#include "GaudiKernel/PathResolver.h"
#include "GaudiKernel/System.h"

#ifdef WIN32
// Disable warning
//   C4996: 'std::copy': Function call with parameters that may be unsafe
// Probably coming from Boost classification.
#pragma warning(disable:4996)
#endif

#include <iostream>
#include <string>
#include <vector>
#include <stdlib.h>

#include <boost/algorithm/string/split.hpp>
#include <boost/algorithm/string/classification.hpp>
#include <boost/filesystem.hpp>

namespace bf = boost::filesystem;
using namespace std;

#ifdef _WIN32
  static const char* path_separator = ",;";
#else
  static const char* path_separator = ",:";
#endif

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

namespace System {

typedef enum {
  PR_regular_file,
  PR_directory
} PR_file_type;

typedef enum {
  PR_local,
  PR_recursive
} PR_search_type;

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

static bool
PR_find( const bf::path& file, const string& search_list,
         PR_file_type file_type, PathResolver::SearchType search_type,
         string& result ) {

  bool found(false);

  // look for file as specified first

  try {
    if ( ( file_type == PR_regular_file && is_regular_file( file ) ) ||
         ( file_type == PR_directory && is_directory( file ) ) ) {
      result = bf::complete(file).string();
      return true;
    }
  } catch (bf::filesystem_error /*err*/) {
  }

  // assume that "." is always part of the search path, so check locally first

  try {
    bf::path local = bf::initial_path() / file;
    if ( ( file_type == PR_regular_file && is_regular_file( local ) ) ||
         ( file_type == PR_directory && is_directory( local ) ) ) {
      result = bf::complete(file).string();
      return true;
    }
  } catch (bf::filesystem_error /*err*/) {
  }


  // iterate through search list
  vector<string> spv;
  split(spv, search_list, boost::is_any_of( path_separator), boost::token_compress_on);
  for (vector<string>::const_iterator itr = spv.begin();
       itr != spv.end(); ++itr ) {

    bf::path fp = *itr / file;

    try {
      if ( ( file_type == PR_regular_file && is_regular_file( fp ) ) ||
           ( file_type == PR_directory && is_directory( fp ) ) ) {
        result = bf::complete(fp).string();
        return true;
      }
    } catch (bf::filesystem_error /*err*/) {
    }


    // if recursive searching requested, drill down
    if (search_type == PathResolver::RecursiveSearch &&
        is_directory( bf::path(*itr) ) ) {

      bf::recursive_directory_iterator end_itr;
      try {
        for ( bf::recursive_directory_iterator ritr( *itr );
              ritr != end_itr; ++ritr) {

          // skip if not a directory
          if (! is_directory( bf::path(*ritr) ) ) { continue; }

          bf::path fp2 = bf::path(*ritr) / file;
          if ( ( file_type == PR_regular_file && is_regular_file( fp2 ) ) ||
               ( file_type == PR_directory && is_directory( fp2 ) ) ) {
            result = bf::complete( fp2 ).string();
            return true;
          }
        }
      } catch (bf::filesystem_error /*err*/) {
      }
    }

  }

  return found;
}

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

string
PathResolver::find_file(const std::string& logical_file_name,
              const std::string& search_path,
              SearchType search_type) {

  std::string path_list;
  System::getEnv(search_path, path_list);

  return (find_file_from_list (logical_file_name, path_list, search_type));
}

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

std::string
PathResolver::find_file_from_list (const std::string& logical_file_name,
                                   const std::string& search_list,
                                   SearchType search_type)
{
  std::string result("");

  bf::path lfn( logical_file_name );

  /* bool found = */
  PR_find (lfn, search_list, PR_regular_file, search_type, result);

  // The following functionality was in the original PathResolver, but I believe
  // that it's WRONG. It extracts the filename of the requested item, and searches
  // for that if the preceding search fails. i.e., if you're looking for "B/a.txt",
  // and that fails, it will look for just "a.txt" in the search list.

  // if (! found && lfn.filename() != lfn ) {
  //   result = "";
  //   PR_find (lfn.filename(), search_list, PR_regular_file, search_type, result);
  // }

  return (result);
}

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

string PathResolver::find_directory (const std::string& logical_file_name,
                                     const std::string& search_path,
                                     SearchType search_type)
{
  std::string path_list;
  System::getEnv(search_path, path_list);

  return (find_directory_from_list (logical_file_name, path_list, search_type));
}

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

string
PathResolver::find_directory_from_list (const std::string& logical_file_name,
                                        const std::string& search_list,
                                        SearchType search_type)
{
  std::string result;

  if (!PR_find (logical_file_name, search_list, PR_directory, search_type, result))
  {
    result = "";
  }

  return (result);
}


/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

PathResolver::SearchPathStatus
PathResolver::check_search_path (const std::string& search_path)
{
  std::string path_list;
  if ( ! System::getEnv(search_path, path_list) )
    return (EnvironmentVariableUndefined);

  vector<string> spv;
  boost::split( spv, path_list, boost::is_any_of( path_separator ), boost::token_compress_on);
  vector<string>::iterator itr=spv.begin();

  try {
    for (; itr!= spv.end(); ++itr) {
      bf::path pp(*itr);
      if (!is_directory(pp)) {
        return (UnknownDirectory);
      }
    }
  } catch(bf::filesystem_error /*err*/) {
    return (UnknownDirectory);
  }

  return ( Ok );
}

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

std::string PathResolverFindXMLFile (const std::string& logical_file_name)
{
  return PathResolver::find_file (logical_file_name, "XMLPATH");
}

std::string PathResolverFindDataFile (const std::string& logical_file_name)
{
  return PathResolver::find_file (logical_file_name, "DATAPATH");
}

}  // System namespace