/*
 * Copyright (c) 2017 ARM Limited.
 *
 * SPDX-License-Identifier: MIT
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
#ifndef __ARM_COMPUTE_TEST_UTILS_H__
#define __ARM_COMPUTE_TEST_UTILS_H__

#include "arm_compute/core/Coordinates.h"
#include "arm_compute/core/Error.h"
#include "arm_compute/core/FixedPoint.h"
#include "arm_compute/core/TensorShape.h"
#include "arm_compute/core/Types.h"

#include <cmath>
#include <cstddef>
#include <limits>
#include <memory>
#include <sstream>
#include <string>
#include <type_traits>

namespace arm_compute
{
namespace test
{
namespace cpp11
{
#ifdef __ANDROID__
/** Convert integer and float values to string.
 *
 * @note This function implements the same behaviour as std::to_string. The
 *       latter is missing in some Android toolchains.
 *
 * @param[in] value Value to be converted to string.
 *
 * @return String representation of @p value.
 */
template <typename T, typename std::enable_if<std::is_arithmetic<typename std::decay<T>::type>::value, int>::type = 0>
std::string to_string(T && value)
{
    std::stringstream stream;
    stream << std::forward<T>(value);
    return stream.str();
}

/** Convert string values to integer.
 *
 * @note This function implements the same behaviour as std::stoi. The latter
 *       is missing in some Android toolchains.
 *
 * @param[in] str String to be converted to int.
 *
 * @return Integer representation of @p str.
 */
inline int stoi(const std::string &str)
{
    std::stringstream stream(str);
    int               value = 0;
    stream >> value;
    return value;
}

/** Convert string values to unsigned long.
 *
 * @note This function implements the same behaviour as std::stoul. The latter
 *       is missing in some Android toolchains.
 *
 * @param[in] str String to be converted to unsigned long.
 *
 * @return Unsigned long representation of @p str.
 */
inline unsigned long stoul(const std::string &str)
{
    std::stringstream stream(str);
    unsigned long     value = 0;
    stream >> value;
    return value;
}

/** Convert string values to float.
 *
 * @note This function implements the same behaviour as std::stof. The latter
 *       is missing in some Android toolchains.
 *
 * @param[in] str String to be converted to float.
 *
 * @return Float representation of @p str.
 */
inline float stof(const std::string &str)
{
    std::stringstream stream(str);
    float             value = 0.f;
    stream >> value;
    return value;
}

/** Round floating-point value with half value rounding away from zero.
 *
 * @note This function implements the same behaviour as std::round except that it doesn't
 *       support Integral type. The latter is not in the namespace std in some Android toolchains.
 *
 * @param[in] value floating-point value to be rounded.
 *
 * @return Floating-point value of rounded @p value.
 */
template <typename T, typename = typename std::enable_if<std::is_floating_point<T>::value>::type>
inline T round(T value)
{
    return ::round(value);
}

/** Truncate floating-point value.
 *
 * @note This function implements the same behaviour as std::truncate except that it doesn't
 *       support Integral type. The latter is not in the namespace std in some Android toolchains.
 *
 * @param[in] value floating-point value to be truncated.
 *
 * @return Floating-point value of truncated @p value.
 */
template <typename T, typename = typename std::enable_if<std::is_floating_point<T>::value>::type>
inline T trunc(T value)
{
    return ::trunc(value);
}

/** Composes a floating point value with the magnitude of @p x and the sign of @p y.
 *
 * @note This function implements the same behaviour as std::copysign except that it doesn't
 *       support Integral type. The latter is not in the namespace std in some Android toolchains.
 *
 * @param[in] x value that contains the magnitued to be used in constructing the result.
 * @param[in] y value that contains the sign to be used in constructin the result.
 *
 * @return Floating-point value with magnitude of @p x and sign of @p y.
 */
template <typename T, typename = typename std::enable_if<std::is_floating_point<T>::value>::type>
inline T copysign(T x, T y)
{
    return ::copysign(x, y);
}
#else
/** Convert integer and float values to string.
 *
 * @note This function acts as a convenience wrapper around std::to_string. The
 *       latter is missing in some Android toolchains.
 *
 * @param[in] value Value to be converted to string.
 *
 * @return String representation of @p value.
 */
template <typename T>
std::string to_string(T &&value)
{
    return ::std::to_string(std::forward<T>(value));
}

