/*

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License as published by

 *  the Free Software Foundation; either version 2 of the License, or

 *  (at your option) any later version.

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License

 *  along with this program; if not, write to the Free Software

 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

 *

 * Copyrights

 *

 * Portions created by or assigned to Jabber.com, Inc. are

 * Copyright (c) 1999-2002 Jabber.com, Inc.  All Rights Reserved.  Contact

 * information for Jabber.com, Inc. is available at http://www.jabber.com/.

 *

 * Portions Copyright (c) 1998-1999 Jeremie Miller.

 *

 * Acknowledgements

 *

 * Special thanks to the Jabber Open Source Contributors for their

 * suggestions and support of Jabber.

 *

 */

/**

 * @file xstream.c

 * @brief handling of incoming XML stream based events

 *

 * xstream is a way to have a consistent method of handling incoming XML stream based events ...

 * it doesn't handle the generation of an XML stream, but provides some facilities to help doing that

 */

#include <time.h>

#include <libxode.h>

/* ========== internal expat callbacks =========== */

/**

 * internal expat callback for read start tags of an element

 */

void _xstream_startElement(xstream xs, const char* name, const char** atts)

{

    pool p;

    /* if xstream is bad, get outa here */

    if(xs->status > XSTREAM_NODE) return;

    if(xs->node == NULL)

    {

        p = pool_heap(5*1024); /* 5k, typically 1-2k each plus copy of self and workspace */

        xs->node = xmlnode_new_tag_pool(p,name);

        xmlnode_put_expat_attribs(xs->node, atts);

        if(xs->status == XSTREAM_ROOT)

        {

            xs->status = XSTREAM_NODE; /* flag status that we're processing nodes now */

            (xs->f)(XSTREAM_ROOT, xs->node, xs->arg); /* send the root, f must free all nodes */

            xs->node = NULL;

        }

    }else{

        xs->node = xmlnode_insert_tag(xs->node, name);

        xmlnode_put_expat_attribs(xs->node, atts);

    }

    /* depth check */

    xs->depth++;

    if(xs->depth > XSTREAM_MAXDEPTH)

        xs->status = XSTREAM_ERR;

}

/**

 * internal expat callback for read end tags of an element

 */

void _xstream_endElement(xstream xs, const char* name)

{

    xmlnode parent;

    /* if xstream is bad, get outa here */

    if(xs->status > XSTREAM_NODE) return;

    /* if it's already NULL we've received </stream>, tell the app and we're outta here */

    if(xs->node == NULL)

    {

        xs->status = XSTREAM_CLOSE;

        (xs->f)(XSTREAM_CLOSE, NULL, xs->arg);

    }else{

        parent = xmlnode_get_parent(xs->node);

        /* we are the top-most node, feed to the app who is responsible to delete it */

        if(parent == NULL)

            (xs->f)(XSTREAM_NODE, xs->node, xs->arg);

        xs->node = parent;

    }

    xs->depth--;

}

/**

 * internal expat callback for read CDATA

 */

void _xstream_charData(xstream xs, const char *str, int len)

{

    /* if xstream is bad, get outa here */

    if(xs->status > XSTREAM_NODE) return;

    if(xs->node == NULL)

    {

        /* we must be in the root of the stream where CDATA is irrelevant */

        return;

    }

    xmlnode_insert_cdata(xs->node, str, len);

}

/**

 * internal function to be registered as pool cleaner, frees a stream if the associated memory pool is freed

 *

 * @param pointer to the xstream to free

 */

void _xstream_cleanup(void *arg)

{

    xstream xs = (xstream)arg;

    xmlnode_free(xs->node); /* cleanup anything left over */

    XML_ParserFree(xs->parser);

}

/**

 * creates a new xstream with given pool, xstream will be cleaned up w/ pool

 *

 * @param p the memory pool to use for the stream

 * @param f function pointer to the event handler function

 * @param arg parameter to pass to the event handler function

 * @return the created xstream

 */

xstream xstream_new(pool p, xstream_onNode f, void *arg)

{

    xstream newx;

    if(p == NULL || f == NULL)

