#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Author: Ricardo Garcia Gonzalez
# License: Public domain code
import htmlentitydefs
import httplib
import math
import netrc
import os
import os.path
import re
import socket
import string
import sys
import time
import urllib
import urllib2

std_headers = {	
	'User-Agent': 'UserAgent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9) Gecko/2008052906 Firefox/3.0',
	'Accept-Charset': 'ISO-8859-1,utf-8;q=0.7,*;q=0.7',
	'Accept': 'text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5',
	'Accept-Language': 'en-us,en;q=0.5',
}

simple_title_chars = string.ascii_letters.decode('ascii') + string.digits.decode('ascii')

class FileDownloader(object):
	"""File Downloader class.

	File downloader objects are the ones responsible of downloading the
	actual video file and writing it to disk if the user has requested
	it, among some other tasks. In most cases there should be one per
	program. As, given a video URL, the downloader doesn't know how to
	extract all the needed information, task that InfoExtractors do, it
	has to pass the URL to one of them.

	For this, file downloader objects have a method that allows
	InfoExtractors to be registered in a given order. When it is passed
	a URL, the file downloader handles it to the first InfoExtractor it
	finds that reports being able to handle it. The InfoExtractor returns
	all the information to the FileDownloader and the latter downloads the
	file or does whatever it's instructed to do.

	File downloaders accept a lot of parameters. In order not to saturate
	the object constructor with arguments, it receives a dictionary of
	options instead. These options are available through the get_params()
	method for the InfoExtractors to use. The FileDownloader also registers
	itself as the downloader in charge for the InfoExtractors that are
	added to it, so this is a "mutual registration".

	Available options:

	username:	Username for authentication purposes.
	password:	Password for authentication purposes.
	usenetrc:	Use netrc for authentication instead.
	quiet:		Do not print messages to stdout.
	simulate:	Do not download the video files.
	format:		Video format code.
	outtmpl:	Template for output names.
	"""

	_params = None
	_ies = []

	def __init__(self, params):
		self._ies = []
		self.set_params(params)
	
	@staticmethod
	def pmkdir(filename):
		"""Create directory components in filename. Similar to Unix "mkdir -p"."""
		components = filename.split(os.sep)
		aggregate = [os.sep.join(components[0:x]) for x in xrange(1, len(components))]
		for dir in aggregate:
			if not os.path.exists(dir):
				os.mkdir(dir)
	
	@staticmethod
	def format_bytes(bytes):
		if bytes is None:
			return 'N/A'
		if bytes == 0:
			exponent = 0
		else:
			exponent = long(math.log(float(bytes), 1024.0))
		suffix = 'bkMGTPEZY'[exponent]
		converted = float(bytes) / float(1024**exponent)
		return '%.2f%s' % (converted, suffix)

	@staticmethod
	def calc_percent(byte_counter, data_len):
		if data_len is None:
			return '---.-%'
		return '%6s' % ('%3.1f%%' % (float(byte_counter) / float(data_len) * 100.0))

	@staticmethod
	def calc_eta(start, now, total, current):
		if total is None:
			return '--:--'
		dif = now - start
		if current == 0 or dif < 0.001: # One millisecond
			return '--:--'
		rate = float(current) / dif
		eta = long((float(total) - float(current)) / rate)
		(eta_mins, eta_secs) = divmod(eta, 60)
		if eta_mins > 99:
			return '--:--'
		return '%02d:%02d' % (eta_mins, eta_secs)

 	@staticmethod
	def calc_speed(start, now, bytes):
		dif = now - start
		if bytes == 0 or dif < 0.001: # One millisecond
			return '%10s' % '---b/s'
		return '%10s' % ('%s/s' % FileDownloader.format_bytes(float(bytes) / dif))

	@staticmethod
	def best_block_size(elapsed_time, bytes):
		new_min = max(bytes / 2.0, 1.0)
		new_max = min(max(bytes * 2.0, 1.0), 4194304) # Do not surpass 4 MB
		if elapsed_time < 0.001:
			return int(new_max)
		rate = bytes / elapsed_time
		if rate > new_max:
			return int(new_max)
		if rate < new_min:
			return int(new_min)
		return int(rate)

	def set_params(self, params):
		"""Sets parameters."""
		if type(params) != dict:
			raise ValueError('params: dictionary expected')
		self._params = params
	
	def get_params(self):
		"""Get parameters."""
		return self._params

	def add_info_extractor(self, ie):
		"""Add an InfoExtractor object to the end of the list."""
		self._ies.append(ie)
		ie.set_downloader(self)
	
	def to_stdout(self, message, skip_eol=False):
		"""Print message to stdout if not in quiet mode."""
		if not self._params.get('quiet', False):
			sys.stdout.write('%s%s' % (message, ['\n', ''][skip_eol]))
			sys.stdout.flush()

