#define VK_USE_PLATFORM_MACOS_MVK
#include "vulkan/vulkan_core.h"
#define GLFW_INCLUDE_VULKAN
#include <GLFW/glfw3.h>
#define GLFW_EXPOSE_NATIVE_COCOA
#include <GLFW/glfw3native.h>

#define GLM_FORCE_RADIANS
#define GLM_FORCE_DEPTH_ZERO_TO_ONE
#include <cglm/types.h>
#include <cglm/mat4.h>
#include <stdio.h>
#include <string.h>

typedef struct QueueIndicesStruct {
  uint32_t graphics_family;
  uint32_t graphics_index;

  uint32_t present_family;
  uint32_t present_index;

  uint32_t transfer_family;
  uint32_t transfer_index;
} QueueIndices;

typedef struct QueuesStruct {
  VkQueue graphics;
  VkQueue present;
  VkQueue transfer;
} Queues;

typedef struct SwapchainDetailsStruct {
  VkSurfaceCapabilitiesKHR capabilities;

  VkSurfaceFormatKHR* formats;
  uint32_t formats_count;

  VkPresentModeKHR* present_modes;
  uint32_t present_modes_count;
} SwapchainDetails;

typedef struct SwapchainImagesStruct {
  VkImage* images;
  uint32_t count;
} SwapchainImages;

typedef struct AllocatedBufferStruct {
  VkBuffer buffer;
  VkDeviceMemory memory;
} AllocatedBuffer;

typedef struct VulkanContextStruct {
  VkInstance instance;
  VkDebugUtilsMessengerEXT debug_messenger;
  VkPhysicalDevice physical_device;

  QueueIndices queue_indices;
  VkDevice device;
  Queues queues;

  VkSurfaceKHR surface;

  SwapchainDetails swapchain_details;
  VkSwapchainKHR swapchain;

  VkSurfaceFormatKHR swapchain_format;
  VkPresentModeKHR swapchain_present_mode;
  VkExtent2D swapchain_extent;

  uint32_t swapchain_image_count;
  // Per image objects
  VkImage* swapchain_images;
  VkImageView* swapchain_image_views;
  VkFramebuffer* swapchain_framebuffers;

  uint32_t max_frames_in_flight;
  // Per frame objects
  VkCommandBuffer* swapchain_command_buffers;
  VkSemaphore* image_available_semaphores;
  VkSemaphore* render_finished_semaphores;
  VkFence* in_flight_fences;

  AllocatedBuffer* uniform_buffers;
  void** uniform_buffer_ptrs;
  VkDescriptorPool descriptor_pool;
  VkDescriptorSet* descriptor_sets;

  VkRenderPass render_pass;

  VkCommandPool graphics_command_pool;
  VkCommandPool transfer_command_pool;

  VkDescriptorSetLayout triangle_descriptor_set;
  VkPipelineLayout triangle_pipeline_layout;
  VkPipeline triangle_pipeline;
  AllocatedBuffer triangle_vertex_buffer;
  AllocatedBuffer triangle_index_buffer;

  uint32_t current_frame;
} VulkanContext;

struct Vertex{
  vec2 pos;
  vec3 color;
};

struct ShaderUBO {
  mat4 model;
  mat4 view;
  mat4 proj;
};

const struct Vertex vertices[] = {
  {.pos = {-0.5f, -0.5f}, .color = {1.0f, 0.0f, 0.0f}},
  {.pos = { 0.5f, -0.5f}, .color = {0.0f, 1.0f, 0.0f}},
  {.pos = { 0.5f,  0.5f}, .color = {0.0f, 0.0f, 1.0f}},
  {.pos = {-0.5f,  0.5f}, .color = {1.0f, 1.0f, 1.0f}},
};

const uint16_t indices[] = {
  0, 1, 2, 2, 3, 0,
};

const char * validation_layers[] = {
  "VK_LAYER_KHRONOS_validation",
  //"VK_LAYER_LUNARG_api_dump",
  //"VK_LAYER_KHRONOS_profiles",
  //"VK_LAYER_KHRONOS_synchronization2",
  "VK_LAYER_KHRONOS_shader_object",
};
uint32_t validation_layer_count = sizeof(validation_layers) / sizeof(const char *);

const char * instance_extensions[] = {
  VK_KHR_PORTABILITY_ENUMERATION_EXTENSION_NAME,
  VK_EXT_DEBUG_UTILS_EXTENSION_NAME,
  VK_MVK_MACOS_SURFACE_EXTENSION_NAME,
  VK_KHR_SURFACE_EXTENSION_NAME,
};
uint32_t instance_extension_count = sizeof(instance_extensions) / sizeof(const char *);

const char * device_extensions[] = {
  VK_KHR_SWAPCHAIN_EXTENSION_NAME,
};
uint32_t device_extension_count = sizeof(device_extensions) / sizeof(const char *);

void glfw_error(int error, const char* description) {
  fprintf(stderr, "GLFW_ERR: 0x%02x - %s\n", error, description);
}

VkVertexInputBindingDescription vertex_bindings[1];
VkVertexInputBindingDescription* vertex_binding_descriptions() {
  vertex_bindings[0].binding = 0;
  vertex_bindings[0].stride = sizeof(struct Vertex);
  vertex_bindings[0].inputRate = VK_VERTEX_INPUT_RATE_VERTEX;

  return vertex_bindings;
}

VkVertexInputAttributeDescription vertex_attributes[2];
VkVertexInputAttributeDescription* vertex_attribute_descriptions() {
  vertex_attributes[0].binding = 0;
  vertex_attributes[0].location = 0;
  vertex_attributes[0].format = VK_FORMAT_R32G32_SFLOAT;
  vertex_attributes[0].offset = offsetof(struct Vertex, pos);

  vertex_attributes[1].binding = 0;
  vertex_attributes[1].location = 1;
  vertex_attributes[1].format = VK_FORMAT_R32G32B32_SFLOAT;
  vertex_attributes[1].offset = offsetof(struct Vertex, color);

  return vertex_attributes;
}

GLFWwindow* init_window(int width, int height) {
  glfwInit();
  glfwSetErrorCallback(glfw_error);

  glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
  glfwWindowHint(GLFW_RESIZABLE, GLFW_FALSE);
  GLFWwindow* window = glfwCreateWindow(width, height, "Vulkan window", 0, 0);


  return window;
}

bool check_validation_layers(const char ** layers, uint32_t num_layers) {
  uint32_t layer_count;
  VkResult result;

  result = vkEnumerateInstanceLayerProperties(&layer_count, 0);
  if(result != VK_SUCCESS) {
    return false;
  }

  VkLayerProperties* available_layers = malloc(sizeof(VkLayerProperties)*layer_count);

  result = vkEnumerateInstanceLayerProperties(&layer_count, available_layers);

  for(uint32_t i = 0; i < num_layers; i++) {
    bool found = false;
    for(uint32_t j = 0; j < layer_count; j++) {
      if(strcmp(layers[i], available_layers[j].layerName) == 0) {
        found = true;
      }
    }
    if(found == false) {
      free(available_layers);
      return false;
    }
  }

  free(available_layers);
  return true;
}

static VKAPI_ATTR VkBool32 VKAPI_CALL debug_callback(
  VkDebugUtilsMessageSeverityFlagBitsEXT severity,
  VkDebugUtilsMessageTypeFlagsEXT type,
  const VkDebugUtilsMessengerCallbackDataEXT* callback_data,
  void* user_data) {

  (void)severity;
  (void)type;
  (void)user_data;

  fprintf(stderr, "Validation layer: %s\n", callback_data->pMessage);

  return VK_FALSE;
}

VkDescriptorSet* create_descriptor_sets(VkDevice device, VkDescriptorSetLayout layout, VkDescriptorPool pool, AllocatedBuffer* uniform_buffers, uint32_t count) {
  VkDescriptorSetLayout* layouts = malloc(sizeof(VkDescriptorSetLayout)*count);
  if(layouts == 0) {
    return 0;
  }

  VkDescriptorSet* sets = malloc(sizeof(VkDescriptorSet)*count);
  if(sets == 0) {
    free(layouts);
    return 0;
  }

  for(uint32_t i = 0; i < count; i++) {
    layouts[i] = layout;
  }

  VkDescriptorSetAllocateInfo alloc_info = {};
  alloc_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
  alloc_info.descriptorPool = pool;
  alloc_info.descriptorSetCount = count;
  alloc_info.pSetLayouts = layouts;

