/*
 *
  ***** BEGIN LICENSE BLOCK *****
 
  Copyright (C) 2009-2017 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 *****

 *
 * XML code
 *
 *                        file          
 *                       +---------+    db2xml_key->       save_db_to_xml->
 *       +-------------> | database| <------------+------------------+
 *       |               +---------+  <-xml2db    | <-load_xml_to_db |
 *       |                                        |                  |
 *       |                                        |                  |
 *       v                                        v                  v
 *   +---------+     <-xml2cvec_key       +-----------+           +---------+
 *   |  cvec   |  <---------------------> | xml cxobj |<--------->| xmlfile |
 *   +---------+   cvec2xml->             +-----------+           +---------+
 *                 cvec2xml_1(yang)->  xml2json->|
 *                                     xml2txt-> |
 *                                     xml2cli-> v
 *                                        +---------+
 *                                        |  file   |
 *                                        +---------+
 */
#ifdef HAVE_CONFIG_H
#include "clixon_config.h" /* generated by config & autoconf */
#endif

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <ctype.h>
#include <string.h>
#include <arpa/inet.h>
#include <assert.h>
#include <syslog.h>
#include <fcntl.h>
#include <netinet/in.h>

/* cligen */
#include <cligen/cligen.h>

/* clicon */

#include "clixon_string.h"
#include "clixon_queue.h"
#include "clixon_hash.h"
#include "clixon_handle.h"
#include "clixon_string.h"
#include "clixon_yang.h"
#include "clixon_yang_type.h"
#include "clixon_plugin.h"
#include "clixon_options.h"
#include "clixon_xml.h"
#include "clixon_xsl.h"
#include "clixon_log.h"
#include "clixon_err.h"
#include "clixon_xml_map.h"

/* Something to do with reverse engineering of junos syntax? */
#undef SPECIAL_TREATMENT_OF_NAME  

/*
 * A node is a leaf if it contains a body.
 */
static cxobj *
leaf(cxobj *xn)
{
    cxobj *xc = NULL;

    while ((xc = xml_child_each(xn, xc, CX_BODY)) != NULL)
	break;
    return xc;
}

/*! x is element and has eactly one child which in turn has none */
static int
tleaf(cxobj *x)
{
    cxobj *c;

    if (xml_type(x) != CX_ELMNT)
	return 0;
    if (xml_child_nr(x) != 1)
	return 0;
    c = xml_child_i(x, 0);
    return (xml_child_nr(c) == 0);
}

/*! Translate XML -> TEXT
 * @param[in]  level  print 4 spaces per level in front of each line
 */
int 
xml2txt(FILE  *f, 
	cxobj *x, 
	int    level)
{
    cxobj *xe = NULL;
    int    children=0;
    char  *term = NULL;
    int    retval = -1;
    int    encr=0;
#ifdef SPECIAL_TREATMENT_OF_NAME  
    cxobj *xname;
#endif

    xe = NULL;     /* count children */
    while ((xe = xml_child_each(x, xe, -1)) != NULL)
	children++;
    if (!children){ 
	if (xml_type(x) == CX_BODY){
	    /* Kludge for escaping encrypted passwords */
	    if (strcmp(xml_name(xml_parent(x)), "encrypted-password")==0)
		encr++;
	    term = xml_value(x);
	}
	else{
	    fprintf(f, "%*s", 4*level, "");
	    term = xml_name(x);
	}
	if (encr)
	    fprintf(f, "\"%s\";\n", term);
	else
	    fprintf(f, "%s;\n", term);
	retval = 0;
	goto done;
    }
    fprintf(f, "%*s", 4*level, "");

#ifdef SPECIAL_TREATMENT_OF_NAME  
    if (strcmp(xml_name(x), "name") != 0)
	fprintf(f, "%s ", xml_name(x));
    if ((xname = xml_find(x, "name")) != NULL){
	if (children > 1)
	    fprintf(f, "%s ", xml_body(xname));
	if (!tleaf(x))
	    fprintf(f, "{\n");
    }
    else
	if (!tleaf(x))
	    fprintf(f, "{\n");
#else
	fprintf(f, "%s ", xml_name(x));
	if (!tleaf(x))
	    fprintf(f, "{\n");
#endif /* SPECIAL_TREATMENT_OF_NAME */

    xe = NULL;
    while ((xe = xml_child_each(x, xe, -1)) != NULL){
#ifdef SPECIAL_TREATMENT_OF_NAME  
	if (xml_type(xe) == CX_ELMNT &&  (strcmp(xml_name(xe), "name")==0) && 
	    (children > 1)) /* skip if this is a name element (unless 0 children) */
	    continue;
#endif
	if (xml2txt(f, xe, level+1) < 0)
	    break;
    }
    if (!tleaf(x))
	fprintf(f, "%*s}\n", 4*level, "");
    retval = 0;
  done:
    return retval;
}

/*! Translate from XML to CLI commands
 * Howto: join strings and pass them down. 
 * Identify unique/index keywords for correct set syntax.
 * Args:
 *  @param[in] f        Where to print cli commands
 *  @param[in] x        XML Parse-tree (to translate)
 *  @param[in] prepend0 Print this text in front of all commands.
 *  @param[in] gt       option to steer cli syntax
 */
int 
xml2cli(FILE              *f, 
	cxobj             *x, 
	char              *prepend0, 
	enum genmodel_type gt)
{
    int              retval = -1;
    cxobj           *xe = NULL;
    char            *term;
    int              bool;
    int              nr;
    int              i;
    cbuf            *cbpre;

    /* Create prepend variable string */
    if ((cbpre = cbuf_new()) == NULL){
	clicon_err(OE_PLUGIN, errno, "cbuf_new");	
	goto done;
    }
    nr = xml_child_nr(x);
    if (!nr){
	if (xml_type(x) == CX_BODY)
	    term = xml_value(x);
	else
	    term = xml_name(x);
	if (prepend0)
	    fprintf(f, "%s ", prepend0);
	fprintf(f, "%s\n", term);
	retval = 0;
	goto done;
    }
    if (prepend0)
	cprintf(cbpre, "%s", prepend0);
/* bool determines when to print a variable keyword:
   !leaf           T for all (ie parameter)
   index GT_NONE   F
   index GT_VARS   F
   index GT_ALL    T
   !index GT_NONE  F
   !index GT_VARS  T
   !index GT_ALL   T
 */
    bool = !leaf(x) || gt == GT_ALL || (gt == GT_VARS);
//    bool = (!x->xn_index || gt == GT_ALL);
    if (bool){
	if (cbuf_len(cbpre))
	    cprintf(cbpre, " ");
	cprintf(cbpre, "%s", xml_name(x));
    }
    xe = NULL;
    /* First child is unique, then add that, before looping. */
    i = 0;
    while ((xe = xml_child_each(x, xe, -1)) != NULL){
	/* Dont call this if it is index and there are other following */
	if (0 && i < nr-1) 
	    ;
	else
	    if (xml2cli(f, xe, cbuf_get(cbpre), gt) < 0)
		goto done;
	if (0){ /* assume index is first, otherwise need one more while */
	    if (gt == GT_ALL)
		cprintf(cbpre, " %s", xml_name(xe));
	    cprintf(cbpre, " %s", xml_value(xml_child_i(xe, 0)));
	}
	i++;
    }
    retval = 0;
  done:
    if (cbpre)
	cbuf_free(cbpre);
    return retval;
}

/*! Validate an xml node of type leafref, ensure the value is one of that path's reference
 * @param[in]  xt    XML leaf node of type leafref
 * @param[in]  ytype Yang type statement belonging to the XML node
 */
static int
validate_leafref(cxobj     *xt,
		 yang_stmt *ytype)
{
    int          retval = -1;
    yang_stmt   *ypath;
    cxobj      **xvec = NULL;
    cxobj       *x;
    int          i;
    size_t       xlen = 0;
    char        *leafrefbody;
    char        *leafbody;


    if ((leafrefbody = xml_body(xt)) == NULL)
	return 0;
    if ((ypath = yang_find((yang_node*)ytype, Y_PATH, NULL)) == NULL){
	clicon_err(OE_DB, 0, "Leafref %s requires path statement", ytype->ys_argument);
	goto done;
    }
    if (xpath_vec(xt, ypath->ys_argument, &xvec, &xlen) < 0) 
	goto done;
    for (i = 0; i < xlen; i++) {
	x = xvec[i];
	if ((leafbody = xml_body(x)) == NULL)
	    continue;
	if (strcmp(leafbody, leafrefbody) == 0)
	    break;
    }
    if (i==xlen){
	clicon_err(OE_DB, 0, "Leafref validation failed, no such leaf: %s",
		   leafrefbody);
	goto done;
    }
    retval = 0;
 done:
    if (xvec)
	free(xvec);
    return retval;
}

