# 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 config
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
    # check contents of directory for some common files
    for f in config.FILE_INDEXES:
        if os.path.isfile(os.path.join(path,f)):
            debugio.debug('pick up %s from directory' % f)
            # the the directory contains an index.html, use that
            return _fetch_file(link, os.path.join(path,f), acceptedtypes)
    # 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)