  VkResult result = vkAllocateDescriptorSets(device, &alloc_info, sets);
  free(layouts);
  if(result != VK_SUCCESS) {
    free(sets);
    return 0;
  }

  for(uint32_t i = 0; i < count; i++) {
    VkDescriptorBufferInfo buffer_info = {};
    buffer_info.buffer = uniform_buffers[i].buffer;
    buffer_info.offset = 0;
    buffer_info.range = sizeof(struct ShaderUBO);

    VkWriteDescriptorSet descriptor_write = {};
    descriptor_write.sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
    descriptor_write.dstSet = sets[i];
    descriptor_write.dstBinding = 0;
    descriptor_write.dstArrayElement = 0;
    descriptor_write.descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
    descriptor_write.descriptorCount = 1;
    descriptor_write.pBufferInfo = &buffer_info;
    descriptor_write.pImageInfo = 0;
    descriptor_write.pTexelBufferView = 0;

    vkUpdateDescriptorSets(device, 1, &descriptor_write, 0, 0);
  }

  return sets;
}

VkDescriptorSetLayout create_descriptor_set_layout(VkDevice device) {
  VkDescriptorSetLayoutBinding layout_binding = {};
  layout_binding.binding = 0;
  layout_binding.descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
  layout_binding.descriptorCount = 1;
  layout_binding.stageFlags = VK_SHADER_STAGE_VERTEX_BIT;
  layout_binding.pImmutableSamplers = 0;

  VkDescriptorSetLayoutCreateInfo layout_info = {};
  layout_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO;
  layout_info.bindingCount = 1;
  layout_info.pBindings = &layout_binding;

  VkDescriptorSetLayout layout;
  VkResult result = vkCreateDescriptorSetLayout(device, &layout_info, 0, &layout);
  if(result != VK_SUCCESS) {
    return VK_NULL_HANDLE;
  }

  return layout;
}

VkSurfaceKHR create_surface_khr(VkInstance instance, GLFWwindow* window) {
  VkSurfaceKHR surface;
  VkResult result = glfwCreateWindowSurface(instance, window, 0, &surface);
  if(result != VK_SUCCESS) {
    return VK_NULL_HANDLE;
  }

  return surface;
}

VkPhysicalDevice get_best_physical_device(VkInstance instance) {
  VkPhysicalDevice device = VK_NULL_HANDLE;

  uint32_t device_count = 0;
  VkResult result;
  result = vkEnumeratePhysicalDevices(instance, &device_count, 0);
  if(result != VK_SUCCESS) {
    return VK_NULL_HANDLE;
  }

  VkPhysicalDevice* devices = malloc(sizeof(VkPhysicalDevice)*device_count);
  result = vkEnumeratePhysicalDevices(instance, &device_count, devices);
  if(result != VK_SUCCESS) {
    free(devices);
    return VK_NULL_HANDLE;
  }

  int top_score = -1;
  for(uint32_t i = 0; i < device_count; i++) {
    int score = 0;

    VkPhysicalDeviceProperties properties;
    vkGetPhysicalDeviceProperties(devices[i], &properties);

    VkPhysicalDeviceFeatures features;
    vkGetPhysicalDeviceFeatures(devices[i], &features);

    switch(properties.deviceType) {
    case VK_PHYSICAL_DEVICE_TYPE_DISCRETE_GPU:
      score += 100;
      break;
    case VK_PHYSICAL_DEVICE_TYPE_VIRTUAL_GPU:
      score += 50;
      break;
    case VK_PHYSICAL_DEVICE_TYPE_INTEGRATED_GPU:
      score += 25;
      break;
    case VK_PHYSICAL_DEVICE_TYPE_CPU:
      score += 0;
      break;
    default:
      continue;
    }

    if(score > top_score) {
      top_score = score;
      device = devices[i];
    }
  }

  free(devices);

  return device;
}

bool check_queue_indices(QueueIndices indices) {
  return ((indices.graphics_family != 0xFFFFFFFF)
      && (indices.present_family != 0xFFFFFFFF)
      && (indices.transfer_family != 0xFFFFFFFF));
}

QueueIndices get_queue_indices(VkPhysicalDevice physical_device, VkSurfaceKHR surface) {
  QueueIndices indices = {};
  indices.graphics_family = 0xFFFFFFFF;
  indices.graphics_index  = 0xFFFFFFFF;
  indices.present_family  = 0xFFFFFFFF;
  indices.present_index   = 0xFFFFFFFF;
  indices.transfer_family = 0xFFFFFFFF;
  indices.transfer_index  = 0xFFFFFFFF;

  uint32_t queue_family_count;
  vkGetPhysicalDeviceQueueFamilyProperties(physical_device, &queue_family_count, 0);

  VkQueueFamilyProperties* queue_families = malloc(sizeof(VkQueueFamilyProperties)*queue_family_count);

  vkGetPhysicalDeviceQueueFamilyProperties(physical_device, &queue_family_count, queue_families);

  for(uint32_t family_idx = 0; family_idx < queue_family_count; family_idx++) {
    VkBool32 present_support;
    vkGetPhysicalDeviceSurfaceSupportKHR(physical_device, family_idx, surface, &present_support);
    for(uint32_t queue_idx = 0; queue_idx < queue_families[family_idx].queueCount; queue_idx++) {
      if(((indices.graphics_family == 0xFFFFFFFF)
            || (indices.present_family == 0xFFFFFFFF)
            || (indices.present_family != indices.graphics_family))
          && (queue_families[family_idx].queueFlags & VK_QUEUE_GRAPHICS_BIT)
          && (present_support == VK_TRUE)) {
        fprintf(stderr, "Selected %d:%d for graphics and present queues\n", family_idx, queue_idx);
        indices.graphics_family = family_idx;
        indices.graphics_index = queue_idx;

        indices.present_family = family_idx;
        indices.present_index = queue_idx;
      } else if((indices.graphics_family == 0xFFFFFFFF)
          && (queue_families[family_idx].queueFlags & VK_QUEUE_GRAPHICS_BIT)) {
        fprintf(stderr, "Selected %d:%d for graphics queue\n", family_idx, queue_idx);
        indices.graphics_family = family_idx;
        indices.graphics_index = queue_idx;
      } else if((indices.present_family == 0xFFFFFFFF)
          && (present_support == VK_TRUE)) {
        fprintf(stderr, "Selected %d:%d for present queue\n", family_idx, queue_idx);
        indices.present_family = family_idx;
        indices.present_index = queue_idx;
      } else if((indices.transfer_family == 0xFFFFFFFF)
          && (queue_families[family_idx].queueFlags & (VK_QUEUE_GRAPHICS_BIT | VK_QUEUE_COMPUTE_BIT))) {
        fprintf(stderr, "Selected %d:%d for transfer queue\n", family_idx, queue_idx);
        indices.transfer_family = family_idx;
        indices.transfer_index = queue_idx;
      }
    }
  }

  free(queue_families);

  return indices;
}

VkDebugUtilsMessengerEXT create_debug_messenger(VkInstance instance) {
  VkDebugUtilsMessengerEXT debug_messenger;

  VkDebugUtilsMessengerCreateInfoEXT messenger_info = {};
  messenger_info.sType = VK_STRUCTURE_TYPE_DEBUG_UTILS_MESSENGER_CREATE_INFO_EXT;
  messenger_info.messageSeverity = VK_DEBUG_UTILS_MESSAGE_SEVERITY_VERBOSE_BIT_EXT;
  messenger_info.messageType = VK_DEBUG_UTILS_MESSAGE_TYPE_GENERAL_BIT_EXT | VK_DEBUG_UTILS_MESSAGE_TYPE_VALIDATION_BIT_EXT | VK_DEBUG_UTILS_MESSAGE_TYPE_PERFORMANCE_BIT_EXT | VK_DEBUG_UTILS_MESSAGE_TYPE_DEVICE_ADDRESS_BINDING_BIT_EXT;
  messenger_info.pfnUserCallback = debug_callback;
  messenger_info.pUserData = 0;

  PFN_vkCreateDebugUtilsMessengerEXT func = (PFN_vkCreateDebugUtilsMessengerEXT)vkGetInstanceProcAddr(instance, "vkCreateDebugUtilsMessengerEXT");

  VkResult result;
  result = func(instance, &messenger_info, 0, &debug_messenger);
  if(result != VK_SUCCESS) {
    fprintf(stderr, "failed to create debug messenger\n");
    return VK_NULL_HANDLE;
  }

  return debug_messenger;
}

VkDescriptorPool create_descriptor_pool(VkDevice device, uint32_t size) {
  VkDescriptorPoolSize pool_size = {};
  pool_size.type = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
  pool_size.descriptorCount = size;

  VkDescriptorPoolCreateInfo pool_info = {};
  pool_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO;
  pool_info.poolSizeCount = 1;
  pool_info.pPoolSizes = &pool_size;
  pool_info.maxSets = size;

