////////////////////////////////////////////////////////////////////////////////
// taskwarrior - a command line task list manager.
//
// Copyright 2006 - 2011, Paul Beckingham, Federico Hernandez.
// All rights reserved.
//
// 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.,
//     51 Franklin Street, Fifth Floor,
//     Boston, MA
//     02110-1301
//     USA
//
////////////////////////////////////////////////////////////////////////////////

#include <Subst.h>
#include <Nibbler.h>
#include <Directory.h>
#include <Context.h>
#include <text.h>
#include <rx.h>
#include <i18n.h>
#include <main.h>

extern Context context;

////////////////////////////////////////////////////////////////////////////////
Subst::Subst ()
: mFrom ("")
, mTo ("")
, mGlobal (false)
{
}

////////////////////////////////////////////////////////////////////////////////
Subst::Subst (const std::string& input)
{
  parse (input);
}

////////////////////////////////////////////////////////////////////////////////
Subst::Subst (const Subst& other)
{
  mFrom   = other.mFrom;
  mTo     = other.mTo;
  mGlobal = other.mGlobal;
}

////////////////////////////////////////////////////////////////////////////////
Subst& Subst::operator= (const Subst& other)
{
  if (this != &other)
  {
    mFrom   = other.mFrom;
    mTo     = other.mTo;
    mGlobal = other.mGlobal;
  }

  return *this;
}

////////////////////////////////////////////////////////////////////////////////
Subst::~Subst ()
{
}

////////////////////////////////////////////////////////////////////////////////
// A Path and a Subst may look similar, and so the rule is that if a Subst looks
// like a path, it must also not exist in the file system in order to actually
// be a Subst.
bool Subst::valid (const std::string& input) const
{
  std::string ignored;
  Nibbler n (input);
  if (n.skip     ('/')            &&
      n.getUntil ('/', ignored)   &&
      n.skip     ('/')            &&
      n.getUntil ('/', ignored)   &&
      n.skip     ('/'))
  {
    n.skip ('g');
    if (n.depleted ())
      return ! Directory (input).exists ();
  }

  return false;
}

////////////////////////////////////////////////////////////////////////////////
void Subst::parse (const std::string& input)
{
  Nibbler n (input);
  if (n.skip     ('/')        &&
      n.getUntil ('/', mFrom) &&
      n.skip     ('/')        &&
      n.getUntil ('/', mTo)   &&
      n.skip     ('/'))
  {
      mGlobal = n.skip ('g');

    if (mFrom == "")
      throw std::string ("Cannot substitute an empty string.");

    if (!n.depleted ())
      throw std::string ("Unrecognized character(s) at end of substitution.");
  }
  else
    throw std::string ("Malformed substitution.");
}

////////////////////////////////////////////////////////////////////////////////
void Subst::apply (
  std::string& description,
  std::vector <Att>& annotations) const
{
  std::string::size_type pattern;
  bool sensitive = context.config.getBoolean ("search.case.sensitive");

  if (mFrom != "")
  {
#ifdef FEATURE_REGEX
    if (context.config.getBoolean ("regex"))
    {
      // Insert capturing parentheses, if necessary.
      std::string pattern;
      if (mFrom.find ('(') != std::string::npos)
        pattern = mFrom;
      else
        pattern = "(" + mFrom + ")";

      std::vector <int> start;
      std::vector <int> end;

      // Perform all subs on description.
      int counter = 0;
      if (regexMatch (start, end, description, pattern, sensitive))
      {
        for (unsigned int i = 0; i < start.size (); ++i)
        {
          description.replace (start[i], end[i] - start[i], mTo);
          if (!mGlobal)
            break;

          if (++counter > 1000)
            throw ("Terminated substitution because more than a thousand changes were made - infinite loop protection.");
        }
      }

      // Perform all subs on annotations.
      counter = 0;
      std::vector <Att>::iterator i;
      for (i = annotations.begin (); i != annotations.end (); ++i)
      {
        std::string annotation = i->value ();
        start.clear ();
        end.clear ();

        if (regexMatch (start, end, annotation, pattern, sensitive))
        {
          for (unsigned int match = 0; match < start.size (); ++match)
          {
            annotation.replace (start[match], end[match] - start[match], mTo);
            i->value (annotation);
            if (!mGlobal)
              break;

            if (++counter > 1000)
              throw ("Terminated substitution because more than a thousand changes were made - infinite loop protection.");
          }
        }
      }
    }
    else
    {
#endif
      if (mGlobal)
      {
        // Perform all subs on description.
        int counter = 0;
        pattern = 0;

        while ((pattern = find (description, mFrom, pattern, sensitive)) != std::string::npos)
        {
          description.replace (pattern, mFrom.length (), mTo);
          pattern += mTo.length ();

          if (++counter > 1000)
            throw ("Terminated substitution because more than a thousand changes were made - infinite loop protection.");
        }

        // Perform all subs on annotations.
        counter = 0;
        std::vector <Att>::iterator i;
        for (i = annotations.begin (); i != annotations.end (); ++i)
        {
          pattern = 0;
          std::string annotation = i->value ();
          while ((pattern = find (annotation, mFrom, pattern, sensitive)) != std::string::npos)
          {
            annotation.replace (pattern, mFrom.length (), mTo);
            pattern += mTo.length ();

            i->value (annotation);

            if (++counter > 1000)
              throw ("Terminated substitution because more than a thousand changes were made - infinite loop protection.");
          }
        }
      }
      else
      {
        // Perform first description substitution.
        if ((pattern = find (description, mFrom, sensitive)) != std::string::npos)
          description.replace (pattern, mFrom.length (), mTo);

        // Failing that, perform the first annotation substitution.
        else
        {
          std::vector <Att>::iterator i;
          for (i = annotations.begin (); i != annotations.end (); ++i)
          {
            std::string annotation = i->value ();
            if ((pattern = find (annotation, mFrom, sensitive)) != std::string::npos)
            {
              annotation.replace (pattern, mFrom.length (), mTo);
              i->value (annotation);
              break;
            }
          }
        }
      }
#ifdef FEATURE_REGEX
    }
#endif
  }
}

////////////////////////////////////////////////////////////////////////////////
void Subst::clear ()
{
  mFrom = "";
  mTo = "";
  mGlobal = false;
}

////////////////////////////////////////////////////////////////////////////////