# file.py - handle urls with a file scheme
#
# Copyright (C) 1998, 1999 Albert Hopkins (marduk)
# Copyright (C) 2002 Mike W. Meyer
# Copyright (C) 2005 Arthur de Jong
#
# This program 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 of the License, or
# (at your option) any later version.
#
# This program 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; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA

"""This module defines the functions needed for creating Link objects for urls
using the file scheme."""

import debugio
import urlparse
import urllib
import os
import mimetypes

def _fetch_directory(link, path, acceptedtypes):
    # if the name does not end with a slash, redirect
    if path[-1:] != os.path.sep:
        debugio.debug('directory referenced without trailing slash')
        link.redirectdepth = 1
        link.add_child(urlparse.urljoin(link.url,link.path+'/'))
        return
    if os.path.isfile(os.path.join(path,'index.html')):
        debugio.debug('pick up index.html from directory')
        # the the directory contains an index.html, use that
        return _fetch_file(link, os.path.join(path,'index.html'), acceptedtypes)
    else:
        # otherwise add the directory's files as children
        debugio.debug('add files as children of this page')
        try:
            link.ispage = True
            for f in os.listdir(path):
                link.add_child(urlparse.urljoin(link.url,urllib.pathname2url(f)))
        except os.error, e:
            link.add_problem(str(e))

def _fetch_file(link, path, acceptedtypes):
    # get stats of file
    try:
        stats = os.stat(path)
        link.size = stats.st_size
        link.mtime = stats.st_mtime
    except os.error, e:
        link.add_problem(str(e))
        return
    # guess mimetype
    if link.mimetype is None:
        link.mimetype = mimetypes.guess_type(path)[0]
    debugio.debug('mimetype='+str(link.mimetype))
    debugio.debug('acceptedtypes='+str(acceptedtypes))
    # fetch the document if there is any point
    if link.mimetype in acceptedtypes:
        debugio.debug('FETCH')
        try:
            # TODO: add size checking
            return open(path,'r').read()
        except IOError, e:
            debugio.debug('PROBLEM: '+str(e))
            ink.add_problem(str(e))

def fetch(link, acceptedtypes):
    """Retreive some basic information about the file.
    Store the results in the link object."""
    # get the local path component
    path=urllib.url2pathname(link.path)
    # do special things if we are a directory
    if os.path.isdir(path):
        return _fetch_directory(link, path, acceptedtypes)
    else:
        return _fetch_file(link, path, acceptedtypes)