/* Can't include krb5.h here, or k5-int.h which includes it, because
   krb5.h needs to be generated with error tables, after util/et,
   which builds after this directory.  */
#include <stdarg.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <k5-err.h>

#include "k5-thread.h"
#include <k5-platform.h>
#include "supp-int.h"

#ifdef _WIN32
#ifndef vsnprintf
#define vsnprintf _vsnprintf
#endif
#endif

/* It would be nice to just use error_message() always.  Pity that
   it's defined in a library that depends on this one, and we're not
   allowed to make circular dependencies.  */
/* We really want a rwlock here, since we should hold it while calling
   the function and copying out its results.  But I haven't
   implemented shims for rwlock yet.  */
static k5_mutex_t krb5int_error_info_support_mutex =
    K5_MUTEX_PARTIAL_INITIALIZER;
static const char *(KRB5_CALLCONV *fptr)(long); /* = &error_message */

int
krb5int_err_init (void)
{
    return k5_mutex_finish_init (&krb5int_error_info_support_mutex);
}
#define initialize()    krb5int_call_thread_support_init()
#define lock()          k5_mutex_lock(&krb5int_error_info_support_mutex)
#define unlock()        k5_mutex_unlock(&krb5int_error_info_support_mutex)

void
krb5int_set_error (struct errinfo *ep, long code, const char *fmt, ...)
{
    va_list args;
    va_start (args, fmt);
    krb5int_vset_error (ep, code, fmt, args);
    va_end (args);
}

void
krb5int_vset_error (struct errinfo *ep, long code,
                    const char *fmt, va_list args)
{
    char *p;

    if (ep->msg && ep->msg != ep->scratch_buf) {
        free ((void *)ep->msg);
        ep->msg = NULL;
    }
    ep->code = code;
#ifdef HAVE_VASPRINTF
    {
        char *str = NULL;
        if (vasprintf(&str, fmt, args) >= 0 && str != NULL) {
            ep->msg = str;
            return;
        }
    }
#endif
    vsnprintf(ep->scratch_buf, sizeof(ep->scratch_buf), fmt, args);
    p = strdup(ep->scratch_buf);
    ep->msg = p ? p : ep->scratch_buf;
}

const char *
krb5int_get_error (struct errinfo *ep, long code)
{
    char *r, *r2;
    if (code == ep->code && ep->msg) {
        r = strdup(ep->msg);
        if (r == NULL) {
            strcpy(ep->scratch_buf, _("Out of memory"));
            r = ep->scratch_buf;
        }
        return r;
    }
    if (initialize() != 0) {
        strncpy(ep->scratch_buf, _("Kerberos library initialization failure"),
                sizeof(ep->scratch_buf));
        ep->scratch_buf[sizeof(ep->scratch_buf)-1] = 0;
        ep->msg = NULL;
        return ep->scratch_buf;
    }
    lock();
    if (fptr == NULL) {
        unlock();
#ifdef HAVE_STRERROR_R
        if (strerror_r (code, ep->scratch_buf, sizeof(ep->scratch_buf)) == 0) {
            char *p = strdup(ep->scratch_buf);
            if (p)
                return p;
            return ep->scratch_buf;
        }
        /* If strerror_r didn't work with the 1K buffer, we can try a
           really big one.  This seems kind of gratuitous though.  */
#define BIG_ERR_BUFSIZ 8192
        r = malloc(BIG_ERR_BUFSIZ);
        if (r) {
            if (strerror_r (code, r, BIG_ERR_BUFSIZ) == 0) {
                r2 = realloc (r, 1 + strlen(r));
                if (r2)
                    return r2;
                return r;
            }
            free (r);
        }
#endif
        r = strerror (code);
        if (r) {
            if (strlen (r) < sizeof (ep->scratch_buf)
                || (r2 = strdup (r)) == NULL) {
                strncpy (ep->scratch_buf, r, sizeof(ep->scratch_buf));
                return ep->scratch_buf;
            } else
                return r2;
        }
    format_number:
        sprintf (ep->scratch_buf, _("error %ld"), code);
        return ep->scratch_buf;
    }
    r = (char *) fptr(code);
    if (r == NULL) {
        unlock();
        goto format_number;
    }
    r2 = strdup (r);
    if (r2 == NULL) {
        strncpy(ep->scratch_buf, r, sizeof(ep->scratch_buf));
        unlock();
        return ep->scratch_buf;
    } else {
        unlock();
        return r2;
    }
}

void
krb5int_free_error (struct errinfo *ep, const char *msg)
{
    if (msg != ep->scratch_buf)
        free ((char *) msg);
}

void
krb5int_clear_error (struct errinfo *ep)
{
    krb5int_free_error (ep, ep->msg);
    ep->msg = NULL;
}

void
krb5int_set_error_info_callout_fn (const char *(KRB5_CALLCONV *f)(long))
{
    initialize();
    lock();
    fptr = f;
    unlock();
}