/** @file

  A brief file description

  @section license License

  Licensed to the Apache Software Foundation (ASF) under one
  or more contributor license agreements.  See the NOTICE file
  distributed with this work for additional information
  regarding copyright ownership.  The ASF licenses this file
  to you under the Apache License, Version 2.0 (the
  "License"); you may not use this file except in compliance
  with the License.  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
 */

/****************************************************************************

  ink_string.c

  String and text processing routines for libts

 ****************************************************************************/

#include "libts.h"   /* MAGIC_EDITING_TAG */

#include <assert.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>


#define INK_MAX_STRING_ARRAY_SIZE 128

/*---------------------------------------------------------------------------*

  char *ink_strncpy(char *dest, char *src, int n)

  This routine is a safer version of strncpy which always NUL terminates
  the destination string.  Note that this routine has the SAME semantics
  as strncpy, such as copying exactly n bytes, padding dest with NULs
  is necessary.  Use ink_string_copy for a non-padding version.

 *---------------------------------------------------------------------------*/

char *
ink_strncpy(char *dest, const char *src, int n)
{
  if (likely(src && dest)) {
    if (n > 1)
      strncpy(dest, src, (n - 1));
    if (n > 0)
      dest[n - 1] = '\0';
  }

  return (dest);
}                               /* End ink_strncpy */


/*---------------------------------------------------------------------------*

  char *ink_string_concatenate_strings(char *dest, ...)

  This routine concatenates a variable number of strings into the buffer
  <dest>, returning the pointer to <dest>.  The sequence of strings must end
  with NULL.

 *---------------------------------------------------------------------------*/

char *
ink_string_concatenate_strings(char *dest, ...)
{
  va_list ap;
  register char *s, *d;

  va_start(ap, dest);

  d = dest;

  while (1) {
    s = va_arg(ap, char *);
    if (s == NULL)
      break;

    while (*s)
      *d++ = *s++;
  }
  *d++ = '\0';
  va_end(ap);
  return (dest);
}                               /* End ink_string_concatenate_strings */


/*---------------------------------------------------------------------------*

  char *ink_string_concatenate_strings_n(char *dest, int n, ...)

  This routine concatenates a variable number of strings into the buffer
  <dest>, returning the pointer to <dest>.  The sequence of strings must end
  with NULL.  A NUL will always be placed after <dest>, and no more than
  <n> - 1 characters will ever be written to <dest>.

 *---------------------------------------------------------------------------*/

char *
ink_string_concatenate_strings_n(char *dest, int n, ...)
{
  va_list ap;
  register char *s, *d;

  va_start(ap, n);

  d = dest;

  while (n > 1) {
    s = va_arg(ap, char *);
    if (s == NULL)
      break;
    while (*s && (n > 1)) {
      *d++ = *s++;
      n--;
    }
  }
  if (n >= 1)
    *d = '\0';
  va_end(ap);
  return (dest);
}                               /* End ink_string_concatenate_strings_n */


/*---------------------------------------------------------------------------*

  char *ink_string_append(char *dest, char *src, int n)

  This routine appends <src> to the end of <dest>, but it insures the
  string pointed to by <dest> never grows beyond <n> characters, including
  the terminating NUL.  A NUL is always written if n > 0.

 *---------------------------------------------------------------------------*/

char *
ink_string_append(char *dest, char *src, int n)
{
  char *d, *s, *last_valid_char;

  ink_assert(src != NULL);
  ink_assert(dest != NULL);
  ink_assert(n >= 0);

  if (n == 0)
    return (dest);

  last_valid_char = dest + n - 1;

  /* Scan For End Of Dest */

  for (d = dest; (d <= last_valid_char) && (*d != '\0'); d++);

  /* If At End Of String, NUL Terminate & Exit */

  if (d > last_valid_char) {
    dest[n - 1] = '\0';
    return (dest);
  }

  /* Append src To String */

  s = src;
  while ((d < last_valid_char) && (*s != '\0'))
    *d++ = *s++;

  /* If At End Of String, NUL Terminate & Exit */

  if (d > last_valid_char)
    dest[n - 1] = '\0';
  else
    *d = '\0';

  return (dest);
}                               /* End ink_string_append */


/*---------------------------------------------------------------------------*

  char *ink_string_duplicate(char *ptr)

  This routine allocates memory for the string <ptr>, and copies the string
  into the new buffer.  The pointer to the new buffer is returned.

