/*  G-Cows - scripting language for creation of web sites
    Copyright (C) 2002, 2003, 2004, 2005, 2006 Andrea Sozzi

This file is part of G-Cows.

G-Cows 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, or (at your option)
any later version.

G-Cows 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; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#include <unistd.h>
#include <cerrno>
#include <fstream>
#include "file_utils.H"
#include "error.H"

using namespace std;

/* Remove unnecessary components in file names; e.g /foo/./bar/../foo
   is converted in /foo/foo.  */

string
opt_file_name (string file_name, bool full_opt) 
{
  //unsigned int slash, end;
  string::size_type slash, end;

  int parents = 0;
  string opt_file;
  end = slash = file_name.rfind ('/');
  string file = file_name.substr (slash + 1, file_name.length ());
  while ( (slash != string::npos) && (slash != 0) ) {
    slash = file_name.rfind ("/", slash - 1);
    string file_name_fragment = file_name.substr (slash + 1, end - slash);
    if ( ( (slash == string::npos) || (slash == 0) ) 
         && ! full_opt && (file_name_fragment == "./") )
      continue;
    if ( file_name_fragment == "../" ) 
      parents++;
    else if ( file_name_fragment != "./" ) 
      {
        if (parents > 0) 
          parents--;
        else 
          opt_file = file_name_fragment + opt_file;
      }
    end = slash;
  }
  string prepend = file_name.substr (0, end+1);
  while ( parents--) 
    prepend += "../";
  return prepend + opt_file + file;
}


char *
get_w_dir () 
{
  int length = 100;
  char *w_dir = new char [length];
  while ( ! (w_dir = getcwd (w_dir, length))) 
    {
      if (errno != ERANGE) 
        Msg::inst()->sys_fatal ("Can't get current dir");
      else 
        {
          delete [] w_dir;
          length *= 2;
          w_dir = new char [length];
        }
    }
  return w_dir;
}


int
set_f_w_dir (string file) 
{
  string dir_name = get_dir_from_file_name (file);
  if ( dir_name != "" )
    if (chdir (dir_name.c_str ()))
      return EXIT_FAILURE;
  return EXIT_SUCCESS;
}


string 
get_dir_from_file_name (string file_name) 
{
  // unsigned int last_slash;
  string::size_type last_slash;
  if ( (last_slash = file_name.rfind ("/")) != string::npos )
    return file_name.substr (0, last_slash) + "/";
  return "";
}

string 
strip_dir (string file_name) 
{
  // unsigned int last_slash;
  string::size_type last_slash;
  if ( (last_slash = file_name.rfind ("/")) != string::npos )
    return file_name.substr (last_slash + 1);
  return file_name;
}


int
get_dir_level () 
{
  int start = -1, level = 1;
  string w_dir;
  char *w_dir_char = get_w_dir ();
  if (w_dir_char) 
    {
      w_dir = w_dir_char;
      while ((start=w_dir.find ("/", start + 1)) != (int)string::npos )
        level++;
      return level;
    }
  else
    return -1;
}

int
get_dir_level (string file_name) 
{
  int start = -1, level = 1;
  string target_file;
  if (*file_name.c_str() == '/')  // absolute file name
    target_file = file_name;
  else 
    {  
      // relative file name .. convert to absolute
      char *w_dir_char = get_w_dir ();
      // if (! w_dir_char)
      //  Msg::inst()->sys_fatal ("Can't get current dir");
      target_file = string (w_dir_char) + string ("/") + file_name;
    }
  target_file = opt_file_name (target_file);
  while ((start=target_file.find ("/", start + 1)) != (int)string::npos )
    level++;
  return level-1;
}

string
to_absolute (string file) 
{
  if (*file.c_str () != '/')
    return string (get_w_dir ()) + "/" + file;
  else 
    return file;
}


string 
add_slash (string file) 
{
  if ( (file == "") || ( *(file.c_str () + file.length () - 1) == '/') )
    return file;
  else
    return file + "/";
}


bool
file_exists (string file)
{
  ifstream input_stream;
  input_stream.open (file.c_str (), ios::in);
  if (input_stream.is_open() )
    {
      input_stream.close();
      return true;
    }
  else
    {
      return false;
    }
}