/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/***************************************************************************
 *            mltokenizer.cc
 *
 *  Tue Nov  4 08:46:35 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 "mltokenizer.h"

static std::string rereplaceescaping(std::string mlvalue)
{
  std::string output;
  size_t i = 0;
  while(i < mlvalue.length()) {
    if(mlvalue[i] == '\1') {
      output += '{';
      i++;
    } else if(mlvalue[i] == '\2') {
      output += '}';
      i++;
    } else {
      output += mlvalue[i];
      i++;
    }
  }
  return output;
}

static std::string replaceescaping(std::string mlvalue)
{
  std::string output;
  size_t i = 0;
  while(i < mlvalue.length()) {
    if(i < mlvalue.length() - 1 && mlvalue[i] == '{' && mlvalue[i + 1] == '{') {
      output += '\1';
      i+=2;
    } else if(i < mlvalue.length() - 1 && mlvalue[i] == '}' && mlvalue[i + 1] == '}') {
      output += '\2';
      i+=2;
    } else {
      output += mlvalue[i];
      i++;
    }
  }
  return output;
}

static std::string gettoken(std::string input, size_t start, std::string term)
{
  std::string output;

  size_t i = start;
  while(i < input.length()) {

    size_t j = 0;
    while(j < term.length()) {
      if(input[i] == term[j]) return output;
      j++;
    }

    output += input[i];
    i++;
  }

  return output;
}

typedef enum {
  NAME,
  VALUE,
  TEXT,
  ENDOFITEM,
  UNDEFINED
} tokenizerstate_t;

std::vector< mltoken_t > mltokenize(std::string mlvalue)
{
  std::vector< mltoken_t > tokens;

  mlvalue = replaceescaping(mlvalue);
  
  tokenizerstate_t state = UNDEFINED;
  mltoken_t token;
  size_t i = 0;
  while(i < mlvalue.length()) {
    switch(state) {
    case NAME:
      token.name = gettoken(mlvalue, i, "|");
      i += token.name.length() + 1;
      token.type = MLTT_VALUE;
      token.value = "";
      state = VALUE;
      break;

    case VALUE:
      token.value = gettoken(mlvalue, i, "}\n");
      i += token.value.length() + 1;

      token.value = rereplaceescaping(token.value);
      token.type = MLTT_VALUE;
      tokens.push_back(token);

      state = UNDEFINED;
      break;

    case TEXT:
      if(mlvalue[i] == '$') token.value = "$";
      else token.value = gettoken(mlvalue, i, "$\n");
      i += token.value.length();

      token.value = rereplaceescaping(token.value);
      token.type = MLTT_TEXT;
      token.name = "";
      if(tokens.size() && tokens.back().type == MLTT_TEXT) tokens.back().value += token.value;
      else tokens.push_back(token);

      state = UNDEFINED;
      break;

    case ENDOFITEM:
      token.value = "\n";
      i++;

      token.type = MLTT_ENDOFITEM;
      token.name = "";
      tokens.push_back(token);

      state = UNDEFINED;
      break;

    case UNDEFINED:
      switch(mlvalue[i]) {
      case '$':
        if(i < mlvalue.length() - 1 && mlvalue[i + 1] == '{') { i++; break; } // ignore
        else { state = TEXT; break; }
      case '{': state = NAME; i++; break;
      case '\n': state = ENDOFITEM; break;
      default: state = TEXT; break;
      }
    }
  }

  if(state != UNDEFINED) {
    printf("Oups... missed something in the end!\n");
    tokens.push_back(token); 
  }

  return tokens;
}

#ifdef TEST_MLTOKENIZER

int main()
{
  std::string mlvalue = "$ab}}c\ndef ${na$me|${{va$lue}}}\n12${34}\n";

  std::vector< mltoken_t > tokens = mltokenize(mlvalue);
  std::vector< mltoken_t >::iterator i = tokens.begin();
  while(i != tokens.end()) {
    printf("Token:\n");
    printf("\tType: ");
    switch(i->type) {
    case MLTT_VALUE: printf("VALUE\n"); break;
    case MLTT_TEXT: printf("TEXT\n"); break;
    case MLTT_ENDOFITEM: printf("ENDOFITEM\n"); break;
    case MLTT_UNDEFINED: printf("UNDEFINED\n"); break;
    }
    printf("\tName: %s\n", i->name.c_str());
    printf("\tValue: %s\n", i->value.c_str());
    printf("\n");
    i++;
  }

  return 0;
}

#endif