  VkDescriptorPool pool;
  VkResult result = vkCreateDescriptorPool(device, &pool_info, 0, &pool);
  if(result != VK_SUCCESS) {
    return VK_NULL_HANDLE;
  }

  return pool;
}

VkInstance create_instance() {
  VkInstance instance;

  if(check_validation_layers(validation_layers, validation_layer_count) == false) {
    fprintf(stderr, "requested validation layers not supported");
    return VK_NULL_HANDLE;
  }

  VkApplicationInfo app_info = {};
  app_info.sType = VK_STRUCTURE_TYPE_APPLICATION_INFO;
  app_info.pApplicationName = "spacegame";
  app_info.applicationVersion = VK_MAKE_VERSION(0, 0, 1);
  app_info.pEngineName = "spacegame";
  app_info.engineVersion = VK_MAKE_VERSION(0, 0, 1);
  app_info.apiVersion = VK_API_VERSION_1_3;

  VkInstanceCreateInfo instance_info = {};
  instance_info.sType = VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO;
  instance_info.pApplicationInfo = &app_info;

  instance_info.enabledLayerCount = validation_layer_count;
  instance_info.ppEnabledLayerNames = validation_layers;

  uint32_t glfwExtensionCount = 0;
  const char** glfwExtensions;

  glfwExtensions = glfwGetRequiredInstanceExtensions(&glfwExtensionCount);

  const char** requested_extensions = malloc(sizeof(char*)*(glfwExtensionCount + instance_extension_count));
  for (uint32_t i = 0; i < glfwExtensionCount; i++) {
    requested_extensions[i] = glfwExtensions[i];
  }

  for (uint32_t i = 0; i < instance_extension_count; i++) {
    requested_extensions[glfwExtensionCount + i] = instance_extensions[i];
  }

  instance_info.enabledExtensionCount = glfwExtensionCount + instance_extension_count;
  instance_info.ppEnabledExtensionNames = requested_extensions;

  instance_info.flags |= VK_INSTANCE_CREATE_ENUMERATE_PORTABILITY_BIT_KHR;

  VkResult result = vkCreateInstance(&instance_info, 0, &instance);
  if(result != VK_SUCCESS) {
    fprintf(stderr, "vkCreateInstance: 0x%02x\n", result);
    return VK_NULL_HANDLE;
  }

  free(requested_extensions);

  return instance;
}

VkDevice create_logical_device(VkPhysicalDevice physical_device, QueueIndices queue_indices) {
  VkDevice device;

  uint32_t unique_families[3] = {0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF};
  uint32_t unique_family_queues[3] = {0, 0, 0};
  uint32_t unique_family_count = 0;

  uint32_t queue_family[] = {queue_indices.transfer_family, queue_indices.graphics_family, queue_indices.present_family};
  uint32_t unique_queue_count = 3;
  if((queue_indices.graphics_family == queue_indices.present_family)
      && (queue_indices.graphics_index == queue_indices.present_index)) {
    unique_queue_count = 2;
  }

  for(uint32_t queue_idx = 0; queue_idx < unique_queue_count; queue_idx++) {
    uint32_t idx = 0xFFFFFFFF;
    for(uint32_t check_idx = 0; check_idx < unique_family_count; check_idx++) {
      if(queue_family[queue_idx] == unique_families[check_idx]) {
        idx = check_idx;
        break;
      }
    }

    if(idx == 0xFFFFFFFF) {
      unique_families[unique_family_count] = queue_family[queue_idx];
      unique_family_queues[unique_family_count] += 1;
      unique_family_count += 1;
    } else {
      unique_family_queues[idx] += 1;
    }
  }

  VkDeviceQueueCreateInfo queue_create_info[3] = {};
  float default_queue_priority = 1.0f;
  for(uint32_t i = 0; i < unique_family_count; i++) {
    queue_create_info[i].sType = VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO;
    queue_create_info[i].queueFamilyIndex = unique_families[i];
    queue_create_info[i].queueCount = unique_family_queues[i];
    queue_create_info[i].pQueuePriorities = &default_queue_priority;
  }

  VkPhysicalDeviceFeatures device_features = {};

  VkDeviceCreateInfo device_create_info = {};
  device_create_info.sType = VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO;
  device_create_info.pQueueCreateInfos = queue_create_info;
  device_create_info.queueCreateInfoCount = unique_family_count;
  device_create_info.pEnabledFeatures = &device_features;

  device_create_info.enabledExtensionCount = device_extension_count;
  device_create_info.ppEnabledExtensionNames = device_extensions;

  device_create_info.enabledLayerCount = validation_layer_count;
  device_create_info.ppEnabledLayerNames = validation_layers;

  VkResult result = vkCreateDevice(physical_device, &device_create_info, 0, &device);
  if(result != VK_SUCCESS) {
    return VK_NULL_HANDLE;
  }

  return device;
}

struct MaybeSwapchainDetails {
  bool valid;
  SwapchainDetails details;
};

struct MaybeSwapchainDetails get_swapchain_details(VkPhysicalDevice physical_device, VkSurfaceKHR surface) {
  struct MaybeSwapchainDetails ret = {};
  ret.valid = false;
  ret.details.formats = 0;
  ret.details.present_modes = 0;

  VkResult result;

  result = vkGetPhysicalDeviceSurfaceCapabilitiesKHR(physical_device, surface, &ret.details.capabilities);
  if(result != VK_SUCCESS) {
    return ret;
  }

  result = vkGetPhysicalDeviceSurfaceFormatsKHR(physical_device, surface, &ret.details.formats_count, 0);
  if(result != VK_SUCCESS) {
    return ret;
  }
  ret.details.formats = malloc(sizeof(VkSurfaceFormatKHR)*ret.details.formats_count);
  result = vkGetPhysicalDeviceSurfaceFormatsKHR(physical_device, surface, &ret.details.formats_count, ret.details.formats);
  if(result != VK_SUCCESS) {
    free(ret.details.formats);
    return ret;
  }

  result = vkGetPhysicalDeviceSurfacePresentModesKHR(physical_device, surface, &ret.details.present_modes_count, 0);
  if(result != VK_SUCCESS) {
    free(ret.details.formats);
    return ret;
  }
  ret.details.present_modes = malloc(sizeof(VkPresentModeKHR)*ret.details.present_modes_count);
  result = vkGetPhysicalDeviceSurfacePresentModesKHR(physical_device, surface, &ret.details.present_modes_count, ret.details.present_modes);
  if(result != VK_SUCCESS) {
    free(ret.details.formats);
    free(ret.details.present_modes);
    return ret;
  }

  ret.valid = true;
  return ret;
}

VkSurfaceFormatKHR choose_swapchain_format(SwapchainDetails swapchain_details) {
  for(uint32_t i = 0; i < swapchain_details.formats_count; i++) {
    VkSurfaceFormatKHR format = swapchain_details.formats[i];
    if(format.format == VK_FORMAT_B8G8R8A8_SRGB && format.colorSpace == VK_COLOR_SPACE_SRGB_NONLINEAR_KHR) {
      return format;
    }
  }
  return swapchain_details.formats[0];
}

VkPresentModeKHR choose_present_mode(SwapchainDetails swapchain_details) {
  for(uint32_t i = 0; i < swapchain_details.present_modes_count; i++) {
    if(swapchain_details.present_modes[i] == VK_PRESENT_MODE_MAILBOX_KHR) {
      return VK_PRESENT_MODE_MAILBOX_KHR;
    }
  }

  return VK_PRESENT_MODE_FIFO_KHR;
}

VkExtent2D choose_swapchain_extent(SwapchainDetails swapchain_details) {
  return swapchain_details.capabilities.currentExtent;
}

VkSwapchainKHR create_swapchain(VkDevice device, VkSurfaceFormatKHR format, VkPresentModeKHR present_mode, VkExtent2D extent, VkSurfaceKHR surface, VkSurfaceCapabilitiesKHR capabilities, QueueIndices indices, VkSwapchainKHR old_swapchain) {
  uint32_t image_count = capabilities.minImageCount + 1;
  uint32_t max_images = capabilities.maxImageCount;
  if((max_images > 0) && (image_count > max_images)) {
    image_count = max_images;
  }

