#include "camera.h"
#include "ui.h"
#include "render_graph.h"

#include <cglm/cam.h>
#include <math.h>
#include <stddef.h>

static vec3 up = {0, 1, 0};

VkResult create_camera(RenderContext* gpu, Camera* camera) {
  VkResult result;
  camera->texture_dynamic = true;
  camera->max_depth = 1;
  for(uint32_t i = 0; i < MAX_FRAMES_IN_FLIGHT; i++) {
    VK_RESULT(create_storage_buffer(
          gpu->allocator,
          0,
          sizeof(GPUCamera),
          &camera->gpu_buffer[i],
          &camera->gpu_buffer_memory[i]));
    camera->gpu_address[i] = buffer_address(gpu->device, camera->gpu_buffer[i]);
  }
  return VK_SUCCESS;
}

void destroy_camera(RenderContext* gpu, Camera* camera) {
  if(camera->has_texture_target) {
    camera_destroy_texture_target(gpu, NULL, camera);
  }
  for(uint32_t i = 0; i < MAX_FRAMES_IN_FLIGHT; i++) {
    vmaDestroyBuffer(gpu->allocator, camera->gpu_buffer[i], camera->gpu_buffer_memory[i]);
  }
}

void camera_update_view(Camera* camera) {
  vec3 eye = {};
  eye[0] = camera->position[0] + camera->distance*cos(camera->rotation[1])*cos(camera->rotation[0]);
  eye[1] = camera->position[1] + camera->distance*sin(camera->rotation[1]);
  eye[2] = camera->position[2] + camera->distance*cos(camera->rotation[1])*sin(camera->rotation[0]);

  glm_lookat(eye, camera->position, up, camera->view);
}

void camera_update_proj(Camera* camera, float aspect) {
  glm_perspective(
      PERSPECTIVE_FOVY,
      aspect,
      PERSPECTIVE_NEARZ,
      PERSPECTIVE_FARZ,
      camera->proj);
}

VkResult camera_sync_gpu(Camera* camera, RenderContext* gpu) {
  GPUCamera data;
  glm_mat4_copy(camera->proj, data.proj);
  glm_mat4_copy(camera->view, data.view);
  return add_transfers(&data, camera->gpu_buffer, 0, sizeof(GPUCamera), gpu);
}

VkResult camera_init_texture_target(
    RenderContext* gpu,
    UIContext* ui,
    Camera* camera,
    uint32_t width,
    uint32_t height) {
  VkResult result;

  camera->texture.width = width;
  camera->texture.height = height;

  VkExtent2D extent = {width, height};
  for(uint32_t i = 0; i < MAX_FRAMES_IN_FLIGHT; i++) {
    VK_RESULT(create_render_target_texture(gpu, ui, width, height, &camera->texture.texture_slot[i]));
    VK_RESULT(create_depth_image(
          gpu->device,
          gpu->depth_format,
          extent,
          gpu->allocator,
          gpu->extra_graphics_pool,
          gpu->graphics_queue,
          &camera->texture.depth_image[i],
          &camera->texture.depth_image_memory[i],
          &camera->texture.depth_image_view[i]));
  }

  camera->has_texture_target = true;
  return VK_SUCCESS;
}

void camera_destroy_texture_target(RenderContext* gpu, UIContext* ui, Camera* camera) {
  (void)ui;
  for(uint32_t i = 0; i < MAX_FRAMES_IN_FLIGHT; i++) {
    vkDestroyImageView(gpu->device, camera->texture.depth_image_view[i], NULL);
    vmaDestroyImage(gpu->allocator, camera->texture.depth_image[i], camera->texture.depth_image_memory[i]);
    // TODO: free camera->texture.texture_slot[i] from the bindless descriptor
    // pool once destroy_render_target_texture is implemented. For now the
    // color slot leaks on destroy - only called from destroy_camera (shutdown).
  }
  camera->has_texture_target = false;
}

