// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0.If a copy of the MPL was not distributed with this
// file, You can obtain one at https ://mozilla.org/MPL/2.0/.

#ifndef VECTOR3_H
#define VECTOR3_H

#include "Vector2.h"

extern "C" {
/// <summary>
/// 3-dimensional Vector representation (C-style)
/// </summary>
/// This is a C-style implementation
/// This uses the right-handed coordinate system.
typedef struct Vec3 {
protected:
  /// <summary>
  /// The right axis of the vector
  /// </summary>
  float x;
  /// <summary>
  /// The upward axis of the vector
  /// </summary>
  float y;
  /// <summary>
  /// The forward axis of the vector
  /// </summary>
  float z;

} Vec3;
}

namespace Passer {
namespace LinearAlgebra {

template <typename T> class SphericalOf;

/// @brief A 3-dimensional vector
/// @remark This uses a right-handed carthesian coordinate system.
/// @note This implementation intentionally avoids the use of x, y and z values.
struct Vector3 : Vec3 {
  friend struct Vec3;

public:
  /// @brief A new 3-dimensional zero vector
  Vector3();
  /// @brief A new 3-dimensional vector
  /// @param right The distance in the right direction in meters
  /// @param up The distance in the upward direction in meters
  /// @param forward The distance in the forward direction in meters
  Vector3(float right, float up, float forward);
  /// @brief Convert a 2-dimenstional vector to a 3-dimensional vector
  /// @param v The vector to convert
  Vector3(Vector2 v);
  /// @brief Convert vector in spherical coordinates to 3d carthesian
  /// coordinates
  /// @param v The vector to convert
  Vector3(SphericalOf<float> v);

  /// @brief Vector3 destructor
  ~Vector3();

  /// @brief A vector with zero for all axis
  const static Vector3 zero;
  /// @brief A vector with one for all axis
  const static Vector3 one;
  /// @brief A normalized forward-oriented vector
  const static Vector3 forward;
  /// @brief A normalized back-oriented vector
  const static Vector3 back;
  /// @brief A normalized right-oriented vector
  const static Vector3 right;
  /// @brief A normalized left-oriented vector
  const static Vector3 left;
  /// @brief A normalized up-oriented vector
  const static Vector3 up;
  /// @brief A normalized down-oriented vector
  const static Vector3 down;

  // Access functions which are intended to replace the use of XYZ
  inline float Forward() const { return z; };
  inline float Up() const { return y; };
  inline float Right() const { return x; };

  /// @brief Check if this vector to the given vector
  /// @param v The vector to check against
  /// @return true if it is identical to the given vector
  /// @note This uses float comparison to check equality which may have strange
  /// effects. Equality on floats should be avoided.
  bool operator==(const Vector3 &v) const;

  /// @brief The vector length
  /// @param v The vector for which you need the length
  /// @return The vector length
  static float Magnitude(const Vector3 &v);
  /// @brief The vector length
  /// @return The vector length
  float magnitude() const;
  /// @brief The squared vector length
  /// @param v The vector for which you need the length
  /// @return The squared vector length
  /// @remark The squared length is computationally simpler than the real
  /// length. Think of Pythagoras A^2 + B^2 = C^2. This leaves out the
  /// calculation of the squared root of C.
  static float SqrMagnitude(const Vector3 &v);
  /// @brief The squared vector length
  /// @return The squared vector length
  /// @remark The squared length is computationally simpler than the real
  /// length. Think of Pythagoras A^2 + B^2 = C^2. This leaves out the
  /// calculation of the squared root of C.
  float sqrMagnitude() const;

  /// @brief Convert the vector to a length of 1
  /// @param v The vector to convert
  /// @return The vector normalized to a length of 1
  static Vector3 Normalize(const Vector3 &v);
  /// @brief Convert the vector to a length of 1
  /// @return The vector normalized to a length of 1
  Vector3 normalized() const;

  /// @brief Negate te vector such that it points in the opposite direction
  /// @return The negated vector
  Vector3 operator-() const;

