/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/***************************************************************************
 *            macro_parser.cc
 *
 *  Mon Sep 24 10:49:55 CEST 2007
 *  Copyright 2007 Bent Bisballe Nyeng, Lars Bisballe Jensen and Peter Skaarup
 *  deva@aasimon.org, elsenator@gmail.com and piparum@piparum.dk
 ****************************************************************************/

/*
 *  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 "macro_parser.h"

// For XML
#include <config.h>

// For open, read and close
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

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

#include <string>
#include <map>

class MacroParser {
public:
  Macro *macro;
  std::vector< Widget* > stack;
  bool done;
};

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

  //  printf("Start tag [%s]\n", el);

  // 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));
  }

  // Do something reasonable with them...

  if(name == "include") {

    Macro inc;
    parse_macro(attributes["name"], inc);

    WidgetList::iterator w = inc.widgets.front().widgets.begin();
    while(w != inc.widgets.front().widgets.end()) {
      parser->stack.back()->widgets.push_back(*w);
      w++;
    }

    return; // Don't do further parsing of this tag.
  }

  Widget widget;
  widget.type = name;

  Widget *wp;

  if(parser->stack.size() > 0) {// We only pushback the child if there is a parent.
    parser->stack.back()->widgets.push_back(widget);
    wp = &parser->stack.back()->widgets.back();
  } else {
    parser->macro->widgets.push_back(widget);
    wp = &parser->macro->widgets.back();
  }
  parser->stack.push_back(wp);

  std::map< std::string, std::string >::iterator i = attributes.begin();
  while(i != attributes.end()) {
    WidgetProperty prop;
    prop.name = i->first;
    prop.value = i->second;

    wp->properties.push_back(prop);

    i++;
  }
}

static void end_hndl(void *p, const char *el)
{
  MacroParser *parser = (MacroParser*)XML_GetUserData(p);
 
  //  printf("End tag [%s]\n", el);

  if(std::string("include") != el) parser->stack.pop_back();

  if(!strcmp(el, "macro")) parser->done = true;
}

void parse_macro(std::string name, Macro &macro)
{

  XML_Parser p = XML_ParserCreate(NULL);
  if (! p) {
    fprintf(stderr, "Couldn't allocate memory for parser\n");
    // throw Exception(...);
    return;
  }

  MacroParser parser;
  parser.macro = &macro;
  parser.done = false;

  XML_SetUserData(p, &parser);
  XML_UseParserAsHandlerArg(p);
  XML_SetElementHandler(p, start_hndl, end_hndl);

  std::string macrofile = std::string(XML) + "/" + name + ".xml";
  int fd = open(macrofile.c_str(), O_RDONLY);

  if(fd == -1) {
    printf("Cannot open file \"%s\"...", macrofile.c_str());
    printf("failed!\n");
    return;
  }

  while(!parser.done) {
    char buf[32];
    int len;

    memset(buf, 0, sizeof(buf));
    len = read(fd, buf, sizeof(buf) - 1);

    parser.done = len == 0;

    if (! XML_Parse(p, buf, len, parser.done)) {
      fprintf(stderr, "Parse error at line %d:\n%s\n",
	      XML_GetCurrentLineNumber(p),
	      XML_ErrorString(XML_GetErrorCode(p)));
      // throw Exception(...);
      return;
    }
  }

  //  printf("%d requests\n", transaction.requests.size());
}