#!/usr/bin/env python

#

# Copyright (c) 2006-2008 Ricardo Garcia Gonzalez

#

# Permission is hereby granted, free of charge, to any person obtaining a

# copy of this software and associated documentation files (the "Software"),

# to deal in the Software without restriction, including without limitation

# the rights to use, copy, modify, merge, publish, distribute, sublicense,

# and/or sell copies of the Software, and to permit persons to whom the

# Software is furnished to do so, subject to the following conditions:

# 

# The above copyright notice and this permission notice shall be included

# in all copies or substantial portions of the Software.

# 

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR

# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,

# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR

# OTHER DEALINGS IN THE SOFTWARE.

# 

# Except as contained in this notice, the name(s) of the above copyright

# holders shall not be used in advertising or otherwise to promote the

# sale, use or other dealings in this Software without prior written

# authorization.

#

import getpass

import httplib

import math

import netrc

import optparse

import os

import re

import socket

import string

import sys

import time

import urllib2

# Global constants

const_1k = 1024

const_initial_block_size = 10 * const_1k

const_epsilon = 0.0001

const_timeout = 120

const_video_url_str = 'http://www.youtube.com/watch?v=%s'

const_video_url_re = re.compile(r'^((?:http://)?(?:\w+\.)?youtube\.com/(?:v/|(?:watch(?:\.php)?)?\?(?:.+&)?v=))?([0-9A-Za-z_-]+)(?(1)[&/].*)?$')

const_login_url_str = 'http://www.youtube.com/login?next=/watch%%3Fv%%3D%s'

const_login_post_str = 'current_form=loginForm&next=%%2Fwatch%%3Fv%%3D%s&username=%s&password=%s&action_login=Log+In'

const_age_url_str = 'http://www.youtube.com/verify_age?next_url=/watch%%3Fv%%3D%s'

const_age_post_str = 'next_url=%%2Fwatch%%3Fv%%3D%s&action_confirm=Confirm'

const_url_t_param_re = re.compile(r', "t": "([^"]+)"')

const_video_url_real_str = 'http://www.youtube.com/get_video?video_id=%s&t=%s'

const_video_title_re = re.compile(r'<title>YouTube - ([^<]*)</title>', re.M | re.I)

# Print error message, followed by standard advice information, and then exit

def error_advice_exit(error_text):

	sys.stderr.write('Error: %s.\n' % error_text)

	sys.stderr.write('Try again several times. It may be a temporary problem.\n')

	sys.stderr.write('Other typical problems:\n\n')

	sys.stderr.write('* Video no longer exists.\n')

	sys.stderr.write('* Video requires age confirmation but you did not provide an account.\n')

	sys.stderr.write('* You provided the account data, but it is not valid.\n')

	sys.stderr.write('* The connection was cut suddenly for some reason.\n')

	sys.stderr.write('* YouTube changed their system, and the program no longer works.\n')

	sys.stderr.write('\nTry to confirm you are able to view the video using a web browser.\n')

	sys.stderr.write('Use the same video URL and account information, if needed, with this program.\n')

	sys.stderr.write('When using a proxy, make sure http_proxy has http://host:port format.\n')

	sys.stderr.write('Try again several times and contact me if the problem persists.\n')

	sys.exit('\n')

# Wrapper to create custom requests with typical headers

def request_create(url, data=None):

	retval = urllib2.Request(url)

	if data is not None:

		retval.add_data(data)

	# Try to mimic Firefox, at least a little bit

	retval.add_header('User-Agent', 'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.11) Gecko/20071127 Firefox/2.0.0.11')

	retval.add_header('Accept-Charset', 'ISO-8859-1,utf-8;q=0.7,*;q=0.7')

	retval.add_header('Accept', 'text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5')

	retval.add_header('Accept-Language', 'en-us,en;q=0.5')

	return retval

# Perform a request, process headers and return response

def perform_request(url, data=None):

	request = request_create(url, data)

	response = urllib2.urlopen(request)

	return response

# Conditional print

def cond_print(str):

	global cmdl_opts

	if not (cmdl_opts.quiet or cmdl_opts.get_url):

		sys.stdout.write(str)

		sys.stdout.flush()

# Title string normalization

def title_string_norm(title):

	title = ''.join((x in string.ascii_letters or x in string.digits) and x or ' ' for x in title)

	title = '_'.join(title.split())

	title = title.lower()

	return title

# Generic download step

def download_step(return_data_flag, step_title, step_error, url, post_data=None):

	try:

		cond_print('%s... ' % step_title)

		data = perform_request(url, post_data).read()

		cond_print('done.\n')

		if return_data_flag:

			return data

		return None

	except (urllib2.URLError, ValueError, httplib.HTTPException, TypeError, socket.error):

		cond_print('failed.\n')

		error_advice_exit(step_error)

	except KeyboardInterrupt:

		sys.exit('\n')

