#include "camera.h"
#include "SDL3/SDL_keyboard.h"
#include "cglm/mat4.h"
#include "cglm/cam.h"
#include "cglm/vec3.h"
#include <SDL3/SDL_mouse.h>
#include <cglm/util.h>
#include <math.h>

static float mouse_x, mouse_y;

Camera Camera_default = {
  .position = {0.0f, 0.0f, 3.0f},
  .forward = {0.0f, 0.0f, -1.0f},
  .yaw = -1.5707963268f, // -90 deg in radians
  .pitch = 0
};

void camera_tick(Camera *camera) {
  // Mouse input
  SDL_GetRelativeMouseState(&mouse_x, &mouse_y);
  camera->yaw += mouse_x * glm_rad(MOUSE_SENSITIVITY);
  camera->pitch -= mouse_y * glm_rad(MOUSE_SENSITIVITY);
  // Restrict pitch
  if (camera->pitch > glm_rad(89.0f))
    camera->pitch = glm_rad(89.0f);
  if (camera->pitch < glm_rad(-89.0f))
    camera->pitch = glm_rad(-89.0f);

  // Camera Direction
  camera->forward[0] = cosf(camera->yaw) * cosf(camera->pitch);
  camera->forward[1] = sinf(camera->pitch);
  camera->forward[2] = sinf(camera->yaw) * cosf(camera->pitch);
  glm_normalize(camera->forward);

  vec3 camera_right;
  vec3 up = {0.0f, 1.0f ,0.0f};
  glm_cross(up, camera->forward, camera_right);
  glm_normalize(camera_right);

  // Move camera based on wasd;
  const bool *keyboardState = SDL_GetKeyboardState(NULL);
  if (keyboardState[SDL_SCANCODE_W]) {
    vec3 calc_buff;
    glm_vec3_scale(camera->forward, MOVEMENT_SPEED, calc_buff);
    glm_vec3_add(camera->position, calc_buff, camera->position);
  }
  if (keyboardState[SDL_SCANCODE_S]) {
    vec3 calc_buff;
    glm_vec3_scale(camera->forward, MOVEMENT_SPEED, calc_buff);
    glm_vec3_sub(camera->position, calc_buff, camera->position);
  }
  if (keyboardState[SDL_SCANCODE_A]) {
    vec3 calc_buff;
    glm_vec3_scale(camera_right, MOVEMENT_SPEED, calc_buff);
    glm_vec3_add(camera->position, calc_buff, camera->position);
  }
  if (keyboardState[SDL_SCANCODE_D]) {
    vec3 calc_buff;
    glm_vec3_scale(camera_right, MOVEMENT_SPEED, calc_buff);
    glm_vec3_sub(camera->position, calc_buff, camera->position);
  }
}

void camera_calc_mvp(mat4 *mvp_result, Camera *camera) {
  // Get position to look and up vector
  vec3 camera_target;
  glm_vec3_add(camera->position , camera->forward, camera_target);
  vec3 up = {0.0f, 1.0f ,0.0f};

  mat4 model;
  glm_mat4_identity(model);

  mat4 view;
  glm_lookat(camera->position, camera_target, up, view);

  mat4 projection;
  float fov = glm_rad(45.0f); // fov y
  float aspect = 800.0f / 600.0f;
  float near = 0.1f;
  float far = 100.0f;
  glm_perspective(fov, aspect, near, far, projection);

  glm_mat4_mulN((mat4*[]){&projection, &view, &model}, 3, *mvp_result);
}