#include <stdio.h>

#include "SDL.h"

static SDL_AudioDeviceID audio_device = 0;
static SDL_Window *window = NULL;
static SDL_Renderer *renderer = NULL;

#if defined(__clang__) || defined(__GNUC__)
static void panic_and_abort(const char *title, const char *text) __attribute__((noreturn));
#endif
static void panic_and_abort(const char *title, const char *text) {
    fprintf(stderr, "PANIC: %s ... %s\n", title, text);
    SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, title, text, window);
    SDL_Quit();
    exit(1);
}

int main(int argc, char **argv) {
    if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) != 0) {
        panic_and_abort("SDL_Init failed", SDL_GetError());
    }

    window = SDL_CreateWindow("sdlamp", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 1024, 768, 0);
    if (!window) {
        panic_and_abort("SDL_CreateWindow failed", SDL_GetError());
    }

    renderer = SDL_CreateRenderer(window, 0, SDL_RENDERER_PRESENTVSYNC);
    if (!renderer) {
        panic_and_abort("SDL_CreateRenderer failed", SDL_GetError());
    }

    // Enable dropfile events
    SDL_EventState(SDL_DROPFILE, SDL_ENABLE);

    const SDL_Rect rewind_rect = {100, 100, 100, 100};
    const SDL_Rect pause_rect = {400, 100, 100, 100};

    SDL_AudioSpec wavspec;
    Uint8 *wavbuf = NULL;
    Uint32 wavlen = 0;

    SDL_bool paused = SDL_TRUE;
    SDL_bool quit = SDL_FALSE;
    while (!quit) {
        SDL_Event e;
        while (SDL_PollEvent(&e)) {
            switch (e.type) {
                case SDL_QUIT:
                    quit = SDL_TRUE;
                    break;

                case SDL_MOUSEBUTTONDOWN: {
                    SDL_Point pt = { e.button.x, e.button.y };
                    if (SDL_PointInRect(&pt, &rewind_rect)) {
                        SDL_ClearQueuedAudio(audio_device);
                        SDL_QueueAudio(audio_device, wavbuf, wavlen);
                    } else if (SDL_PointInRect(&pt, &pause_rect)) {
                        paused = paused ? SDL_FALSE : SDL_TRUE;
                        SDL_PauseAudioDevice(audio_device, paused);
                    }
                    break;
                }

                case SDL_DROPFILE: {
                    if (audio_device) {
                        SDL_CloseAudioDevice(audio_device);
                        audio_device = 0;
                    }

                    SDL_FreeWAV(wavbuf);
                    wavbuf = NULL;
                    wavlen = 0;

                    if (SDL_LoadWAV(e.drop.file, &wavspec, &wavbuf, &wavlen) == NULL) {
                        SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, "Couldn't load wav file!", SDL_GetError(), window);
                    }

                    audio_device = SDL_OpenAudioDevice(NULL, 0, &wavspec, NULL, 0);
                    if (audio_device == 0) {
                        SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, "Couldn't load audio device!", SDL_GetError(), window);
                        SDL_free(wavbuf);
                        wavbuf = NULL;
                        wavlen = 0;
                    } else {
                        SDL_QueueAudio(audio_device, wavbuf, wavlen);
                        SDL_PauseAudioDevice(audio_device, 0);
                    }
                    SDL_free(e.drop.file);
                    break;
                }
            }
        }


        SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
        SDL_RenderClear(renderer);

        SDL_SetRenderDrawColor(renderer, 255, 255, 255, 255);
        SDL_RenderFillRect(renderer, &rewind_rect);
        SDL_RenderFillRect(renderer, &pause_rect);

        SDL_RenderPresent(renderer);
    }

    SDL_FreeWAV(wavbuf);
    SDL_CloseAudioDevice(audio_device);
    SDL_DestroyRenderer(renderer);
    SDL_DestroyWindow(window);
    SDL_Quit();

    return 0;
}