/*! Validate a single XML node with yang specification for added entry
 * 1. Check if mandatory leafs present as subs.
 * 2. Check leaf values, eg int ranges and string regexps.
 * @param[in]  xt  XML node to be validated
 * @retval     0   Valid OK
 * @retval    -1   Validation failed
 * @see xml_yang_validate_all
 */
int
xml_yang_validate_add(cxobj   *xt, 
		      void    *arg)
{
    int        retval = -1;
    cg_var    *cv = NULL;
    char      *reason = NULL;
    yang_stmt *yc;
    int        i;
    yang_stmt *ys;
    char      *body;
    
    /* if not given by argument (overide) use default link */
    if ((ys = xml_spec(xt)) != NULL){
	switch (ys->ys_keyword){
	case Y_LIST:
	    /* fall thru */
	case Y_CONTAINER:
	    for (i=0; i<ys->ys_len; i++){
		yc = ys->ys_stmt[i];
		if (yc->ys_keyword != Y_LEAF)
		    continue;
		if (yang_mandatory(yc) && xml_find(xt, yc->ys_argument)==NULL){
		    clicon_err(OE_CFG, 0,"Missing mandatory variable: %s",
			       yc->ys_argument);
		    goto done;
		}
	    }
	    break;
	case Y_LEAF:
	    /* fall thru */
	case Y_LEAF_LIST:
	    /* validate value against ranges, etc */
	    if ((cv = cv_dup(ys->ys_cv)) == NULL){
		clicon_err(OE_UNIX, errno, "cv_dup");
		goto done;
	    }
	    /* In the union case, value is parsed as generic REST type,
	     * needs to be reparsed when concrete type is selected
	     */
	    if ((body = xml_body(xt)) != NULL){
		if (cv_parse(body, cv) <0){
		    clicon_err(OE_UNIX, errno, "cv_parse");
		    goto done;
		}
		if ((ys_cv_validate(cv, ys, &reason)) != 1){
		    clicon_err(OE_DB, 0,
			       "validation of %s failed %s",
			       ys->ys_argument, reason?reason:"");
		    if (reason)
			free(reason);
		    goto done;
		}
	    }
	    break;
	default:
	    break;
	}
    }
    retval = 0;
 done:
    if (cv)
	cv_free(cv);
    return retval;
}

/*! Validate a single XML node with yang specification for all (not only added) entries
 * 1. Check leafrefs. Eg you delete a leaf and a leafref references it.
 * @param[in]  xt  XML node to be validated
 * @retval     0   Valid OK
 * @retval    -1   Validation failed
 * @see xml_yang_validate_add
 */
int
xml_yang_validate_all(cxobj   *xt, 
		      void    *arg)
{
    int        retval = -1;
    yang_stmt *ys;
    yang_stmt *ytype;
    
    /* if not given by argument (overide) use default link */
    if ((ys = xml_spec(xt)) != NULL){
	switch (ys->ys_keyword){
	case Y_LEAF:
	    /* fall thru */
	case Y_LEAF_LIST:
	    /* Special case if leaf is leafref, then first check against
	       current xml tree
	    */
	    if ((ytype = yang_find((yang_node*)ys, Y_TYPE, NULL)) != NULL &&
		strcmp(ytype->ys_argument, "leafref") == 0)
		if (validate_leafref(xt, ytype) < 0)
		    goto done;
	    break;
	default:
	    break;
	}
    }
    retval = 0;
 done:
    return retval;
}

/*! Translate a single xml node to a cligen variable vector. Note not recursive 
 * @param[in]  xt   XML tree containing one top node
 * @param[in]  ys   Yang spec containing type specification of top-node of xt
 * @param[out] cvv  CLIgen variable vector. Should be freed by cvec_free()
 * @retval     0    Everything OK, cvv allocated and set
 * @retval    -1    Something wrong, clicon_err() called to set error. No cvv returned
 * 'Not recursive' means that only one level of XML bodies is translated to cvec:s.
 * yang is needed to know which type an xml element has.
 * Example: 
    <a>
      <b>23</b>
      <c>88</c>
      <d>      
        <e>99</e>
      </d>
    </a> 
         --> b:23, c:88
 * @see cvec2xml
 */
int
xml2cvec(cxobj      *xt, 
	 yang_stmt  *yt, 
	 cvec      **cvv0)
{
    int               retval = -1;
    cvec             *cvv = NULL;
    cxobj            *xc;         /* xml iteration variable */
    yang_stmt        *ys;         /* yang spec */
    cg_var           *cv;
    cg_var           *ycv;
    char             *body;
    char             *reason = NULL;
    int               ret;
    int               i = 0;
    int               len = 0;
    char             *name;

    xc = NULL;
    while ((xc = xml_child_each(xt, xc, CX_ELMNT)) != NULL)
	len++;
    if ((cvv = cvec_new(len)) == NULL){
	clicon_err(OE_UNIX, errno, "cvec_new");
	goto err;
    }
    xc = NULL;
    /* Go through all children of the xml tree */
    while ((xc = xml_child_each(xt, xc, CX_ELMNT)) != NULL){
	name = xml_name(xc);
	if ((ys = yang_find_datanode((yang_node*)yt, name)) == NULL){
	    clicon_debug(0, "%s: yang sanity problem: %s in xml but not present in yang under %s",
			 __FUNCTION__, name, yt->ys_argument);
	    if ((body = xml_body(xc)) != NULL){
		cv = cvec_i(cvv, i++);
		cv_type_set(cv, CGV_STRING);
		cv_name_set(cv, name);
		if ((ret = cv_parse1(body, cv, &reason)) < 0){
		    clicon_err(OE_PLUGIN, errno, "cv_parse");
		    goto err;
		}
		if (ret == 0){
		    clicon_err(OE_PLUGIN, errno, "cv_parse: %s", reason);
		    if (reason)
			free(reason);
		    goto err;
		}
	    }
	}
	else
	if ((ycv = ys->ys_cv) != NULL){
	    if ((body = xml_body(xc)) != NULL){
		/* XXX: cvec_add uses realloc, can we avoid that? */
		cv = cvec_i(cvv, i++);
		if (cv_cp(cv, ycv) < 0){
		    clicon_err(OE_PLUGIN, errno, "cv_cp");
		    goto err;
		}
		if ((ret = cv_parse1(body, cv, &reason)) < 0){
		    clicon_err(OE_PLUGIN, errno, "cv_parse");
		    goto err;
		}
		if (ret == 0){
		    clicon_err(OE_PLUGIN, errno, "cv_parse: %s", reason);
		    if (reason)
			free(reason);
		    goto err;
		}
	    }
	}
    }
    if (debug > 1){
	clicon_debug(2, "%s cvv:\n", __FUNCTION__);
	cvec_print(stderr, cvv);
    }
    *cvv0 = cvv;
    return 0;
 err:
    if (cvv)
	cvec_free(cvv);
    return retval;
}