/** Convert string values to integer.
 *
 * @note This function acts as a convenience wrapper around std::stoi. The
 *       latter is missing in some Android toolchains.
 *
 * @param[in] args Arguments forwarded to std::stoi.
 *
 * @return Integer representation of input string.
 */
template <typename... Ts>
int stoi(Ts &&... args)
{
    return ::std::stoi(std::forward<Ts>(args)...);
}

/** Convert string values to unsigned long.
 *
 * @note This function acts as a convenience wrapper around std::stoul. The
 *       latter is missing in some Android toolchains.
 *
 * @param[in] args Arguments forwarded to std::stoul.
 *
 * @return Unsigned long representation of input string.
 */
template <typename... Ts>
int stoul(Ts &&... args)
{
    return ::std::stoul(std::forward<Ts>(args)...);
}

/** Convert string values to float.
 *
 * @note This function acts as a convenience wrapper around std::stof. The
 *       latter is missing in some Android toolchains.
 *
 * @param[in] args Arguments forwarded to std::stof.
 *
 * @return Float representation of input string.
 */
template <typename... Ts>
int stof(Ts &&... args)
{
    return ::std::stof(std::forward<Ts>(args)...);
}

/** Round floating-point value with half value rounding away from zero.
 *
 * @note This function implements the same behaviour as std::round except that it doesn't
 *       support Integral type. The latter is not in the namespace std in some Android toolchains.
 *
 * @param[in] value floating-point value to be rounded.
 *
 * @return Floating-point value of rounded @p value.
 */
template <typename T, typename = typename std::enable_if<std::is_floating_point<T>::value>::type>
inline T round(T value)
{
    return std::round(value);
}

/** Truncate floating-point value.
 *
 * @note This function implements the same behaviour as std::truncate except that it doesn't
 *       support Integral type. The latter is not in the namespace std in some Android toolchains.
 *
 * @param[in] value floating-point value to be truncated.
 *
 * @return Floating-point value of truncated @p value.
 */
template <typename T, typename = typename std::enable_if<std::is_floating_point<T>::value>::type>
inline T trunc(T value)
{
    return std::trunc(value);
}

/** Composes a floating point value with the magnitude of @p x and the sign of @p y.
 *
 * @note This function implements the same behaviour as std::copysign except that it doesn't
 *       support Integral type. The latter is not in the namespace std in some Android toolchains.
 *
 * @param[in] x value that contains the magnitued to be used in constructing the result.
 * @param[in] y value that contains the sign to be used in constructin the result.
 *
 * @return Floating-point value with magnitude of @p x and sign of @p y.
 */
template <typename T, typename = typename std::enable_if<std::is_floating_point<T>::value>::type>
inline T copysign(T x, T y)
{
    return std::copysign(x, y);
}
#endif

/** Round floating-point value with half value rounding to positive infinity.
 *
 * @param[in] value floating-point value to be rounded.
 *
 * @return Floating-point value of rounded @p value.
 */
template <typename T, typename = typename std::enable_if<std::is_floating_point<T>::value>::type>
inline T round_half_up(T value)
{
    return std::floor(value + 0.5f);
}

