#define _DEFAULT_SOURCE
#include <dlfcn.h>
#include <err.h>
#include <stdbool.h>
#include <stdio.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include "tune.h"

struct tune_dl {
	void *handle;
	ino_t inode;
	struct tune *tune;
};

static int tune_dl_load(struct tune_dl *dl, const char *libfname)
{
    struct stat st;
	if (stat(libfname, &st) < 0) {
		warn("stat");
		return -1;
	}
    if (dl->inode == st.st_ino) {
		// file unchanged
		return 0;
	}
	// reload the library
	if (dl->handle) {
		dlclose(dl->handle);
		dl->inode = 0;
	}
	dl->handle = dlopen(libfname, RTLD_NOW);
	if (dl->handle == NULL) {
		// warnx("dlopen: %s", dlerror());
		return 0;
	}
	dl->tune = dlsym(dl->handle, "TUNE");
	if (dl->tune == NULL) {
		warn("dlsym");
		dlclose(dl->handle);
		return 0;
	}
	dl->inode = st.st_ino;
	if (dl->tune->reload) {
		dl->tune->reload(dl->tune);
	}
	return 0;
}

int main(int argc, char *argv[])
{
	struct tune_dl dl = {0};
	const char *fname = "./tune.so";
	if (tune_dl_load(&dl, fname) < 0) {
		return 1;
	}
	if (dl.tune->init) {
		dl.tune->init(dl.tune);
	}
	int t = 0;
	while (1) {
		(void) tune_dl_load(&dl, fname);
		if (dl.handle && dl.tune->play) {
			double sample = dl.tune->play(dl.tune, t);
			printf("%d %f\n", t, sample);
		}
		(void) tune_dl_load(&dl, fname);
        usleep(100000);
		t++;
	}
	if (dl.tune->deinit) {
		dl.tune->deinit(dl.tune);
	}
}