/**
 * Copyright (c) 2025 Dominic Masters
 * 
 * This software is released under the MIT License.
 * https://opensource.org/licenses/MIT
 */

#include "camera.h"
#include "display/display.h"
#include "assert/assert.h"
#include "display/framebuffer/framebuffer.h"

void cameraInit(camera_t *camera) {
  assertNotNull(camera, "Not a camera component");

  camera->projType = CAMERA_PROJECTION_TYPE_PERSPECTIVE;
  camera->perspective.fov = glm_rad(45.0f);
  camera->nearClip = 0.1f;
  camera->farClip = 100.0f;

  camera->viewType = CAMERA_VIEW_TYPE_LOOKAT;
  glm_vec3_copy((vec3){ 5.0f, 5.0f, 5.0f }, camera->lookat.position);
  glm_vec3_copy((vec3){ 0.0f, 1.0f, 0.0f }, camera->lookat.up);
  glm_vec3_copy((vec3){ 0.0f, 0.0f, 0.0f }, camera->lookat.target);
}

void cameraPushMatrix(camera_t *camera) {
  assertNotNull(camera, "Not a camera component");

  mat4 projection;
  mat4 view;

  switch(camera->projType) {
    case CAMERA_PROJECTION_TYPE_ORTHOGRAPHIC:
      glm_ortho(
        camera->orthographic.left,
        camera->orthographic.right,
        camera->orthographic.bottom,
        camera->orthographic.top,
        camera->nearClip,
        camera->farClip,
        projection
      );
      break;

    case CAMERA_PROJECTION_TYPE_PERSPECTIVE:
      const float_t aspect = (
        (float_t)frameBufferGetWidth(FRAMEBUFFER_BOUND) /
        (float_t)frameBufferGetHeight(FRAMEBUFFER_BOUND)
      );
      glm_perspective(
        camera->perspective.fov,
        aspect,
        camera->nearClip,
        camera->farClip,
        projection
      );
  }

  switch(camera->viewType) {
    case CAMERA_VIEW_TYPE_MATRIX:
      glm_mat4_copy(camera->view, view);
      break;

    case CAMERA_VIEW_TYPE_LOOKAT:
      glm_lookat(
        camera->lookat.position,
        camera->lookat.target,
        camera->lookat.up,
        view
      );
      break;

    case CAMERA_VIEW_TYPE_2D:
      glm_mat4_identity(view);
      glm_translate(view, (vec3){
        -camera->_2d.position[0],
        -camera->_2d.position[1],
        0.0f
      });
      glm_scale(view, (vec3){
        camera->_2d.zoom,
        camera->_2d.zoom,
        1.0f
      });
      break;

    default:
      assertUnreachable("Invalid camera view type");
  }

  #if DISPLAY_SDL2
    // mat4 pv;
    // glm_mat4_mul(projection, camera->transform, pv);

    glPushMatrix();
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glLoadMatrixf((const GLfloat*)projection);

    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    glLoadMatrixf((const GLfloat*)view);
  #endif
}

void cameraPopMatrix(void) {
  #if DISPLAY_SDL2
    glPopMatrix();
  #endif
}