/** Round floating-point value with half value rounding to nearest even.
 *
 * @param[in] value   floating-point value to be rounded.
 * @param[in] epsilon precision.
 *
 * @return Floating-point value of rounded @p value.
 */
template <typename T, typename = typename std::enable_if<std::is_floating_point<T>::value>::type>
inline T round_half_even(T value, T epsilon = std::numeric_limits<T>::epsilon())
{
    T positive_value = std::abs(value);
    T ipart          = 0;
    std::modf(positive_value, &ipart);
    // If 'value' is exactly halfway between two integers
    if(std::abs(positive_value - (ipart + 0.5f)) < epsilon)
    {
        // If 'ipart' is even then return 'ipart'
        if(std::fmod(ipart, 2.f) < epsilon)
        {
            return cpp11::copysign(ipart, value);
        }
        // Else return the nearest even integer
        return cpp11::copysign(std::ceil(ipart + 0.5f), value);
    }
    // Otherwise use the usual round to closest
    return cpp11::copysign(cpp11::round(positive_value), value);
}
} // namespace cpp11

namespace cpp14
{
/** make_unqiue is missing in CPP11. Reimplement it according to the standard
 * proposal.
 */
template <class T>
struct _Unique_if
{
    typedef std::unique_ptr<T> _Single_object;
};

template <class T>
struct _Unique_if<T[]>
{
    typedef std::unique_ptr<T[]> _Unknown_bound;
};

template <class T, size_t N>
struct _Unique_if<T[N]>
{
    typedef void _Known_bound;
};

template <class T, class... Args>
typename _Unique_if<T>::_Single_object
make_unique(Args &&... args)
{
    return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
}

template <class T>
typename _Unique_if<T>::_Unknown_bound
make_unique(size_t n)
{
    typedef typename std::remove_extent<T>::type U;
    return std::unique_ptr<T>(new U[n]());
}

template <class T, class... Args>
typename _Unique_if<T>::_Known_bound
make_unique(Args &&...) = delete;
} // namespace cpp14

namespace traits
{
// *INDENT-OFF*
// clang-format off
template <typename T> struct promote { };
template <> struct promote<uint8_t> { using type = uint16_t; };
template <> struct promote<int8_t> { using type = int16_t; };
template <> struct promote<uint16_t> { using type = uint32_t; };
template <> struct promote<int16_t> { using type = int32_t; };
template <> struct promote<uint32_t> { using type = uint64_t; };
template <> struct promote<int32_t> { using type = int64_t; };
template <> struct promote<float> { using type = float; };

template <typename T>
using promote_t = typename promote<T>::type;

template <typename T>
using make_signed_conditional_t = typename std::conditional<std::is_integral<T>::value, std::make_signed<T>, std::common_type<T>>::type;
// clang-format on
// *INDENT-ON*
}

/** Look up the format corresponding to a channel.
 *
 * @param[in] channel Channel type.
 *
 * @return Format that contains the given channel.
 */
inline Format get_format_for_channel(Channel channel)
{
    switch(channel)
    {
        case Channel::R:
        case Channel::G:
        case Channel::B:
            return Format::RGB888;
        default:
            throw std::runtime_error("Unsupported channel");
    }
}

/** Return the format of a channel.
 *
 * @param[in] channel Channel type.
 *
 * @return Format of the given channel.
 */
inline Format get_channel_format(Channel channel)
{
    switch(channel)
    {
        case Channel::R:
        case Channel::G:
        case Channel::B:
            return Format::U8;
        default:
            throw std::runtime_error("Unsupported channel");
    }
}

/** Base case of foldl.
 *
 * @return value.
 */
template <typename F, typename T>
inline T foldl(F &&, const T &value)
{
    return value;
}

/** Base case of foldl.
 *
 * @return func(value1, value2).
 */
template <typename F, typename T, typename U>
inline auto foldl(F &&func, T &&value1, U &&value2) -> decltype(func(value1, value2))
{
    return func(value1, value2);
}

/** Fold left.
 *
 * @param[in] func    Binary function to be called.
 * @param[in] initial Initial value.
 * @param[in] value   Argument passed to the function.
 * @param[in] values  Remaining arguments.
 */
template <typename F, typename I, typename T, typename... Vs>
inline I foldl(F &&func, I &&initial, T &&value, Vs &&... values)
{
    return foldl(std::forward<F>(func), func(std::forward<I>(initial), std::forward<T>(value)), std::forward<Vs>(values)...);
}

