#include <error.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "libc.h"

void (*error_print_progname) (void) = 0;
unsigned int error_message_count = 0;
int error_one_per_line = 0;

static unsigned int saved_linenum = 0;
static const char *saved_file = 0;

static void errorv(int status, int errnum, const char *file, unsigned int linenum, const char *fmt, va_list ap)
{
	++error_message_count;

	fflush(stdout);
	flockfile(stderr);

	if (error_print_progname)
		error_print_progname();
	else {
		fprintf(stderr, "%s:", __progname_full);
		if (!file)
			fputc(' ', stderr);
	}

	if (file)
		fprintf(stderr, "%s:%u: ", file, linenum);

	vfprintf(stderr, fmt, ap);
	if (errnum)
		fprintf(stderr, ": %s", strerror(errnum));
	fputc('\n', stderr);

	funlockfile(stderr);

	if (status)
		exit(status);
}

void error(int status, int errnum, const char *fmt, ...)
{
	va_list ap;
	va_start(ap, fmt);
	errorv(status, errnum, NULL, 0, fmt, ap);
	va_end(ap);
}

void error_at_line(int status, int errnum, const char *file, unsigned int linenum, const char *fmt, ...)
{
	if (error_one_per_line) {
		if(saved_linenum == linenum && file != NULL &&
		   saved_file != NULL && !strcmp(file, saved_file))
			return;
		saved_linenum = linenum;
		// Assuming that the lifetime of the passed in file name extends
		// until the next call is rather questionable, but appears to be
		// the expected semantics.
		saved_file = file;
	}

	va_list ap;
	va_start(ap, fmt);
	errorv(status, errnum, file, linenum, fmt, ap);
	va_end(ap);
}