#include "gpu.h"
#include <string.h>
#define VK_NO_PROTOTYPES
#include <vulkan/vulkan.h>
#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#else
#include <dlfcn.h>
#endif

// State

static struct {
  void* library;
  gpu_config config;
} state;

// Helpers

#define MIN(a, b) (a < b ? a : b)
#define MAX(a, b) (a > b ? a : b)
#define COUNTOF(x) (sizeof(x) / sizeof(x[0]))
#define VK(f, s) if (!vcheck(f, s))
#define CHECK(c, s) if (!check(c, s))

static VkBool32 relay(VkDebugUtilsMessageSeverityFlagBitsEXT severity, VkDebugUtilsMessageTypeFlagsEXT flags, const VkDebugUtilsMessengerCallbackDataEXT* data, void* userdata);
static bool vcheck(VkResult result, const char* message);
static bool check(bool condition, const char* message);

// Loader

// Functions that don't require an instance
#define GPU_FOREACH_ANONYMOUS(X)\
  X(vkCreateInstance)

// Functions that require an instance but don't require a device
#define GPU_FOREACH_INSTANCE(X)\
  X(vkDestroyInstance)\
  X(vkCreateDebugUtilsMessengerEXT)\
  X(vkDestroyDebugUtilsMessengerEXT)\
  X(vkDestroySurfaceKHR)\
  X(vkEnumeratePhysicalDevices)\
  X(vkGetPhysicalDeviceProperties2)\
  X(vkGetPhysicalDeviceFeatures2)\
  X(vkGetPhysicalDeviceMemoryProperties)\
  X(vkGetPhysicalDeviceFormatProperties)\
  X(vkGetPhysicalDeviceQueueFamilyProperties)\
  X(vkGetPhysicalDeviceSurfaceSupportKHR)\
  X(vkGetPhysicalDeviceSurfaceCapabilitiesKHR)\
  X(vkGetPhysicalDeviceSurfaceFormatsKHR)\
  X(vkCreateDevice)\
  X(vkDestroyDevice)\
  X(vkGetDeviceQueue)\
  X(vkGetDeviceProcAddr)

// Functions that require a device
#define GPU_FOREACH_DEVICE(X)\
  X(vkSetDebugUtilsObjectNameEXT)\
  X(vkCmdBeginDebugUtilsLabelEXT)\
  X(vkCmdEndDebugUtilsLabelEXT)\
  X(vkDeviceWaitIdle)\
  X(vkQueueSubmit)\
  X(vkQueuePresentKHR)\
  X(vkCreateSwapchainKHR)\
  X(vkDestroySwapchainKHR)\
  X(vkGetSwapchainImagesKHR)\
  X(vkAcquireNextImageKHR)\
  X(vkCreateCommandPool)\
  X(vkDestroyCommandPool)\
  X(vkResetCommandPool)\
  X(vkAllocateCommandBuffers)\
  X(vkBeginCommandBuffer)\
  X(vkEndCommandBuffer)\
  X(vkCreateFence)\
  X(vkDestroyFence)\
  X(vkResetFences)\
  X(vkGetFenceStatus)\
  X(vkWaitForFences)\
  X(vkCreateSemaphore)\
  X(vkDestroySemaphore)\
  X(vkCmdPipelineBarrier)\
  X(vkCreateQueryPool)\
  X(vkDestroyQueryPool)\
  X(vkCmdResetQueryPool)\
  X(vkCmdWriteTimestamp)\
  X(vkCmdCopyQueryPoolResults)\
  X(vkCreateBuffer)\
  X(vkDestroyBuffer)\
  X(vkGetBufferMemoryRequirements)\
  X(vkBindBufferMemory)\
  X(vkCreateImage)\
  X(vkDestroyImage)\
  X(vkGetImageMemoryRequirements)\
  X(vkBindImageMemory)\
  X(vkCmdCopyBuffer)\
  X(vkCmdCopyImage)\
  X(vkCmdBlitImage)\
  X(vkCmdCopyBufferToImage)\
  X(vkCmdCopyImageToBuffer)\
  X(vkCmdFillBuffer)\
  X(vkCmdClearColorImage)\
  X(vkAllocateMemory)\
  X(vkFreeMemory)\
  X(vkMapMemory)\
  X(vkCreateSampler)\
  X(vkDestroySampler)\
  X(vkCreateRenderPass)\
  X(vkDestroyRenderPass)\
  X(vkCmdBeginRenderPass)\
  X(vkCmdEndRenderPass)\
  X(vkCreateImageView)\
  X(vkDestroyImageView)\
  X(vkCreateFramebuffer)\
  X(vkDestroyFramebuffer)\
  X(vkCreateShaderModule)\
  X(vkDestroyShaderModule)\
  X(vkCreateDescriptorSetLayout)\
  X(vkDestroyDescriptorSetLayout)\
  X(vkCreatePipelineLayout)\
  X(vkDestroyPipelineLayout)\
  X(vkCreateDescriptorPool)\
  X(vkDestroyDescriptorPool)\
  X(vkAllocateDescriptorSets)\
  X(vkResetDescriptorPool)\
  X(vkUpdateDescriptorSets)\
  X(vkCreatePipelineCache)\
  X(vkDestroyPipelineCache)\
  X(vkCreateGraphicsPipelines)\
  X(vkCreateComputePipelines)\
  X(vkDestroyPipeline)\
  X(vkCmdSetViewport)\
  X(vkCmdSetScissor)\
  X(vkCmdPushConstants)\
  X(vkCmdBindPipeline)\
  X(vkCmdBindDescriptorSets)\
  X(vkCmdBindVertexBuffers)\
  X(vkCmdBindIndexBuffer)\
  X(vkCmdDraw)\
  X(vkCmdDrawIndexed)\
  X(vkCmdDrawIndirect)\
  X(vkCmdDrawIndexedIndirect)\
  X(vkCmdDispatch)\
  X(vkCmdDispatchIndirect)

