#pragma once

#include <vulkan/vulkan.h>
#include <SDL.h>
#include <SDL_vulkan.h>
#include <imgui.h>
#include <backends/imgui_impl_sdl2.h>
#include <backends/imgui_impl_vulkan.h>
#include <iostream>
#include <vector>
#include <stdexcept>

class MinimalImGuiVulkan {
public:
    /* run application; borrows calling thread for event loop,
     * until application exit
     */
    void run();

private:
    /* create SDL window for application.
     * populates @ref window_
     */
    void init_sdl_window();

    /* setup vulkan state. swapchain, command buffers etc */
    void init_vulkan();

    /* create vulkan instance.
     * populates @ref instance_
     */
    void create_instance();

    /* create vulkan surface.
     * populates @ref surface_
     */
    void create_surface();

    /* choose physical device (1:1 with graphics card, presumably)
     * populates @ref physical_device_, @ref graphics_queue_family_
     */
    void pick_physical_device();

    /*
     * require: pick_physical_device() has run successfully
     * populates @ref device_, @ref graphics_queue_
     */
    void create_logical_device();

    /* populates @ref swapchain_, @ref swapchain_images_,
     * @ref swapchain_image_views_, @ref framebuffers_.
     * Also $ref render_pass_ iff @p create_render_pass_flag
     */
    void create_xswapchain(bool create_render_pass_flag);

    /*
     * populates @ref swapchain_, @ref swapchain_images_
     */
    void create_swapchain();

    /*
     * populate @ref swapchain_image_views_
     */
    void create_image_views();

    /*
     * populate @ref render_pass_
     */
    void create_render_pass();

    /*
     * populate @ref framebuffers_
     */
    void create_framebuffers();

    /*
     * populate @ref command_pool_
     */
    void create_command_pool();

    /*
     * populate @ref command_buffers_
     */
    void create_command_buffers();

    /*
     * populate
     *   @ref image_available_semaphores_,
     *   @ref render_finished_semaphores_,
     *   @ref inflight_fences_
     */
    void create_sync_objects();

    /*
     * populate @ref descriptor_pool_
     */
    void create_descriptor_pool();

    /* setup imgui "framework" */
    void init_imgui();

    /* Allocate buffer for 'single-time' commands (to be run once?).
     * Pair with call to end_single_time_commands()
     */
    VkCommandBuffer begin_single_time_commands();

    /* complete command buffer begun with begin_single_time_commands();
     * also submit, wait for completion + cleanup
     */
    void end_single_time_commands(VkCommandBuffer commandBuffer);

    /* borrow calling thread, run until application end
     * Require: app state initialized. see init_sdl_window(), init_vulkan(), init_imgui()
     */
    void main_loop();

    /* Accumulate drawing command for next frame.
     * Reserves and modifies the @ref current_frame_ element of
     *   @ref command_buffers_
     *   @ref image_available_semaphores_
     *   @ref inflight_fences_
     * Advances current_frame_ so that it refers to available resources
     */
    void draw_frame();

    /* record draw instructions into cmdbuf, framebuffers_[image_ix] */
    void record_command_buffer(VkCommandBuffer commandBuffer, uint32_t image_ix);

    /* Teardown + create swapchain (swapchain + framebuffers + image views).
     * Need this after window size changes
     */
    void recreate_xswapchain();

    /* wait until non-minimized window */
    void wait_not_minimized();

    /* orderly disposal of swapchin + image_views + framebuffers */
    void cleanup_xswapchain();

    /* orderly disposal of @ref framebuffers_ */
    void cleanup_framebuffers();

    /* orderly disposal of @ref swapchain_image_views_ */
    void cleanup_image_views();

    /* orderly disposal of @ref swapchain_ */
    void cleanup_swapchain();

    /* orderly shutdown */
    void cleanup();

private:
    SDL_Window* window_ = nullptr;

    VkInstance instance_;

    /* abstraction for presentation area (?) */
    VkSurfaceKHR surface_;

    /* physical device (graphics card) */
    VkPhysicalDevice physical_device_;
    uint32_t graphics_queue_family_ = 0;

    /* logical device (graphics card, abstract api (?)) */
    VkDevice device_;
    VkQueue graphics_queue_;

    /* drawing state, dependent on window size */
    VkFormat swapchain_image_format_;
    VkExtent2D swapchain_extent_;
    VkSwapchainKHR swapchain_;
    std::vector<VkImage> swapchain_images_;

    std::vector<VkImageView> swapchain_image_views_;

    VkRenderPass render_pass_;

    std::vector<VkFramebuffer> framebuffers_;

    VkCommandPool command_pool_;

    std::vector<VkCommandBuffer> command_buffers_;

    std::vector<VkSemaphore> image_available_semaphores_;
    std::vector<VkSemaphore> render_finished_semaphores_;
    std::vector<VkFence> inflight_fences_;

    VkDescriptorPool descriptor_pool_;

    uint32_t current_frame_ = 0;
    const int MAX_FRAMES_IN_FLIGHT = 2;
    /* true when window resize behavior detected,
     * until swapchain in consistent state.
     */
    bool framebuffer_resized_flag_ = false;
    bool quit_flag_ = false;
}; /*MinimalImGuiVulkan*/