#!/usr/bin/python
# -*- coding: utf-8 -*-

# Licensed under GNU General Public License v3 or later
# Written by Sebastian Lohff (seba@seba-geek.de)
# http://seba-geek.de/stuff/servefile/

__version__ = '0.3.2'

import argparse
import BaseHTTPServer
import commands
import urllib
import os
import SocketServer
import socket
from stat import ST_SIZE
from subprocess import Popen, PIPE
import sys

class FileHandler(BaseHTTPServer.BaseHTTPRequestHandler):
	fileName = "Undefined"
	filePath = "/dev/null"
	fileLength = 0
	blockSize = 1024 * 1024
	
	def do_GET(self):
		if urllib.unquote(self.path) != "/" + self.fileName:
			self.send_response(302)
			self.send_header('Location', '/' + self.fileName)
			self.end_headers()
			return

		myfile = open(self.filePath, 'rb')
		
		# find out if this is a continuing download
		fromto = None
		if "Range" in self.headers:
			cont = self.headers.get("Range").split("=")
			if len(cont) > 1 and cont[0] == 'bytes':
				fromto = cont[1].split('-')
				if len(fromto) > 1:
					if fromto[1] == '':
						fromto[1] = self.fileLength-1
					fromto[0] = int(fromto[0])
					fromto[1] = int(fromto[1])
					if fromto[0] >= self.fileLength or fromto[0] < 0 or fromto[1] >= self.fileLength or fromto[1]-fromto[0] < 0:
						# oops, already done!
						self.send_response(416)
						self.send_header('Content-Range', 'bytes */%s' % self.fileLength)
						self.end_headers()
						return
					# now we can wind the file *brrrrrr*
					myfile.seek(fromto[0])
		
		if fromto != None:
			self.send_response(216)
			self.send_header('Content-Range', 'bytes %s-%s/%s' % (fromto[0], fromto[1], self.fileLength))
			self.send_header('Content-Length', fromto[1]-fromto[0]+1)
		else:
			self.send_response(200)
			self.send_header('Content-Length', self.fileLength)
		self.send_header('Content-Disposition', 'attachment; filename="%s"' % self.fileName)
		self.send_header('Content-type', 'application/octet-stream')
		self.send_header('Content-Transfer-Encoding', ' binary')
		self.end_headers()
		block = self.getChunk(myfile, fromto)
		while block:
			try:
				self.wfile.write(block)
			except socket.error, e:
				print "%s ABORTED transmission (Reason %s: %s)" % (self.client_address[0], e[0], e[1])
				return
			block = self.getChunk(myfile, fromto)
		myfile.close()
		print "%s finished downloading" % (self.client_address[0])
		return
	
	def getChunk(self, myfile, fromto):
		if fromto and myfile.tell()+self.blockSize >= fromto[1]:
			readsize = fromto[1]-myfile.tell()+1
		else:
			readsize = self.blockSize
		return myfile.read(readsize)

class ThreadedHTTPServer(SocketServer.ThreadingMixIn, BaseHTTPServer.HTTPServer):
	pass

def main():
	parser = argparse.ArgumentParser(description='Serve a single file via HTTP')
	parser.add_argument('--version', action='version', version='%(prog)s ' + __version__)
	parser.add_argument('filename', metavar='file/directory', type=str)
	parser.add_argument('-p', '--port', type=int, default=8080, \
	                    help='port to listen on')
	
	args = parser.parse_args()
		
	try:
		testit = open(args.filename, 'r')
		testit.close()
		FileHandler.filePath = args.filename
		FileHandler.fileName = os.path.basename(args.filename)
		FileHandler.fileLength = os.stat(args.filename)[ST_SIZE]
	except IOError:
		print "Error: Could not open file!"
		sys.exit(3)

	server = ThreadedHTTPServer(('', args.port), FileHandler)
	print "Serving \"%s\" under port %d" % (args.filename, args.port)

	# print urls with local network adresses
	print "\nSome addresses this file will be available under:"

	# ip and ifconfig sometimes are located in /sbin/
	os.environ['PATH'] += ':/sbin:/usr/sbin'
	proc = Popen(r"ip addr|" + \
	              "sed -n -e 's/.*inet6\? \([0-9.a-fA-F:]\+\)\/.*/\\1/ p'|" + \
	              "grep -v '^fe80\|^127.0.0.1\|^::1'", shell=True, stdout=PIPE)
	if proc.wait() != 0:
		# ip failed somehow, falling back to ifconfig
		oldLang = os.environ.get("LC_ALL", None)
		os.environ['LC_ALL'] = "C"
		proc = Popen(r"ifconfig|" + \
		              "sed -n 's/.*inet6\? addr: \?\([0-9a-fA-F.:]*\).*/" + \
					  "\\1/p'|" + \
					  "grep -v '^fe80\|^127.0.0.1\|^::1'", \
					  shell=True, stdout=PIPE, stderr=PIPE)
		if oldLang:
			os.environ['LC_ALL'] = oldLang
		else:
			del(os.environ['LC_ALL'])
		if proc.wait() != 0:
			print "Error: Could not locate any ips for you."
			proc = None
	if proc:
		ips = proc.stdout.read().strip()
		for ip in ips.split("\n"):
			if ip.find(":") >= 0:
				# ipv6
				ip = "[%s]" % ip
				# FIXME: When BaseHTTP supports ipv6 properly, delete this line
				continue	
			print "http://%s:%d/" % (ip, args.port)

	try:
		server.serve_forever()
	except KeyboardInterrupt:
		server.socket.close()
	print "Good bye.."

if __name__ == '__main__':
	main()