 *---------------------------------------------------------------------------*/

char *
ink_string_duplicate(char *ptr)
{
  char *n = NULL;

  if (likely(ptr)) {
    const size_t nSize = strlen(ptr) + 1;
    n = (char *) ink_malloc(nSize);
    ink_strncpy(n, ptr, nSize);
  }
  return (n);
}                               /* End ink_string_duplicate */


/*---------------------------------------------------------------------------*

  char *ink_string_find_dotted_extension(char *str, char *ext, int max_ext_len)

  This routine takes a string <str>, copies the period-separated extension to
  <ext> (up to <max_ext_len - 1> characters) NUL terminates <ext>, and
  returns a pointer into the string <str> where the '.' of the extension
  begins, or NULL if there is no extension.

 *---------------------------------------------------------------------------*/

char *
ink_string_find_dotted_extension(char *str, char *ext, int max_ext_len)
{
  char *p = NULL;

  if (ext) {
    *ext = '\0';
    if (str) {
      for (p = (str + strlen(str)) - 1; p >= str; p--)
        if (*p == '.')
          break;

      if (p <= str)
        return (NULL);

      ink_string_copy(ext, (p + 1), max_ext_len);
    }
  }
  return (p);
}                               /* End ink_string_find_dotted_extension */

/*---------------------------------------------------------------------------*

  char *ink_string_mpath(int nstrings, char *str1, bool free1,
    char *str2, bool free2, ...);

  This routine joins multiple path components together to make
  a new path.  Each component can optionally start with a / in which
  case all the preceeding components are ignored.

  Each component can optionally be free()d.

  Space is malloc()d to hold the resulting path.

 *---------------------------------------------------------------------------*/

char *
ink_string_mpath(int nstrings, ...)
{
  va_list ap;

  char *e[INK_MAX_STRING_ARRAY_SIZE];
  bool f[INK_MAX_STRING_ARRAY_SIZE];
  size_t s[INK_MAX_STRING_ARRAY_SIZE];
  int slash = 0;
  size_t ts = 0;
  char *ns = NULL;
  char *p;
  int i;

  if (likely(nstrings < INK_MAX_STRING_ARRAY_SIZE)) {
    va_start(ap, nstrings);

    for (i = 0; i < nstrings; i++) {
      e[i] = va_arg(ap, char *);
      f[i] = va_arg(ap, int);
    }

    for (i = nstrings - 1; i >= 0; i--) {
      if (!e[i])
        continue;
      s[i] = strlen(e[i]);
      ts += s[i] + 1;
      if (e[i][0] == '/') {
        slash = i;
        break;
      }
    }
    if ((slash == nstrings - 1) && f[slash]) {
      for (i = 0; i < nstrings - 1; i++) {
        if (f[i])
          xfree(e[i]);
      }
      va_end(ap);
      return e[slash];
    } else {
      const size_t nsSize = ts + 1;
      p = (ns = (char *) xmalloc(nsSize));
      ink_assert(ns);
      for (i = slash; i < nstrings - 1; i++) {
        ink_strncpy(p, e[i], (nsSize - (p - ns)));
        p += s[i];
        *p++ = '/';
      }
      ink_strncpy(p, e[nstrings - 1], (nsSize - (p - ns)));
    }
    for (i = 0; i < nstrings; i++) {
      if (f[i])
        xfree(e[i]);
    }
    va_end(ap);
  }
  return ns;
}

/*---------------------------------------------------------------------------*

  char *ink_string_mcopy(char *source);

  This simply makes a copy of a string into freshly malloc()ed space.

 *---------------------------------------------------------------------------*/

char *
ink_string_mcopy(char *source)
{
  char *n = NULL;

  if (likely(source)) {
    const size_t nSize = strlen(source) + 1;
    n = (char *) xmalloc(nSize);
    ink_strncpy(n, source, nSize);
  }
  return n;
}

/*---------------------------------------------------------------------------*

  char *ink_string_mjoin(int nstrings, char *str1, bool free1,
    char *str2, bool free2, ...);

  This routine joins multiple strings components together to make
  a new string.  Each component can optionally be free()d.

  Space is malloc()d to hold the resulting path.