# Generic extract step

def extract_step(step_title, step_error, regexp, data):

	try:

		cond_print('%s... ' % step_title)

		match = regexp.search(data)

		if match is None:

			cond_print('failed.\n')

			error_advice_exit(step_error)

		extracted_data = match.group(1)

		cond_print('done.\n')

		return extracted_data

	except KeyboardInterrupt:

		sys.exit('\n')

# Calculate new block size based on previous block size

def new_block_size(before, after, bytes):

	new_min = max(bytes / 2.0, 1.0)

	new_max = max(bytes * 2.0, 1.0)

	dif = after - before

	if dif < const_epsilon:

		return int(new_max)

	rate = bytes / dif

	if rate > new_max:

		return int(new_max)

	if rate < new_min:

		return int(new_min)

	return int(rate)

# Get optimum 1k exponent to represent a number of bytes

def optimum_k_exp(num_bytes):

	global const_1k

	if num_bytes == 0:

		return 0

	return long(math.log(num_bytes, const_1k))

# Get optimum representation of number of bytes

def format_bytes(num_bytes):

	global const_1k

	try:

		exp = optimum_k_exp(num_bytes)

		suffix = 'bkMGTPEZY'[exp]

		if exp == 0:

			return '%s%s' % (num_bytes, suffix)

		converted = float(num_bytes) / float(const_1k**exp)

		return '%.2f%s' % (converted, suffix)

	except IndexError:

		sys.exit('Error: internal error formatting number of bytes.')

# Calculate ETA and return it in string format as MM:SS

def calc_eta(start, now, total, current):

	dif = now - start

	if current == 0 or dif < const_epsilon:

		return '--:--'

	rate = float(current) / dif

	eta = long((total - current) / rate)

	(eta_mins, eta_secs) = divmod(eta, 60)

	if eta_mins > 99:

		return '--:--'

	return '%02d:%02d' % (eta_mins, eta_secs)

# Calculate speed and return it in string format

def calc_speed(start, now, bytes):

	dif = now - start

	if bytes == 0 or dif < const_epsilon:

		return 'N/A b'

	return format_bytes(float(bytes) / dif)

# Title string minimal transformation

def title_string_touch(title):

	return title.replace(os.sep, '%')

# Create the command line options parser and parse command line

cmdl_usage = 'usage: %prog [options] video_url'

cmdl_version = '2008.01.24'

cmdl_parser = optparse.OptionParser(usage=cmdl_usage, version=cmdl_version, conflict_handler='resolve')

cmdl_parser.add_option('-h', '--help', action='help', help='print this help text and exit')

cmdl_parser.add_option('-v', '--version', action='version', help='print program version and exit')

cmdl_parser.add_option('-u', '--username', dest='username', metavar='USERNAME', help='account username')

cmdl_parser.add_option('-p', '--password', dest='password', metavar='PASSWORD', help='account password')

cmdl_parser.add_option('-o', '--output', dest='outfile', metavar='FILE', help='output video file name')

cmdl_parser.add_option('-q', '--quiet', action='store_true', dest='quiet', help='activates quiet mode')

cmdl_parser.add_option('-s', '--simulate', action='store_true', dest='simulate', help='do not download video')

cmdl_parser.add_option('-t', '--title', action='store_true', dest='use_title', help='use title in file name')

cmdl_parser.add_option('-l', '--literal', action='store_true', dest='use_literal', help='use literal title in file name')

cmdl_parser.add_option('-n', '--netrc', action='store_true', dest='use_netrc', help='use .netrc authentication data')

cmdl_parser.add_option('-g', '--get-url', action='store_true', dest='get_url', help='print final video URL only')

cmdl_parser.add_option('-2', '--title-too', action='store_true', dest='get_title', help='used with -g, print title too')

(cmdl_opts, cmdl_args) = cmdl_parser.parse_args()

# Set socket timeout

socket.setdefaulttimeout(const_timeout)

# Get video URL

if len(cmdl_args) != 1:

	cmdl_parser.print_help()

	sys.exit('\n')

video_url_cmdl = cmdl_args[0]

# Verify video URL format and convert to "standard" format

video_url_mo = const_video_url_re.match(video_url_cmdl)

if video_url_mo is None:

	sys.exit('Error: URL does not seem to be a youtube video URL. If it is, report a bug.')

video_url_id = video_url_mo.group(2)

video_url = const_video_url_str % video_url_id

# Check conflicting options

if cmdl_opts.outfile is not None and (cmdl_opts.simulate or cmdl_opts.get_url):

	sys.stderr.write('Warning: video file name given but will not be used.\n')

if cmdl_opts.outfile is not None and (cmdl_opts.use_title or cmdl_opts.use_literal):

	sys.exit('Error: using the video title conflicts with using a given file name.')

if cmdl_opts.use_title and cmdl_opts.use_literal:

	sys.exit('Error: cannot use title and literal title at the same time.')

if cmdl_opts.quiet and cmdl_opts.get_url:

	sys.exit('Error: cannot be quiet and print final URL at the same time.')

