#!/usr/bin/python2.6

#

# CDDL HEADER START

#

# The contents of this file are subject to the terms of the

# Common Development and Distribution License (the "License").

# You may not use this file except in compliance with the License.

#

# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE

# or http://www.opensolaris.org/os/licensing.

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# fields enclosed by brackets "[]" replaced with your own identifying

# information: Portions Copyright [yyyy] [name of copyright owner]

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#

# Copyright (c) 2010, Oracle and/or it's affiliates.  All rights reserved.

#

#

# fetch.py - a file download utility

#

#  A simple program similiar to wget(1), but handles local file copy, ignores

#  directories, and verifies file hashes.

#

import os

import sys

def validate(filename, hash):

	import hashlib

	try:

		file = open(filename, 'r')

	except IOError:

		return False

	if (hash == None):

		return True

	algorithm, value = hash.split(':')

	try:

		m = hashlib.new(algorithm)

	except ValueError:

		return False

	while True:

		block = file.read()

		m.update(block)

		if block == '':

			break

	return m.hexdigest() == value

def download(url, filename = None, hash = None, verbose = False):

	from urllib import splittype, urlopen

	import hashlib

	src = None

	filename = None

	#print "Downloading %s from %s" % (filename, url)

	# open the download source

	if splittype(url)[0]:

		try:

			src = urlopen(url)

		except IOError:

			return None

		remote_name = src.geturl().split('/')[-1]

	elif os.path.isfile(url):

		os.symlink(url, filename)

		return filename, filehash(filename)

		src = open(url, 'r')

		remote_name = url.split('/')[-1]

	else:

		return None

	if filename == None:

		filename = remote_name

	# if we have a source to download, open a destination and copy the data

	if src:

		dst = open(filename, 'wb');

		if verbose:

			print "Downloading %s from %s" % (filename, url)

		while True:

			block = src.read()

			if block == '':

				break;

			dst.write(block)

		dst.close()

	# return the name of the file that we downloaded the data to.

	return filename

def download_paths(search, filename):

	tmp = os.getenv('DOWNLOAD_SEARCH_PATH')

	if tmp:

		search += tmp.split(' ')

	base = os.path.basename(filename)

	urls = list()

	for path in search:

		urls.append(path+'/'+base)

	return urls

def usage():

	print "Usage: %s [-v|--verbose] [-f|--file (file)] [-h|--hash (hash)] --url (url)" % (sys.argv[0].split('/')[-1])

	sys.exit(1)

def main():

	from urllib import splittype, urlopen

	import getopt

	import sys

	# FLUSH STDOUT 

	sys.stdout = os.fdopen(sys.stdout.fileno(), 'w', 0)

	verbose = False

	filename = None

	url = None

	hash = None

	search = list()

	try:

		opts, args = getopt.getopt(sys.argv[1:], "f:h:s:u:v",

			["file=", "hash=", "search=", "url=", "verbose"])

	except getopt.GetoptError, err:

		print str(err)

		usage()

	for opt, arg in opts:

		if opt in [ "-f", "--file" ]:

			filename = arg

		elif opt in [ "-h", "--hash" ]:

			hash = arg

		elif opt in [ "-s", "--search" ]:

			search.append(arg)

		elif opt in [ "-u", "--url" ]:

			url = arg

		elif opt in [ "-v", "--verbose" ]:

			verbose = True

		else:

			assert False, "unknown option"

	if url == None:

		usage()

	print "Fetching %s" % filename

	if validate(filename, hash):

		print "\tcurrent copy is ok, nothing to do"

		sys.exit(0)

	# generate a list of URLS to search for a suitable download

	urls = download_paths(search, filename)

	urls.append(url)

	for url in urls:

		print "\tTrying %s..." % url,

		if os.path.isfile(url):

			os.symlink(url, filename)

		elif splittype(url)[0]:

			if download(url, filename) == None:

				print "failed"

				continue

		print "retrieved...",

		if validate(filename, hash):

			print "validated"

			sys.exit(0)

		else:

			print "corrupt"

		try:

			os.remove(filename)

		except OSError:

			pass

	sys.exit(1)

if __name__ == "__main__":

	main()