 *---------------------------------------------------------------------------*/

char *
ink_string_mjoin(int nstrings, ...)
{
  va_list ap;

  char *e[INK_MAX_STRING_ARRAY_SIZE];
  bool f[INK_MAX_STRING_ARRAY_SIZE];

  size_t s[INK_MAX_STRING_ARRAY_SIZE];
  int slash = 0;
  size_t ts = 0;
  char *ns = NULL;
  char *p;
  int i;

  if (likely(nstrings < INK_MAX_STRING_ARRAY_SIZE)) {
    va_start(ap, nstrings);

    for (i = 0; i < nstrings; i++) {
      e[i] = va_arg(ap, char *);
      f[i] = va_arg(ap, int);
      if (e[i]) {
        s[i] = strlen(e[i]);
        ts += s[i];
      }
    }
    const size_t nsSize = ts + 1;
    p = (ns = (char *) xmalloc(nsSize));
    for (i = slash; i < nstrings - 1; i++) {
      ink_strncpy(p, e[i], (nsSize - (p - ns)));
      p += s[i];
    }
    ink_strncpy(p, e[nstrings - 1], (nsSize - (p - ns)));
    for (i = 0; i < nstrings; i++) {
      if (f[i])
        xfree(e[i]);
    }
    va_end(ap);
  }
  return ns;
}

#if !TS_HAS_STRNDUP
char *
ink_strndup(const char *str, size_t n)
{
  char *cstr = NULL;

  if (likely(str)) {
    size_t len = strlen(str);
    cstr = (char *)xmalloc(len + 1);
    if (cstr == NULL)
      return (NULL);
    memcpy(cstr, str, len);
    cstr[len] = '\0';
  }
  return (cstr);
}
#endif

#if !TS_HAS_STRLCPY
size_t
ink_strlcpy(char *dst, const char *src, size_t siz)
{
  char *d = dst;
  const char *s = src;
  size_t n = siz;

  /* Copy as many bytes as will fit */
  if (n != 0) {
    while (--n != 0) {
      if ((*d++ = *s++) == '\0')
        break;
    }
  }

  /* Not enough room in dst, add NUL and traverse rest of src */
  if (n == 0) {
    if (siz != 0)
                            *d = '\0';      /* NUL-terminate dst */
    while (*s++)
      ;
  }

  return (s - src - 1);   /* count does not include NUL */
}
#endif

#if !TS_HAS_STRLCAT
size_t
ink_strlcat(char *dst, const char *src, size_t siz)
{
  char *d = dst;
  const char *s = src;
  size_t n = siz;
  size_t dlen;

  /* Find the end of dst and adjust bytes left but don't go past end */
  while (n-- != 0 && *d != '\0')
    d++;
  dlen = d - dst;
  n = siz - dlen;

  if (n == 0)
    return (dlen + strlen(s));
  while (*s != '\0') {
    if (n != 1) {
      *d++ = *s;
      n--;
    }
    s++;
  }
  *d = '\0';

  return (dlen + (s - src));  /* count does not include NUL */
}
#endif

char *
ink_strtok_r(char *s1, const char *s2, char **lasts)
{
  return strtok_r(s1, s2, lasts);
}

// XXX/lomew this might not be portable.  If not check in configure
//   and always squash if no iconv available.
#include <iconv.h>

/*
 * This is a front-end to iconv(3).
 *
 * latin-1 is a subset of utf-8 so the output string len you pass
 * can be the same as the input string len.
 */
void
ink_utf8_to_latin1(const char *in, int inlen, char *out, int *outlen)
{
  size_t inbytesleft, outbytesleft;
  iconv_t ic;

  // XXX/lomew should have a configure test for the first arg
  ic = iconv_open("8859-1", "UTF-8");   // solaris
  if (ic == (iconv_t) - 1) {
    ic = iconv_open("iso-8859-1", "UTF-8");     // linux
    if (ic == (iconv_t) - 1) {
      goto strip;
    }
  }

  inbytesleft = inlen;
  outbytesleft = *outlen;
#if !defined(kfreebsd) && (defined(freebsd) || defined(solaris))
  if (iconv(ic, &in, &inbytesleft, &out, &outbytesleft) == (size_t) - 1)
#else
  if (iconv(ic, (char **) &in, &inbytesleft, &out, &outbytesleft) == (size_t) - 1)
#endif
    {
      iconv_close(ic);
      goto strip;
    }

  *outlen -= outbytesleft;
  iconv_close(ic);
  return;

strip:

  /* Strip out chars with the high bit set.
     This only happens if iconv can't convert. */
  inbytesleft = inlen;
  outbytesleft = *outlen;
  while (inbytesleft && outbytesleft) {
    if (!(*in & 0x80)) {
      *out++ = *in;
      outbytesleft--;
    }
    in++;
    inbytesleft--;
  }
  *outlen -= outbytesleft;
}