#include "Camera.h"
namespace NB {

// Camera class
Camera::Camera(const Vec3& pos, const Vec3& tar, const Vec3& up) {
    _pos = pos;
    _tar = tar;
    _world_up = glm::normalize(up);
    _dir = glm::normalize(_tar-_pos);
    _right = normCross(_dir, _world_up);
    _up = normCross(_right, _dir);
    _proj = glm::ortho(-1.0f, 1.0f, -1.0f, 1.0f, -1.0f, 1.0f);
    _calcLook();
}

void Camera::_calcLook() {
    _look = glm::lookAt(_pos, _tar, (_lock_world_up)?_world_up:_up);
}

glm::vec3 Camera::normCross(const Vec3& a, const Vec3& b) {
    return glm::normalize(glm::cross(a, b));
}

glm::vec3 Camera::transformVec(const Mat4& mat, const Vec3& vec) {
    return Vec3(mat * glm::vec4(vec, 1.0f));
}

glm::vec3 Camera::getPos() const { return _pos; }

glm::vec3 Camera::getTarget() const { return _tar; }

glm::vec3 Camera::getDirection() const { return _dir; }

glm::vec3 Camera::getWorldUp() const { return _world_up; }

glm::vec3 Camera::getUp() const { return _up; }

glm::vec3 Camera::getRight() const { return _right; }

glm::mat4 Camera::getLookMatrix() const { return _look; }

glm::mat4 Camera::getProjectionMatrix() const { return _proj; }

glm::mat4 Camera::getFlattenedMatrices() const { return _proj * _look; }

bool Camera::isUpLocked() const { return _lock_world_up; }

void Camera::setProjection(const Mat4& proj) {
    _proj = proj;
}

void Camera::setPos(const Vec3& pos) {
    _pos = pos;
    _calcLook();
}

void Camera::setTarget(const Vec3& tar) {
    _tar = tar;
    _dir = glm::normalize(_tar-_pos);
    _right = normCross(_dir, _world_up);
    _up = normCross(_right, _dir);
    _calcLook();
}

void Camera::setDirection(const Vec3& dir) {
    setTarget(glm::normalize(dir)+_pos);
}

void Camera::setWorldUp(const Vec3& up) {
    _world_up = up;
    _right = normCross(_dir, _up);
    _up = normCross(_right, _dir);
    _calcLook();
}

void Camera::lockToWorldUp(bool lock) {
    if (!_lock_world_up && lock) {
        resetUp();
    }
    _lock_world_up = lock;
}

void Camera::resetUp() {
    _right = normCross(_dir, _world_up);
    _up = normCross(_right, _dir);
    _calcLook();
}

void Camera::addPos(const Vec3& add) {
    _pos += add;
    _dir = glm::normalize(_tar-_pos);
    if (_lock_world_up) {
        _right = normCross(_dir, _world_up);
    } else {
        _right = normCross(_dir, _up);
        _up = normCross(_right, _dir);
    }
    _calcLook();
}

void Camera::panPos(const Vec3& add) {
    _tar += add;
    addPos(add);
}

void Camera::panPosRelative(const Vec3& add) {
    panPos(add.x*_right + add.y*((_lock_world_up)?_world_up:_up) + add.z*_dir);
}

void Camera::addTarget(const Vec3& add) {
    _tar += add;
    _dir = glm::normalize(_tar-_pos);
    _right = normCross(_dir, _world_up);
    _up = normCross(_right, _dir);
    _calcLook();
}

void Camera::roll(float ang) {
    if (!_lock_world_up) {
        Mat4 rot_mat = glm::rotate(Mat4(1.0f), ang, _dir);
        _right = transformVec(rot_mat, _right);
        _up = transformVec(rot_mat, _up);
        _calcLook();
    }
}

void Camera::pitch(float ang) {
    Mat4 rot_mat = glm::rotate(Mat4(1.0f), ang, _right);
    _dir = transformVec(rot_mat, _dir);
    _up = transformVec(rot_mat, _up);
    _tar = _pos + _dir;
    _calcLook();
}

void Camera::yaw(float ang) {
    Mat4 rot_mat = glm::rotate(Mat4(1.0f), ang, ((_lock_world_up)?_world_up:_up));
    _dir = transformVec(rot_mat, _dir);
    _right = transformVec(rot_mat, _right);
    _up = normCross(_right, _dir);
    _tar = _pos + _dir;
    _calcLook();
}

// OrthographicCamera class
OrthographicCamera::OrthographicCamera(
    const Vec3& pos,
    const Vec3& tar,
    const Vec3& up,
    float left,
    float right,
    float bottom,
    float top,
    float near,
    float far
) : Camera(pos, tar, up), _leftPlane(left), _rightPlane(right), _bottomPlane(bottom), _topPlane(top), _nearPlane(near), _farPlane(far) {
    _proj = glm::ortho(_leftPlane, _rightPlane, _bottomPlane, _topPlane, _nearPlane, _farPlane);
}

// PerspectiveCamera class
/* PerspectiveCamera::PerspectiveCamera(
    const Vec3& pos,
    const Vec3& tar,
    const Vec3& up,
    float left,
    float right,
    float bottom,
    float top,
    float near,
    float far
) : Camera(pos, tar, up), _leftPlane(left), _rightPlane(right), _bottomPlane(bottom), _topPlane(top), _nearPlane(near), _farPlane(far) {
    _proj = glm::ortho(_leftPlane, _rightPlane, _bottomPlane, _topPlane, _nearPlane, _farPlane);
} */
}