/*
 *
  ***** BEGIN LICENSE BLOCK *****
 
  Copyright (C) 2009-2019 Olof Hagsand and Benny Holmgren

  This file is part of CLIXON.

  Licensed 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.

  Alternatively, the contents of this file may be used under the terms of
  the GNU General Public License Version 3 or later (the "GPL"),
  in which case the provisions of the GPL are applicable instead
  of those above. If you wish to allow use of your version of this file only
  under the terms of the GPL, and not to allow others to
  use your version of this file under the terms of Apache License version 2, 
  indicate your decision by deleting the provisions above and replace them with
  the  notice and other provisions required by the GPL. If you do not delete
  the provisions above, a recipient may use your version of this file under
  the terms of any one of the Apache License version 2 or the GPL.

  ***** END LICENSE BLOCK *****

 */
/* Error handling: dont use clicon_err, treat as unix system calls. That is,
   ensure errno is set and return -1/NULL */

#ifdef HAVE_CONFIG_H
#include "clixon_config.h"
#endif

#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <stdlib.h>
#include <errno.h>
#include <regex.h>
#include <ctype.h>

#include <cligen/cligen.h>

/* clicon */
#include "clixon_queue.h"
#include "clixon_string.h"
#include "clixon_err.h"

/*! Split string into a vector based on character delimiters. Using malloc
 *
 * The given string is split into a vector where the delimiter can be
 * _any_ of the characters in the specified delimiter string. 
 *
 * The vector returned is one single memory block that must be freed
 * by the caller
 *
 * @code
 * char **vec = NULL;
 * char  *v;
 * int    nvec;
 * if ((vec = clicon_strsep("/home/user/src/clixon", "/", &nvec)) == NULL)
 *    err;
 * for (i=0; i<nvec; i++){
 *    v = vec[i++]; 
 *    ...
 * }
 * free(vec); 
 * @endcode
 * @param[in]   string     String to be split
 * @param[in]   delim      String of delimiter characters
 * @param[out]  nvec       Number of entries in returned vector
 * @retval      vec        Vector of strings. NULL terminated. Free after use
 * @retval      NULL       Error * 
 */
char **
clicon_strsep(char *string, 
	      char *delim, 
	      int  *nvec0)
{
    char **vec = NULL;
    char  *ptr;
    char  *p;
    int   nvec = 1;
    int   i;
    size_t siz;
    char *s;
    char *d;
    
    if ((s = string)==NULL)
	goto done;
    while (*s){
	if ((d = index(delim, *s)) != NULL)
	    nvec++;
	s++;
    }
    /* alloc vector and append copy of string */
    siz = (nvec+1)* sizeof(char*) + strlen(string)+1;
    if ((vec = (char**)malloc(siz)) == NULL){
	clicon_err(OE_UNIX, errno, "malloc"); 
	goto done;
    } 
    memset(vec, 0, siz);
    ptr = (char*)vec + (nvec+1)* sizeof(char*); /* this is where ptr starts */
    strncpy(ptr, string, strlen(string)+1);
    i = 0;
    while ((p = strsep(&ptr, delim)) != NULL)
	vec[i++] = p;
    *nvec0 = nvec;
 done:
    return vec;
}

/*! Concatenate elements of a string array into a string. 
 * An optional delimiter string can be specified which will be inserted betwen 
 * each element. 
 * @retval  str   Joined string. Free after use.
 * @retval  NULL  Failure
 */
char *
clicon_strjoin(int         argc, 
	       char      **argv, 
	       char       *delim)
{
    int i;
    int len;
    char *str;

    len = 0;
    for (i = 0; i < argc; i++)
	len += strlen(argv[i]);
    if (delim)
	len += (strlen(delim) * argc);
    len += 1; /* '\0' */
    if ((str = malloc(len)) == NULL)
	return NULL;
    memset(str, '\0', len);
    for (i = 0; i < argc; i++) {
	if (i != 0)
	    strncat(str, delim, len - strlen(str));
	strncat(str, argv[i], len - strlen(str));
    }
    return str;
}