  VkSwapchainCreateInfoKHR swapchain_info = {};
  swapchain_info.sType = VK_STRUCTURE_TYPE_SWAPCHAIN_CREATE_INFO_KHR;
  swapchain_info.surface = surface;
  swapchain_info.minImageCount = image_count;
  swapchain_info.imageFormat = format.format;
  swapchain_info.imageColorSpace = format.colorSpace;
  swapchain_info.imageExtent = extent;
  swapchain_info.imageArrayLayers = 1;
  swapchain_info.imageUsage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT;

  uint32_t queue_families[2] = {indices.graphics_family, indices.present_index};
  if(indices.graphics_family != indices.present_family) {
    swapchain_info.imageSharingMode = VK_SHARING_MODE_CONCURRENT;
    swapchain_info.queueFamilyIndexCount = 2;
    swapchain_info.pQueueFamilyIndices = queue_families;
  } else {
    swapchain_info.imageSharingMode = VK_SHARING_MODE_EXCLUSIVE;
    swapchain_info.queueFamilyIndexCount = 0;
    swapchain_info.pQueueFamilyIndices = 0;
  }

  swapchain_info.preTransform = capabilities.currentTransform;
  swapchain_info.compositeAlpha = VK_COMPOSITE_ALPHA_INHERIT_BIT_KHR;
  swapchain_info.presentMode = present_mode;
  swapchain_info.clipped = VK_TRUE;

  swapchain_info.oldSwapchain = old_swapchain;

  VkSwapchainKHR swapchain;
  VkResult result;
  result = vkCreateSwapchainKHR(device, &swapchain_info, 0, &swapchain);
  if(result != VK_SUCCESS) {
    return VK_NULL_HANDLE;
  }

  return swapchain;
}

SwapchainImages get_swapchain_images(VkDevice device, VkSwapchainKHR swapchain) {
  SwapchainImages images;
  images.images = 0;
  images.count = 0;

  VkResult result;
  result = vkGetSwapchainImagesKHR(device, swapchain, &images.count, 0);
  if(result != VK_SUCCESS) {
    images.count = 0;
    return images;
  }

  images.images = malloc(sizeof(VkImage)*images.count);
  if(images.images == 0) {
    images.count = 0;
    return images;
  }

  result = vkGetSwapchainImagesKHR(device, swapchain, &images.count, images.images);
  if(result != VK_SUCCESS) {
    images.count = 0;
    return images;
  }

  return images;
}

VkImageView* create_image_views(VkDevice device, uint32_t image_count, VkImage* images, VkSurfaceFormatKHR format) {
  VkImageView* image_views = malloc(sizeof(VkImageView)*image_count);
  if(image_views == 0) {
    return 0;
  }

  for(uint32_t i = 0; i < image_count; i++) {
    VkImageViewCreateInfo view_info = {};
    view_info.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
    view_info.image = images[i];
    view_info.viewType = VK_IMAGE_VIEW_TYPE_2D;
    view_info.format = format.format;

    view_info.components.r = VK_COMPONENT_SWIZZLE_IDENTITY;
    view_info.components.g = VK_COMPONENT_SWIZZLE_IDENTITY;
    view_info.components.b = VK_COMPONENT_SWIZZLE_IDENTITY;
    view_info.components.a = VK_COMPONENT_SWIZZLE_IDENTITY;

    view_info.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
    view_info.subresourceRange.baseMipLevel = 0;
    view_info.subresourceRange.levelCount = 1;
    view_info.subresourceRange.baseArrayLayer = 0;
    view_info.subresourceRange.layerCount = 1;

    VkResult result = vkCreateImageView(device, &view_info, 0, &image_views[i]);
    if(result != VK_SUCCESS) {
      free(image_views);
      return 0;
    }
  }

  return image_views;
}

VkFramebuffer* create_swapchain_framebuffers(VkDevice device, uint32_t image_count, VkImageView* image_views, VkRenderPass render_pass, VkExtent2D extent) {
  VkFramebuffer* framebuffers = malloc(sizeof(VkFramebuffer)*image_count);
  if(framebuffers == 0) {
    return 0;
  }

  for(uint32_t i = 0; i < image_count; i++) {
    VkImageView attachments[] = {
      image_views[i],
    };

    VkFramebufferCreateInfo framebuffer_info = {};
    framebuffer_info.sType = VK_STRUCTURE_TYPE_FRAMEBUFFER_CREATE_INFO;
    framebuffer_info.renderPass = render_pass;
    framebuffer_info.attachmentCount = 1;
    framebuffer_info.pAttachments = attachments;
    framebuffer_info.width = extent.width;
    framebuffer_info.height = extent.height;
    framebuffer_info.layers = 1;

    VkResult result = vkCreateFramebuffer(device, &framebuffer_info, 0, &framebuffers[i]);
    if(result != VK_SUCCESS) {
      free(framebuffers);
      return 0;
    }
  }

  return framebuffers;
}

VkShaderModule create_shader_module(VkDevice device, const char * code, uint32_t code_size) {
  VkShaderModuleCreateInfo shader_info = {};
  shader_info.sType = VK_STRUCTURE_TYPE_SHADER_CREATE_INFO_EXT;
  shader_info.codeSize = code_size;
  shader_info.pCode = (uint32_t*)code;

  VkShaderModule shader;
  VkResult result;
  result = vkCreateShaderModule(device, &shader_info, 0, &shader);
  if(result != VK_SUCCESS) {
    return VK_NULL_HANDLE;
  }

  return shader;
}

VkShaderModule load_shader_file(uint32_t buffer_size, const char* path, VkDevice device) {
  FILE* file;
  file = fopen(path, "r");
  if(file == 0) {
    return VK_NULL_HANDLE;
  }

  char * buffer = malloc(buffer_size);
  if(buffer == 0) {
    return VK_NULL_HANDLE;
  }

  size_t read = fread(buffer, 1, buffer_size, file);

  VkShaderModule shader = create_shader_module(device, buffer, read);
  free(buffer);
  return shader;
}

VkRenderPass create_render_pass(VkDevice device, VkSurfaceFormatKHR format) {
  VkAttachmentDescription color_attachment;
  color_attachment.format = format.format;
  color_attachment.samples = VK_SAMPLE_COUNT_1_BIT;
  color_attachment.loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
  color_attachment.storeOp = VK_ATTACHMENT_STORE_OP_STORE;
  color_attachment.stencilLoadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
  color_attachment.stencilStoreOp = VK_ATTACHMENT_STORE_OP_STORE;
  color_attachment.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
  color_attachment.finalLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;

  VkAttachmentReference color_attachment_ref = {};
  color_attachment_ref.attachment = 0;
  color_attachment_ref.layout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;

  VkSubpassDescription subpass = {};
  subpass.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
  subpass.colorAttachmentCount = 1;
  subpass.pColorAttachments = &color_attachment_ref;

  VkSubpassDependency dependency = {};
  dependency.srcSubpass = VK_SUBPASS_EXTERNAL;
  dependency.dstSubpass = 0;
  dependency.srcStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
  dependency.srcAccessMask = 0;
  dependency.dstStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
  dependency.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;

  VkRenderPassCreateInfo render_info = {};
  render_info.sType = VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO;
  render_info.attachmentCount = 1;
  render_info.pAttachments = &color_attachment;
  render_info.subpassCount = 1;
  render_info.pSubpasses = &subpass;
  render_info.dependencyCount = 1;
  render_info.pDependencies = &dependency;

  VkRenderPass render_pass;
  VkResult result = vkCreateRenderPass(device, &render_info, 0, &render_pass);
  if(result != VK_SUCCESS) {
    return VK_NULL_HANDLE;
  }

  return render_pass;
}

VkPipelineLayout create_pipeline_layout(VkDevice device, uint32_t set_count, VkDescriptorSetLayout* sets, uint32_t pcr_count, VkPushConstantRange* pcrs) {
  VkPipelineLayout layout;
  VkPipelineLayoutCreateInfo layout_info = {};
  layout_info.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
  layout_info.setLayoutCount = set_count;
  layout_info.pSetLayouts = sets;
  layout_info.pushConstantRangeCount = pcr_count;
  layout_info.pPushConstantRanges = pcrs;

  VkResult result;
  result = vkCreatePipelineLayout(device, &layout_info, 0, &layout);
  if(result != VK_SUCCESS) {
    return VK_NULL_HANDLE;
  }

  return layout;
}

uint32_t find_memory_type(VkPhysicalDevice physical_device, uint32_t type_filter, VkMemoryPropertyFlags properties) {
  VkPhysicalDeviceMemoryProperties memory_properties;
  vkGetPhysicalDeviceMemoryProperties(physical_device, &memory_properties);

  for(uint32_t i = 0; i < memory_properties.memoryTypeCount; i++) {
    if ((type_filter & (1 << i)) && (memory_properties.memoryTypes[i].propertyFlags & properties) == properties) {
      return i;
    }
  }

  return 0xFFFFFFFF;
}

AllocatedBuffer allocate_buffer(VkPhysicalDevice physical_device, VkDevice device, VkDeviceSize size, VkBufferUsageFlags usage, VkMemoryPropertyFlags properties) {
  AllocatedBuffer ret = {};
  ret.memory = VK_NULL_HANDLE;
  ret.buffer = VK_NULL_HANDLE;