VkResult camera_recreate_texture_target(
    Camera* camera,
    RenderContext* gpu,
    UIContext* ui,
    uint32_t width,
    uint32_t height) {
  VkResult result;
  VkExtent2D extent = {width, height};
  for(uint32_t i = 0; i < MAX_FRAMES_IN_FLIGHT; i++) {
    VK_RESULT(recreate_render_target_texture(gpu, ui, camera->texture.texture_slot[i], width, height));
    vkDestroyImageView(gpu->device, camera->texture.depth_image_view[i], NULL);
    vmaDestroyImage(gpu->allocator, camera->texture.depth_image[i], camera->texture.depth_image_memory[i]);
    VK_RESULT(create_depth_image(
        gpu->device, gpu->depth_format, extent, gpu->allocator,
        gpu->extra_graphics_pool, gpu->graphics_queue,
        &camera->texture.depth_image[i],
        &camera->texture.depth_image_memory[i],
        &camera->texture.depth_image_view[i]));
  }
  camera->texture.width = width;
  camera->texture.height = height;
  return VK_SUCCESS;
}

VkResult camera_display(Camera* camera, Container* container, RenderContext* gpu, UIContext* ui) {
  VkResult result;

  container_set_camera(container, camera);

  if(!camera->has_texture_target) {
    uint32_t w, h;
    if(camera->texture_dynamic) {
      VkRect2D rect;
      container_screen_rect(gpu, container, &rect);
      w = rect.extent.width > 0 ? rect.extent.width : 1;
      h = rect.extent.height > 0 ? rect.extent.height : 1;
    } else {
      w = camera->texture.width > 0 ? camera->texture.width : 1;
      h = camera->texture.height > 0 ? camera->texture.height : 1;
    }
    VK_RESULT(camera_init_texture_target(gpu, ui, camera, w, h));
  }

  if(ui->render_graph != NULL) {
    camera->rg_node = render_graph_add_camera_node(ui->render_graph, camera);
    ui->render_graph_dirty = true;
  } else {
    camera->rg_node = UINT32_MAX;
  }

  GPUDrawable bg = {
    .pos = {0.0f, 0.0f},
    .size = {container->data.size[0], container->data.size[1]},
    .color = {
      {1.0f, 1.0f, 1.0f, 1.0f},
      {1.0f, 1.0f, 1.0f, 1.0f},
      {1.0f, 1.0f, 1.0f, 1.0f},
      {1.0f, 1.0f, 1.0f, 1.0f},
    },
    .type = DRAWABLE_TYPE_IMAGE,
    .var = camera->texture.texture_slot[0],
    .events = 0,
    .z = -1e30f,
  };

  uint32_t bg_slot;
  VK_RESULT(ui_create_drawable(container, &bg, gpu, &bg_slot));

  // ui_create_drawable → add_transfers uploads var=texture_slot[0] to both
  // frames. Override frame 1's var in-place (the coalesce in add_transfer
  // rewrites the staging data without adding a new entry).
  VK_RESULT(add_transfer(
      &camera->texture.texture_slot[1],
      container->drawables[1],
      sizeof(GPUDrawable) * bg_slot + offsetof(GPUDrawable, var),
      sizeof(uint32_t),
      1,
      gpu));

  container->camera_background_drawable = bg_slot;
  return VK_SUCCESS;
}

VkResult camera_undisplay(Camera* camera, Container* container, RenderContext* gpu, UIContext* ui) {
  if(ui->render_graph != NULL && camera->rg_node != UINT32_MAX) {
    render_graph_remove_node(ui->render_graph, camera->rg_node);
    camera->rg_node = UINT32_MAX;
    ui->render_graph_dirty = true;
  }

  VkResult result = VK_SUCCESS;
  if(container->camera_background_drawable != UINT32_MAX) {
    result = ui_destroy_drawable(container, container->camera_background_drawable, gpu);
    container->camera_background_drawable = UINT32_MAX;
  }
  container_set_camera(container, NULL);
  return result;
}