/* Author: Romain "Artefact2" Dal Maso <artefact2@gmail.com> */

/* This program is free software. It comes without any warranty, to the
 * extent permitted by applicable law. You can redistribute it and/or
 * modify it under the terms of the Do What The Fuck You Want To Public
 * License, Version 2, as published by Sam Hocevar. See
 * http://sam.zoy.org/wtfpl/COPYING for more details. */

#include <assert.h>
#include <stdio.h>
#include <sys/mman.h>
#include <sys/resource.h>
#include <xm.h>

static const unsigned int channels = 2;
static const unsigned int rate = 48000;
static const size_t buffer_size = (1 << 12);

static void puts_uint32_be(uint32_t i) {
	char* c = (char*)(&i);

	if(XM_BIG_ENDIAN) {
		putchar(c[0]);
		putchar(c[1]);
		putchar(c[2]);
		putchar(c[3]);
	} else {
		putchar(c[3]);
		putchar(c[2]);
		putchar(c[1]);
		putchar(c[0]);
	}
}

int main(int argc, char** argv) {
	float buffer[buffer_size];
	xm_context_t* ctx;
	void* data;
	size_t datalen;
	FILE* fp;

	if(argc != 2) return 1;

	fp = fopen(argv[1], "rb");
	assert(fp);
	assert(fread(&datalen, sizeof(size_t), 1, fp));
	rewind(fp);
	data = mmap(0, datalen, PROT_READ|PROT_WRITE, MAP_PRIVATE, fileno(fp), 0);
	assert(data != MAP_FAILED);
	xm_create_context_from_libxmize(&ctx, data, rate);

	puts_uint32_be(0x2E736E64); /* .snd magic number */
	puts_uint32_be(28); /* Header size */
	puts_uint32_be((uint32_t)(-1)); /* Data size, unknown */
	puts_uint32_be(6); /* Encoding: 32-bit IEEE floating point */
	puts_uint32_be(rate); /* Sample rate */
	puts_uint32_be(channels); /* Number of interleaved channels */
	puts_uint32_be(0); /* Optional text information */

	while(!xm_get_loop_count(ctx)) {
		xm_generate_samples(ctx, buffer, sizeof(buffer) / (channels * sizeof(float)));
		for(size_t k = 0; k < buffer_size; ++k) {
			union {
				float f;
				uint32_t i;
			} u;

			u.f = buffer[k];
			puts_uint32_be(u.i);
		}
	}

	struct rusage r;
	assert(!getrusage(RUSAGE_SELF, &r));
	fprintf(stderr, "%s: libxmized length %lu, ru_maxrss %ld\n", argv[0], datalen, r.ru_maxrss);

	munmap(data, datalen);
	fclose(fp);
	return 0;
}