// Copyright (C) 2018-2024 Intel Corporation
// SPDX-License-Identifier: Apache-2.0
//

#pragma once

#include <cmath>
#include <iostream>
#include <limits>
#include <memory>
#include <string>
#include <vector>

#include "openvino/core/core_visibility.hpp"

namespace ov {

/**
 * @brief Class to represent the f8e4m3 type.
 */
class OPENVINO_API float8_e4m3 {
public:
    float8_e4m3() = default;
    float8_e4m3(uint32_t sign, uint32_t biased_exponent, uint32_t fraction);
    float8_e4m3(float value);

    template <typename I>
    explicit float8_e4m3(I value) : m_value{float8_e4m3{static_cast<float>(value)}.m_value} {}

    template <typename T>
    bool operator==(const T& other) const;
    template <typename T>
    bool operator!=(const T& other) const {
        return !(*this == other);
    }

    template <typename T>
    bool operator<(const T& other) const;
    template <typename T>
    bool operator<=(const T& other) const;
    template <typename T>
    bool operator>(const T& other) const;
    template <typename T>
    bool operator>=(const T& other) const;
    template <typename T>
    float8_e4m3 operator+(const T& other) const;
    template <typename T>
    float8_e4m3 operator+=(const T& other);
    template <typename T>
    float8_e4m3 operator-(const T& other) const;
    template <typename T>
    float8_e4m3 operator-=(const T& other);
    template <typename T>
    float8_e4m3 operator*(const T& other) const;
    template <typename T>
    float8_e4m3 operator*=(const T& other);
    template <typename T>
    float8_e4m3 operator/(const T& other) const;
    template <typename T>
    float8_e4m3 operator/=(const T& other);

    operator float() const;

    static constexpr float8_e4m3 from_bits(uint8_t bits) {
        return float8_e4m3(bits, true);
    }
    uint8_t to_bits() const;
    friend std::ostream& operator<<(std::ostream& out, const float8_e4m3& obj) {
        out << static_cast<float>(obj);
        return out;
    }

private:
    constexpr float8_e4m3(uint8_t x, bool) : m_value{x} {}

    uint8_t m_value;
};

#if defined(_MSC_VER)
#    pragma warning(push)
#    pragma warning(disable : 4756)
#endif
template <typename T>
bool float8_e4m3::operator==(const T& other) const {
#if defined(__GNUC__)
#    pragma GCC diagnostic push
#    pragma GCC diagnostic ignored "-Wfloat-equal"
#endif
    return (static_cast<float>(*this) == static_cast<float>(other));
#if defined(__GNUC__)
#    pragma GCC diagnostic pop
#endif
}

template <typename T>
bool float8_e4m3::operator<(const T& other) const {
    return (static_cast<float>(*this) < static_cast<float>(other));
}

template <typename T>
bool float8_e4m3::operator<=(const T& other) const {
    return (static_cast<float>(*this) <= static_cast<float>(other));
}

template <typename T>
bool float8_e4m3::operator>(const T& other) const {
    return (static_cast<float>(*this) > static_cast<float>(other));
}

template <typename T>
bool float8_e4m3::operator>=(const T& other) const {
    return (static_cast<float>(*this) >= static_cast<float>(other));
}

template <typename T>
float8_e4m3 float8_e4m3::operator+(const T& other) const {
    return {static_cast<float>(*this) + static_cast<float>(other)};
}

template <typename T>
float8_e4m3 float8_e4m3::operator+=(const T& other) {
    return *this = *this + other;
}

template <typename T>
float8_e4m3 float8_e4m3::operator-(const T& other) const {
    return {static_cast<float>(*this) - static_cast<float>(other)};
}

template <typename T>
float8_e4m3 float8_e4m3::operator-=(const T& other) {
    return *this = *this - other;
}

template <typename T>
float8_e4m3 float8_e4m3::operator*(const T& other) const {
    return {static_cast<float>(*this) * static_cast<float>(other)};
}

template <typename T>
float8_e4m3 float8_e4m3::operator*=(const T& other) {
    return *this = *this * other;
}

template <typename T>
float8_e4m3 float8_e4m3::operator/(const T& other) const {
    return {static_cast<float>(*this) / static_cast<float>(other)};
}

template <typename T>
float8_e4m3 float8_e4m3::operator/=(const T& other) {
    return *this = *this / other;
}
#if defined(_MSC_VER)
#    pragma warning(pop)
#endif
}  // namespace ov

namespace std {
template <>
class numeric_limits<ov::float8_e4m3> {
public:
    static constexpr bool is_specialized = true;
    static constexpr ov::float8_e4m3 min() noexcept {
        return ov::float8_e4m3::from_bits(0b00001000);  // minimum positive normalized value
    }
    static constexpr ov::float8_e4m3 max() noexcept {
        return ov::float8_e4m3::from_bits(0b01111110);
    }
    static constexpr ov::float8_e4m3 lowest() noexcept {
        return ov::float8_e4m3::from_bits(0b11111110);
    }
    static constexpr int digits = 4;
    static constexpr int digits10 = 0;

    static constexpr bool is_signed = true;
    static constexpr bool is_integer = false;
    static constexpr bool is_exact = false;

    static constexpr int radix = 2;

    static constexpr ov::float8_e4m3 epsilon() noexcept {
        return ov::float8_e4m3::from_bits(0b00000001);
    }
    static constexpr ov::float8_e4m3 round_error() noexcept {
        return ov::float8_e4m3::from_bits(0b00110000);
    }

    static constexpr int min_exponent = -5;
    static constexpr int min_exponent10 = -2;
    static constexpr int max_exponent = 10;
    static constexpr int max_exponent10 = 2;

    static constexpr bool has_infinity = false;
    static constexpr bool has_quiet_NaN = true;
    static constexpr bool has_signaling_NaN = false;

    static constexpr float_denorm_style has_denorm = denorm_present;
    static constexpr bool has_denorm_loss = false;

    static constexpr ov::float8_e4m3 infinity() noexcept {
        return ov::float8_e4m3::from_bits(0);  // no infinity
    }
    static constexpr ov::float8_e4m3 quiet_NaN() noexcept {
        return ov::float8_e4m3::from_bits(0b01111111);
    }
    static constexpr ov::float8_e4m3 signaling_NaN() noexcept {
        return ov::float8_e4m3::from_bits(0);  // no signaling NaN
    }

    static constexpr ov::float8_e4m3 denorm_min() noexcept {
        return ov::float8_e4m3::from_bits(0b00000001);  // minimum positive denormalized value
    }
    static constexpr bool is_iec559 = false;
    static constexpr bool is_bounded = false;
    static constexpr bool is_modulo = false;
    static constexpr bool traps = false;
    static constexpr bool tinyness_before = false;
    static constexpr float_round_style round_style = round_to_nearest;
};
}  // namespace std