/*! Translate a cligen variable vector to an XML tree with depth one 
 * @param[in]   cvv  CLIgen variable vector. Should be freed by cvec_free()
 * @param[in]   toptag    The XML tree in xt will have this XML tag
 * @param[in]   xt   Parent, or NULL
 * @param[out]  xt   Pointer to XML tree containing one top node. Should be freed with xml_free
 * @retval      0    Everything OK, cvv allocated and set
 * @retval     -1    Something wrong, clicon_err() called to set error. No xt returned
 * @see xml2cvec
 * @see cvec2xml   This does more but has an internal xml2cvec translation
*/
int
cvec2xml_1(cvec   *cvv, 
	   char   *toptag, 
	   cxobj  *xp,
	   cxobj **xt0)
{
    int               retval = -1;
    cxobj            *xt = NULL;
    cxobj            *xn;
    cxobj            *xb;
    cg_var           *cv;
    char             *val;
    int               len=0;
    int               i;

    cv = NULL;
    while ((cv = cvec_each(cvv, cv)) != NULL) 
	len++;
    if ((xt = xml_new(toptag, xp)) == NULL)
	goto err;
    if (xml_childvec_set(xt, len) < 0)
	goto err;
    cv = NULL;
    i = 0;
    while ((cv = cvec_each(cvv, cv)) != NULL) {
	if ((xn = xml_new(cv_name_get(cv), NULL)) == NULL) /* this leaks */
	    goto err;
	xml_parent_set(xn, xt);
	xml_child_i_set(xt, i++, xn);
	if ((xb = xml_new("body", xn)) == NULL) /* this leaks */
	    goto err;
	xml_type_set(xb, CX_BODY);
	val = cv2str_dup(cv);
	xml_value_set(xb, val); /* this leaks */
	if (val)
	    free(val);
    }
    *xt0 = xt;
    return 0;
 err:
    if (xt)
	xml_free(xt);
    return retval;
}

/*! Given child tree x1c, find matching child in base tree x0
 * param[in]  x0   Base tree node
 * param[in]  x1c  Modification tree child
 * param[in]  yc   Yang spec of tree child
 * param[out] x0cp Matching base tree child (if any)
 * @note XXX: room for optimization? on 1K calls we have 1M body calls and
	   500K xml_child_each/cvec_each calls. 
	   The outer loop is large for large lists
	   The inner loop is small
	   Major time in xml_find_body()
	   Can one do a binary search in the x0 list?
*/
int
match_base_child(cxobj     *x0, 
		 cxobj     *x1c,
		 cxobj    **x0cp,
		 yang_stmt *yc)
{
    int        retval = -1;
    char      *x1cname;
    cxobj     *x0c = NULL; /* x0 child */
    cvec      *cvk = NULL; /* vector of index keys */
    cg_var    *cvi;
    char      *b0;
    char      *b1;
    yang_stmt *ykey;
    char      *keyname;
    int        equal;
    char     **b1vec = NULL;
    int        i;
#if (XML_CHILD_HASH==1)
    cxobj **p;
    cbuf   *key = NULL; /* cligen buffer hash key */
    size_t  vlen;

    *x0cp = NULL; /* return value */	    
    if (xml_hash(x0) == NULL)
	goto nohash;
    if ((key = cbuf_new()) == NULL){
	clicon_err(OE_XML, errno, "cbuf_new");
	goto done1;
    }
    if (xml_hash_key(x1c, yc, key) < 0)
	goto done;
    x0c = NULL;
    if (cbuf_len(key))
	if ((p = hash_value(xml_hash(x0), cbuf_get(key), &vlen)) != NULL){
	    assert(vlen == sizeof(x0c));
	    x0c = *p;
	}
    //    fprintf(stderr, "%s get %s = 0x%x\n", __FUNCTION__, cbuf_get(key), (unsigned int)x0c);
    *x0cp = x0c;
    retval = 0;
 done1:
    if (key)
	cbuf_free(key);
    return retval;
 nohash:
#endif /* XML_CHILD_HASH */
    *x0cp = NULL; /* return value */	    
    x1cname = xml_name(x1c);
    switch (yc->ys_keyword){
    case Y_CONTAINER: 	/* Equal regardless */
    case Y_LEAF: 	/* Equal regardless */
	x0c = xml_find(x0, x1cname);
	break;
    case Y_LEAF_LIST: /* Match with name and value */
	if ((b1 = xml_body(x1c)) == NULL)
	    goto ok;
	x0c = xml_find_body_obj(x0, x1cname, b1);
	break;
    case Y_LIST: /* Match with key values */
	if ((ykey = yang_find((yang_node*)yc, Y_KEY, NULL)) == NULL){
	    clicon_err(OE_XML, errno, "%s: List statement \"%s\" has no key", 
		       __FUNCTION__, yc->ys_argument);
	    goto done;
	}
	/* The value is a list of keys: <key>[ <key>]*  */
	if ((cvk = yang_arg2cvec(ykey, " ")) == NULL)
	    goto done;
	cvi = NULL; i = 0;
	while ((cvi = cvec_each(cvk, cvi)) != NULL) 
	    i++;
	if ((b1vec = calloc(i, sizeof(b1))) == NULL){
	    clicon_err(OE_UNIX, errno, "calloc");
	    goto done;
	}
	cvi = NULL; i = 0;
	while ((cvi = cvec_each(cvk, cvi)) != NULL) {
	    keyname = cv_string_get(cvi);
	    if ((b1 = xml_find_body(x1c, keyname)) == NULL){
		clicon_err(OE_UNIX, errno, "key %s not found", keyname);
		goto done;
	    }
	    b1vec[i++] = b1;
	}
	/* Iterate over x0 tree to (1) find a child that matches name
	   (2) that have keys that matches */
	x0c = NULL;
	while ((x0c = xml_child_each(x0, x0c, CX_ELMNT)) != NULL){
	    equal = 0;
	    if (strcmp(xml_name(x0c), x1cname))
		continue;
	    /* Must be inner loop */
	    cvi = NULL; i = 0;
	    while ((cvi = cvec_each(cvk, cvi)) != NULL) {
		b1 = b1vec[i++];
		equal = 0;
		keyname = cv_string_get(cvi);
		if ((b0 = xml_find_body(x0c, keyname)) == NULL)
		    break; /* error case */
		if (strcmp(b0, b1))
		    break; /* stop as soon as inequal key found */
		equal=1; /* reaches here for all keynames, x0c is found. */
	    }
	    if (equal) /* x0c and x1c equal, otherwise look for other */
		break;
	} /* while x0c */
	break;
    default:
	break;
    }
 ok:
    *x0cp = x0c;
    retval = 0;
 done:
    if (b1vec)
	free(b1vec);
    if (cvk)
	cvec_free(cvk);
    return retval;
}

/*! Find next yang node, either start from yang_spec or some yang-node
 * @param[in]  y    Node spec or sny yang-node
 * @param[in]  name Name of childnode to find
 * @retval  ys      yang statement
 * @retval  NULL    Error: no node found
 */
static yang_stmt *
yang_next(yang_node *y, 
	  char      *name)
{
    yang_stmt *ys;

    if (y->yn_keyword == Y_SPEC)
	ys = yang_find_topnode((yang_spec*)y, name, 0);
    else
	ys = yang_find_datanode(y, name);
    if (ys == NULL)
	clicon_err(OE_UNIX, errno, "No yang node found: %s", name);
    return ys;
}

/*! Recursive help function to compute differences between two xml trees
 * @param[in]  x1       First XML tree
 * @param[in]  x2       Second XML tree
 * @param[out] x1vec     Pointervector to XML nodes existing in only first tree
 * @param[out] x1veclen  Length of first vector
 * @param[out] x2vec    Pointervector to XML nodes existing in only second tree
 * @param[out] x2veclen Length of x2vec vector
 * @param[out] changed_x1  Pointervector to XML nodes changed orig value
 * @param[out] changed_x2  Pointervector to XML nodes changed wanted value
 * @param[out] changedlen Length of changed vector
 */
static int
xml_diff1(yang_stmt *ys, 
	  cxobj     *x1, 
	  cxobj     *x2,
	  cxobj   ***x1vec,
	  size_t    *x1veclen,
	  cxobj   ***x2vec,
	  size_t    *x2veclen,
	  cxobj   ***changed_x1,
	  cxobj   ***changed_x2,
	  size_t    *changedlen)
{
    int        retval = -1;
    cxobj     *x1c = NULL; /* x1 child */
    cxobj     *x2c = NULL; /* x2 child */
    yang_stmt *yc;
    char      *b1;
    char      *b2;

