#include <cstdlib>
#include <nng/nng.h>

#include <imgui.h>
#include <backends/imgui_impl_sdl.h>
#include <backends/imgui_impl_sdlrenderer.h>
#include <SDL.h>

#include "dp_common.h"
#include "log.h"

void dp_sdl_fatal(const char *const msg)
{
    log_fatal("%s: %s", msg, SDL_GetError());
    abort();
}

static const size_t NumDooms = 3;

int doom_controller_loop(nng_socket pubSock, nng_socket subSock, SDL_Window *window, SDL_Renderer *renderer)
{
    bool show_demo_window = true;
    bool show_another_window = false;
    ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);

    bool done = false;

    while (!done)
    {
        SDL_Event event;
        while (SDL_PollEvent(&event))
        {
            ImGui_ImplSDL2_ProcessEvent(&event);

            if (event.type == SDL_QUIT)
                done = true;
            if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window))
                done = true;
        }

        // Start the Dear ImGui frame
        ImGui_ImplSDLRenderer_NewFrame();
        ImGui_ImplSDL2_NewFrame();
        ImGui::NewFrame();

        if (show_demo_window)
            ImGui::ShowDemoWindow(&show_demo_window);

        // Rendering
        ImGui::Render();
        SDL_SetRenderDrawColor(renderer, (Uint8)(clear_color.x * 255), (Uint8)(clear_color.y * 255), (Uint8)(clear_color.z * 255), (Uint8)(clear_color.w * 255));
        SDL_RenderClear(renderer);
        ImGui_ImplSDLRenderer_RenderDrawData(ImGui::GetDrawData());
        SDL_RenderPresent(renderer);
    }

    return 0;
}

int main(int argc, char *argv[])
{
    (void) argc;
    (void) argv;

    log_info("doompanning ctrl starting");

    dp_nng_init_limits(1, 1, 1);

    auto pubSock = make_ctrl_pub(CtrlUrl);
    auto subSock = make_ctrl_sub(DoomUrl);

    if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER))
        dp_sdl_fatal("SDL_Init");

#ifdef SDL_HINT_IME_SHOW_UI
    SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");
#endif

    const auto windowFlags = SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI;
    auto window = SDL_CreateWindow("doompanning", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, windowFlags);
    if (!window)
        dp_sdl_fatal("SDL_CreateWindow");

    auto renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_PRESENTVSYNC | SDL_RENDERER_ACCELERATED);

    if (!renderer)
        dp_sdl_fatal("SDL_CreateRenderer");

    IMGUI_CHECKVERSION();
    ImGui::CreateContext();
    ImGui::StyleColorsDark();
    ImGui_ImplSDL2_InitForSDLRenderer(window, renderer);
    ImGui_ImplSDLRenderer_Init(renderer);

    int ret = doom_controller_loop(pubSock, subSock, window, renderer);

    nng_close(pubSock);
    nng_close(subSock);

    return ret;
}

// doomctrl test code
    #if 0
    size_t readyCount = 0;

    log_debug("ctrl waiting for hello from dooms");
    while (readyCount < numDooms)
    {
        char *buf = nullptr;
        size_t sz = 0;

        if (auto res = nng_recv(subSock, &buf, &sz, NNG_FLAG_ALLOC))
            dp_nng_fatal("run_ctrl/sub/go", res);

        log_debug("ctrl received %zu bytes from a doom", sz);
        nng_free(buf, sz);
        ++readyCount;
    }

    log_debug("ctrl is unleashing dooms");

    if (auto res = nng_send(pubSock, (void *)&readyCount, sizeof(readyCount), 0))
        dp_nng_fatal("run_ctrl/pub/unleash", res);

    #endif

// doomsim test code
    #if 0
    while (true) // FIXME: ctrl code does not work this way
    {
        log_debug("doom%zu sending hello", id);
        if (auto res = nng_send(pubSock, (void *)&id, sizeof(id), 0))
            dp_nng_fatal("run_doom/pub/hello", res);

        {
            char *buf = nullptr;
            size_t sz = 0;

            log_debug("doom%zu waiting for unleash", id);
            auto res = nng_recv(subSock, &buf, &sz, NNG_FLAG_ALLOC | NNG_FLAG_NONBLOCK);

            if (res == NNG_EAGAIN)
            {
                usleep(10 * 1000);
                continue;
            }
            else if (res)
                dp_nng_fatal("run_doom/sub/go", res);

            log_debug("doom%zu unleashed by %zu bytes!", id, sz);
            nng_free(buf, sz);
            break;
        }
    }
    #endif