/** Create a valid region covering the enitre tensor shape.
 *
 * @param[in] shape Shape used as size of the valid region.
 *
 * @return A valid region starting at (0, 0, ...) with size of @p shape.
 */
inline ValidRegion shape_to_valid_region(TensorShape shape)
{
    Coordinates anchor;
    anchor.set(std::max<int>(0, shape.num_dimensions() - 1), 0);
    return ValidRegion(std::move(anchor), std::move(shape));
}

/** Create a valid region covering the tensor shape with UNDEFINED border mode and specified border size.
 *
 * @param[in] shape       Shape used as size of the valid region.
 * @param[in] border_size Border size used to specify the region to exclude.
 *
 * @return A valid region starting at (@p border_size.left, @p border_size.top, ...) with reduced size of @p shape.
 */
inline ValidRegion shape_to_valid_region_undefined_border(TensorShape shape, BorderSize border_size)
{
    ARM_COMPUTE_ERROR_ON(shape.num_dimensions() < 2);
    Coordinates anchor;
    anchor.set(std::max<int>(0, shape.num_dimensions() - 1), 0);
    anchor.set(0, border_size.left);
    anchor.set(1, border_size.top);
    shape.set(0, shape.x() - border_size.left - border_size.right);
    shape.set(1, shape.y() - border_size.top - border_size.bottom);
    return ValidRegion(std::move(anchor), shape);
}

/** Calculate the required padding given the available @p size and the required.
 * @p step.
 *
 * @param[in] size Available size.
 * @param[in] step Required step size.
 *
 * @return Difference between next greater multiple of @p step and @p size.
 */
inline int required_padding(int size, int step)
{
    return ((size + step - 1) / step) * step - size;
}

/** Calculate the required padding for writing operation with UNDEFINED border mode.
 *
 * @param[in] size        Available size.
 * @param[in] step        Required step size; number of elements to write at each iteration.
 * @param[in] border_size Border size.
 *
 * @return Required padding size plus border size.
 */
inline int required_padding_undefined_border_write(int size, int step, int border_size)
{
    return required_padding(size, step) + border_size;
}

/** Calculate the required padding for reading operation with UNDEFINED border mode.
 *
 * @param[in] size         Available size.
 * @param[in] read_step    Required step size; number of elements to read at each iteration.
 * @param[in] process_step Required step size; number of elements to process at each iteration.
 *
 * @return Required padding size.
 */
inline int required_padding_undefined_border_read(int size, int read_step, int process_step)
{
    return required_padding(size, process_step) + read_step - process_step;
}

/** Write the value after casting the pointer according to @p data_type.
 *
 * @warning The type of the value must match the specified data type.
 *
 * @param[out] ptr       Pointer to memory where the @p value will be written.
 * @param[in]  value     Value that will be written.
 * @param[in]  data_type Data type that will be written.
 */
template <typename T>
void store_value_with_data_type(void *ptr, T value, DataType data_type)
{
    switch(data_type)
    {
        case DataType::U8:
            *reinterpret_cast<uint8_t *>(ptr) = value;
            break;
        case DataType::S8:
        case DataType::QS8:
            *reinterpret_cast<int8_t *>(ptr) = value;
            break;
        case DataType::U16:
            *reinterpret_cast<uint16_t *>(ptr) = value;
            break;
        case DataType::S16:
            *reinterpret_cast<int16_t *>(ptr) = value;
            break;
        case DataType::U32:
            *reinterpret_cast<uint32_t *>(ptr) = value;
            break;
        case DataType::S32:
            *reinterpret_cast<int32_t *>(ptr) = value;
            break;
        case DataType::U64:
            *reinterpret_cast<uint64_t *>(ptr) = value;
            break;
        case DataType::S64:
            *reinterpret_cast<int64_t *>(ptr) = value;
            break;
#ifdef ENABLE_FP16
        case DataType::F16:
            *reinterpret_cast<float16_t *>(ptr) = value;
            break;
#endif /* ENABLE_FP16 */
        case DataType::F32:
            *reinterpret_cast<float *>(ptr) = value;
            break;
        case DataType::F64:
            *reinterpret_cast<double *>(ptr) = value;
            break;
        case DataType::SIZET:
            *reinterpret_cast<size_t *>(ptr) = value;
            break;
        default:
            ARM_COMPUTE_ERROR("NOT SUPPORTED!");
    }
}

