#include <stdlib.h>
#include <errno.h>
#include <stdint.h>
#include <limits.h>
#include <arpa/inet.h>
#include <string.h>
#include <sys/types.h>
#include <dirent.h>
#include <fcntl.h>
#include <unistd.h>

#include "main.h"
#include "utils.h"

static unsigned total_malloc_count = 0;
static int malloc_count = 0;

LIST_HEAD(malloc_list);

struct allocation {
	const char *allocfn;
	const char *callerfn;
	int line;
	void *ptr;
	size_t size;
	struct list_head list;
};

static void
add_allocation(const char *allocfn, const char *callerfn, int line, void *ptr, size_t size)
{
	struct allocation *a = malloc(sizeof(*a));

	fprintf(stderr, "Allocation: %s:%i %s(%zu) = %p\n",
	        callerfn, line, allocfn, size, ptr);
	a->allocfn = allocfn;
	a->callerfn = callerfn;
	a->line = line;
	a->ptr = ptr;
	a->size = size;
	list_add(&a->list, &malloc_list);
	total_malloc_count++;
	malloc_count++;
}

void *
__zmalloc(const char *fn, int line, size_t size)
{
	void *ptr;

	ptr = calloc(1, size);
	if (ptr)
		add_allocation("zmalloc", fn, line, ptr, size);
	else
		perrordie("zmalloc");
	return ptr;
}

char *
__xstrdup(const char *fn, int line, const char *s)
{
	char *ptr;

	ptr = strdup(s);
	if (ptr)
		add_allocation("xstrdup", fn, line, ptr, strlen(s) + 1);
	else
		perrordie("strdup");
	return ptr;
}

char *
__xstrndup(const char *fn, int line, const char *s, size_t n)
{
	char *ptr;

	ptr = strndup(s, n);
	if (ptr)
		add_allocation("xstrndup", fn, line, ptr, n);
	else
		perrordie("strndup");
	return ptr;
}

void
__xfree(const char *fn, int line, void *ptr)
{
	struct allocation *a, *tmp;
	unsigned delete_count = 0;

	if (!ptr)
		return;
	free(ptr);
	malloc_count--;

	fprintf(stderr, "Deallocation: %s:%i %p\n", fn, line, ptr);
	list_for_each_entry_safe(a, tmp, &malloc_list, list) {
		if (a->ptr == ptr) {
			list_del(&a->list);
			free(a);
			delete_count++;
		}
	}

	if (delete_count != 1) {
		error("Delete count is %u for ptr 0x%p\n", delete_count, ptr);
		exit(EXIT_FAILURE);
	}
}

void
debug_resource_usage()
{
	struct allocation *a;
	DIR *dir;
	struct dirent *dent;
	char buf[4096];
	ssize_t r;
	unsigned file_count = 0;

	fprintf(stderr, "Still malloced %i (total %u)\n",
		malloc_count, total_malloc_count);

	list_for_each_entry(a, &malloc_list, list) {
		fprintf(stderr, "* Lost allocation - %s:%i - ptr: %p, size: %zu\n",
			a->callerfn, a->line, a->ptr, a->size);
	}

	dir = opendir("/proc/self/fd");
	if (!dir) {
		fprintf(stderr, "Failed to open fd dir\n");
		return;
	}

	fprintf(stderr, "Open files:\n");
	while ((dent = readdir(dir)) != NULL) {
		if (!strcmp(dent->d_name, ".") ||
		    !strcmp(dent->d_name, ".."))
			continue;

		r = readlinkat(dirfd(dir), dent->d_name, buf, sizeof(buf));
		if (r < 0) {
			fprintf(stderr, "Failed to readlink %s\n", dent->d_name);
			continue;
		}
		buf[r] = '\0';
		fprintf(stderr, " * %s -> %s\n", dent->d_name, buf);
		file_count++;
	}
	closedir(dir);

	if (file_count > 4) {
		fprintf(stderr, "Lost file descriptor(s)\n");
		exit(EXIT_FAILURE);
	}
}

uint16_t sockaddr_port(struct sockaddr_in46 *addr)
{
	switch (addr->storage.ss_family) {
	case AF_INET:
		return ntohs(addr->in4.sin_port);
	case AF_INET6:
		return ntohs(addr->in6.sin6_port);
	default:
		return 0;
	}
}

char *
sockaddr_to_str(struct sockaddr_in46 *addr, char *buf, size_t buflen)
{
	char abuf[ADDRSTRLEN];

	switch (addr->storage.ss_family) {
	case AF_INET:
		snprintf(buf, buflen, "AF_INET4 %s %u",
			 inet_ntop(addr->in4.sin_family, &addr->in4.sin_addr, abuf, sizeof(abuf)),
			 (unsigned)ntohs(addr->in4.sin_port));
		break;
	case AF_INET6:
		snprintf(buf, buflen, "AF_INET6 %s %u",
			 inet_ntop(addr->in6.sin6_family, &addr->in6.sin6_addr, abuf, sizeof(abuf)),
			 (unsigned)ntohs(addr->in6.sin6_port));
		break;
	default:
		snprintf(buf, buflen, "AF_UNKNOWN");
		break;
	}

	return buf;
}

int
strtou16_strict(const char *str, uint16_t *result)
{
	char *end;
	long val;

	if (!str)
		return -EINVAL;

	errno = 0;
	val = strtol(str, &end, 10);

	if (errno == ERANGE && (val == LONG_MAX || val == LONG_MIN))
		return -EINVAL;
	
	if (errno != 0 && val == 0)
		return -EINVAL;

	if (end == str)
		return -EINVAL;

	if (*end != '\0')
		return -EINVAL;

	if (val < 1 || val > UINT16_MAX)
		return -EINVAL;

	if (result)
		*result = val;
	return 0;
}