static int
uri_unreserved(unsigned char in)
{
    switch(in) {
    case '0': case '1': case '2': case '3': case '4':
    case '5': case '6': case '7': case '8': case '9':
    case 'a': case 'b': case 'c': case 'd': case 'e':
    case 'f': case 'g': case 'h': case 'i': case 'j':
    case 'k': case 'l': case 'm': case 'n': case 'o':
    case 'p': case 'q': case 'r': case 's': case 't':
    case 'u': case 'v': case 'w': case 'x': case 'y': case 'z':
    case 'A': case 'B': case 'C': case 'D': case 'E':
    case 'F': case 'G': case 'H': case 'I': case 'J':
    case 'K': case 'L': case 'M': case 'N': case 'O':
    case 'P': case 'Q': case 'R': case 'S': case 'T':
    case 'U': case 'V': case 'W': case 'X': case 'Y': case 'Z':
    case '-': case '.': case '_': case '~':
	return 1;
    default:
	break;
    }
    return 0;
}

/*! Percent encoding according to RFC 3986 URI Syntax
 * @param[out]  encp   Encoded malloced output string
 * @param[in]   fmt    Not-encoded input string (stdarg format string)
 * @param[in]   ...    stdarg variable parameters
 * @retval      0      OK
 * @retval     -1      Error
 * @code
 *  char *enc;
 *  if (uri_percent_encode(&enc, "formatstr: <>= %s", "substr<>") < 0)
 *    err;
 *  if(enc)
 *    free(enc);
 * @endcode
 * @see RFC 3986 Uniform Resource Identifier (URI): Generic Syntax
 * @see uri_percent_decode
 * @see xml_chardata_encode
 */
int
uri_percent_encode(char **encp, 
		   char  *fmt, ...)
{
    int     retval = -1;
    char   *str = NULL;  /* Expanded format string w stdarg */
    char   *enc = NULL;
    int     fmtlen;
    int     len;
    int     i, j;
    va_list args;

    /* Two steps: (1) read in the complete format string */
    va_start(args, fmt); /* dryrun */
    fmtlen = vsnprintf(NULL, 0, fmt, args) + 1;
    va_end(args);
    if ((str = malloc(fmtlen)) == NULL){
	clicon_err(OE_UNIX, errno, "malloc");
	goto done;
    }
    memset(str, 0, fmtlen);
    va_start(args, fmt); /* real */
    fmtlen = vsnprintf(str, fmtlen, fmt, args) + 1;
    va_end(args);
    /* Now str is the combined fmt + ... */

    /* Step (2) encode and expand str --> enc */
    /* This is max */
    len = strlen(str)*3+1;
    if ((enc = malloc(len)) == NULL){
	clicon_err(OE_UNIX, errno, "malloc"); 
	goto done;
    }
    memset(enc, 0, len);
    j = 0;
    for (i=0; i<strlen(str); i++){
	if (uri_unreserved(str[i]))
	    enc[j++] = str[i];
	else{
	    snprintf(&enc[j], 4, "%%%02X", str[i]&0xff);
	    j += 3;
	}
    }
    *encp = enc;
    retval = 0;
 done:
    if (str)
	free(str);
    if (retval < 0 && enc)
	free(enc);
    return retval;
}

/*! Percent decoding according to RFC 3986 URI Syntax
 * @param[in]   enc    Encoded input string     
 * @param[out]  strp   Decoded malloced output string. Deallocate with free()
 * @retval      0      OK
 * @retval     -1      Error
 * @see RFC 3986 Uniform Resource Identifier (URI): Generic Syntax
 * @see uri_percent_encode
 */
int
uri_percent_decode(char  *enc, 
		   char **strp)
{
    int   retval = -1;
    char *str = NULL;
    int   i, j;
    char  hstr[3];
    int   len;
    char *ptr;
    