/** Saturate a value of type T against the numeric limits of type U.
 *
 * @param[in] val Value to be saturated.
 *
 * @return saturated value.
 */
template <typename U, typename T>
T saturate_cast(T val)
{
    if(val > static_cast<T>(std::numeric_limits<U>::max()))
    {
        val = static_cast<T>(std::numeric_limits<U>::max());
    }
    if(val < static_cast<T>(std::numeric_limits<U>::lowest()))
    {
        val = static_cast<T>(std::numeric_limits<U>::lowest());
    }
    return val;
}

/** Find the signed promoted common type.
 */
template <typename... T>
struct common_promoted_signed_type
{
    using common_type       = typename std::common_type<T...>::type;
    using promoted_type     = traits::promote_t<common_type>;
    using intermediate_type = typename traits::make_signed_conditional_t<promoted_type>::type;
};

/** Convert a linear index into n-dimensional coordinates.
 *
 * @param[in] shape Shape of the n-dimensional tensor.
 * @param[in] index Linear index specifying the i-th element.
 *
 * @return n-dimensional coordinates.
 */
inline Coordinates index2coord(const TensorShape &shape, int index)
{
    int num_elements = shape.total_size();

    ARM_COMPUTE_ERROR_ON_MSG(index < 0 || index >= num_elements, "Index has to be in [0, num_elements]");
    ARM_COMPUTE_ERROR_ON_MSG(num_elements == 0, "Cannot create coordinate from empty shape");

    Coordinates coord{ 0 };

    for(int d = shape.num_dimensions() - 1; d >= 0; --d)
    {
        num_elements /= shape[d];
        coord.set(d, index / num_elements);
        index %= num_elements;
    }

    return coord;
}

/** Linearise the given coordinate.
 *
 * Transforms the given coordinate into a linear offset in terms of
 * elements.
 *
 * @param[in] shape Shape of the n-dimensional tensor.
 * @param[in] coord The to be converted coordinate.
 *
 * @return Linear offset to the element.
 */
inline int coord2index(const TensorShape &shape, const Coordinates &coord)
{
    ARM_COMPUTE_ERROR_ON_MSG(shape.total_size() == 0, "Cannot get index from empty shape");
    ARM_COMPUTE_ERROR_ON_MSG(coord.num_dimensions() == 0, "Cannot get index of empty coordinate");

    int index    = 0;
    int dim_size = 1;

    for(unsigned int i = 0; i < coord.num_dimensions(); ++i)
    {
        index += coord[i] * dim_size;
        dim_size *= shape[i];
    }

    return index;
}

/** Check if a coordinate is within a valid region */
inline bool is_in_valid_region(const ValidRegion &valid_region, const Coordinates &coord)
{
    ARM_COMPUTE_ERROR_ON_MSG(valid_region.shape.num_dimensions() != coord.num_dimensions(), "Shapes of valid region and coordinates do not agree");
    for(int d = 0; static_cast<size_t>(d) < coord.num_dimensions(); ++d)
    {
        if(coord[d] < valid_region.start(d) || coord[d] >= valid_region.end(d))
        {
            return false;
        }
    }
    return true;
}
} // namespace test
} // namespace arm_compute
#endif