#ifndef BWIDGETS_MATH_HPP
#define BWIDGETS_MATH_HPP

#include <algorithm>
#include <cmath>

#include <SDL2/SDL_rect.h>

#include <basic_widgets/core/type/color.hpp>
#include <basic_widgets/core/type/concepts.hpp>
#include <basic_widgets/core/type/size.hpp>

namespace bwidgets
{
    // NOLINTNEXTLINE(clang-diagnostic-unused-function)
    [[nodiscard]] static inline auto center_line(int available_len, int used_len) noexcept -> int
    {
        return (available_len - used_len) / 2;
    }

    [[nodiscard]] static inline auto distance_sqrd(const SDL_Point& a, const SDL_Point& b) noexcept
      -> float
    {
        // NOLINTNEXTLINE(bugprone-narrowing-conversions)
        return (a.x - b.x) * (a.x - b.x)
             + (a.y - b.y) * (a.y - b.y);
    }

    // NOLINTNEXTLINE(clang-diagnostic-unused-function)
    [[nodiscard]] static inline auto distance(const SDL_Point& a, const SDL_Point& b) noexcept -> float
    {
        return std::sqrt(distance_sqrd(a, b));
    }

    template<FloatingPoint F>
    [[nodiscard]] static inline auto lerp(const Color& a, const Color& b, F x, bool op_alpha=false, bool op_color=true) -> Color
    {
        return {{
            op_color ? (uint8_t)std::lerp(a().r, b().r, x) : a().r,
            op_color ? (uint8_t)std::lerp(a().g, b().g, x) : a().g,
            op_color ? (uint8_t)std::lerp(a().b, b().b, x) : a().b,
            op_alpha ? (uint8_t)std::lerp(a().a, b().a, x) : a().a,
        }};
    }

    template<Numeric N>
    [[nodiscard]] static inline auto linear(N x, N a, N b) noexcept -> float
    {
        return (float)(x - a) / (float)(b - a);
    }

    // NOLINTNEXTLINE(clang-diagnostic-unused-function)
    [[nodiscard]] static inline auto rect_in_rect(const SDL_Rect outer, const SDL_Rect inner) noexcept
      -> bool
    {
        SDL_Point top_left {inner.x, inner.y};
        SDL_Point bottom_right {inner.x + inner.w, inner.y + inner.h};

        return (SDL_PointInRect(&top_left, &outer) == SDL_TRUE)
            && (SDL_PointInRect(&bottom_right, &outer) == SDL_TRUE);
    }

    // NOLINTNEXTLINE(clang-diagnostic-unused-function)
    [[nodiscard]] static inline auto rect_margin(const SDL_Rect& r, const Size& margin) noexcept
      -> SDL_Rect
    {
        return {r.x + margin.w, r.y + margin.h, r.w - 2 * margin.w, r.h - 2 * margin.h};
    }

    [[nodiscard]] static inline auto rect_offset(const SDL_Rect& r, const SDL_Point& offset) noexcept
      -> SDL_Rect
    {
        return {r.x + offset.x, r.y + offset.y, r.w, r.h};
    }

    // NOLINTNEXTLINE(clang-diagnostic-unused-function)
    [[nodiscard]] static inline auto rect_offset(const SDL_Rect& r, const SDL_Rect& offset) noexcept
      -> SDL_Rect
    {
        return rect_offset(r, SDL_Point {offset.x, offset.y});
    }

    template<Numeric N>
    [[nodiscard]] static inline auto smoothstep(N x, N a, N b) noexcept -> float
    {
        const float x_norm = linear(std::clamp<float>(x, a, b), a, b);
        return 3 * x_norm * x_norm - 2 * x_norm * x_norm * x_norm;
    }
}

#endif