#! /usr/bin/env python
"""XML Virtual FileSystem for Midnight Commander

The script requires Midnight Commander 3.1+
(http://www.midnight-commander.org/), Python 2.4+ (http://www.python.org/).

For mc 4.7+ put the script in $HOME/.mc/extfs.d.
For older versions put it in /usr/[local/][lib|share]/mc/extfs
and add a line "xml" to the /usr/[local/][lib|share]/mc/extfs/extfs.ini.
Make the script executable.

Run this "cd" command in the Midnight Commander (in the "bindings" file the
command is "%cd"): cd file.xml#xml, where "file.xml" is the name of your xml
file.

The VFS represents tags as directories; the directories are numbered to
distinguish tags with the same name. Attributes, text nodes and comments are
represented as files. The filesystem is read-only.

The VFS was inspired by a FUSE xmlfs: https://github.com/halhen/xmlfs

"""

__version__ = "0.1.0"
__author__ = "Oleg Broytman <phd@phdru.name>"
__copyright__ = "Copyright (C) 2013 PhiloSoft Design"
__license__ = "GPL"

import math
import sys
import xml.dom.minidom

try:
   import locale
   use_locale = True
except ImportError:
   use_locale = False

if use_locale:
   # Get the default charset.
   try:
      lcAll = locale.getdefaultlocale()
   except locale.Error, err:
      print >>sys.stderr, "WARNING:", err
      lcAll = []

   if len(lcAll) == 2:
      default_encoding = lcAll[1]
   else:
      try:
         default_encoding = locale.getpreferredencoding()
      except locale.Error, err:
         print >>sys.stderr, "WARNING:", err
         default_encoding = sys.getdefaultencoding()
else:
   default_encoding = sys.getdefaultencoding()

import logging
logger = logging.getLogger('xml-mcextfs')
log_err_handler = logging.StreamHandler(sys.stderr)
logger.addHandler(log_err_handler)
logger.setLevel(logging.INFO)

if len(sys.argv) < 3:
    logger.critical("""\
XML Virtual FileSystem for Midnight Commander version %s
Author: %s
%s

This is not a program. Put the script in $HOME/.mc/extfs.d or
/usr/[local/][lib|share]/mc/extfs. For more information read the source!""",
   __version__, __author__, __copyright__
)
    sys.exit(1)

locale.setlocale(locale.LC_ALL, '')


def _list(node, path=''):
    childNodes = node.childNodes
    n = 0
    for element in childNodes:
        if element.localName:
            n += 1
    if n:
        width = int(math.log10(n))+1
        template = "%%0%dd" % width
    else:
        template = "%d"
    n = 0
    for element in childNodes:
        if element.localName:
            n += 1
            if path:
                subpath = '%s/%s %s' % (path, template % n, element.localName)
            else:
                subpath = '%s %s' % (template % n, element.localName)
            subpath_encoded = subpath.encode(default_encoding, "replace")
            print "dr--r--r-- 1 user group 0 Jan 1 00:00 %s" % subpath_encoded
            _list(element, subpath)

def mcxml_list():
    """List the entire VFS"""

    dom = xml.dom.minidom.parse(sys.argv[2])
    _list(dom)


def mcxml_copyout():
    """Extract a file from the VFS"""


def mcxml_copyin():
    """Put a file to the VFS"""
    sys.exit("XML VFS doesn't support adding files (read-only filesystem)")

def mcxml_rm():
    """Remove a file from the VFS"""
    sys.exit("XML VFS doesn't support removing files/directories (read-only filesystem)")

mcxml_rmdir = mcxml_rm

def mcxml_mkdir():
    """Create a directory in the VFS"""
    sys.exit("XML VFS doesn't support creating directories (read-only filesystem)")


command = sys.argv[1]
procname = "mcxml_" + command

g = globals()
if not g.has_key(procname):
    logger.critical("Unknown command %s", command)
    sys.exit(1)

try:
    g[procname]()
except SystemExit:
    raise
except:
    logger.exception("Error during run")