#include "camera.h"

#include "util/util_time.h"

static const float movementSpeed = 40.0f;

void Camera_Init(camera_t* camera)
{
    camera->position = (vec3_t){ 4.0f, 40.0f, 4.0f };
    camera->viewDirection = (vec3_t){ -1.0f, -1.0f, 0.0f };
    camera->needsUpdate = true;
    camera->up = (vec3_t){ 0.0f, 1.0f, 0.0f };
}

void Camera_Move_Up(camera_t* camera)
{
    vec3_t temp = vec3_scalar_mul(&camera->up, movementSpeed * Time_GetFrameTime());
    camera->position = vec3_add(&camera->position, &temp);
}

void Camera_Move_Down(camera_t* camera)
{
    vec3_t temp = vec3_scalar_mul(&camera->up, -movementSpeed * Time_GetFrameTime());
    camera->position = vec3_add(&camera->position, &temp);
}

void Camera_Move_Left(camera_t* camera)
{
    vec3_t strafeDirection = vec3_cross_mul(&camera->viewDirection, &camera->up);
    strafeDirection = vec3_scalar_mul(&strafeDirection, -movementSpeed * Time_GetFrameTime());
    camera->position = vec3_add(&camera->position, &strafeDirection);
}

void Camera_Move_Right(camera_t* camera)
{
    vec3_t strafeDirection = vec3_cross_mul(&camera->viewDirection, &camera->up);
    strafeDirection = vec3_scalar_mul(&strafeDirection, movementSpeed * Time_GetFrameTime());
    camera->position = vec3_add(&camera->position, &strafeDirection);
}

void Camera_Move_Foward(camera_t* camera)
{
    vec3_t temp = vec3_scalar_mul(&camera->viewDirection, movementSpeed * Time_GetFrameTime());
    camera->position = vec3_add(&camera->position, &temp);
}

void Camera_Move_Backward(camera_t* camera)
{
    vec3_t temp = vec3_scalar_mul(&camera->viewDirection, -movementSpeed * Time_GetFrameTime());
    camera->position = vec3_add(&camera->position, &temp);
}

void Camera_MouseUpdate(camera_t* camera, const vec2_t* newMousePosition)
{
    vec2_t mouseDelta = vec2_sub(newMousePosition, &camera->mousePosition);

    /* El if evita que el mouse se teletrasporte al cambiar de posicion muy rapido */
    if(vec2_length(&mouseDelta) > 50.0f){
        camera->mousePosition = *newMousePosition;
        return;
    }

    vec3_t verticalRotation = vec3_cross_mul(&camera->viewDirection, &camera->up);

    mat4_t temp = mat4_rotate(mouseDelta.x * -0.5f, &camera->up);

    camera->viewDirection = mat4_mul_vec3(&temp, &camera->viewDirection);

    temp = mat4_rotate(mouseDelta.y * -0.5f, &verticalRotation);
    camera->viewDirection = mat4_mul_vec3(&temp, &camera->viewDirection);

    camera->mousePosition = *newMousePosition;

    camera->needsUpdate = true;
}

mat4_t Camera_GetModelToViewMatrix(camera_t* camera)
{
    if(camera->needsUpdate)
    {
        vec3_t temp = vec3_add(&camera->position, &camera->viewDirection);
        camera->viewMatrix = mat4_lookAt(&camera->position, &temp, &camera->up);
    }
    return camera->viewMatrix;
}