/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/***************************************************************************
 *            saxparser.cc
 *
 *  Mon Mar 24 14:40:15 CET 2008
 *  Copyright 2008 Bent Bisballe Nyeng
 *  deva@aasimon.org
 ****************************************************************************/

/*
 *  This file is part of Pracro.
 *
 *  Pracro 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.
 *
 *  Pracro 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 Pracro; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
 */
#include "saxparser.h"

#include "hugin.hpp"

#include <string.h>
#include <stdio.h>

static void character_hndl(void *p, const XML_Char *s, int len)
{
	SAXParser *parser = (SAXParser*)XML_GetUserData(p);
	std::string chars;
	chars.append(s, len);
	parser->characterData(chars);
}

static void start_hndl(void *p, const char *el, const char **attr)
{
	SAXParser *parser = (SAXParser*)XML_GetUserData(p);

	// Convert to comfy C++ values...
	std::string name = el;
	std::map< std::string, std::string > attributes;

	while(*attr)
	{
		std::string at_name = *attr;
		attr++;
		std::string at_value = *attr;
		attr++;

		attributes.insert(make_pair(at_name, at_value));
	}

	if(parser->outertag == "")
	{
		parser->outertag = name;
	}

	parser->startTag(name, attributes);
}

static void end_hndl(void *p, const char *el)
{
	SAXParser *parser = (SAXParser*)XML_GetUserData(p);
	std::string name = el;

	if(name == parser->outertag)
	{
		parser->done = true;
	}

	parser->endTag(name);
}


SAXParser::SAXParser()
{
	p = XML_ParserCreate(NULL);
	if(!p)
	{
		ERR(sax, "Couldn't allocate memory for parser\n");
		// throw Exception(...);
		return;
	}

	//  XML_SetEncoding(p, "UTF-8");
	XML_SetUserData(p, this);
	XML_UseParserAsHandlerArg(p);
	XML_SetElementHandler(p, start_hndl, end_hndl);
	XML_SetCharacterDataHandler(p, character_hndl);

	bufferbytes = 0;
	totalbytes = 0;
	done = false;
}

SAXParser::~SAXParser()
{
	if(p)
	{
		XML_ParserFree(p);
	}
}

int SAXParser::parse()
{
	char buf[32];
	int len;

	do
	{
		len = readData(buf, sizeof(buf) - 1);
		if(! XML_Parse(p, buf, len, len == 0))
		{
			parseError(buf, len, XML_ErrorString(XML_GetErrorCode(p)),
			           (int)XML_GetCurrentLineNumber(p));
			return 1;
		}

		memset(buf, 0, sizeof(buf));
	}
	while(len);

	return 0;
}

static bool iswhitespace(const char *buf, size_t size)
{
	for(size_t i = 0; i < size; i++)
	{
		if(buf[i] != ' ' && buf[i] != '\n' && buf[i] != '\t' && buf[i] != '\r')
		{
			return false;
		}
	}
	return true;
}

bool SAXParser::parse(const char *data, size_t size)
{
	std::string xml;
	xml.append(data, size);
	DEBUG(sax, "parse %d bytes [%s]\n", (int)size, xml.c_str());

	if(data == NULL || size == 0)
	{
		return done;
	}

	bufferbytes = size;
	totalbytes += bufferbytes;

	if(! XML_Parse(p, data, size, false))
	{
		if(XML_GetErrorCode(p) == XML_ERROR_JUNK_AFTER_DOC_ELEMENT)
		{
			return true;
		}
		if(XML_GetErrorCode(p) == XML_ERROR_FINISHED &&
		   iswhitespace(data, size))
		{
			return true;
		}
		if(done && XML_GetErrorCode(p) == XML_ERROR_UNCLOSED_TOKEN)
		{
			return true;
		}
		parseError(data, size, XML_ErrorString(XML_GetErrorCode(p)),
		           (int)XML_GetCurrentLineNumber(p));
		return false;
	}

	if(done)
	{
		if(!XML_Parse(p, data, 0, true))
		{
			if(XML_GetErrorCode(p) == XML_ERROR_JUNK_AFTER_DOC_ELEMENT)
			{
				return true;
			}
			if(XML_GetErrorCode(p) == XML_ERROR_FINISHED &&
			   iswhitespace(data, size))
			{
				return true;
			}
			if(XML_GetErrorCode(p) == XML_ERROR_UNCLOSED_TOKEN)
			{
				return true;
			}
			parseError(data, 0, XML_ErrorString(XML_GetErrorCode(p)),
			           (int)XML_GetCurrentLineNumber(p));
			return false;
		}
	}

	if(done)
	{
		DEBUG(sax, "Got END_OF_DOCUMENT [%s] at %ld\n",
		      outertag.c_str(), XML_GetCurrentByteIndex(p));
	}

	return done;
}

void SAXParser::parseError(const char *buf, size_t len,
                           std::string error, int lineno)
{
	fprintf(stderr, "SAXParser error at line %d: %s\n", lineno, error.c_str());
	fprintf(stderr, "\tBuffer %u bytes: [", (int)len);
	if(fwrite(buf, len, 1, stderr) != len) {}
	fprintf(stderr, "]\n");
	fflush(stderr);
}

unsigned int SAXParser::usedBytes()
{
	return bufferbytes + (XML_GetCurrentByteIndex(p) - totalbytes);
}

int SAXParser::readData(char *, size_t)
{
	return 0;
}

void SAXParser::endTag(std::string)
{
}

void SAXParser::startTag(std::string, attributes_t &)
{
}

void SAXParser::characterData(const std::string &)
{
}