  VkBufferCreateInfo buffer_info = {};
  buffer_info.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
  buffer_info.size = size;
  buffer_info.usage = usage;
  buffer_info.sharingMode = VK_SHARING_MODE_EXCLUSIVE;

  VkResult result = vkCreateBuffer(device, &buffer_info, 0, &ret.buffer);
  if(result != VK_SUCCESS) {
    ret.buffer = VK_NULL_HANDLE;
    ret.memory = VK_NULL_HANDLE;
    return ret;
  }

  VkMemoryRequirements memory_requirements;
  vkGetBufferMemoryRequirements(device, ret.buffer, &memory_requirements);

  VkMemoryAllocateInfo alloc_info = {};
  alloc_info.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
  alloc_info.allocationSize = memory_requirements.size;
  alloc_info.memoryTypeIndex = find_memory_type(physical_device, memory_requirements.memoryTypeBits, properties);

  result = vkAllocateMemory(device, &alloc_info, 0, &ret.memory);
  if(result != VK_SUCCESS) {
    vkDestroyBuffer(device, ret.buffer, 0);
    ret.buffer = VK_NULL_HANDLE;
    ret.memory = VK_NULL_HANDLE;
    return ret;
  }

  result = vkBindBufferMemory(device, ret.buffer, ret.memory, 0);
  if(result != VK_SUCCESS) {
    vkDestroyBuffer(device, ret.buffer, 0);
    ret.buffer = VK_NULL_HANDLE;
    ret.memory = VK_NULL_HANDLE;
    return ret;
  }

  return ret;
}

void deallocate_buffer(VkDevice device, AllocatedBuffer buffer) {
  vkDestroyBuffer(device, buffer.buffer, 0);
  vkFreeMemory(device, buffer.memory, 0);
};

AllocatedBuffer* allocate_buffers(VkPhysicalDevice physical_device, VkDevice device, VkDeviceSize size, VkBufferUsageFlags usage, VkMemoryPropertyFlags properties, uint32_t count) {
  AllocatedBuffer* buffers = malloc(sizeof(AllocatedBuffer)*count);
  if(buffers == 0) {
    return 0;
  }

  for(uint32_t i = 0; i < count; i++) {
    buffers[i] = allocate_buffer(physical_device, device, size, usage, properties);
    if(buffers[i].memory == VK_NULL_HANDLE) {
      for(uint32_t j = 0; j < i; j++) {
        deallocate_buffer(device, buffers[i]);
      }

      free(buffers);
      return 0;
    }
  }

  return buffers;
}

VkResult command_copy_buffers(VkDevice device, VkCommandPool transfer_pool, VkQueue transfer_queue, VkBuffer source, VkBuffer dest, VkDeviceSize size) {
  VkCommandBufferAllocateInfo command_info = {};
  command_info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO;
  command_info.level = VK_COMMAND_BUFFER_LEVEL_PRIMARY;
  command_info.commandPool = transfer_pool;
  command_info.commandBufferCount = 1;

  VkCommandBuffer command_buffer;
  VkResult result = vkAllocateCommandBuffers(device, &command_info, &command_buffer);
  if(result != VK_SUCCESS) {
    return result;
  }

  VkCommandBufferBeginInfo begin_info = {};
  begin_info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
  begin_info.flags = VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT;

  result = vkBeginCommandBuffer(command_buffer, &begin_info);
  if(result != VK_SUCCESS) {
    vkFreeCommandBuffers(device, transfer_pool, 1, &command_buffer);
    return result;
  }

  VkBufferCopy copy_region = {};
  copy_region.srcOffset = 0;
  copy_region.dstOffset = 0;
  copy_region.size = size;

  vkCmdCopyBuffer(command_buffer, source, dest, 1, &copy_region);
  result = vkEndCommandBuffer(command_buffer);
  if(result != VK_SUCCESS) {
    vkFreeCommandBuffers(device, transfer_pool, 1, &command_buffer);
    return result;
  }

  VkSubmitInfo submit_info = {};
  submit_info.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
  submit_info.commandBufferCount = 1;
  submit_info.pCommandBuffers = &command_buffer;

  result = vkQueueSubmit(transfer_queue, 1, &submit_info, 0);
  if(result != VK_SUCCESS) {
    vkFreeCommandBuffers(device, transfer_pool, 1, &command_buffer);
    return result;
  }

  result = vkQueueWaitIdle(transfer_queue);
  if(result != VK_SUCCESS) {
    vkFreeCommandBuffers(device, transfer_pool, 1, &command_buffer);
    return result;
  }

  vkFreeCommandBuffers(device, transfer_pool, 1, &command_buffer);

  return VK_SUCCESS;
}

AllocatedBuffer create_populated_buffer(VkPhysicalDevice physical_device, VkDevice device, void* data, VkDeviceSize size, VkCommandPool transfer_pool, VkQueue transfer_queue, VkBufferUsageFlags usage) {
  AllocatedBuffer staging_buffer = {};
  AllocatedBuffer vertex_buffer = {}; 
  staging_buffer = allocate_buffer(physical_device, device, size, VK_BUFFER_USAGE_TRANSFER_SRC_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT);
  if(staging_buffer.memory == VK_NULL_HANDLE) {
    return vertex_buffer;
  }


  void* buffer_data;
  VkResult result = vkMapMemory(device, staging_buffer.memory, 0, size, 0, &buffer_data);
  if(result != VK_SUCCESS) {
    deallocate_buffer(device, staging_buffer);
    return vertex_buffer;
  }

  memcpy(buffer_data, data, size);

  vkUnmapMemory(device, staging_buffer.memory);

  vertex_buffer = allocate_buffer(physical_device, device, size, VK_BUFFER_USAGE_TRANSFER_DST_BIT | usage, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT);
  if(vertex_buffer.memory == VK_NULL_HANDLE) {
    deallocate_buffer(device, staging_buffer);
    return vertex_buffer;
  }

  result = command_copy_buffers(device, transfer_pool, transfer_queue, staging_buffer.buffer, vertex_buffer.buffer, size);
  if(result != VK_SUCCESS) {
    deallocate_buffer(device, staging_buffer);
    deallocate_buffer(device, vertex_buffer);
    vertex_buffer.buffer = VK_NULL_HANDLE;
    vertex_buffer.memory = VK_NULL_HANDLE;
    return vertex_buffer;
  }

  return vertex_buffer;
}

VkPipeline create_graphics_pipeline(VkDevice device, VkExtent2D extent, VkPipelineLayout layout, VkRenderPass render_pass) {
  VkShaderModule vert_shader = load_shader_file(2048, "shader_src/basic.vert.spv", device);
  VkShaderModule frag_shader = load_shader_file(2048, "shader_src/basic.frag.spv", device);

  VkPipelineShaderStageCreateInfo shader_stages[2] = {};
  shader_stages[0].sType = VK_STRUCTURE_TYPE_SHADER_CREATE_INFO_EXT;
  shader_stages[0].stage = VK_SHADER_STAGE_VERTEX_BIT;
  shader_stages[0].module = vert_shader;
  shader_stages[0].pName = "main";

  shader_stages[1].sType = VK_STRUCTURE_TYPE_SHADER_CREATE_INFO_EXT;
  shader_stages[1].stage = VK_SHADER_STAGE_FRAGMENT_BIT;
  shader_stages[1].module = frag_shader;
  shader_stages[1].pName = "main";

  VkDynamicState dynamic_states[] = {
    VK_DYNAMIC_STATE_VIEWPORT,
    VK_DYNAMIC_STATE_SCISSOR,
  };
  uint32_t dynamic_state_count = sizeof(dynamic_states)/sizeof(VkDynamicState);

  VkPipelineDynamicStateCreateInfo dynamic_info = {};
  dynamic_info.sType = VK_STRUCTURE_TYPE_PIPELINE_DYNAMIC_STATE_CREATE_INFO;
  dynamic_info.dynamicStateCount = dynamic_state_count;
  dynamic_info.pDynamicStates = dynamic_states;

  VkPipelineVertexInputStateCreateInfo vertex_input_info = {};
  vertex_input_info.sType = VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO;
  vertex_input_info.vertexBindingDescriptionCount = 1;
  vertex_input_info.pVertexBindingDescriptions = vertex_binding_descriptions();
  vertex_input_info.vertexAttributeDescriptionCount = 2;
  vertex_input_info.pVertexAttributeDescriptions = vertex_attribute_descriptions();

