std::make_pair("  10   e", wrong_result));
    cases.push_back(std::make_pair("a   12", wrong_result));
    cases.push_back(std::make_pair("eeeeeeeeeeeeeeeeee", wrong_result));
    cases.push_back(std::make_pair("200000000000000000000000000", wrong_result));
    cases.push_back(std::make_pair("-1", wrong_result));
    cases.push_back(std::make_pair("-100", wrong_result));
    cases.push_back(std::make_pair("-200000000000000000000000000", wrong_result));
    cases.push_back(std::make_pair("ABBDDRR", wrong_result));
    cases.push_back(std::make_pair("10  10", wrong_result));
    cases.push_back(std::make_pair("true", wrong_result));
    cases.push_back(std::make_pair("false", wrong_result));
    cases.push_back(std::make_pair("1A", wrong_result));
    cases.push_back(std::make_pair("_123", wrong_result));
    cases.push_back(std::make_pair(std::string(large_length, 'A').c_str(), wrong_result));

    // Prepare string with LONG_MAX + 1 value
    ss << LONG_MAX / 10 << (LONG_MAX % 10 + 1);
    cases.push_back(std::make_pair(ss.str().c_str(), -1));
    ss.str("");

    prepare_random_cases(cases);
    return cases;
}

template <typename T>
void test_environment_variable( T (*environment_variables_handler)( const char* ), T wrong_result ) {
    REQUIRE_MESSAGE(environment_variables_handler(environment_variable_name) == wrong_result,
                    "Tested environment variable should not be defined in the beginning");

    // Each pair is a test case:
    // pair.first -> value of environment variable
    // pair.second -> expected result
    std::vector<std::pair<std::string, T>> cases = initialize_cases(wrong_result);

    for (std::size_t i = 0; i != cases.size(); ++i) {
        set_and_get_test_variable(environment_variables_handler, cases[i]);
    }
}

//! \brief \ref error_guessing
TEST_CASE("testing GetBoolEnvironmentVariable") {
    test_environment_variable(tbb::detail::r1::GetBoolEnvironmentVariable, false);
}

//! \brief \ref error_guessing
TEST_CASE("testing GetIntegralEnvironmentVariable") {
    test_environment_variable(tbb::detail::r1::GetIntegralEnvironmentVariable, -1L);
}

#endif // !__TBB_WIN8UI_SUPPORT