    /* This is max */
    len = strlen(enc)+1;
    if ((str = malloc(len)) == NULL){
	clicon_err(OE_UNIX, errno, "malloc"); 
	goto done;
    }
    memset(str, 0, len);
    j = 0;
    for (i=0; i<strlen(enc); i++){
	if (enc[i] == '%' && strlen(enc)-i > 2 && 
	    isxdigit(enc[i+1]) && isxdigit(enc[i+2])){
	    hstr[0] = enc[i+1];
	    hstr[1] = enc[i+2];
	    hstr[2] = 0;
	    str[j] = strtoul(hstr, &ptr, 16);
	    i += 2;
	}
	else
	    str[j] = enc[i];
	j++;
    }
    str[j++] = '\0';
    *strp = str;
    retval = 0;
 done:
    if (retval < 0 && str)
	free(str);
    return retval;
}

/*! Escape characters according to XML definition
 * @param[out]  encp   Encoded malloced output string
 * @param[in]   fmt    Not-encoded input string (stdarg format string)
 * @param[in]   ...    stdarg variable parameters
 * @retval      0      OK
 * @retval     -1      Error
 * @see https://www.w3.org/TR/2008/REC-xml-20081126/#syntax chapter 2.6
 * @see uri_percent_encode
 * @see AMPERSAND mode in clixon_xml_parse.l
 * @code
 *   char *encstr = NULL;
 *   if (xml_chardata_encode(&encstr, "fmtstr<>& %s", "substr<>") < 0)
 *      err;
 *   if (encstr)
 *      free(encstr);
 * @endcode
 * Essentially encode as follows:
 *     & -> "&amp; "   must
 *     < -> "&lt; "    must
 *     > -> "&gt; "    must for backward compatibility
 *     ' -> "&apos; "  may
 *     ' -> "&quot; "  may
 * Optionally >
 */
int
xml_chardata_encode(char **escp,
		    char  *fmt,...)
{
    int     retval = -1;
    char   *str = NULL;  /* Expanded format string w stdarg */
    int     fmtlen;
    char   *esc = NULL;
    int     l;
    int     len;
    int     i, j;
    int     cdata; /* when set, skip encoding */
    va_list args;
    
    /* Two steps: (1) read in the complete format string */
    va_start(args, fmt); /* dryrun */
    fmtlen = vsnprintf(NULL, 0, fmt, args) + 1;
    va_end(args);
    if ((str = malloc(fmtlen)) == NULL){
	clicon_err(OE_UNIX, errno, "malloc");
	goto done;
    }
    memset(str, 0, fmtlen);
    va_start(args, fmt); /* real */
    fmtlen = vsnprintf(str, fmtlen, fmt, args) + 1;
    va_end(args);
    /* Now str is the combined fmt + ... */

    /* Step (2) encode and expand str --> enc */
    /* First compute length (do nothing) */
    len = 0; cdata = 0;
    for (i=0; i<strlen(str); i++){
	if (cdata){
	    if (strncmp(&str[i], "]]>", strlen("]]>")) == 0)
		cdata = 0;
	    len++;
	}
	else
	    switch (str[i]){
	    case '&':
		len += strlen("&amp;");
		break;
	    case '<':
		if (strncmp(&str[i], "<![CDATA[", strlen("<![CDATA[")) == 0){
		    len++;
		    cdata++;
		}
		else
		    len += strlen("&lt;");
		break;
	    case '>':
		len += strlen("&gt;");
		break;
	    default:
		len++;
	    }
    }
    len++; /* trailing \0 */
    /* We know length, allocate encoding buffer  */
    if ((esc = malloc(len)) == NULL){
	clicon_err(OE_UNIX, errno, "malloc"); 
	goto done;
    }
    memset(esc, 0, len);