// Used to load/declare Vulkan functions without lots of clutter
#define GPU_LOAD_ANONYMOUS(fn) fn = (PFN_##fn) vkGetInstanceProcAddr(NULL, #fn);
#define GPU_LOAD_INSTANCE(fn) fn = (PFN_##fn) vkGetInstanceProcAddr(state.instance, #fn);
#define GPU_LOAD_DEVICE(fn) fn = (PFN_##fn) vkGetDeviceProcAddr(state.device, #fn);
#define GPU_DECLARE(fn) static PFN_##fn fn;

// Declare function pointers
GPU_FOREACH_ANONYMOUS(GPU_DECLARE)
GPU_FOREACH_INSTANCE(GPU_DECLARE)
GPU_FOREACH_DEVICE(GPU_DECLARE)

// Entry

bool gpu_init(gpu_config* config) {
  state.config = *config;

  // Load
#ifdef _WIN32
  state.library = LoadLibraryA("vulkan-1.dll");
  CHECK(state.library, "Failed to load vulkan library") return gpu_destroy(), false;
  PFN_vkGetInstanceProcAddr vkGetInstanceProcAddr = (PFN_vkGetInstanceProcAddr) GetProcAddress(state.library, "vkGetInstanceProcAddr");
#elif __APPLE__
  state.library = dlopen("libvulkan.1.dylib", RTLD_NOW | RTLD_LOCAL);
  CHECK(state.library, "Failed to load vulkan library") return gpu_destroy(), false;
  PFN_vkGetInstanceProcAddr vkGetInstanceProcAddr = (PFN_vkGetInstanceProcAddr) dlsym(state.library, "vkGetInstanceProcAddr");
#else
  state.library = dlopen("libvulkan.so", RTLD_NOW | RTLD_LOCAL);
  CHECK(state.library, "Failed to load vulkan library") return gpu_destroy(), false;
  PFN_vkGetInstanceProcAddr vkGetInstanceProcAddr = (PFN_vkGetInstanceProcAddr) dlsym(state.library, "vkGetInstanceProcAddr");
#endif
  GPU_FOREACH_ANONYMOUS(GPU_LOAD_ANONYMOUS);

  return true;
}

void gpu_destroy(void) {
#ifdef _WIN32
  if (state.library) FreeLibrary(state.library);
#else
  if (state.library) dlclose(state.library);
#endif
  memset(&state, 0, sizeof(state));
}

// Helpers

static VkBool32 relay(VkDebugUtilsMessageSeverityFlagBitsEXT severity, VkDebugUtilsMessageTypeFlagsEXT flags, const VkDebugUtilsMessengerCallbackDataEXT* data, void* userdata) {
  if (state.config.callback) {
    bool severe = severity & VK_DEBUG_UTILS_MESSAGE_SEVERITY_ERROR_BIT_EXT;
    state.config.callback(state.config.userdata, data->pMessage, severe);
  }
  return VK_FALSE;
}

static bool vcheck(VkResult result, const char* message) {
  if (result >= 0) return true;
  if (!state.config.callback) return false;
#define CASE(x) case x: state.config.callback(state.config.userdata, "Vulkan error: " #x, false); break;
  switch (result) {
    CASE(VK_ERROR_OUT_OF_HOST_MEMORY);
    CASE(VK_ERROR_OUT_OF_DEVICE_MEMORY);
    CASE(VK_ERROR_INITIALIZATION_FAILED);
    CASE(VK_ERROR_DEVICE_LOST);
    CASE(VK_ERROR_MEMORY_MAP_FAILED);
    CASE(VK_ERROR_LAYER_NOT_PRESENT);
    CASE(VK_ERROR_EXTENSION_NOT_PRESENT);
    CASE(VK_ERROR_FEATURE_NOT_PRESENT);
    CASE(VK_ERROR_TOO_MANY_OBJECTS);
    CASE(VK_ERROR_FORMAT_NOT_SUPPORTED);
    CASE(VK_ERROR_FRAGMENTED_POOL);
    CASE(VK_ERROR_OUT_OF_POOL_MEMORY);
    default: break;
  }
#undef CASE
  state.config.callback(state.config.userdata, message, true);
  return false;
}

static bool check(bool condition, const char* message) {
  if (!condition && state.config.callback) {
    state.config.callback(state.config.userdata, message, true);
  }
  return condition;
}