  VkPipelineInputAssemblyStateCreateInfo input_assemvly_info = {};
  input_assemvly_info.sType = VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO;
  input_assemvly_info.topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST;
  input_assemvly_info.primitiveRestartEnable = VK_FALSE;

  VkViewport viewport = {};
  viewport.x = 0.0f;
  viewport.y = 0.0f;
  viewport.width = (float)(extent.width);
  viewport.height = (float)(extent.height);
  viewport.minDepth = 0.0f;
  viewport.maxDepth = 1.0f;

  VkRect2D scissor = {};
  VkOffset2D scissor_offset = {.x = 0, .y = 0};
  scissor.offset = scissor_offset;
  scissor.extent = extent;

  VkPipelineViewportStateCreateInfo viewport_state = {};
  viewport_state.sType = VK_STRUCTURE_TYPE_PIPELINE_VIEWPORT_STATE_CREATE_INFO;
  viewport_state.viewportCount = 1;
  viewport_state.pViewports = &viewport;
  viewport_state.scissorCount = 1;
  viewport_state.pScissors = &scissor;

  VkPipelineRasterizationStateCreateInfo raster_info = {};
  raster_info.sType = VK_STRUCTURE_TYPE_PIPELINE_RASTERIZATION_STATE_CREATE_INFO;
  raster_info.depthClampEnable = VK_FALSE;
  raster_info.rasterizerDiscardEnable = VK_FALSE;
  raster_info.polygonMode = VK_POLYGON_MODE_FILL;
  raster_info.lineWidth = 1.0f;
  raster_info.cullMode = VK_CULL_MODE_BACK_BIT;
  raster_info.frontFace = VK_FRONT_FACE_CLOCKWISE;
  raster_info.depthBiasEnable = VK_FALSE;
  raster_info.depthBiasConstantFactor = 0.0f;
  raster_info.depthBiasClamp = 0.0f;
  raster_info.depthBiasSlopeFactor = 0.0f;

  VkPipelineMultisampleStateCreateInfo multisample_info = {};
  multisample_info.sType = VK_STRUCTURE_TYPE_PIPELINE_MULTISAMPLE_STATE_CREATE_INFO;
  multisample_info.sampleShadingEnable = VK_FALSE;
  multisample_info.rasterizationSamples = VK_SAMPLE_COUNT_1_BIT;
  multisample_info.minSampleShading = 1.0f;
  multisample_info.pSampleMask = 0;
  multisample_info.alphaToCoverageEnable = VK_FALSE;
  multisample_info.alphaToOneEnable = VK_FALSE;

  VkPipelineColorBlendAttachmentState color_blend_attachment = {};
  color_blend_attachment.colorWriteMask = VK_COLOR_COMPONENT_R_BIT | VK_COLOR_COMPONENT_G_BIT | VK_COLOR_COMPONENT_B_BIT | VK_COLOR_COMPONENT_A_BIT;
  color_blend_attachment.blendEnable = VK_TRUE;
  color_blend_attachment.srcColorBlendFactor = VK_BLEND_FACTOR_SRC_ALPHA;
  color_blend_attachment.dstColorBlendFactor = VK_BLEND_FACTOR_ONE_MINUS_SRC_ALPHA;
  color_blend_attachment.colorBlendOp = VK_BLEND_OP_ADD;
  color_blend_attachment.srcAlphaBlendFactor = VK_BLEND_FACTOR_ONE;
  color_blend_attachment.dstAlphaBlendFactor = VK_BLEND_FACTOR_ZERO;
  color_blend_attachment.alphaBlendOp = VK_BLEND_OP_ADD;

  VkPipelineColorBlendStateCreateInfo color_blend_info = {};
  color_blend_info.sType = VK_STRUCTURE_TYPE_PIPELINE_COLOR_BLEND_STATE_CREATE_INFO;
  color_blend_info.logicOpEnable = VK_FALSE;
  color_blend_info.logicOp = VK_LOGIC_OP_COPY;
  color_blend_info.attachmentCount = 1;
  color_blend_info.pAttachments = &color_blend_attachment;
  color_blend_info.blendConstants[0] = 0.0f;
  color_blend_info.blendConstants[1] = 0.0f;
  color_blend_info.blendConstants[2] = 0.0f;
  color_blend_info.blendConstants[3] = 0.0f;

  VkGraphicsPipelineCreateInfo pipeline_info = {};
  pipeline_info.sType = VK_STRUCTURE_TYPE_GRAPHICS_PIPELINE_CREATE_INFO;
  pipeline_info.stageCount = 2;
  pipeline_info.pStages = shader_stages;
  pipeline_info.pVertexInputState = &vertex_input_info;
  pipeline_info.pInputAssemblyState = &input_assemvly_info;
  pipeline_info.pViewportState = &viewport_state;
  pipeline_info.pRasterizationState = &raster_info;
  pipeline_info.pDepthStencilState = 0;
  pipeline_info.pColorBlendState = &color_blend_info;
  pipeline_info.pDynamicState = &dynamic_info;
  pipeline_info.layout = layout;
  pipeline_info.renderPass = render_pass;
  pipeline_info.subpass = 0;

  pipeline_info.basePipelineHandle = VK_NULL_HANDLE;
  pipeline_info.basePipelineIndex = -1;

  VkPipeline pipeline;
  VkResult result = vkCreateGraphicsPipelines(device, VK_NULL_HANDLE, 1, &pipeline_info, 0, &pipeline);
  if(result != VK_SUCCESS) {
    return VK_NULL_HANDLE;
  }

  return pipeline;
}

VkCommandPool create_command_pool(VkDevice device, uint32_t queue_family) {
  VkCommandPoolCreateInfo pool_info = {};
  pool_info.sType = VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO;
  pool_info.flags = VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT;
  pool_info.queueFamilyIndex = queue_family;

  VkCommandPool command_pool;
  VkResult result = vkCreateCommandPool(device, &pool_info, 0, &command_pool);
  if(result != VK_SUCCESS) {
    return VK_NULL_HANDLE;
  }

  return command_pool;
}

VkResult record_command_buffer_triangle(VkCommandBuffer command_buffer, uint32_t image_index, VkRenderPass render_pass, VkFramebuffer* framebuffers, VkExtent2D extent, VkPipeline graphics_pipeline, VkPipelineLayout pipeline_layout, VkDescriptorSet descriptor_set, VkBuffer vertex_buffer, VkBuffer index_buffer, uint32_t num_vertices) {
  VkCommandBufferBeginInfo begin_info = {};
  begin_info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
  begin_info.flags = 0;
  begin_info.pInheritanceInfo = 0;

  VkResult result = vkBeginCommandBuffer(command_buffer, &begin_info);
  if(result != VK_SUCCESS) {
    return result;
  }

  VkRenderPassBeginInfo render_pass_info = {};
  render_pass_info.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
  render_pass_info.renderPass = render_pass;
  render_pass_info.framebuffer = framebuffers[image_index];
  VkOffset2D render_offset = {.x = 0, .y = 0};
  render_pass_info.renderArea.offset = render_offset;
  render_pass_info.renderArea.extent = extent;
  VkClearValue clear_color = {{{0.0f, 0.0f, 0.0f, 1.0f}}};
  render_pass_info.clearValueCount = 1;
  render_pass_info.pClearValues = &clear_color;

  vkCmdBeginRenderPass(command_buffer, &render_pass_info, VK_SUBPASS_CONTENTS_INLINE);
  vkCmdBindPipeline(command_buffer, VK_PIPELINE_BIND_POINT_GRAPHICS, graphics_pipeline);

  VkBuffer vertex_buffers[] = {vertex_buffer};
  VkDeviceSize offsets[] = {0};
  vkCmdBindVertexBuffers(command_buffer, 0, 1, vertex_buffers, offsets);
  vkCmdBindIndexBuffer(command_buffer, index_buffer, 0, VK_INDEX_TYPE_UINT16);

  VkViewport viewport = {};
  viewport.x = 0.0f;
  viewport.y = 0.0f;
  viewport.width = (float)(extent.width);
  viewport.height = (float)(extent.height);
  viewport.minDepth = 0.0f;
  viewport.maxDepth = 1.0f;
  vkCmdSetViewport(command_buffer, 0, 1, &viewport);

  VkRect2D scissor = {};
  VkOffset2D scissor_offset = {.x = 0.0f, .y = 0.0f};
  scissor.offset = scissor_offset;
  scissor.extent = extent;
  vkCmdSetScissor(command_buffer, 0, 1, &scissor);

  vkCmdBindDescriptorSets(command_buffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipeline_layout, 0, 1, &descriptor_set, 0, 0);
  vkCmdDrawIndexed(command_buffer, num_vertices, 1, 0, 0, 0);
  vkCmdEndRenderPass(command_buffer);

  return vkEndCommandBuffer(command_buffer);
}

VkCommandBuffer* create_command_buffers(VkDevice device, VkCommandPool command_pool, uint32_t image_count)  {
  VkCommandBufferAllocateInfo alloc_info = {};
  alloc_info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO;
  alloc_info.commandPool = command_pool;
  alloc_info.level = VK_COMMAND_BUFFER_LEVEL_PRIMARY;
  alloc_info.commandBufferCount = image_count;