    clicon_debug(2, "%s: %s", __FUNCTION__, ys->ys_argument?ys->ys_argument:"yspec");
    /* Check nodes present in x1 and x2 + nodes only in x1
     * Loop over x1
     * XXX: room for improvement. Compare with match_base_child()
     */
    x1c = NULL;
    while ((x1c = xml_child_each(x1, x1c, CX_ELMNT)) != NULL){
	if ((yc = yang_next((yang_node*)ys, xml_name(x1c))) == NULL)
	    goto done;
	if (match_base_child(x2, x1c, &x2c, yc) < 0)
	    goto done;
	if (x2c == NULL){
	    if (cxvec_append(x1c, x1vec, x1veclen) < 0) 
		goto done;
	}
	else{
	    if (yc->ys_keyword == Y_LEAF){
		if ((b1 = xml_body(x1c)) == NULL) /* empty type */
		    break;
		if ((b2 = xml_body(x2c)) == NULL) /* empty type */
		    break;
		if (strcmp(b1, b2)){
		    if (cxvec_append(x1c, changed_x1, changedlen) < 0) 
			goto done;
		    (*changedlen)--; /* append two vectors */
		    if (cxvec_append(x2c, changed_x2, changedlen) < 0) 
			goto done;
		}
	    }
	    if (xml_diff1(yc, x1c, x2c,   
			  x1vec, x1veclen, 
			  x2vec, x2veclen, 
			  changed_x1, changed_x2, changedlen)< 0)
		goto done;
	}
    } /* while x1 */
    /* Check nodes present only in x2
     * Loop over x2
     */
    x2c = NULL;
    while ((x2c = xml_child_each(x2, x2c, CX_ELMNT)) != NULL){
	if ((yc = yang_next((yang_node*)ys, xml_name(x2c))) == NULL)
	    goto done;
        if (match_base_child(x1, x2c, &x1c, yc) < 0)
	    goto done;
	if (x1c == NULL)
	    if (cxvec_append(x2c, x2vec, x2veclen) < 0) 
		goto done;
    } /* while x1 */
    retval = 0;
 done:
    return retval;
}

/*! Compute differences between two xml trees
 * @param[in]  yspec     Yang specification
 * @param[in]  x1       First XML tree
 * @param[in]  x2       Second XML tree
 * @param[out] first     Pointervector to XML nodes existing in only first tree
 * @param[out] firstlen  Length of first vector
 * @param[out] second    Pointervector to XML nodes existing in only second tree
 * @param[out] secondlen Length of second vector
 * @param[out] changed1  Pointervector to XML nodes changed orig value
 * @param[out] changed2  Pointervector to XML nodes changed wanted value
 * @param[out] changedlen Length of changed vector
 * All xml vectors should be freed after use.
 * Bot xml trees should be freed with xml_free()
 */
int
xml_diff(yang_spec *yspec, 
	 cxobj     *x1, 
	 cxobj     *x2,
	 cxobj   ***first,
	 size_t    *firstlen,
	 cxobj   ***second,
	 size_t    *secondlen,
	 cxobj   ***changed1,
	 cxobj   ***changed2,
	 size_t    *changedlen)
{
    int retval = -1;

    *firstlen = 0;
    *secondlen = 0;    
    *changedlen = 0;
    if (x1 == NULL && x2 == NULL)
	return 0;
    if (x2 == NULL){
	if (cxvec_append(x1, first, firstlen) < 0) 
	    goto done;
	goto ok;
    }
    if (x1 == NULL){
	if (cxvec_append(x1, second, secondlen) < 0) 
	    goto done;
	goto ok;
    }
    if (xml_diff1((yang_stmt*)yspec, x1, x2,
		  first, firstlen, 
		  second, secondlen, 
		  changed1, changed2, changedlen) < 0)
	goto done;
 ok:
    retval = 0;
 done:
    return retval;
}

/*! Construct an xml key format from yang statement using wildcards for keys
 * Recursively construct it to the top.
 * Example: 
 *   yang:  container a -> list b -> key c -> leaf d
 *   xpath: /a/b/%s/d
 * @param[in]  ys      Yang statement
 * @param[in]  inclkey If set include key leaf (eg last leaf d in ex)
 * @param[out] cb      api_path_fmt,
 */ 
static int
yang2api_path_fmt_1(yang_stmt *ys, 
		    int        inclkey,
		    cbuf      *cb)
{
    yang_node *yp; /* parent */
    yang_stmt *ykey;
    int        i;
    cvec      *cvk = NULL; /* vector of index keys */
    int        retval = -1;

    yp = ys->ys_parent;
    if (yp != NULL && 
	yp->yn_keyword != Y_MODULE && 
	yp->yn_keyword != Y_SUBMODULE){
	if (yang2api_path_fmt_1((yang_stmt *)yp, 1, cb) < 0)
	    goto done;
    }
    if (inclkey){
	if (ys->ys_keyword != Y_CHOICE && ys->ys_keyword != Y_CASE)
	    cprintf(cb, "/%s", ys->ys_argument);
    }
    else{
#if 1
	if (ys->ys_keyword == Y_LEAF && yp && 
	    yp->yn_keyword == Y_LIST){
	    if (yang_key_match(yp, ys->ys_argument) == 0)
		cprintf(cb, "/%s", ys->ys_argument); /* Not if leaf and key */
	}
	else  
#endif
	    if (ys->ys_keyword != Y_CHOICE && ys->ys_keyword != Y_CASE)
		cprintf(cb, "/%s", ys->ys_argument);
    }

    switch (ys->ys_keyword){
    case Y_LIST:
	if ((ykey = yang_find((yang_node*)ys, Y_KEY, NULL)) == NULL){
	    clicon_err(OE_XML, errno, "%s: List statement \"%s\" has no key", 
		       __FUNCTION__, ys->ys_argument);
	    goto done;
	}
	/* The value is a list of keys: <key>[ <key>]*  */
	if ((cvk = yang_arg2cvec(ykey, " ")) == NULL)
	    goto done;
	if (cvec_len(cvk))
	    cprintf(cb, "=");
	/* Iterate over individual keys  */
	for (i=0; i<cvec_len(cvk); i++){
	    if (i)
		cprintf(cb, ",");
	    cprintf(cb, "%%s");
	}
	break;
    case Y_LEAF_LIST:
	cprintf(cb, "=%%s");
	break;
    default:
	break;
    } /* switch */
    retval = 0;
 done:
    if (cvk)
	cvec_free(cvk);
    return retval;
}

/*! Construct an api_path_format from yang statement using wildcards for keys
 * Recursively construct it to the top.
 * Example: 
 *   yang:  container a -> list b -> key c -> leaf d
 *   api_path: /a/b=%s/d
 * @param[in]  ys           Yang statement
 * @param[in]  inclkey      If set include key leaf (eg last leaf d in ex)
 * @param[out] api_path_fmt XML api path. Needs to be freed after use.
 */ 
int
yang2api_path_fmt(yang_stmt *ys, 
		  int        inclkey,
		  char     **api_path_fmt)
{
    int   retval = -1;
    cbuf *cb = NULL;

    if ((cb = cbuf_new()) == NULL){
	clicon_err(OE_UNIX, errno, "cbuf_new");
	goto done;
    }
    if (yang2api_path_fmt_1(ys, inclkey, cb) < 0)
	goto done;
    if ((*api_path_fmt = strdup(cbuf_get(cb))) == NULL){
	clicon_err(OE_UNIX, errno, "strdup");
	goto done;
    }
    retval = 0;
 done:
    if (cb)
	cbuf_free(cb);
    return retval;
}


/*! Transform an xml key format and a vector of values to an XML key
 * Used for actual key, eg in clicon_rpc_change(), xmldb_put_xkey()
 * Example: 
 *   xmlkeyfmt:  /aaa/%s/name
 *   cvv:        key=17
 *   xmlkey:     /aaa/17/name
 * @param[in]  api_path_fmt  XML key format, eg /aaa/%s/name
 * @param[in]  cvv           cligen variable vector, one for every wildchar in api_path_fmt
 * @param[out] api_path      api_path, eg /aaa/17. Free after use
 * @param[out] yang_arg      yang-stmt argument name. Free after use
 * @note first and last elements of cvv are not used,..
 * @see cli_dbxml where this function is called
 */ 
int
api_path_fmt2api_path(char  *api_path_fmt, 
		      cvec  *cvv, 
		      char **api_path)
{
    int   retval = -1;
    char  c;
    int   esc=0;
    cbuf *cb = NULL;
    int   i;
    int   j;
    char *str;
    char *strenc=NULL;

