// Filename: virtualFile.cxx
// Created by:  drose (03Aug02)
//
////////////////////////////////////////////////////////////////////
//
// PANDA 3D SOFTWARE
// Copyright (c) 2001, Disney Enterprises, Inc.  All rights reserved
//
// All use of this software is subject to the terms of the Panda 3d
// Software license.  You should have received a copy of this license
// along with this source code; you will also find a current copy of
// the license at http://www.panda3d.org/license.txt .
//
// To contact the maintainers of this program write to
// panda3d@yahoogroups.com .
//
////////////////////////////////////////////////////////////////////

#include "virtualFile.h"
#include "virtualFileSystem.h"
#include "virtualFileList.h"
#include "config_util.h"

TypeHandle VirtualFile::_type_handle;

////////////////////////////////////////////////////////////////////
//     Function: VirtualFile::is_directory
//       Access: Published, Virtual
//  Description: Returns true if this file represents a directory (and
//               scan_directory() may be called), false otherwise.
////////////////////////////////////////////////////////////////////
bool VirtualFile::
is_directory() const {
  return false;
}

////////////////////////////////////////////////////////////////////
//     Function: VirtualFile::is_regular_file
//       Access: Published, Virtual
//  Description: Returns true if this file represents a regular file
//               (and read_file() may be called), false otherwise.
////////////////////////////////////////////////////////////////////
bool VirtualFile::
is_regular_file() const {
  return false;
}

////////////////////////////////////////////////////////////////////
//     Function: VirtualFile::read_file
//       Access: Published
//  Description: Fills up the indicated Datagram with the contents of
//               the file, if it is a regular file.  Returns true on
//               success, false otherwise.
////////////////////////////////////////////////////////////////////
bool VirtualFile::
read_file(Datagram &data) const {
  data.clear();

  istream *in = open_read_file();
  if (in == (istream *)NULL) {
    util_cat.info()
      << "Unable to read " << get_filename() << "\n";
    return false;
  }
  int byte = in->get();
  while (!in->eof() && !in->fail()) {
    data.add_int8(byte);
    byte = in->get();
  }
  bool failed = in->fail();
  delete in;

  if (failed) {
    util_cat.info()
      << "Error while reading " << get_filename() << "\n";
  }
  return failed;
}

////////////////////////////////////////////////////////////////////
//     Function: VirtualFile::open_read_file
//       Access: Published, Virtual
//  Description: Opens the file for reading.  Returns a newly
//               allocated istream on success (which you should
//               eventually delete when you are done reading).
//               Returns NULL on failure.
////////////////////////////////////////////////////////////////////
istream *VirtualFile::
open_read_file() const {
  return NULL;
}

////////////////////////////////////////////////////////////////////
//     Function: VirtualFile::scan_directory
//       Access: Published
//  Description: If the file represents a directory (that is,
//               is_directory() returns true), this returns the list
//               of files within the directory at the current time.
//               Returns NULL if the file is not a directory or if the
//               directory cannot be read.
////////////////////////////////////////////////////////////////////
PT(VirtualFileList) VirtualFile::
scan_directory() const {
  // First, we have to make sure there aren't any mount points attached
  // under this directory.  These will override any local filenames.
  VirtualFileSystem *file_system = get_file_system();
  Filename this_filename = get_filename();
  vector_string mount_points_flat;
  file_system->scan_mount_points(mount_points_flat, this_filename);

  // Copy the set of nested mount points to a sorted list so we can
  // search it quickly.
  ov_set<string> mount_points;
  copy(mount_points_flat.begin(), mount_points_flat.end(),
       back_inserter(mount_points));
  mount_points.sort();

  
  PT(VirtualFileList) file_list = new VirtualFileList;

  // Each of those mount points maps to a directory root or something
  // from the file system.
  ov_set<string>::const_iterator mi;
  for (mi = mount_points.begin(); mi != mount_points.end(); ++mi) {
    const string &basename = (*mi);
    Filename filename(this_filename, basename);
    PT(VirtualFile) file = file_system->get_file(filename);
    file_list->add_file(file);
  }

  // Now, get the actual local files in this directory.
  vector_string names;
  if (!scan_local_directory(file_list, mount_points)) {
    // Not a directory, or unable to read directory.
    if (file_list->get_num_files() == 0) {
      return NULL;
    }

    // We couldn't read the physical directory, but we do have some
    // mounted files to return.
    return file_list;
  }

  return file_list;
}

////////////////////////////////////////////////////////////////////
//     Function: VirtualFile::output
//       Access: Published
//  Description: 
////////////////////////////////////////////////////////////////////
void VirtualFile::
output(ostream &out) const {
  out << get_filename();
}

////////////////////////////////////////////////////////////////////
//     Function: VirtualFile::ls
//       Access: Published
//  Description: If the file represents a directory, lists its
//               contents.
////////////////////////////////////////////////////////////////////
void VirtualFile::
ls(ostream &out) const {
  CPT(VirtualFileList) contents = scan_directory();
  if (contents == NULL) {
    if (!is_directory()) {
      out << get_filename() << " is not a directory.\n";
    } else {
      out << get_filename() << " cannot be read.\n";
    }
    return;
  }

  int num_files = contents->get_num_files();
  for (int i = 0; i < num_files; i++) {
    VirtualFile *file = contents->get_file(i);
    out << file->get_filename().get_basename() << "\n";
  }
}

////////////////////////////////////////////////////////////////////
//     Function: VirtualFile::ls_all
//       Access: Published
//  Description: If the file represents a directory, recursively lists
//               its contents and those of all subdirectories.
////////////////////////////////////////////////////////////////////
void VirtualFile::
ls_all(ostream &out) const {
  if (!is_directory()) {
    out << get_filename() << " is not a directory.\n";
  } else {
    r_ls_all(out, get_filename());
  }
}

////////////////////////////////////////////////////////////////////
//     Function: VirtualFile::scan_local_directory
//       Access: Protected, Virtual
//  Description: Fills file_list up with the list of files that are
//               within this directory, excluding those whose
//               basenames are listed in mount_points.  Returns true
//               if successful, false if the file is not a directory
//               or the directory cannot be read.
////////////////////////////////////////////////////////////////////
bool VirtualFile::
scan_local_directory(VirtualFileList *, const ov_set<string> &) const {
  return false;
}

////////////////////////////////////////////////////////////////////
//     Function: VirtualFile::r_ls_all
//       Access: Private
//  Description: The recursive implementation of ls_all().
////////////////////////////////////////////////////////////////////
void VirtualFile::
r_ls_all(ostream &out, const Filename &root) const {
  CPT(VirtualFileList) contents = scan_directory();
  if (contents == NULL) {
    return;
  }

  int num_files = contents->get_num_files();
  for (int i = 0; i < num_files; i++) {
    VirtualFile *file = contents->get_file(i);
    Filename filename = file->get_filename();
    filename.make_relative_to(root);
    out << filename << "\n";
    if (file->is_directory()) {
      file->r_ls_all(out, root);
    }
  }
}