/*
 * error.c
 *
 * Summary:  Exception handling functions.
 *
 * Author:  David Hardy
 */

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


int mdio_warn(const char *fmt, ...)
{
  int ret;
  va_list v;

  va_start(v, fmt);
  ret = fprintf(stderr, "MDIO WARNING:  ");
  ret += vfprintf(stderr, fmt, v);
  va_end(v);
  return ret;
}


int mdio_error(const char *fmt, ...)
{
  int ret;
  va_list v;

  va_start(v, fmt);
  ret = fprintf(stderr, "MDIO ERROR:  ");
  ret += vfprintf(stderr, fmt, v);
  va_end(v);
  return ret;
}


void mdio_fatal(const char *fmt, ...)
{
  va_list v;

  va_start(v, fmt);
  (void) fprintf(stderr, "MDIO FATAL ERROR:  ");
  (void) vfprintf(stderr, fmt, v);
  va_end(v);
  exit(-1);
}


static const char *ERRMSG[] = {          /* form: 0x________ */
  "status OK",                                 /*        0x0 */
  "unknown token from input file",             /*        0x1 */
  "non-terminated comment from input file",    /*        0x2 */
  "truncated line from input file",            /*        0x4 */
  "unused",                                    /*        0x8 */
  "unused",                                    /*       0x10 */
  "unused",                                    /*       0x20 */
  "unused",                                    /*       0x40 */
  "unused",                                    /*       0x80 */
  "unused",                                    /*      0x100 */
  "unused",                                    /*      0x200 */
  "unused",                                    /*      0x400 */
  "illegal format from input file",            /*      0x800 */
  "cannot allocate memory",                    /*     0x1000 */
  "cannot open file",                          /*     0x2000 */
  "cannot close file",                         /*     0x4000 */
  "cannot read from file",                     /*     0x8000 */
  "cannot write to file",                      /*    0x10000 */
  "unsupported feature",                       /*    0x20000 */
  "unused",                                    /*    0x40000 */
  "unused",                                    /*    0x80000 */
  "unused",                                    /*   0x100000 */
  "unused",                                    /*   0x200000 */
  "unused",                                    /*   0x400000 */
  "unused",                                    /*   0x800000 */
  "unused",                                    /*  0x1000000 */
  "unused",                                    /*  0x2000000 */
  "unused",                                    /*  0x4000000 */
  "unused",                                    /*  0x8000000 */
  "unused",                                    /* 0x10000000 */
  "unused",                                    /* 0x20000000 */
  "unused",                                    /* 0x40000000 */
  ""
};

/*
 * unfortunately, this function isn't thread safe
 */
const char *mdio_errmsg(int status)
{
  static char errmsg[2560];  /* == 32 * 80, more space than we actually need */
  int k, chkbit;
  char *p = errmsg;
  const char *q;

  if (status < 0) {
    return "status number out of range";
  }
  else if (status == 0) {
    return ERRMSG[0];
  }
  else {
    for (k = 1, chkbit = 1; ;  k++, chkbit <<= 1) {
      MDIO_ASSERT(k < 32 && chkbit > 0);
      if (chkbit & status) {
        for (q = ERRMSG[k];  (*p = *q) != '\0';  p++, q++) ;  /* fast strcat */
        status ^= chkbit;  /* clear bits as we check them */
        if (status == 0) break;
        *p++ = ',';
        *p++ = ' ';  /* strcat ", " on end */
      }
    }
    return (const char *) errmsg;
  }
}


#if defined(MDIO_TEST) || defined(MDIO_MODULE_TEST)  
/* define functions used to test module */
int error_test(void)
{
  /* check out all status messages individually */
  mdio_warn("%s\n", mdio_errmsg(MDIO_WARN_UNKNOWN));
  mdio_warn("%s\n", mdio_errmsg(MDIO_WARN_COMMENT));
  mdio_warn("%s\n", mdio_errmsg(MDIO_WARN_TRUNC));
  mdio_error("%s\n", mdio_errmsg(MDIO_ERR_LEVEL));
  mdio_error("%s\n", mdio_errmsg(MDIO_ERR_FORMAT));
  mdio_error("%s\n", mdio_errmsg(MDIO_ERR_MEMALLOC));
  mdio_error("%s\n", mdio_errmsg(MDIO_ERR_OPEN));
  mdio_error("%s\n", mdio_errmsg(MDIO_ERR_CLOSE));
  mdio_error("%s\n", mdio_errmsg(MDIO_ERR_READ));
  mdio_error("%s\n", mdio_errmsg(MDIO_ERR_WRITE));
  mdio_error("%s\n", mdio_errmsg(MDIO_ERR_UNSUPPORTED));

  /* now check them out all ORed together */
  mdio_fatal("%s\n", 
      mdio_errmsg(MDIO_WARN_UNKNOWN
                | MDIO_WARN_COMMENT
                | MDIO_WARN_TRUNC
                | MDIO_ERR_LEVEL
                | MDIO_ERR_FORMAT
                | MDIO_ERR_MEMALLOC
                | MDIO_ERR_OPEN
                | MDIO_ERR_CLOSE
                | MDIO_ERR_READ
                | MDIO_ERR_WRITE
                | MDIO_ERR_UNSUPPORTED));

  /* this statement is not reached */
  return 0;
}
#endif


#if defined(MDIO_MODULE_TEST)
/* define main() to test this module */
int main(void)
{
  (void) error_test();
  return 0;
}
#endif