    /* Same code again, but now actually encode into output buffer */
    j = 0; cdata = 0;
    for (i=0; i<strlen(str); i++){
	if (cdata){
	    if (strncmp(&str[i], "]]>", strlen("]]>")) == 0){
		cdata = 0;
		esc[j++] = str[i++];
		esc[j++] = str[i++];
	    }
	    esc[j++] = str[i];
	}
	else
	switch (str[i]){
	case '&':
	    if ((l=snprintf(&esc[j], 6, "&amp;")) < 0){
		clicon_err(OE_UNIX, errno, "snprintf");
		goto done;
	    }
	    j += l;
	    break;
	case '<':
	    if (strncmp(&str[i], "<![CDATA[", strlen("<![CDATA[")) == 0){
		esc[j++] = str[i];
		cdata++;
		break;
	    }
	    if ((l=snprintf(&esc[j], 5, "&lt;")) < 0){
		clicon_err(OE_UNIX, errno, "snprintf");
		goto done;
	    }
	    j += l;
	    break;
	case '>':
	    if ((l=snprintf(&esc[j], 5, "&gt;")) < 0){
		clicon_err(OE_UNIX, errno, "snprintf");
		goto done;
	    }
	    j += l;
	    break;
	default:
	    esc[j++] = str[i];
	}
    }
    *escp = esc;
    retval = 0;
 done:
    if (str)
	free(str);
    if (retval < 0 && esc)
	free(esc);
    return retval;
}

/*! Split a string into a cligen variable vector using 1st and 2nd delimiter 
 * Split a string first into elements delimited by delim1, then into
 * pairs delimited by delim2.
 * @param[in]  string String to split
 * @param[in]  delim1 First delimiter char that delimits between elements
 * @param[in]  delim2 Second delimiter char for pairs within an element
 * @param[out] cvp    Created cligen variable vector, deallocate w cvec_free
 * @retval     0      OK
 * @retval    -1      error
 * @code
 * cvec  *cvv = NULL;
 * if (str2cvec("a=b&c=d", ';', '=', &cvv) < 0)
 *   err;
 * @endcode
 *
 * a=b&c=d    ->  [[a,"b"][c="d"]
 * kalle&c=d  ->  [[c="d"]]  # Discard elements with no delim2
 * XXX differentiate between error and null cvec.
 */
int
str2cvec(char  *string, 
	 char   delim1, 
	 char   delim2, 
	 cvec **cvp)
{
    int     retval = -1;
    char   *s;
    char   *s0 = NULL;;
    char   *val;     /* value */
    char   *valu;    /* unescaped value */
    char   *snext; /* next element in string */
    cvec   *cvv = NULL;
    cg_var *cv;

    if ((s0 = strdup(string)) == NULL){
	clicon_err(OE_UNIX, errno, "strdup");
	goto err;
    }
    s = s0;
    if ((cvv = cvec_new(0)) ==NULL){
	clicon_err(OE_UNIX, errno, "cvec_new");
	goto err;
    }
    while (s != NULL) {
	/*
	 * In the pointer algorithm below:
	 * name1=val1;  name2=val2;
	 * ^     ^      ^
	 * |     |      |
	 * s     val    snext
	 */
	if ((snext = index(s, delim1)) != NULL)
	    *(snext++) = '\0';
	if ((val = index(s, delim2)) != NULL){
	    *(val++) = '\0';
	    if (uri_percent_decode(val, &valu) < 0)
		goto err;
	    if ((cv = cvec_add(cvv, CGV_STRING)) == NULL){
		clicon_err(OE_UNIX, errno, "cvec_add");
		goto err;
	    }
	    while ((strlen(s) > 0) && isblank(*s))
		s++;
	    cv_name_set(cv, s);
	    cv_string_set(cv, valu);
	    free(valu); valu = NULL;
	}
	else{
	    if (strlen(s)){
		if ((cv = cvec_add(cvv, CGV_STRING)) == NULL){
		    clicon_err(OE_UNIX, errno, "cvec_add");
		    goto err;
		}
		cv_name_set(cv, s);
		cv_string_set(cv, "");
	    }
	}
	s = snext;
    }
    retval = 0;
 done:
    *cvp = cvv;
    if (s0)
	free(s0);
    return retval;
 err:
    if (cvv){
	cvec_free(cvv);
	cvv = NULL;
    }
    goto done;
}