    /* Sanity check */
#if 0
    j = 0; /* Count % */
    for (i=0; i<strlen(api_path_fmt); i++)
	if (api_path_fmt[i] == '%')
	    j++;
    if (j+2 < cvec_len(cvv)) {
	clicon_log(LOG_WARNING, "%s xmlkey format string mismatch(j=%d, cvec_len=%d): %s", 
		   api_path_fmt, 
		   j,
		   cvec_len(cvv), 
		   cv_string_get(cvec_i(cvv, 0)));
	goto done;
    }
#endif
    if ((cb = cbuf_new()) == NULL){
	clicon_err(OE_UNIX, errno, "cbuf_new");
	goto done;
    }
    j = 1; /* j==0 is cli string */
    for (i=0; i<strlen(api_path_fmt); i++){
	c = api_path_fmt[i];
	if (esc){
	    esc = 0;
	    if (c!='s')
		continue;
	    if ((str = cv2str_dup(cvec_i(cvv, j++))) == NULL){
		clicon_err(OE_UNIX, errno, "strdup");
		goto done;
	    }
	    if (percent_encode(str, &strenc) < 0)
		goto done;
	    cprintf(cb, "%s", strenc); 
	    free(strenc); strenc = NULL;
	    free(str); str = NULL;
	}
	else
	    if (c == '%')
		esc++;
	    else if (c == '/'){
		cprintf(cb, "%c", c);
	    }
	    else
		cprintf(cb, "%c", c);
    }
    if ((*api_path = strdup(cbuf_get(cb))) == NULL){
	clicon_err(OE_UNIX, errno, "strdup");
	goto done;
    }
    retval = 0;
 done:
    if (cb)
	cbuf_free(cb);
    return retval;
}

/*! Transform an xml key format and a vector of values to an XML path
 * Used to input xmldb_get() or xmldb_get_vec
 * Add .* in last %s position.
 * Example: 
 *   xmlkeyfmt:  /interface/%s/address/%s OLDXXX
 *   xmlkeyfmt:  /interface=%s/address=%s
 *   cvv:        name=eth0
 *   xmlkey:     /interface/[name=eth0]/address
 * Example2:
 *   xmlkeyfmt:  /ip/me/%s (if key)
 *   cvv:        -
 *   xmlkey:     /ipv4/me/a
 * @param[in]  api_path_fmt  XML key format
 * @param[in]  cvv    cligen variable vector, one for every wildchar in api_path_fmt
 * @param[out] xpath     XPATH
 */ 
int
api_path_fmt2xpath(char  *api_path_fmt, 
		   cvec  *cvv, 
		   char **xpath)
{
    int     retval = -1;
    char    c;
    int     esc=0;
    cbuf   *cb = NULL;
    int     i;
    int     j;
    char   *str;
    cg_var *cv;
    int     skip = 0;

    /* Sanity check: count '%' */
#if 0
    j = 0; /* Count % */
    for (i=0; i<strlen(api_path_fmt); i++)
	if (api_path_fmt[i] == '%')
	    j++;
    if (j < cvec_len(cvv)-1) {
	clicon_log(LOG_WARNING, "%s xmlkey format string mismatch(j=%d, cvec_len=%d): %s", 
		   api_path_fmt, 
		   j,
		   cvec_len(cvv), 
		   cv_string_get(cvec_i(cvv, 0)));
	//	goto done;
    }
#endif
    if ((cb = cbuf_new()) == NULL){
	clicon_err(OE_UNIX, errno, "cbuf_new");
	goto done;
    }
    j = 1; /* j==0 is cli string */
    for (i=0; i<strlen(api_path_fmt); i++){
	c = api_path_fmt[i];
	if (esc){
	    esc = 0;
	    if (c!='s')
		continue;

	    if (j == cvec_len(cvv)) /* last element */
		//skip++;
		;
	    else{
		cv = cvec_i(cvv, j++);
		if ((str = cv2str_dup(cv)) == NULL){
		    clicon_err(OE_UNIX, errno, "cv2str_dup");
		    goto done;
		}
		cprintf(cb, "[%s=%s]", cv_name_get(cv), str);
		free(str);
	    }
	}
	else /* regular char */
	    if (c == '%')
		esc++;
	    else{
		if (skip)
		    skip=0;
		else
		    if ((c == '=' || c == ',') && api_path_fmt[i+1]=='%')
			; /* skip */
		    else
			cprintf(cb, "%c", c);
	    }
    }
    if ((*xpath = strdup4(cbuf_get(cb))) == NULL){
	clicon_err(OE_UNIX, errno, "strdup");
	goto done;
    }
    retval = 0;
 done:
    if (cb)
	cbuf_free(cb);
    return retval;
}

/*! Prune everything that does not pass test or have at least a child* does not
 * @param[in]   xt      XML tree with some node marked
 * @param[in]   flag    Which flag to test for
 * @param[in]   test    1: test that flag is set, 0: test that flag is not set
 * @param[out]  upmark  Set if a child (recursively) has marked set.
 * The function removes all branches that does not pass the test
 * Purge all nodes that dont have MARK flag set recursively.
 * Save all nodes that is MARK:ed or have at least one (grand*)child that is MARKed
 * @code
 *    xml_tree_prune_flagged_sub(xt, XML_FLAG_MARK, 1, NULL);
 * @endcode
 * @note This function seems a little too complex semantics
 * @see xml_tree_prune_flagged for a simpler variant
 */
int
xml_tree_prune_flagged_sub(cxobj *xt, 
			   int    flag,
			   int    test,
			   int   *upmark)
{
    int        retval = -1;
    int        submark;
    int        mark;
    cxobj     *x;
    cxobj     *xprev;
    int        iskey;
    int        anykey=0;
    yang_node *yt;

    mark = 0;
    yt = xml_spec(xt); /* xan be null */
    x = NULL;
    xprev = x = NULL;
    while ((x = xml_child_each(xt, x, CX_ELMNT)) != NULL) {
	if (xml_flag(x, flag) == test?flag:0){
	    /* Pass test */
	    mark++;
	    xprev = x;
	    continue; /* mark and stop here */
	}
	/* If it is key dont remove it yet (see second round) */
	if (yt){
	    if ((iskey = yang_key_match(yt, xml_name(x))) < 0)
		goto done;
	    if (iskey){
		anykey++;
		xprev = x; /* skip if this is key */
		continue;
	    }
	}
	if (xml_tree_prune_flagged_sub(x, flag, test, &submark) < 0)
	    goto done;
	/* if xt is list and submark anywhere, then key subs are also marked
	 */
	if (submark)
	    mark++;
	else{ /* Safe with xml_child_each if last */
	    if (xml_purge(x) < 0)
		goto done;
	    x = xprev;
	}
	xprev = x;
    }
    /* Second round: if any keys were found, and no marks detected, purge now */
    if (anykey && !mark){
	x = NULL;
	xprev = x = NULL;
	while ((x = xml_child_each(xt, x, CX_ELMNT)) != NULL) {
	    /* If it is key remove it here */
	    if (yt){
		if ((iskey = yang_key_match(yt, xml_name(x))) < 0)
		    goto done;
		if (iskey && xml_purge(x) < 0)
		    goto done;
		x = xprev;
	    }
	    xprev = x; 
	}
    }
    retval = 0;
 done:
    if (upmark)
	*upmark = mark;
    return retval;
}


