/**
 * 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"
#include "display/screen/screen.h"

void cameraInit(camera_t *camera) {
  cameraInitPerspective(camera);
}

void cameraInitPerspective(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 = 10000.0f;

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

  camera->projType = CAMERA_PROJECTION_TYPE_ORTHOGRAPHIC;
  camera->orthographic.left = 0.0f;
  camera->orthographic.right = SCREEN.width;
  camera->orthographic.top = SCREEN.height;
  camera->orthographic.bottom = 0.0f;
  camera->nearClip = 0.1f;
  camera->farClip = 1.0f;

  camera->viewType = CAMERA_VIEW_TYPE_2D;
  glm_vec2_copy((vec2){ 0.0f, 0.0f }, camera->_2d.position);
  camera->_2d.zoom = 1.0f;
}

void cameraGetProjectionMatrix(camera_t *camera, mat4 dest) {
  assertNotNull(camera, "Not a camera component");
  assertNotNull(dest, "Destination matrix must not be null");

  if(
    camera->projType == CAMERA_PROJECTION_TYPE_PERSPECTIVE ||
    camera->projType == CAMERA_PROJECTION_TYPE_PERSPECTIVE_FLIPPED
  ) {
    glm_mat4_identity(dest);
    glm_perspective(
      camera->perspective.fov,
      SCREEN.aspect,
      camera->nearClip,
      camera->farClip,
      dest
    );

    if(camera->projType == CAMERA_PROJECTION_TYPE_PERSPECTIVE_FLIPPED) {
      dest[1][1] *= -1.0f;
    }
  } else if(camera->projType == CAMERA_PROJECTION_TYPE_ORTHOGRAPHIC) {
    glm_mat4_identity(dest);
    glm_ortho(
      camera->orthographic.left,
      camera->orthographic.right,
      camera->orthographic.top,
      camera->orthographic.bottom,
      camera->nearClip,
      camera->farClip,
      dest
    );
  }
}

void cameraGetViewMatrix(camera_t *camera, mat4 dest) {
  assertNotNull(camera, "Not a camera component");
  assertNotNull(dest, "Destination matrix must not be null");

  if(camera->viewType == CAMERA_VIEW_TYPE_MATRIX) {
    glm_mat4_ucopy(camera->view, dest);
  } else if(camera->viewType == CAMERA_VIEW_TYPE_LOOKAT) {
    glm_mat4_identity(dest);
    glm_lookat(
      camera->lookat.position,
      camera->lookat.target,
      camera->lookat.up,
      dest
    );
  } else if(camera->viewType == CAMERA_VIEW_TYPE_2D) {
    glm_mat4_identity(dest);
    glm_lookat(
      (vec3){ camera->_2d.position[0], camera->_2d.position[1], 0.5f },
      (vec3){ camera->_2d.position[0], camera->_2d.position[1], 0.0f },
      (vec3){ 0.0f, 1.0f, 0.0f },
      dest
    );
  } else if(camera->viewType == CAMERA_VIEW_TYPE_LOOKAT_PIXEL_PERFECT) {
    assertUnreachable("LOOKAT_PIXEL_PERFECT view type is not implemented yet");
  }
}