  VkCommandBuffer* command_buffers = malloc(sizeof(VkCommandBuffer)*image_count);
  if(command_buffers == 0) {
    return 0;
  }

  VkResult result = vkAllocateCommandBuffers(device, &alloc_info, command_buffers);
  if(result != VK_SUCCESS) {
    return VK_NULL_HANDLE;
  }

  return command_buffers;
}

VkSemaphore* create_semaphores(VkDevice device, VkSemaphoreCreateFlags flags, uint32_t count) {
  VkSemaphore* semaphores = malloc(sizeof(VkSemaphore)*count);
  if(semaphores == 0) {
    return 0;
  }

  VkSemaphoreCreateInfo semaphore_info = {};
  semaphore_info.sType = VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO;
  semaphore_info.flags = flags;

  for(uint32_t i = 0; i < count; i++) {
    VkResult result = vkCreateSemaphore(device, &semaphore_info, 0, &semaphores[i]);
    if(result != VK_SUCCESS) {
      free(semaphores);
      return 0;
    }
  }
  return semaphores;
}

VkFence* create_fences(VkDevice device, VkFenceCreateFlags flags, uint32_t count) {
  VkFence* fences = malloc(sizeof(VkFence)*count);
  if(fences == 0) {
    return 0;
  }

  VkFenceCreateInfo fence_info = {};
  fence_info.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO;
  fence_info.flags = flags;

  for(uint32_t i = 0; i < count; i++) {
    VkResult result = vkCreateFence(device, &fence_info, 0, &fences[i]);
    if(result != VK_SUCCESS) {
      free(fences);
      return 0;
    }
  }
  return fences;
}

VulkanContext* init_vulkan(GLFWwindow* window, uint32_t max_frames_in_flight) {
  VulkanContext* context = (VulkanContext*)malloc(sizeof(VulkanContext));

  VkInstance instance = create_instance();
  if(instance == VK_NULL_HANDLE) {
    fprintf(stderr, "failed to initialize vulkan instance\n");
    return 0;
  } else {
    context->instance = instance;
  }

  VkDebugUtilsMessengerEXT debug_messenger = create_debug_messenger(context->instance);
  if(debug_messenger == VK_NULL_HANDLE) {
    fprintf(stderr, "failed to initialize vulkan debug messenger\n");
    return 0;
  } else {
    context->debug_messenger = debug_messenger;
  }

  VkPhysicalDevice physical_device = get_best_physical_device(context->instance);
  if(physical_device == VK_NULL_HANDLE) {
    fprintf(stderr, "failed to pick vulkan physical device\n");
    return 0;
  } else {
    context->physical_device = physical_device;
  }

  VkSurfaceKHR surface = create_surface_khr(context->instance, window);
  if(surface == VK_NULL_HANDLE) {
    fprintf(stderr, "failed to create vulkan surface\n");
    return 0;
  } else {
    context->surface = surface;
  }

  QueueIndices queue_indices = get_queue_indices(context->physical_device, context->surface);
  if(check_queue_indices(queue_indices) == false) {
    fprintf(stderr, "failed to get vulkan queue indices\n");
    return 0;
  } else {
    context->queue_indices = queue_indices;
  }

  VkDevice device = create_logical_device(context->physical_device, context->queue_indices);
  if(device == VK_NULL_HANDLE) {
    fprintf(stderr, "failed to create vulkan logical device\n");
    return 0;
  } else {
    context->device = device;
  }
  vkGetDeviceQueue(device, context->queue_indices.graphics_family, context->queue_indices.graphics_index, &context->queues.graphics);
  vkGetDeviceQueue(device, context->queue_indices.present_family, context->queue_indices.present_index, &context->queues.present);
  vkGetDeviceQueue(device, context->queue_indices.transfer_family, context->queue_indices.transfer_index, &context->queues.transfer);

  struct MaybeSwapchainDetails maybe_details = get_swapchain_details(context->physical_device, context->surface);
  if(maybe_details.valid == false) {
    fprintf(stderr, "failed to create vulkan logical device\n");
    return 0;
  } else {
    context->swapchain_details = maybe_details.details;
  }

  context->swapchain_format = choose_swapchain_format(context->swapchain_details);
  context->swapchain_present_mode = choose_present_mode(context->swapchain_details);
  context->swapchain_extent = choose_swapchain_extent(context->swapchain_details);

  VkSwapchainKHR swapchain = create_swapchain(context->device, context->swapchain_format, context->swapchain_present_mode, context->swapchain_extent, context->surface, context->swapchain_details.capabilities, context->queue_indices, VK_NULL_HANDLE);
  if(swapchain == VK_NULL_HANDLE) {
    fprintf(stderr, "failed to create vulkan swapchain\n");
    return 0;
  } else {
    context->swapchain = swapchain;
  }

  SwapchainImages swapchain_images = get_swapchain_images(context->device, context->swapchain);
  if(swapchain_images.count == 0) {
    fprintf(stderr, "failed to get vulkan swapchain images\n");
    return 0;
  } else {
    context->swapchain_image_count = swapchain_images.count;
    context->swapchain_images = swapchain_images.images;
  }

  VkImageView* image_views = create_image_views(context->device, context->swapchain_image_count, context->swapchain_images, context->swapchain_format);
  if(image_views == 0) {
    fprintf(stderr, "failed to create vulkan image views\n");
    return 0;
  } else {
    context->swapchain_image_views = image_views;
  }

  VkRenderPass render_pass = create_render_pass(context->device, context->swapchain_format);
  if(render_pass == VK_NULL_HANDLE) {
    fprintf(stderr, "failed to create vulkan render pass\n");
    return 0;
  } else {
    context->render_pass = render_pass;
  }

  VkFramebuffer* framebuffers = create_swapchain_framebuffers(context->device, context->swapchain_image_count, context->swapchain_image_views, context->render_pass, context->swapchain_extent);
  if(framebuffers == 0) {
    fprintf(stderr, "failed to create vulkan framebuffers\n");
    return 0;
  } else {
    context->swapchain_framebuffers = framebuffers;
  }

  VkCommandPool graphics_command_pool = create_command_pool(context->device, context->queue_indices.graphics_family);
  if(graphics_command_pool == VK_NULL_HANDLE) {
    fprintf(stderr, "failed to create vulkan graphics command pool");
    return 0;
  } else {
    context->graphics_command_pool = graphics_command_pool;
  }

  VkCommandPool transfer_command_pool = create_command_pool(context->device, context->queue_indices.transfer_family);
  if(transfer_command_pool == VK_NULL_HANDLE) {
    fprintf(stderr, "failed to create vulkan transfer command pool");
    return 0;
  } else {
    context->transfer_command_pool = transfer_command_pool;
  }

  context->max_frames_in_flight = max_frames_in_flight;

  VkCommandBuffer* swapchain_command_buffers = create_command_buffers(context->device, context->graphics_command_pool, max_frames_in_flight);
  if(swapchain_command_buffers == VK_NULL_HANDLE) {
    fprintf(stderr, "failed to create vulkan swapchain command buffer\n");
    return 0;
  } else {
    context->swapchain_command_buffers = swapchain_command_buffers;
  }

  VkSemaphore* ia_semaphores = create_semaphores(context->device, 0, max_frames_in_flight);
  if(ia_semaphores == 0) {
    fprintf(stderr, "failed to create vulkan image available semaphores\n");
    return 0;
  } else {
    context->image_available_semaphores = ia_semaphores;
  }

  VkSemaphore* rf_semaphores = create_semaphores(context->device, 0, max_frames_in_flight);
  if(rf_semaphores == 0) {
    fprintf(stderr, "failed to create vulkan render finished semaphores\n");
    return 0;
  } else {
    context->render_finished_semaphores = rf_semaphores;
  }

  VkFence* if_fences = create_fences(context->device, VK_FENCE_CREATE_SIGNALED_BIT, max_frames_in_flight);
  if(if_fences == 0) {
    fprintf(stderr, "failed to create vulkan in flight fence\n");
    return 0;
  } else {
    context->in_flight_fences = if_fences;
  }