/*! Prune everything that passes test
 * @param[in]   xt      XML tree with some node marked
 * @param[in]   flag    Which flag to test for
 * @param[in]   test    1: test that flag is set, 0: test that flag is not set
 * The function removes all branches that does not pass test
 * @code
 *    xml_tree_prune_flagged(xt, XML_FLAG_MARK, 1, NULL);
 * @endcode
 */
int
xml_tree_prune_flagged(cxobj *xt, 
		       int    flag,
		       int    test)
{
    int        retval = -1;
    cxobj     *x;
    cxobj     *xprev;

    x = NULL;
    xprev = x = NULL;
    while ((x = xml_child_each(xt, x, CX_ELMNT)) != NULL) {
	if (xml_flag(x, flag) == test?flag:0){ 	/* Pass test means purge */
	    if (xml_purge(x) < 0)
		goto done;
	    x = xprev;
	    continue; 
	}
	if (xml_tree_prune_flagged(x, flag, test) < 0)
	    goto done;
	xprev = x;
    }
    retval = 0;
 done:
    return retval;
}

/*! Add default values (if not set)
 * @param[in]   xt      XML tree with some node marked
 */
int
xml_default(cxobj *xt, 
	   void   *arg)
{
    int        retval = -1;
    yang_stmt *ys;
    yang_stmt *y;
    int        i;
    cxobj     *xc;
    cxobj     *xb;
    char      *str;

    if ((ys = (yang_stmt*)xml_spec(xt)) == NULL){
	retval = 0;
	goto done;
    }
    /* Check leaf defaults */
    if (ys->ys_keyword == Y_CONTAINER || ys->ys_keyword == Y_LIST){
	for (i=0; i<ys->ys_len; i++){
	    y = ys->ys_stmt[i];
	    if (y->ys_keyword != Y_LEAF)
		continue;
	    assert(y->ys_cv);
	    if (!cv_flag(y->ys_cv, V_UNSET)){  /* Default value exists */
		if (!xml_find(xt, y->ys_argument)){
		    if ((xc = xml_new_spec(y->ys_argument, xt, y)) == NULL)
			goto done;
		    if ((xb = xml_new("body", xc)) == NULL)
			goto done;
		    xml_type_set(xb, CX_BODY);
		    if ((str = cv2str_dup(y->ys_cv)) == NULL){
			clicon_err(OE_UNIX, errno, "cv2str_dup");
			goto done;
		    }
		    if (xml_value_set(xb, str) < 0)
			goto done;
		    free(str);
		}
	    }
	}
    }
    retval = 0;
 done:
    return retval;
}

/*! Order XML children according to YANG
 * @param[in]   xt      XML top of tree
 */
int
xml_order(cxobj *xt, 
	  void  *arg)
{
    int        retval = -1;
    yang_stmt *y;
    yang_stmt *yc;
    int        i;
    int        j0;
    int        j;
    cxobj     *xc;
    cxobj     *xj;
    char      *yname; /* yang child name */
    char      *xname; /* xml child name */

    if ((y = (yang_stmt*)xml_spec(xt)) == NULL){
	retval = 0;
	goto done;
    }
    j0 = 0;
 /* Go through xml children and ensure they are same order as yspec children */
    for (i=0; i<y->ys_len; i++){
	yc = y->ys_stmt[i];
	if (!yang_datanode(yc))
	    continue;
	yname = yc->ys_argument;
	/* First go thru xml children with same name */
	for (; j0<xml_child_nr(xt); j0++){
	    xc = xml_child_i(xt, j0);
	    if (xml_type(xc) != CX_ELMNT)
		continue;
	    xname = xml_name(xc);
	    if (strcmp(xname, yname))
		break;
	}
	/* Now we have children not with same name */
	for (j=j0; j<xml_child_nr(xt); j++){
	    xc = xml_child_i(xt, j);
	    if (xml_type(xc) != CX_ELMNT)
		continue;
	    xname = xml_name(xc);
	    if (strcmp(xname, yname))
		continue;
	    /* reorder */
	    xj = xml_child_i(xt, j0);
	    xml_child_i_set(xt, j0, xc);
	    xml_child_i_set(xt, j, xj);
	    j0++;
	}
    }
    retval = 0;
 done:
    return retval;
}

/*! Sanitize an xml tree: xml node has matching yang_stmt pointer 
 * @param[in]   xt      XML top of tree
 */
int
xml_sanity(cxobj *xt, 
	   void  *arg)
{
    int        retval = -1;
    yang_stmt *ys;
    char      *name;

    if ((ys = (yang_stmt*)xml_spec(xt)) == NULL){
	retval = 0;
	goto done;
    }
    name = xml_name(xt);
    if (strstr(ys->ys_argument, name)==NULL){
	clicon_err(OE_XML, 0, "xml node name '%s' does not match yang spec arg '%s'", 
		   name, ys->ys_argument);
	goto done;
    }
    retval = 0;
 done:
    return retval;
}

/*! Mark all nodes that are not configure data and set return
 * @param[in]   xt      XML tree 
 * @param[out]  arg     If set, set to 1 as int* if not config data
 */
int
xml_non_config_data(cxobj *xt, 
		    void   *arg) /* Set to 1 if state node */
{
    int        retval = -1;
    yang_stmt *ys;

    if ((ys = (yang_stmt*)xml_spec(xt)) == NULL){
	retval = 0;
	goto done;
    }
    if (!yang_config(ys)){ /* config == false means state data: mark for remove */
	xml_flag_set(xt, XML_FLAG_MARK);
	if (arg)
	    (*(int*)arg) = 1;
    }
    retval = 0;
 done:
    return retval;
}

/*! Add yang specification backpoint to XML node
 * @param[in]   xt      XML tree node
 * @note This should really be unnecessary since yspec should be set on creation
 * @note For subs to anyxml nodes will not have spec set
 * @code
 * xml_apply(xc, CX_ELMNT, xml_spec_populate, yspec)
 * @endcode
 */
int
xml_spec_populate(cxobj  *x, 
		  void   *arg)
{
    int        retval = -1;
    yang_spec *yspec = (yang_spec*)arg;
    char      *name;
    yang_stmt *y=NULL;  /* yang node */
    cxobj     *xp;      /* xml parent */ 
    yang_stmt *yp;      /* parent yang */

    name = xml_name(x);
    if ((xp = xml_parent(x)) != NULL &&
	(yp = xml_spec(xp)) != NULL)
	y = yang_find_datanode((yang_node*)yp, xml_name(x));
    else
	y = yang_find_topnode(yspec, name, 0); /* still NULL for config */
#ifdef XXX_OBSOLETE /* Add validate elsewhere */
    if (y==NULL){
	clicon_err(OE_XML, EBADF, "yang spec not found for xml node '%s' xml parent name: '%s' yangspec:'%s']", 
		   name, 
		   xp?xml_name(xp):"", yp?yp->ys_argument:"");
	goto done;
    }
#endif
    if (y)
	xml_spec_set(x, y);
    retval = 0;
    // done:
    return retval;
}


/*! Translate from restconf api-path in cvv form to xml xpath
 * eg a/b=c -> a/[b=c] 
 * @param[in]  yspec Yang spec
 * @param[in]  pcvec api-path as cvec
 * @param[in]  pi    Offset of cvec, where api-path starts
 * @param[out] path  The xpath as cbuf variable string, must be initializeed
 * The api-path has some wierd encoding, use api_path2xpath() if you are 
 * confused. 
 * It works like this:
 * Assume origin incoming path is 
 * "www.foo.com/restconf/a/b=c",  pi is 2 and pcvec is:
 *   ["www.foo.com" "restconf" "a" "b=c"]
 * which means the api-path is ["a" "b=c"] corresponding to "a/b=c"
 * @code
 *   cbuf *xpath = cbuf_new();
 *   if (api_path2xpath_cvv(yspec, cvv, i, xpath)
 *      err;
 *   ... access xpath as cbuf_get(xpath) 
 *   cbuf_free(xpath)
 * @endcode
 * @see api_path2xpath for string api-path argument
 */
int
api_path2xpath_cvv(yang_spec *yspec,
		   cvec      *cvv,
		   int        offset,
		   cbuf      *xpath)
{
    int        retval = -1;
    int        i;
    cg_var    *cv;
    char      *name;
    cvec      *cvk = NULL; /* vector of index keys */
    yang_stmt *y = NULL;
    char      *val;
    char      *v;
    yang_stmt *ykey;
    cg_var    *cvi;

