#include "rendering.h"

#include <glad.h>

#include <cstring>

#include "cglm/types.h"
#include "utils.h"

bool wayc_image_init(texture_t* texture, image_type_e type,
                     image_format_e format, u32 width, u32 height) {
  wayc_notnull(texture);

  glCreateTextures(type, 1, texture);
  if (*texture == 0) return false;

  switch (type) {
    case IMAGE_TYPE_2D:
      // TODO: add error checking
      glTextureStorage2D(*texture, 1, format, width, height);
      break;
    default:
      break;
  }

  return true;
}

bool wayc_image_upload(texture_t texture, ivec2 offset, u32 width, u32 height,
                       image_type_e type, image_format_e format,
                       image_data_type_e data_type, i32 alignment,
                       const u8* data) {
  wayc_notnull(data);

  glPixelStorei(GL_UNPACK_ALIGNMENT, alignment);

  switch (type) {
    case IMAGE_TYPE_2D:
      // TODO: add error checking
      glTextureSubImage2D(texture, 0, offset[0], offset[1], width, height,
                          format, data_type, data);
      break;
    default:
      break;
  }

  return true;
}

void wayc_image_use(texture_t texture, u32 slot) {
  glBindTextureUnit(slot, texture);
}

void wayc_image_deinit(texture_t* texture) {
  wayc_notnull(texture);
  glDeleteTextures(1, texture);
}

bool wayc_sampler_init(sampler_t* sampler, sample_filter_e filter,
                       sample_wrap_e wrap) {
  wayc_notnull(sampler);

  glCreateSamplers(1, sampler);
  if (*sampler == 0) return false;

  glSamplerParameteri(*sampler, GL_TEXTURE_MIN_FILTER, filter);
  glSamplerParameteri(*sampler, GL_TEXTURE_MAG_FILTER, filter);
  glSamplerParameteri(*sampler, GL_TEXTURE_WRAP_S, wrap);
  glSamplerParameteri(*sampler, GL_TEXTURE_WRAP_T, wrap);

  return true;
}

void wayc_sampler_use(sampler_t sampler, u32 slot) {
  glBindSampler(slot, sampler);
}

void wayc_sampler_deinit(sampler_t* sampler) { glDeleteSamplers(1, sampler); }

bool wayc_atlas_init(atlas_s* atlas, image_format_e format, u32 width,
                     u32 height) {
  wayc_notnull(atlas);
  memset(atlas, 0, sizeof(*atlas));

  bool success = false;

  texture_t texture;
  bool ok = wayc_image_init(&texture, IMAGE_TYPE_2D, format, width, height);
  if (!ok) return false;
  wayc_defer_cond(wayc_image_deinit(&texture);, success, true);

  sampler_t sampler;
  ok = wayc_sampler_init(&sampler, SAMPLE_FILTER_NEAREST,
                         SAMPLE_WRAP_CLAMP_TO_EDGE);
  if (!ok) return false;

  atlas->texture = texture;
  atlas->sampler = sampler;
  atlas->width = width;
  atlas->height = height;

  success = true;
  return true;
}

void wayc_atlas_use(atlas_s* atlas, u32 slot) {
  wayc_image_use(atlas->texture, slot);
  wayc_sampler_use(atlas->sampler, slot);
}

bool wayc_atlas_set(atlas_s* atlas, image_data_type_e data_type, ivec2 offset,
                    u32 width, u32 height, i32 alignment, const u8* data) {
  wayc_notnull(atlas);
  wayc_notnull(data);

  u32 final_x = offset[0] + width;
  u32 final_y = offset[1] + height;
  if (final_x > atlas->width || final_y > atlas->height) return false;

  wayc_image_upload(atlas->texture, offset, width, height, IMAGE_TYPE_2D,
                    atlas->format, data_type, alignment, data);
  return true;
}

void wayc_atlas_deinit(atlas_s* atlas) {
  wayc_notnull(atlas);
  wayc_sampler_deinit(&atlas->sampler);
  wayc_image_deinit(&atlas->texture);
}

static inline void wayc_atlas_packer_wrap(struct atlas_packer_s* packer) {
  WAYC_X(packer->cursor) = 0;
  WAYC_Y(packer->cursor) += packer->row_height;
  packer->row_height = 0;
}

bool wayc_atlas_packer_allocate(struct atlas_packer_s* packer, u32 width,
                                u32 height, ivec2 out) {
  wayc_notnull(packer);

  struct atlas_s* atlas = packer->atlas;
  wayc_notnull(atlas);

  if (width > atlas->width || height > atlas->height) return false;

  if (WAYC_X(packer->cursor) + width > atlas->width)
    wayc_atlas_packer_wrap(packer);

  if (WAYC_Y(packer->cursor) + height > atlas->height) return false;

  glm_ivec2_copy(packer->cursor, out);
  WAYC_X(packer->cursor) += width;
  packer->row_height = wayc_max(packer->row_height, height);

  return true;
}