# Incorrect option formatting

if cmdl_opts.username is None and cmdl_opts.password is not None:

	sys.exit('Error: password give but username is missing.')

if cmdl_opts.use_netrc and (cmdl_opts.username is not None or cmdl_opts.password is not None):

	sys.exit('Error: cannot use netrc and username/password at the same time.')

if cmdl_opts.get_url is None and cmdl_opts.get_title is not None:

	sys.exit('Error: getting title requires getting URL.')

# Get account information if any

account_username = None

account_password = None

if cmdl_opts.use_netrc:

	try:

		info = netrc.netrc().authenticators('youtube')

		if info is None:

			sys.exit('Error: no authenticators for machine youtube.')

		account_username = info[0]

		account_password = info[2]

	except IOError:

		sys.exit('Error: unable to read .netrc file.')

	except netrc.NetrcParseError:

		sys.exit('Error: unable to parse .netrc file.')

else:

	account_username = cmdl_opts.username

	if account_username is not None:

		if cmdl_opts.password is None:

			account_password = getpass.getpass('Type YouTube password and press return: ')

		else:

			account_password = cmdl_opts.password

# Get output file name 

if cmdl_opts.outfile is None:

	video_filename = '%s.flv' % video_url_id

else:

	video_filename = cmdl_opts.outfile

# Install cookie and proxy handlers

urllib2.install_opener(urllib2.build_opener(urllib2.ProxyHandler()))

urllib2.install_opener(urllib2.build_opener(urllib2.HTTPCookieProcessor()))

# Log in and confirm age if needed

if account_username is not None:

	url = const_login_url_str % video_url_id

	post = const_login_post_str % (video_url_id, account_username, account_password)

	download_step(False, 'Logging in', 'unable to log in', url, post)

	url = const_age_url_str % video_url_id

	post = const_age_post_str % video_url_id

	download_step(False, 'Confirming age', 'unable to confirm age', url, post)

# Retrieve video webpage

video_webpage = download_step(True, 'Retrieving video webpage', 'unable to retrieve video webpage', video_url)

# Extract video title if needed

if cmdl_opts.use_title or cmdl_opts.use_literal or cmdl_opts.get_title:

	video_title = extract_step('Extracting video title', 'unable to extract video title', const_video_title_re, video_webpage)

# Extract needed video URL parameters

video_url_t_param = extract_step('Extracting URL "t" parameter', 'unable to extract URL "t" parameter', const_url_t_param_re, video_webpage)

video_url_real = const_video_url_real_str % (video_url_id, video_url_t_param)

# Rebuild filename if needed

if cmdl_opts.use_title or cmdl_opts.use_literal:

	if cmdl_opts.use_title:

		prefix = title_string_norm(video_title)

	else:

		prefix = title_string_touch(video_title)

	video_filename = '%s-%s.flv' % (prefix, video_url_id)

# Check name

if not video_filename.lower().endswith('.flv'):

	sys.stderr.write('Warning: video file name does not end in .flv\n')

# Retrieve video data

try:

	cond_print('Requesting video file... ')

	video_data = perform_request(video_url_real)

	cond_print('done.\n')

	cond_print('Video data found at %s\n' % video_data.geturl())

	if cmdl_opts.get_title:

		print video_title

	if cmdl_opts.get_url:

		print video_data.geturl()

	if cmdl_opts.simulate or cmdl_opts.get_url:

		sys.exit()

	try:

		video_file = open(video_filename, 'wb')

	except (IOError, OSError):

		sys.exit('Error: unable to open "%s" for writing.' % video_filename)

	try:

		video_len = long(video_data.info()['Content-length'])

		video_len_str = format_bytes(video_len)

	except KeyError:

		video_len = None

		video_len_str = 'N/A'

	byte_counter = 0

	block_size = const_initial_block_size

	start_time = time.time()

	while True:

		if video_len is not None:

			percent = float(byte_counter) / float(video_len) * 100.0

			percent_str = '%.1f' % percent

			eta_str = calc_eta(start_time, time.time(), video_len, byte_counter)

		else:

			percent_str = '---.-'

			eta_str = '--:--'

		counter = format_bytes(byte_counter)

		speed_str = calc_speed(start_time, time.time(), byte_counter)

		cond_print('\rRetrieving video data: %5s%% (%8s of %s) at %8s/s ETA %s ' % (percent_str, counter, video_len_str, speed_str, eta_str))

		before = time.time()

		video_block = video_data.read(block_size)

		after = time.time()

		dl_bytes = len(video_block)

		if dl_bytes == 0:

			break

		byte_counter += dl_bytes

		video_file.write(video_block)

		block_size = new_block_size(before, after, dl_bytes)

	if video_len is not None and byte_counter != video_len:

		error_advice_exit('server did not send the expected ammount of data')

	video_file.close()

	cond_print('done.\n')

	cond_print('Video data saved to %s\n' % video_filename)

except (urllib2.URLError, ValueError, httplib.HTTPException, TypeError, socket.error):

	cond_print('failed.\n')

	error_advice_exit('unable to download video data')

except KeyboardInterrupt:

	sys.exit('\n')

# Finish

sys.exit()