    {

        fprintf(stderr,"Fatal Programming Error: xstream_new() was improperly called with NULL.\n");

        return NULL;

    }

    newx = pmalloco(p, sizeof(_xstream));

    newx->p = p;

    newx->f = f;

    newx->arg = arg;

    /* create expat parser and ensure cleanup */

    newx->parser = XML_ParserCreate(NULL);

    XML_SetUserData(newx->parser, (void *)newx);

    XML_SetElementHandler(newx->parser,

                          (XML_StartElementHandler)_xstream_startElement,

                          (XML_EndElementHandler)_xstream_endElement);

    XML_SetCharacterDataHandler(newx->parser,

                                (XML_CharacterDataHandler)_xstream_charData);

    pool_cleanup(p, _xstream_cleanup, (void *)newx);

    return newx;

}

/**

 * attempts to parse the buff onto this stream firing events to the handler

 *

 * @param xs the xstream to parse the data on

 * @param buff the new data

 * @param len length of the data

 * @return last known xstream status

 */

int xstream_eat(xstream xs, char *buff, int len)

{

    char *err;

    xmlnode xerr;

    static char maxerr[] = "maximum node size reached";

    static char deeperr[] = "maximum node depth reached";

    if(xs == NULL)

    {

        fprintf(stderr,"Fatal Programming Error: xstream_eat() was improperly called with NULL.\n");

        return XSTREAM_ERR;

    }

    if(len == 0 || buff == NULL)

        return xs->status;

    if(len == -1) /* easy for hand-fed eat calls */

        len = strlen(buff);

    if(!XML_Parse(xs->parser, buff, len, 0))

    {

        err = (char *)XML_ErrorString(XML_GetErrorCode(xs->parser));

        xs->status = XSTREAM_ERR;

    }else if(pool_size(xmlnode_pool(xs->node)) > XSTREAM_MAXNODE || xs->cdata_len > XSTREAM_MAXNODE){

        err = maxerr;

        xs->status = XSTREAM_ERR;

    }else if(xs->status == XSTREAM_ERR){ /* set within expat handlers */

        err = deeperr;

    }

    /* fire parsing error event, make a node containing the error string */

    if(xs->status == XSTREAM_ERR)

    {

        xerr = xmlnode_new_tag("error");

        xmlnode_insert_cdata(xerr,err,-1);

        (xs->f)(XSTREAM_ERR, xerr, xs->arg);

    }

    return xs->status;

}

/* STREAM CREATION UTILITIES */

/** give a standard template xmlnode to work from 

 *

 * @param namespace ("jabber:client", "jabber:server", ...)

 * @param to where the stream is sent to

 * @param from where we are (source of the stream)

 * @return the xmlnode that has been generated as the template

 */

xmlnode xstream_header(char *namespace, char *to, char *from)

{

    xmlnode x;

    char id[11];

    sprintf(id,"%X",(int)time(NULL));

    x = xmlnode_new_tag("stream:stream");

    xmlnode_put_attrib(x, "xmlns:stream", "http://etherx.jabber.org/streams");

    xmlnode_put_attrib(x, "id", id);

    if(namespace != NULL)

        xmlnode_put_attrib(x, "xmlns", namespace);

    if(to != NULL)

        xmlnode_put_attrib(x, "to", to);

    if(from != NULL)

        xmlnode_put_attrib(x, "from", from);

    return x;

}

/**

 * trim the xmlnode to only the opening header :)

 *

 * @note NO CHILDREN ALLOWED

 *

 * @param x the xmlnode

 * @return string representation of the start tag

 */

char *xstream_header_char(xmlnode x)

{

    spool s;

    char *fixr, *head;

    if(xmlnode_has_children(x)) {

        fprintf(stderr,"Fatal Programming Error: xstream_header_char() was sent a header with children!\n");

        return NULL;

    }

    s = spool_new(xmlnode_pool(x));

    spooler(s,"<?xml version='1.0'?>",xmlnode2str(x),s);

    head = spool_print(s);

    fixr = strstr(head,"/>");

    *fixr = '>';

    ++fixr;

    *fixr = '\0';

    return head;

}