/*! Map from int to string using str2int map
 * @param[in] ms   String, integer map
 * @param[in] i    Input integer
 * @retval    str  String value
 * @retval    NULL Error, not found
 * @note linear search
 */
const char *
clicon_int2str(const map_str2int *mstab, 
	       int                i)
{
    const struct map_str2int *ms;

    for (ms = &mstab[0]; ms->ms_str; ms++)
	if (ms->ms_int == i)
	    return ms->ms_str;
    return NULL;
}

/*! Map from string to int using str2int map
 * @param[in] ms   String, integer map
 * @param[in] str  Input string
 * @retval    int  Value
 * @retval   -1    Error, not found
 * @note linear search
 */
int
clicon_str2int(const map_str2int *mstab, 
	       char              *str)
{
    const struct map_str2int *ms;

    for (ms = &mstab[0]; ms->ms_str; ms++)
	if (strcmp(ms->ms_str, str) == 0)
	    return ms->ms_int;
    return -1;
}

/*! Split colon-separated node identifier into prefix and name
 * @param[in]  node-id
 * @param[out] prefix  Malloced string. May be NULL.
 * @param[out] id      Malloced identifier.
 * @retval     0       OK
 * @retval    -1       Error
 * @code
 *    char      *prefix = NULL;
 *    char      *id = NULL;
 *    if (nodeid_split(nodeid, &prefix, &id) < 0)
 *	 goto done;
 *    if (prefix)
 *	 free(prefix);
 *    if (id)
 *	 free(id);
 * @note caller need to free id and prefix after use
 */
int
nodeid_split(char  *nodeid,
	     char **prefix,
	     char **id)
{
    int   retval = -1;
    char *str;
    
    if ((str = strchr(nodeid, ':')) == NULL){
	if ((*id = strdup(nodeid)) == NULL){
	    clicon_err(OE_YANG, errno, "strdup");
	    goto done;
	}
    }
    else{
	if ((*prefix = strdup(nodeid)) == NULL){
	    clicon_err(OE_YANG, errno, "strdup");
	    goto done;
	}
	(*prefix)[str-nodeid] = '\0';
	str++;
	if ((*id = strdup(str)) == NULL){
	    clicon_err(OE_YANG, errno, "strdup");
	    goto done;
	}
    }
    retval = 0;
 done:
    return retval;
}

/*! Trim blanks from front and end of a string, return new string 
 * @param[in]  str 
 * @retval     s   Pointer into existing str after trimming blanks
 */
char *
clixon_trim(char *str)
{
    char *s = str;
    int   i;

    while (strlen(s) && isblank(s[0])) /* trim from front */
	s++;
    for (i=strlen(s)-1; i>=0; i--){ /* trim from rear */
	if (isblank(s[i]))
	    s[i] = '\0';
	else
	    break;
    }
    return s;
}

/*! Transform from XSD regex to posix ERE
 * The usecase is that Yang (RFC7950) supports XSD regular expressions but
 * CLIgen supports POSIX ERE
 * POSIX ERE regexps according to man regex(3).
 * @param[in]  xsd    Input regex string according XSD
 * @param[out] posix  Output (malloced) string according to POSIX ERE
 * @see https://www.w3.org/TR/2004/REC-xmlschema-2-20041028/#regexs
 * @see https://www.regular-expressions.info/posixbrackets.html#class translation
 * @see https://www.regular-expressions.info/xml.html
 * Translation is not complete but covers some character sequences:
 * \d decimal digit
 * \w all characters except the set of "punctuation", "separator" and 
 *    "other" characters: #x0000-#x10FFFF]-[\p{P}\p{Z}\p{C}]
 * \i letters + underscore and colon
 * \c XML Namechar, see: https://www.w3.org/TR/2008/REC-xml-20081126/#NT-NameChar
 */
int
regexp_xsd2posix(char  *xsd,
		 char **posix)
{
    int   retval = -1;
    cbuf *cb = NULL;
    char  x;
    int   i;
    int   esc;
    int   minus = 0;

