#include <time.h>
#include <sys/stat.h>
#include <map>
#include "SearchPath.h"


const char SearchPath::dirSep  = '/';
const char SearchPath::pathSep = ':';


SearchPath::SearchPath( const char *envar, const string &fallbacks )
{
  if (envar) {
    const char * const envalue = getenv( envar );
    if (envalue) addPaths( envalue );
  }
  if (empty()) addPaths( fallbacks );
}


void SearchPath::addPaths( const string &paths )
{
  typedef string::size_type pos;
  pos begin = 0;
    
  for (;;) {
    const pos end = paths.find( pathSep, begin );
    if (end == string::npos) {
      addPath( paths.substr( begin ) );
      break;
    } else {
      addPath( paths.substr( begin, end - begin ) );
      begin = end + 1;
    }
  }
}


void SearchPath::addPath( const string &path )
{
  if (!path.empty())
    push_back( path + dirSep );
}


DIR *SearchPath::opendir( string &target ) const
{
  for (const_iterator candidate = begin(); candidate != end(); candidate++) {
    const string fullname = *candidate + target;
    DIR * const directory = ::opendir( fullname.c_str() );
    if (directory) {
      target = fullname;
      return directory;
    }
  }
  return 0;
}


FILE *SearchPath::openSource( string &target ) const
{
  for (const_iterator candidate = begin(); candidate != end(); candidate++) {
    FILE *file;
    if ((file = tryOpen( *candidate, target, "ti"   ))) return file;
    if ((file = tryOpen( *candidate, target, "java" ))) return file;
  }
  return 0;
}


FILE *SearchPath::tryOpen( const string &directory, string &target, const char suffix[] ) const
{
  const string fullname = directory + target + '.' + suffix;
  FILE * const file = ti_fopen( fullname.c_str(), "r" );

  if (file) {
    target = fullname;
    return file;
  } else
    return 0;
}

/* special versions of fopen/fclose that maintain filename info */
static map<FILE *, string *> fname_map;
FILE *ti_fopen(const char *path, const char *mode) {
  FILE *fp = ::fopen(path, mode);
  if (fp) {
    char fullpath[PATH_MAX]; /* make path canonical */
    if (!realpath(path,fullpath)) strcpy(fullpath, path);
    fname_map[fp] = new string(fullpath); 
  }
  return fp;
}
int ti_fclose(FILE *stream) {
  int retval = ::fclose(stream);
  if (!retval) {
    map<FILE *, string *>::iterator it = fname_map.find(stream);
    delete (*it).second;
    fname_map.erase(it); 
  }
  return retval;
}
string *ti_fname(FILE *stream) {
  return fname_map[stream];
}