#define SDL_MAIN_HANDLED
#include <SDL2/SDL.h>

#include <stdbool.h>
#include <stdlib.h>
#include <stdio.h>

#include <libopenmpt/libopenmpt.h>

#define eprintf(...) fprintf(stderr, __VA_ARGS__)

static const int WINDOW_WIDTH = 160, WINDOW_HEIGHT = 90;

SDL_Window *window = NULL;

struct blob load_file(char const *const name);

#include "include.h"
struct userdata userdata = {
	.callback = NULL,
	.user = NULL,
};

void audio_callback(void *userdata_void, unsigned char *stream_void, int const length) {
	struct userdata *user = userdata_void;
	float *stream = (float *) stream_void;
	if (user->callback == NULL) {
		for (int i = 0; i < length / sizeof (float); i++) {
			stream[i] = 0.0;
		}
	} else {
		user->callback(user->user, stream_void, length);
	}
}

int main(void) {
	if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO)) {
		eprintf("failed to init SDL: %s\n");
		return EXIT_FAILURE;
	}
	
	SDL_StopTextInput();
	
	if ((window = SDL_CreateWindow("mu-sdl", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, WINDOW_WIDTH, WINDOW_HEIGHT, SDL_WINDOW_RESIZABLE)) == NULL) {
		eprintf("failed to create a window: %s\n");
		SDL_Quit();
		return EXIT_FAILURE;
	}
	
	SDL_AudioSpec desired = {
		.freq = 48000,
		.format = AUDIO_F32SYS,
		.channels = 2,
		.samples = 8096,
		.callback = audio_callback,
		.userdata = &userdata,
	};
	SDL_AudioDeviceID audio = SDL_OpenAudioDevice(NULL, 0, &desired, NULL, 0);
	
	SDL_PauseAudioDevice(audio, 0);
	while (true) {
		SDL_Event evt;
		while (SDL_PollEvent(&evt)) {
			switch (evt.type) {
				case SDL_QUIT:
					goto done;
				
				case SDL_KEYDOWN:
					// ^Q
					if (evt.key.keysym.sym == SDLK_q && evt.key.keysym.mod & KMOD_CTRL) {
						goto done;
					}
					// ESC
					if (evt.key.keysym.sym == SDLK_ESCAPE) {
						goto done;
					}
					break;
				
				case SDL_DROPFILE:
					puts(evt.drop.file);
					struct blob file = load_file(evt.drop.file);
					if (file.data == NULL) {
						perror(evt.drop.file);
						SDL_free(evt.drop.file);
						break;
					}
					SDL_free(evt.drop.file);
					//SDL_LockAudioDevice(audio);
					//openmpt_module *mod = openmpt_module_create_from_memory2(file.data, file.size, &libopenmpt_example_logfunc, NULL, &libopenmpt_example_errfunc, NULL, &mod_err, &mod_err_str, NULL);
					//SDL_UnlockAudioDevice(audio);
					free(file.data);
					break;
				
				default:
			}
		}
	}
	done:
	
	SDL_DestroyWindow(window);
	
	SDL_CloseAudioDevice(audio);
	
	SDL_Quit();
	
	return EXIT_SUCCESS;
}

struct blob load_file(char const *const name) {
	const size_t START_SIZE = 1;
	FILE *file = fopen(name, "rb");
	if (file == NULL) {
		return (struct blob) {.data = NULL};
	}
	void *data = malloc(START_SIZE);
	size_t allocated = START_SIZE;
	size_t used = 0;
	while (1) {
		size_t read = fread(data + used, 1, allocated - used, file);
		if (read != allocated - used) {
			used += read;
			break;
		}
		used += read;
		allocated *= 2;
		void *const newdata = realloc(data, allocated);
		if (newdata == NULL) {
			goto realloc_error;
		}
		data = newdata;
	}
	void *const newdata = realloc(data, used);
	if (newdata == NULL && used != 0) {
		goto realloc_error;
	}
	fclose(file);
	return (struct blob) {.data = newdata, .size = used};
	
	realloc_error:
	free(data);
	fclose(file);
	return (struct blob) {.data = NULL};
}