// -*- C++ -*-
//===-- transform_reduce.pass.cpp -----------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include "support/pstl_test_config.h"

#include <execution>
#include <numeric>

#include "support/utils.h"

using namespace TestUtils;

// Equal for all types
template <typename T>
static bool
Equal(T x, T y)
{
    return x == y;
}

// Functor for xor-operation for modeling binary operations in inner_product
class XOR
{
  public:
    template <typename T>
    T
    operator()(const T& left, const T& right) const
    {
        return left ^ right;
    }
};

// Model of User-defined class
class MyClass
{
  public:
    int32_t my_field;
    MyClass() { my_field = 0; }
    MyClass(int32_t in) { my_field = in; }
    MyClass(const MyClass& in) { my_field = in.my_field; }

    friend MyClass
    operator+(const MyClass& x, const MyClass& y)
    {
        return MyClass(x.my_field + y.my_field);
    }
    friend MyClass
    operator-(const MyClass& x)
    {
        return MyClass(-x.my_field);
    }
    friend MyClass operator*(const MyClass& x, const MyClass& y) { return MyClass(x.my_field * y.my_field); }
    bool
    operator==(const MyClass& in)
    {
        return my_field == in.my_field;
    }
};

template <typename T>
void
CheckResults(const T& expected, const T& in)
{
    EXPECT_TRUE(Equal(expected, in), "wrong result of transform_reduce");
}

// We need to check correctness only for "int" (for example) except cases
// if we have "floating-point type"-specialization
void
CheckResults(const float32_t&, const float32_t&)
{
}

// Test for different types and operations with different iterators
struct test_transform_reduce
{
    template <typename Policy, typename InputIterator1, typename InputIterator2, typename T, typename BinaryOperation1,
              typename BinaryOperation2, typename UnaryOp>
    void
    operator()(Policy&& exec, InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2,
               T init, BinaryOperation1 opB1, BinaryOperation2 opB2, UnaryOp opU)
    {

        auto expectedB = std::inner_product(first1, last1, first2, init, opB1, opB2);
        auto expectedU = transform_reduce_serial(first1, last1, init, opB1, opU);
        T resRA = std::transform_reduce(exec, first1, last1, first2, init, opB1, opB2);
        CheckResults(expectedB, resRA);
        resRA = std::transform_reduce(exec, first1, last1, init, opB1, opU);
        CheckResults(expectedU, resRA);
    }
};

template <typename T, typename BinaryOperation1, typename BinaryOperation2, typename UnaryOp, typename Initializer>
void
test_by_type(T init, BinaryOperation1 opB1, BinaryOperation2 opB2, UnaryOp opU, Initializer initObj)
{

    std::size_t maxSize = 100000;
    Sequence<T> in1(maxSize, initObj);
    Sequence<T> in2(maxSize, initObj);

    for (std::size_t n = 0; n < maxSize; n = n < 16 ? n + 1 : size_t(3.1415 * n))
    {
        invoke_on_all_policies(test_transform_reduce(), in1.begin(), in1.begin() + n, in2.begin(), in2.begin() + n,
                               init, opB1, opB2, opU);
        invoke_on_all_policies(test_transform_reduce(), in1.cbegin(), in1.cbegin() + n, in2.cbegin(), in2.cbegin() + n,
                               init, opB1, opB2, opU);
    }
}

int32_t
main()
{
    test_by_type<int32_t>(42, std::plus<int32_t>(), std::multiplies<int32_t>(), std::negate<int32_t>(),
                          [](std::size_t) -> int32_t { return int32_t(rand() % 1000); });
    test_by_type<int64_t>(0, [](const int64_t& a, const int64_t& b) -> int64_t { return a | b; }, XOR(),
                          [](const int64_t& x) -> int64_t { return x * 2; },
                          [](std::size_t) -> int64_t { return int64_t(rand() % 1000); });
    test_by_type<float32_t>(1.0f, std::multiplies<float32_t>(),
                            [](const float32_t& a, const float32_t& b) -> float32_t { return a + b; },
                            [](const float32_t& x) -> float32_t { return x + 2; },
                            [](std::size_t) -> float32_t { return rand() % 1000; });
    test_by_type<MyClass>(MyClass(), std::plus<MyClass>(), std::multiplies<MyClass>(), std::negate<MyClass>(),
                          [](std::size_t) -> MyClass { return MyClass(rand() % 1000); });

    std::cout << done() << std::endl;
    return 0;
}