  AllocatedBuffer* uniform_buffers = allocate_buffers(context->physical_device, context->device, sizeof(struct ShaderUBO), VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, max_frames_in_flight);
  if(uniform_buffers == 0) {
    fprintf(stderr, "failed to create vulkan uniform buffers\n");
    return 0;
  } else {
    context->uniform_buffers = uniform_buffers;
    context->uniform_buffer_ptrs = malloc(sizeof(void*)*max_frames_in_flight);
    if(context->uniform_buffer_ptrs == 0) {
      fprintf(stderr, "failed to allocate cpu pointers for uniform buffers\n");
      return 0;
    }
    for(uint32_t i = 0; i < max_frames_in_flight; i++) {
      VkResult result = vkMapMemory(context->device, context->uniform_buffers[i].memory, 0, sizeof(struct ShaderUBO), 0, &context->uniform_buffer_ptrs[i]);
      if(result != VK_SUCCESS) {
        fprintf(stderr, "failed to map cpu pointer for uniform buffer\n");
        return 0;
      }
    }
  }

  VkDescriptorPool descriptor_pool = create_descriptor_pool(context->device, max_frames_in_flight);
  if(descriptor_pool == VK_NULL_HANDLE) {
    fprintf(stderr, "failed to create vulkan descriptor pool\n");
    return 0;
  } else {
    context->descriptor_pool = descriptor_pool;
  }

  VkDescriptorSetLayout triangle_descriptor_set = create_descriptor_set_layout(device);
  if(triangle_descriptor_set == VK_NULL_HANDLE) {
    fprintf(stderr, "failed to create vulkan descriptor set layout\n");
    return 0;
  } else {
    context->triangle_descriptor_set = triangle_descriptor_set;
  }

  VkDescriptorSet* descriptor_sets = create_descriptor_sets(context->device, context->triangle_descriptor_set, context->descriptor_pool, context->uniform_buffers, max_frames_in_flight);
  if(descriptor_sets == 0) {
    fprintf(stderr, "failed to create vulkan descriptor sets\n");
    return 0;
  } else {
    context->descriptor_sets = descriptor_sets;
  }

  VkPipelineLayout triangle_pipeline_layout = create_pipeline_layout(device, 1, &context->triangle_descriptor_set, 0, 0);
  if(triangle_pipeline_layout == VK_NULL_HANDLE) {
    fprintf(stderr, "failed to create vulkan pipeline layout\n");
    return 0;
  } else {
    context->triangle_pipeline_layout = triangle_pipeline_layout;
  }

  VkPipeline triangle_pipeline = create_graphics_pipeline(context->device, context->swapchain_extent, context->triangle_pipeline_layout, context->render_pass);
  if(triangle_pipeline == VK_NULL_HANDLE) {
    fprintf(stderr, "failed to create vulkan graphics pipeline\n");
    return 0;
  } else {
    context->triangle_pipeline = triangle_pipeline;
  }

  AllocatedBuffer triangle_vertex_buffer = create_populated_buffer(context->physical_device, context->device, (void*)vertices, sizeof(vertices), context->transfer_command_pool, context->queues.transfer, VK_BUFFER_USAGE_VERTEX_BUFFER_BIT);
  if(triangle_vertex_buffer.memory == VK_NULL_HANDLE) {
    fprintf(stderr, "failed to allocate vulkan buffer for triangle buffer\n");
  } else {
    context->triangle_vertex_buffer = triangle_vertex_buffer;
  }

  AllocatedBuffer triangle_index_buffer = create_populated_buffer(context->physical_device, context->device, (void*)indices, sizeof(indices), context->transfer_command_pool, context->queues.transfer, VK_BUFFER_USAGE_INDEX_BUFFER_BIT);
  if(triangle_index_buffer.memory == VK_NULL_HANDLE) {
    fprintf(stderr, "failed to allocate vulkan buffer for triangle buffer\n");
  } else {
    context->triangle_index_buffer = triangle_index_buffer;
  }

  return context;
}

VkResult update_ubo(void** buffers, uint32_t frame_index) {
  struct ShaderUBO ubo = {};
  glm_mat4_identity(ubo.proj);
  glm_mat4_identity(ubo.view);
  glm_mat4_identity(ubo.model);

  memcpy(buffers[frame_index], (void*)&ubo, sizeof(ubo));

  return VK_SUCCESS;
}

VkResult draw_frame(VulkanContext* context) {
  update_ubo(context->uniform_buffer_ptrs, context->current_frame);

  VkResult result;
  result = vkWaitForFences(context->device, 1, &context->in_flight_fences[context->current_frame], VK_TRUE, UINT64_MAX);
  if(result != VK_SUCCESS) {
    return result;
  }

  result = vkResetFences(context->device, 1, &context->in_flight_fences[context->current_frame]);
  if(result != VK_SUCCESS) {
    return result;
  }

  uint32_t image_index;
  result = vkAcquireNextImageKHR(context->device, context->swapchain, UINT64_MAX, context->image_available_semaphores[context->current_frame], VK_NULL_HANDLE, &image_index);
  if(result != VK_SUCCESS) {
    return result;
  }

  result = vkResetCommandBuffer(context->swapchain_command_buffers[context->current_frame], 0);
  if(result != VK_SUCCESS) {
    return result;
  }

  result = record_command_buffer_triangle(context->swapchain_command_buffers[context->current_frame], image_index, context->render_pass, context->swapchain_framebuffers, context->swapchain_extent, context->triangle_pipeline, context->triangle_pipeline_layout, context->descriptor_sets[context->current_frame], context->triangle_vertex_buffer.buffer, context->triangle_index_buffer.buffer, 6);
  if(result != VK_SUCCESS) {
    return result;
  }

  VkSubmitInfo submit_info = {};
  VkPipelineStageFlags wait_stages[] = {VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT};
  submit_info.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
  submit_info.waitSemaphoreCount = 1;
  submit_info.pWaitSemaphores = &context->image_available_semaphores[context->current_frame];
  submit_info.pWaitDstStageMask = wait_stages;
  submit_info.commandBufferCount = 1;
  submit_info.pCommandBuffers = &context->swapchain_command_buffers[context->current_frame];
  submit_info.signalSemaphoreCount = 1;
  submit_info.pSignalSemaphores = &context->render_finished_semaphores[context->current_frame];

  result = vkQueueSubmit(context->queues.graphics, 1, &submit_info, context->in_flight_fences[context->current_frame]);
  if(result != VK_SUCCESS) {
    return result;
  }

  VkPresentInfoKHR present_info = {};
  present_info.sType = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR;
  present_info.waitSemaphoreCount = 1;
  present_info.pWaitSemaphores = &context->render_finished_semaphores[context->current_frame];
  present_info.swapchainCount = 1;
  present_info.pSwapchains = &context->swapchain;
  present_info.pImageIndices = &image_index;
  present_info.pResults = 0;

  return vkQueuePresentKHR(context->queues.present, &present_info);
}

void main_loop(GLFWwindow* window, VulkanContext* context) {
  context->current_frame = 0;
  while(!glfwWindowShouldClose(window)) {
    glfwPollEvents();
    draw_frame(context);
    context->current_frame += 1;
    if(context->current_frame >= context->max_frames_in_flight) {
      context->current_frame = 0;
    }
  }

  vkDeviceWaitIdle(context->device);
}

void cleanup(GLFWwindow* window, VulkanContext* context) {
  if(context != 0) {
    if(context->instance != VK_NULL_HANDLE) {
      if(context->swapchain != VK_NULL_HANDLE) {
        vkDestroySwapchainKHR(context->device, context->swapchain, 0);
      }

      if(context->surface != VK_NULL_HANDLE) {
        vkDestroySurfaceKHR(context->instance, context->surface, 0);
      }

      if(context->device != VK_NULL_HANDLE) {
        vkDestroyDevice(context->device, 0);
      }

      if(context->debug_messenger != VK_NULL_HANDLE) {
        PFN_vkDestroyDebugUtilsMessengerEXT destroy_messenger = (PFN_vkDestroyDebugUtilsMessengerEXT)vkGetInstanceProcAddr(context->instance, "vkDestroyDebugUtilsMessengerEXT");
        destroy_messenger(context->instance, context->debug_messenger, 0);
      }

      vkDestroyInstance(context->instance, 0);
    }
    free(context);
  }

  if(window != 0) {
    glfwDestroyWindow(window);
    glfwTerminate();
  }
}

int main() {
  GLFWwindow* window = init_window(800, 600);
  if(window == 0) {
    fprintf(stderr, "failed to initialize glfw window\n");
    return 1;
  }

  VulkanContext* context = init_vulkan(window, 2);
  if (context == 0) {
    fprintf(stderr, "failed to initialize vulkan context\n");
    return 2;
  }

  main_loop(window, context);

  cleanup(window, context);

  return 0;
}