#ifndef MATH_VECTOR_H
#define MATH_VECTOR_H

#include <cmath>
#include "math/quat.h"

namespace engine::math {

struct Vector2 {
    float x, y;

    constexpr bool operator==(const Vector2& other) const & {
        return x == other.x && y == other.y;
    }

    constexpr bool operator!=(const Vector2& other) const & {
        return !(*this == other);
    }

    constexpr Vector2 operator+() const & {
        return *this;
    }

    constexpr Vector2 operator-() const & {
        return { -x, -y };
    }

    constexpr Vector2 operator+(const Vector2& other) const & {
        return { x + other.x, y + other.y };
    }

    constexpr Vector2 operator-(const Vector2& other) const & {
        return *this + (-other);
    }

    constexpr Vector2 operator+=(const Vector2& other) & {
        x += other.x;
        y += other.y;
        return *this;
    }

    constexpr float det(const Vector2& other) const & {
        return this->x * other.y - other.x * this->y;
    }

    constexpr Vector2 round() const & {
        return { std::round(x), std::round(y) };
    }

    constexpr Vector2 mul_term(const Vector2& other) const & {
        return { x * other.x, y * other.y };
    }
};

constexpr Vector2 operator*(float n, const Vector2& other) {
    return { n * other.x, n * other.y };
}

constexpr Vector2 operator*(const Vector2& other, float n) {
    return n * other;
}

constexpr Vector2 operator/(const Vector2& other, float n) {
    return { other.x / n, other.y / n };
}

constexpr Vector2 operator+(const Vector2& other, float n) {
    return { other.x + n, other.y + n };
}

constexpr Vector2 operator-(const Vector2& other, float n) {
    return { other.x - n, other.y - n };
}

struct Vector3;
constexpr Vector3 operator*(float n, const Vector3& other);
constexpr Vector3 operator/(const Vector3& other, float n);

struct Vector3 {
    static constexpr Vector3 bilerp(const Vector3& v1, const Vector3& v2, const Vector3& v3, float b0, float b1) {
        return b0 * v1 + b1 * v2 + (1.f - b0 - b1) * v3;
    }

    float x, y, z;

    constexpr bool operator==(const Vector3& other) const & {
        return x == other.x && y == other.y && z == other.z;
    }

    constexpr bool operator!=(const Vector3& other) const & {
        return !(*this == other);
    }

    constexpr Vector3 operator+() const & {
        return *this;
    }

    constexpr Vector3 operator-() const & {
        return { -x, -y, -z };
    }

    constexpr Vector3 operator+(const Vector3& other) const & {
        return { x + other.x, y + other.y, z + other.z };
    }

    constexpr Vector3 operator-(const Vector3& other) const & {
        return *this + (-other);
    }

    constexpr Vector3 operator+=(const Vector3& other) & {
        x += other.x;
        y += other.y;
        z += other.z;
        return *this;
    }

    constexpr Vector3 round() {
        return { std::round(x), std::round(y), std::round(z) };
    }

    constexpr Vector3 cross(const Vector3& other) const & {
        return {
            y * other.z - z * other.y,
            z * other.x - x * other.z,
            x * other.y - y * other.x
        };
    }

    constexpr Vector3 rot(const Quaternion& q) const & {
        return {
            (2.f * (q.w * q.w + q.x * q.x) - 1.f) * x + (2.f * (q.x * q.y - q.w * q.z)      ) * y + (2.f * (q.x * q.z + q.w * q.y)      ) * z,
            (2.f * (q.x * q.y + q.w * q.z)      ) * x + (2.f * (q.w * q.w + q.y * q.y) - 1.f) * y + (2.f * (q.y * q.z - q.w * q.x)      ) * z,
            (2.f * (q.x * q.z - q.w * q.y)      ) * x + (2.f * (q.y * q.z + q.w * q.x)      ) * y + (2.f * (q.w * q.w + q.z * q.z) - 1.f) * z,
        };
    }

    constexpr float dot(const Vector3& other) const & {
        return x * other.x + y * other.y + z * other.z;
    }

    constexpr float length_squared() const & {
        return dot(*this);
    }

    constexpr float length() const & {
        return std::sqrt(length_squared());
    }

    constexpr Vector3 normalize() const & {
        return *this / length();
    }
};

constexpr Vector3 operator*(float n, const Vector3& other) {
    return { n * other.x, n * other.y, n * other.z };
}

constexpr Vector3 operator*(const Vector3& other, float n) {
    return n * other;
}

constexpr Vector3 operator/(float n, const Vector3& other) {
    return { n / other.x, n / other.y, n / other.z };
}

constexpr Vector3 operator/(const Vector3& other, float n) {
    return { other.x / n, other.y / n, other.z / n };
}

struct Vector4 {
    float x, y, z, w;

    constexpr Vector4() {}
    constexpr Vector4(float x, float y, float z, float w) : x{x}, y{y}, z{z}, w{w} {}
    constexpr Vector4(float x, float y, float z) : x{x}, y{y}, z{z}, w{1.f} {}
    constexpr Vector4(const Vector2& v, float z, float w) : x{v.x}, y{v.y}, z{z}, w{w} {}
    constexpr Vector4(const Vector2& v, float z) : x{v.x}, y{v.y}, z{z}, w{1.f} {}
    constexpr Vector4(const Vector3& v, float w) : x{v.x}, y{v.y}, z{v.z}, w{w} {}
    constexpr Vector4(const Vector3& v) : x{v.x}, y{v.y}, z{v.z}, w{1.f} {}

    constexpr bool operator==(const Vector4& other) const & {
        return x == other.x && y == other.y && z == other.z && w == other.w;
    }

    constexpr bool operator!=(const Vector4& other) const & {
        return !(*this == other);
    }

    constexpr Vector4 operator+() const & {
        return *this;
    }

    constexpr Vector4 operator-() const & {
        return { -x, -y, -z, -w };
    }

    constexpr Vector4 operator+(const Vector4& other) const & {
        return { x + other.x, y + other.y, z + other.z, w + other.w };
    }

    constexpr Vector4 operator-(const Vector4& other) const & {
        return *this + (-other);
    }

    constexpr Vector4 round() const & {
        return { std::round(x), std::round(y), std::round(z), std::round(w) };
    }

    constexpr Vector2 xy() const & {
        return { x, y };
    }

    constexpr Vector3 xyz() const & {
        return { x, y, z };
    }

    constexpr Vector4 div_by_w() const & {
        return {x / w, y / w, z / w, w};
    }
};

constexpr Vector4 operator*(float n, const Vector4& other) {
    return { n * other.x, n * other.y, n * other.z, n * other.w };
}

constexpr Vector4 operator*(const Vector4& other, float n) {
    return n * other;
}

constexpr Vector4 operator/(const Vector4& other, float n) {
    return { other.x / n, other.y / n, other.z / n, other.w / n };
}

}

#endif // MATH_VECTOR_H