  /// @brief Subtract a vector from this vector
  /// @param v The vector to subtract from this vector
  /// @return The result of this subtraction
  Vector3 operator-(const Vector3 &v) const;
  Vector3 operator-=(const Vector3 &v);
  /// @brief Add a vector to this vector
  /// @param v The vector to add to this vector
  /// @return The result of the addition
  Vector3 operator+(const Vector3 &v) const;
  Vector3 operator+=(const Vector3 &v);

  /// @brief Scale the vector using another vector
  /// @param v1 The vector to scale
  /// @param v2 A vector with the scaling factors
  /// @return The scaled vector
  /// @remark Each component of the vector v1 will be multiplied with the
  /// matching component from the scaling vector v2.
  static Vector3 Scale(const Vector3 &v1, const Vector3 &v2);
  /// @brief Scale the vector uniformly up
  /// @param f The scaling factor
  /// @return The scaled vector
  /// @remark Each component of the vector will be multipled with the same
  /// factor f.
  friend Vector3 operator*(const Vector3 &v, float f) {
    return Vector3(v.x * f, v.y * f, v.z * f);
  }
  friend Vector3 operator*(float f, const Vector3 &v) {
    // return Vector3(f * v.x, f * v.y, f * v.z);
    return Vector3(v.x * f, v.y * f, v.z * f);
  }
  Vector3 operator*=(float f);
  /// @brief Scale the vector uniformly down
  /// @param f The scaling factor
  /// @return The scaled vector
  /// @remark Each componet of the vector will be divided by the same factor.
  friend Vector3 operator/(const Vector3 &v, float f) {
    return Vector3(v.x / f, v.y / f, v.z / f);
  }
  friend Vector3 operator/(float f, const Vector3 &v) {
    // return Vector3(f / v.x, f / v.y, f / v.z);
    return Vector3(v.x / f, v.y / f, v.z / f);
  }
  Vector3 operator/=(float f);

  /// @brief The distance between two vectors
  /// @param v1 The first vector
  /// @param v2 The second vector
  /// @return The distance between the two vectors
  static float Distance(const Vector3 &v1, const Vector3 &v2);

  /// @brief The dot product of two vectors
  /// @param v1 The first vector
  /// @param v2 The second vector
  /// @return The dot product of the two vectors
  static float Dot(const Vector3 &v1, const Vector3 &v2);

  /// @brief The cross product of two vectors
  /// @param v1 The first vector
  /// @param v2 The second vector
  /// @return The cross product of the two vectors
  static Vector3 Cross(const Vector3 &v1, const Vector3 &v2);

  /// @brief Project the vector on another vector
  /// @param v The vector to project
  /// @param n The normal vecto to project on
  /// @return The projected vector
  static Vector3 Project(const Vector3 &v, const Vector3 &n);
  /// @brief Project the vector on a plane defined by a normal orthogonal to the
  /// plane.
  /// @param v The vector to project
  /// @param n The normal of the plane to project on
  /// @return Teh projected vector
  static Vector3 ProjectOnPlane(const Vector3 &v, const Vector3 &n);

  /// @brief The angle between two vectors
  /// @param v1 The first vector
  /// @param v2 The second vector
  /// @return The angle between the two vectors
  /// @remark This reterns an unsigned angle which is the shortest distance
  /// between the two vectors. Use Vector3::SignedAngle if a signed angle is
  /// needed.
  static AngleOf<float> Angle(const Vector3 &v1, const Vector3 &v2);
  /// @brief The signed angle between two vectors
  /// @param v1 The starting vector
  /// @param v2 The ending vector
  /// @param axis The axis to rotate around
  /// @return The signed angle between the two vectors
  static AngleOf<float> SignedAngle(const Vector3 &v1, const Vector3 &v2,
                                    const Vector3 &axis);

  /// @brief Lerp (linear interpolation) between two vectors
  /// @param v1 The starting vector
  /// @param v2 The ending vector
  /// @param f The interpolation distance
  /// @return The lerped vector
  /// @remark The factor f is unclamped. Value 0 matches the vector *v1*, Value
  /// 1 matches vector *v2*. Value -1 is vector *v1* minus the difference
  /// between *v1* and *v2* etc.
  static Vector3 Lerp(const Vector3 &v1, const Vector3 &v2, float f);
};

} // namespace LinearAlgebra
} // namespace Passer
using namespace Passer::LinearAlgebra;

#include "Spherical.h"

#endif