#define _GNU_SOURCE 1

#include <dlfcn.h>
#include <errno.h>
#include <paths.h>
#include <stdarg.h>
#include <stdbool.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <limits.h>
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>

// #define DEBUG 1

static int (*libc_open)(const char *pathname, int flags, ...);
static int (*libc_close)(int fd);

static char logs_path[128];
static int logs_fd = -1;


static void __init__() __attribute__((constructor));
static void __fini__() __attribute__((destructor));

void __init__() {
	libc_close = dlsym(RTLD_NEXT, "close");
	libc_open = dlsym(RTLD_NEXT, "open");
#if DEBUG
	fprintf(stderr, "found real close %p and open %p\n", libc_close, libc_open);
#endif
}

void __fini__ () {
	if (logs_fd != -1) {
		fprintf(stderr, "closing %d\n", logs_fd);
		libc_close(logs_fd);
	}
}

int close(int fd) {
	if (fd != logs_fd)
		return libc_close(fd);

	return 0;
}

int open(const char *pathname, int flags, ...) {
	int mode = -1;
	va_list ap;

	if (flags & O_CREAT) {
		va_start(ap, flags);
		mode = va_arg(ap, int);
		va_end(ap);
	}

#if DEBUG
	fprintf(stderr, "caught %s\n", pathname);
#endif
	// 25341 openat(AT_FDCWD, "/home/asmadeus/.wine/dosdevices/z:/EverQuest/Logs/eqlog_Asmadeus_antonius.txt", O_WRONLY|O_CREAT|O_NONBLOCK, 0666) = 160
	if (strstr(pathname, "Logs/eqlog_")) {
#if DEBUG
		fprintf(stderr, "found Logs/eqlog_\n");
#endif
		if (strncmp(pathname, logs_path, sizeof(logs_path)-1) == 0)
			return logs_fd;
		else if (logs_fd != -1)
			libc_close(logs_fd);
		strncpy(logs_path, pathname, sizeof(logs_path));
		logs_fd = libc_open(pathname, flags, mode);
		fprintf(stderr, "new path %s, opened %d, flags %x\n", pathname, logs_fd, flags);
		return logs_fd;
	}

	if (mode >= 0)
		return libc_open(pathname, flags, mode);
	else
		return libc_open(pathname, flags);
}