    for (i=offset; i<cvec_len(cvv); i++){
        cv = cvec_i(cvv, i);
	name = cv_name_get(cv);
	clicon_debug(1, "[%d] cvname:%s", i, name);
	clicon_debug(1, "cv2str%d", cv2str(cv, NULL, 0));
	if (i == offset){
	    if ((y = yang_find_topnode(yspec, name, 0)) == NULL){
		clicon_err(OE_UNIX, errno, "No yang node found: %s", name);
		goto done;
	    }
	}
	else{
	    assert(y!=NULL);
	    if ((y = yang_find_datanode((yang_node*)y, name)) == NULL){
		clicon_err(OE_UNIX, errno, "No yang node found: %s", name);
		goto done;
	    }
	}
	/* Check if has value, means '=' */
        if (cv2str(cv, NULL, 0) > 0){
            if ((val = cv2str_dup(cv)) == NULL)
                goto done;
	    v = val;
	    /* XXX sync with yang */
	    while((v=index(v, ',')) != NULL){
		*v = '\0';
		v++;
	    }
	    /* Find keys */
	    if ((ykey = yang_find((yang_node*)y, Y_KEY, NULL)) == NULL){
		clicon_err(OE_XML, errno, "%s: List statement \"%s\" has no key", 
			   __FUNCTION__, y->ys_argument);
		goto done;
	    }
	    clicon_debug(1, "ykey:%s", ykey->ys_argument);

	    /* The value is a list of keys: <key>[ <key>]*  */
	    if ((cvk = yang_arg2cvec(ykey, " ")) == NULL)
		goto done;
	    cvi = NULL;
	    /* Iterate over individual yang keys  */
	    cprintf(xpath, "/%s", name);
	    v = val;
	    while ((cvi = cvec_each(cvk, cvi)) != NULL){
		cprintf(xpath, "[%s=%s]", cv_string_get(cvi), v);
		v += strlen(v)+1;
	    }
	    if (val)
		free(val);
        }
        else{
            cprintf(xpath, "%s%s", (i==offset?"":"/"), name);
        }
    }
    retval = 0;
 done:
    return retval;
}

/*! Translate from restconf api-path to xml xpath
 * eg a/b=c -> a/[b=c] 
 * @param[in]  yspec Yang spec
 * @param[in]  str   API-path as string
 * @param[out] path  The xpath as cbuf variable string, must be initializeed
 * @code
 *   cbuf *xpath = cbuf_new();
 *   if (api_path2xpath(yspec, "a/b=c", xpath)
 *      err;
 *   ... access xpath as cbuf_get(xpath) 
 *   cbuf_free(xpath)
 * @endcode
 */
int
api_path2xpath(yang_spec *yspec,
	       char      *api_path,
	       cbuf      *xpath)
{
    int   retval = -1;
    cvec *api_path_cvv = NULL; 

    /* rest url eg /album=ricky/foo */
    if (str2cvec(api_path, '/', '=', &api_path_cvv) < 0) 
	goto done;
    if (api_path2xpath_cvv(yspec, api_path_cvv, 0, xpath) < 0)
	goto done;
    retval = 0;
 done:
    if (api_path_cvv)
	cvec_free(api_path_cvv);
    return retval;
}

/*! Create xml tree from api-path as vector
 * @param[in]   vec       APIpath as char* vector
 * @param[in]   nvec      Length of vec
 * @param[in]   x0        Xpath tree so far
 * @param[in]   y0        Yang spec for x0
 * @param[in]   schemanode If set use schema nodes otherwise data nodes.
 * @param[out]  xpathp    Resulting xml tree 
 * @param[out]  ypathp    Yang spec matching xpathp
 * @see api_path2xml
 */
static int
api_path2xml_vec(char             **vec,
		 int                nvec,
		 cxobj             *x0,
		 yang_node         *y0,
		 int                schemanode,
		 cxobj            **xpathp,
		 yang_node        **ypathp)
{
    int        retval = -1;
    int        j;
    char      *name;
    char      *restval = NULL;
    char      *restval_enc;
    yang_stmt *ykey;
    cxobj     *xn = NULL; /* new */
    cxobj     *xb;        /* body */
    cvec      *cvk = NULL; /* vector of index keys */
    cg_var    *cvi;
    char      *keyname;
    char      *val2;
    char     **valvec = NULL;
    int        nvalvec;
    cxobj     *x = NULL;
    yang_stmt *y = NULL;
    char      *local;

    if ((name = vec[0]) == NULL){
	if (xpathp)
	    *xpathp = x0;
	if (ypathp)
	    *ypathp = y0;
	return 0;
    } /* E.g "x=1,2" -> name:x restval=1,2 */
    /* restval is RFC 3896 encoded */
    if ((restval_enc = index(name, '=')) != NULL){
	*restval_enc = '\0';
	restval_enc++;
	if (percent_decode(restval_enc, &restval) < 0)
	    goto done;
    }
    /* Split into prefix and localname, ignore prefix for now */
    if ((local = index(name, ':')) != NULL){
	*local = '\0';
	local++;
	name = local;
    }
    if (y0->yn_keyword == Y_SPEC){ /* top-node */
	clicon_debug(1, "%s 1 %s", __FUNCTION__, name);
	y = yang_find_topnode((yang_spec*)y0, name, schemanode);
    }
    else {
	clicon_debug(1, "%s 2 %s", __FUNCTION__, name);
	y = schemanode?yang_find_schemanode((yang_node*)y0, name):
	    yang_find_datanode((yang_node*)y0, name);
    }
    if (y == NULL){
	clicon_err(OE_YANG, errno, "No yang node found: %s", name);
	goto done;
    }
    switch (y->ys_keyword){
    case Y_LEAF_LIST:
	if (restval==NULL){
	    clicon_err(OE_XML, 0, "malformed key, expected '=<restval>'");
	    goto done;
	}
	if ((x = xml_new_spec(y->ys_argument, x0, y)) == NULL)
	    goto done;
	xml_type_set(x, CX_ELMNT);
	if ((xb = xml_new("body", x)) == NULL)
	    goto done; 
	xml_type_set(xb, CX_BODY);
	if (xml_value_set(xb, restval) < 0)
	    goto done;
	break;
    case Y_LIST:
	/* Get the yang list key */
	if ((ykey = yang_find((yang_node*)y, Y_KEY, NULL)) == NULL){
	    clicon_err(OE_XML, errno, "%s: List statement \"%s\" has no key", 
		       __FUNCTION__, y->ys_argument);
	    goto done;
	}
	/* The value is a list of keys: <key>[ <key>]*  */
	if ((cvk = yang_arg2cvec(ykey, " ")) == NULL)
	    goto done;
	if (valvec){
	    free(valvec);
	    valvec = NULL;
	}
	if (restval==NULL){
	    // XXX patch to allow for lists without restval tobe backward compat
	    //	    clicon_err(OE_XML, 0, "malformed key, expected '=<restval>'");
	    //	    goto done;
	}
	else{
	    if ((valvec = clicon_strsep(restval, ",", &nvalvec)) == NULL)
		goto done;
	    if (cvec_len(cvk) != nvalvec){ 	    
		clicon_err(OE_XML, errno, "List %s  key length mismatch", name);
		goto done;
	    }
	}
	cvi = NULL;
	/* create list object */
	if ((x = xml_new_spec(name, x0, y)) == NULL)
	    goto done; 
	xml_type_set(x, CX_ELMNT);
	j = 0;
	/* Create keys */
	while ((cvi = cvec_each(cvk, cvi)) != NULL) {
	    keyname = cv_string_get(cvi);

	    if ((xn = xml_new(keyname, x)) == NULL)
		goto done; 
	    xml_type_set(xn, CX_ELMNT);
	    if ((xb = xml_new("body", xn)) == NULL)
		goto done; 
	    xml_type_set(xb, CX_BODY);
	    val2 = valvec?valvec[j++]:NULL;
	    if (xml_value_set(xb, val2) <0)
		goto done;
	}
	if (cvk){
	    cvec_free(cvk);
	    cvk = NULL;
	}
	break;
    default: /* eg Y_CONTAINER, Y_LEAF */
	if ((x = xml_new_spec(name, x0, y)) == NULL)
	    goto done; 
	xml_type_set(x, CX_ELMNT);
	break;
    }
    if (api_path2xml_vec(vec+1, nvec-1, 
			 x, (yang_node*)y, 
			 schemanode,
			 xpathp, ypathp) < 0)
	goto done;
    retval = 0;
 done:
    if (restval)
	free(restval);
    if (valvec)
	free(valvec);
    return retval;
}