    if ((cb = cbuf_new()) == NULL){
	clicon_err(OE_UNIX, errno, "cbuf_new");
	goto done;
    }
    esc=0;
    for (i=0; i<strlen(xsd); i++){
	x = xsd[i];
	if (esc){
	    esc = 0;
	    switch (x){
	    case '-': /* \- is translated to -], ie must be last in bracket */
		minus++;
		break;
	    case 'c': /* xml namechar */
		cprintf(cb, "[0-9a-zA-Z._:-]"); /* also interpunct */
		break;
	    case 'd':
		cprintf(cb, "[0-9]");
		break;
	    case 'i': /* initial */
		cprintf(cb, "[a-zA-Z_:]");
		break;
	    case 'w': /* word */
		//cprintf(cb, "[0-9a-zA-Z_\\\\-]")
		cprintf(cb, "[^[:punct:][:space:][:cntrl:]]"); 
		break;
	    case 'W': /* inverse of \w */
		cprintf(cb, "[[:punct:][:space:][:cntrl:]]"); 
		break;
	    case 's':
		cprintf(cb, "[ \t\r\n]");
		break;
	    case 'S':
		cprintf(cb, "[^ \t\r\n]");
		break;
	    default:
		cprintf(cb, "\\%c", x);
		break;
	    }
	}
	else if (x == '\\')
	    esc++;
	else if (x == ']' && minus){
	    cprintf(cb, "-]");
	    minus = 0;
	}
	else
	    cprintf(cb, "%c", x);
    }
    if ((*posix = strdup(cbuf_get(cb))) == NULL){
	clicon_err(OE_UNIX, errno, "strdup");
	goto done;
    }
    retval = 0;
 done:
    if (cb)
	cbuf_free(cb);
    return retval;
}

/*! strndup() for systems without it, such as xBSD
 */
#ifndef HAVE_STRNDUP
char *
clicon_strndup(const char *str, 
	       size_t      len)
{
  char *new;
  size_t slen;

  slen  = strlen(str);
  len = (len < slen ? len : slen);

  new = malloc(len + 1);
  if (new == NULL)
    return NULL;

  new[len] = '\0';
  memcpy(new, str, len);

  return new;
}
#endif /* ! HAVE_STRNDUP */



/*
 * Turn this on for uni-test programs
 * Usage: clixon_string join
 * Example compile:
 gcc -g -o clixon_string -I. -I../clixon ./clixon_string.c -lclixon -lcligen
 * Example run:
*/
#if 0 /* Test program */

static int
usage(char *argv0)
{
    fprintf(stderr, "usage:%s <string>\n", argv0);
    exit(0);
}

int
main(int argc, char **argv)
{
    int nvec;
    char **vec;
    char *str0;
    char *str1;
    int   i;

    if (argc != 2){
	usage(argv[0]);
	return 0;
    }
    str0 = argv[1];
    if ((vec = clicon_strsep(str0, " \t", &nvec)) == NULL)
	return -1;
    fprintf(stderr, "nvec: %d\n", nvec);
    for (i=0; i<nvec+1; i++)
	fprintf(stderr, "vec[%d]: %s\n", i, vec[i]);
    if ((str1 = clicon_strjoin(nvec, vec, " ")) == NULL)
	return -1;
    fprintf(stderr, "join: %s\n", str1);
    free(vec);
    free(str1);
    return 0;
}

#endif /* Test program */