/*! Create xml tree from api-path
 * @param[in]   api_path  API-path as defined in RFC 8040
 * @param[in]   yspec     Yang spec
 * @param[in]   schemanode If set use schema nodes otherwise data nodes.
 * @param[out]  xpathp    Resulting xml tree 
 * @param[out]  ypathp    Yang spec matching xpathp
 * @see api_path2xml_vec
 */
int
api_path2xml(char       *api_path,
	     yang_spec  *yspec,
	     cxobj      *xpath,
	     int         schemanode,
	     cxobj     **xpathp,
	     yang_node **ypathp)
{
    int    retval = -1;
    char **vec = NULL;
    int    nvec;

    clicon_debug(1, "%s 0", __FUNCTION__);
    if (*api_path!='/'){
	clicon_err(OE_DB, 0, "Invalid key: %s", api_path);
	goto done;
    }
    if ((vec = clicon_strsep(api_path, "/", &nvec)) == NULL)
	goto done;
    /* Remove trailing '/'. Like in /a/ -> /a */
    if (nvec > 1 && !strlen(vec[nvec-1]))
	nvec--;
    if (nvec < 1){
	    clicon_err(OE_XML, 0, "Malformed key: %s", api_path);
	    goto done;
	}
    nvec--; /* NULL-terminated */
    if (api_path2xml_vec(vec+1, nvec, 
			 xpath, (yang_node*)yspec, schemanode,
			 xpathp, ypathp) < 0)
	goto done;
    retval = 0;
 done:
    if (vec)
	free(vec);
    return retval;
}


/*! Merge a base tree x0 with x1 with yang spec y
 * @param[in]  x0  Base xml tree (can be NULL in add scenarios)
 * @param[in]  y0  Yang spec corresponding to xml-node x0. NULL if x0 is NULL
 * @param[in]  x0p Parent of x0
 * @param[in]  x1  xml tree which modifies base
 * Assume x0 and x1 are same on entry and that y is the spec
 * @see put in clixon_keyvalue.c
 */
static int
xml_merge1(cxobj              *x0,
	   yang_node          *y0,
	   cxobj              *x0p,
	   cxobj              *x1)
{
    int        retval = -1;
    char      *x1name;
    char      *x1cname; /* child name */
    cxobj     *x0c; /* base child */
    cxobj     *x0b; /* base body */
    cxobj     *x1c; /* mod child */
    char      *x1bstr; /* mod body string */
    yang_stmt *yc;  /* yang child */

    assert(x1 && xml_type(x1) == CX_ELMNT);
    assert(y0);

    x1name = xml_name(x1);
    if (y0->yn_keyword == Y_LEAF_LIST || y0->yn_keyword == Y_LEAF){
	x1bstr = xml_body(x1);
	if (x0==NULL){
	    if ((x0 = xml_new_spec(x1name, x0p, y0)) == NULL)
		goto done;
	    if (x1bstr){ /* empty type does not have body */
		if ((x0b = xml_new("body", x0)) == NULL)
		    goto done; 
		xml_type_set(x0b, CX_BODY);
	    }
	}
	if (x1bstr){
	    if ((x0b = xml_body_get(x0)) == NULL){
		if ((x0b = xml_new("body", x0)) == NULL)
		    goto done; 
		xml_type_set(x0b, CX_BODY);
	    }
	    if (xml_value_set(x0b, x1bstr) < 0)
		goto done;
	}

    } /* if LEAF|LEAF_LIST */
    else { /* eg Y_CONTAINER, Y_LIST  */
	if (x0==NULL){
	    if ((x0 = xml_new_spec(x1name, x0p, y0)) == NULL)
		goto done;
	}
	/* Loop through children of the modification tree */
	x1c = NULL;
	while ((x1c = xml_child_each(x1, x1c, CX_ELMNT)) != NULL) {
	    x1cname = xml_name(x1c);
	    /* Get yang spec of the child */
	    if ((yc = yang_find_datanode(y0, x1cname)) == NULL){
		clicon_err(OE_YANG, errno, "No yang node found: %s", x1cname);
		goto done;
	    }
	    /* See if there is a corresponding node in the base tree */
	    x0c = NULL;
	    if (yc && match_base_child(x0, x1c, &x0c, yc) < 0)
		goto done;
	    if (xml_merge1(x0c, (yang_node*)yc, x0, x1c) < 0)
		goto done;
	}
    } /* else Y_CONTAINER  */
    // ok:
    retval = 0;
 done:
    return retval;
}

/*! Merge XML trees x1 into x0 according to yang spec yspec
 * @note both x0 and x1 need to be top-level trees
 * @see text_modify_top as more generic variant (in datastore text)
 */
int
xml_merge(cxobj     *x0,
	  cxobj     *x1,
	  yang_spec *yspec)
{
    int        retval = -1;
    char      *x1cname; /* child name */
    cxobj     *x0c; /* base child */
    cxobj     *x1c; /* mod child */
    yang_stmt *yc;

    /* Loop through children of the modification tree */
    x1c = NULL;
    while ((x1c = xml_child_each(x1, x1c, CX_ELMNT)) != NULL) {
	x1cname = xml_name(x1c);
	/* Get yang spec of the child */
	if ((yc = yang_find_topnode(yspec, x1cname, 0)) == NULL){
	    clicon_err(OE_YANG, ENOENT, "No yang spec");
	    goto done;
	}
	/* See if there is a corresponding node in the base tree */
	if (match_base_child(x0, x1c, &x0c, yc) < 0)
	    goto done;
	if (xml_merge1(x0c, (yang_node*)yc, x0, x1c) < 0)
	    goto done;
    }
    retval = 0;
 done:
    return retval;
}

/*! Get integer value from xml node from yang enumeration 
 * @param[in]  node XML node in a tree
 * @param[out] val  Integer value returned
 * @retval     0    OK, value parsed
 * @retval    -1    Error, value not obtained or parsed, no reason given
 * @note assume yang spec set
 * @note The function only returns assigned values, but according to RFC:
   If a value is not specified, then one will be automatically assigned.
   If the "enum" substatement is the first one defined, the assigned
   value is zero (0); otherwise, the assigned value is one greater than
   the current highest enum value (i.e., the highest enum value,
   * Thanks: Matthew Smith
 */
int
yang_enum_int_value(cxobj   *node, 
		    int32_t *val)
{
    int retval = -1;
    yang_spec *yspec;
    yang_stmt *ys;
    yang_stmt *ytype;
    yang_stmt *yrestype;  /* resolved type */
    yang_stmt *yenum; 
    yang_stmt *yval; 
    char      *reason = NULL;

    if (node == NULL)
	goto done;
    if ((ys = (yang_stmt *) xml_spec(node)) == NULL)
	goto done;
    if ((yspec = ys_spec(ys)) == NULL)
	goto done;
    if ((ytype = yang_find((yang_node *)ys, Y_TYPE, NULL)) == NULL)
	goto done;
    if (yang_type_resolve(ys, ytype, &yrestype, 
			  NULL, NULL, NULL, NULL, NULL) < 0)
	goto done;
    if (yrestype==NULL || strcmp(yrestype->ys_argument, "enumeration"))
	goto done;
    if ((yenum = yang_find((yang_node *)yrestype, Y_ENUM, xml_body(node))) == NULL)
	goto done;
    /* Should assign value if yval not found */
    if ((yval = yang_find((yang_node *)yenum, Y_VALUE, NULL)) == NULL)
	goto done;
    /* reason is string containing why int could not be parsed */
    if (parse_int32(yval->ys_argument, val, &reason) < 0)
	goto done;
    retval = 0;
done:
    return retval;
}