	def download(self, url_list):
		"""Download a given list of URLs."""
		for url in url_list:
			suitable_found = False
			for ie in self._ies:
				if not ie.suitable(url):
					continue
				# Suitable InfoExtractor found
				suitable_found = True
				results = [x for x in ie.extract(url) if x is not None]

				if (len(url_list) > 1 or len(results) > 1) and re.search(r'%\(.+?\)s', self._params['outtmpl']) is None:
					sys.exit('ERROR: fixed output name but more than one file to download')

				if self._params.get('simulate', False):
					continue

				for result in results:
					try:
						filename = self._params['outtmpl'] % result
					except (KeyError), err:
						sys.stderr.write('ERROR: invalid output template: %s\n' % str(err))
						continue
					try:
						self.pmkdir(filename)
					except (OSError, IOError), err:
						sys.stderr.write('ERROR: unable to create directories: %s\n' % str(err))
						continue
					try:
						outstream = open(filename, 'wb')
					except (OSError, IOError), err:
						sys.stderr.write('ERROR: unable to open for writing: %s\n' % str(err))
						continue
					try:
						self._do_download(outstream, result['url'])
						outstream.close()
					except (OSError, IOError), err:
						sys.stderr.write('ERROR: unable to write video data: %s\n' % str(err))
						continue
					except (urllib2.URLError, httplib.HTTPException, socket.error), err:
						sys.stderr.write('ERROR: unable to download video data: %s\n' % str(err))
						continue
				break
			if not suitable_found:
				sys.stderr.write('ERROR: no suitable InfoExtractor: %s\n' % url)
	
	def _do_download(self, stream, url):
		request = urllib2.Request(url, None, std_headers)
		data = urllib2.urlopen(request)
		data_len = data.info().get('Content-length', None)
		data_len_str = self.format_bytes(data_len)
		byte_counter = 0
		block_size = 1024
		start = time.time()
		while True:
			percent_str = self.calc_percent(byte_counter, data_len)
			eta_str = self.calc_eta(start, time.time(), data_len, byte_counter)
			speed_str = self.calc_speed(start, time.time(), byte_counter)
			self.to_stdout('\r[download] %s of %s at %s ETA %s' %
					(percent_str, data_len_str, speed_str, eta_str), skip_eol=True)

			before = time.time()
			data_block = data.read(block_size)
			after = time.time()
			data_block_len = len(data_block)
			if data_block_len == 0:
				break
			byte_counter += data_block_len
			stream.write(data_block)
			block_size = self.best_block_size(after - before, data_block_len)

		self.to_stdout('')
		if data_len is not None and str(byte_counter) != data_len:
			raise ValueError('Content too short: %s/%s bytes' % (byte_counter, data_len))

class InfoExtractor(object):
	"""Information Extractor class.

	Information extractors are the classes that, given a URL, extract
	information from the video (or videos) the URL refers to. This
	information includes the real video URL, the video title and simplified
	title, author and others. It is returned in a list of dictionaries when
	calling its extract() method. It is a list because a URL can refer to
	more than one video (think of playlists). The dictionaries must include
	the following fields:

	id:		Video identifier.
	url:		Final video URL.
	uploader:	Nickname of the video uploader.
	title:		Literal title.
	stitle:		Simplified title.
	ext:		Video filename extension.

	Subclasses of this one should re-define the _real_initialize() and
	_real_extract() methods, as well as the suitable() static method.
	Probably, they should also be instantiated and added to the main
	downloader.
	"""

	_ready = False
	_downloader = None

	def __init__(self, downloader=None):
		"""Constructor. Receives an optional downloader."""
		self._ready = False
		self.set_downloader(downloader)

	@staticmethod
	def suitable(url):
		"""Receives a URL and returns True if suitable for this IE."""
		return True

	def initialize(self):
		"""Initializes an instance (login, etc)."""
		if not self._ready:
			self._real_initialize()
			self._ready = True

	def extract(self, url):
		"""Extracts URL information and returns it in list of dicts."""
		self.initialize()
		return self._real_extract(url)

	def set_downloader(self, downloader):
		"""Sets the downloader for this IE."""
		self._downloader = downloader
	
	def to_stdout(self, message):
		if self._downloader is None or not self._downloader.get_params().get('quiet', False):
			print message
	
	def to_stderr(self, message):
		sys.stderr.write('%s\n' % message)

	def _real_initialize(self):
		"""Real initialization process. Redefine in subclasses."""
		pass

	def _real_extract(self, url):
		"""Real extraction process. Redefine in subclasses."""
		pass

class YoutubeIE(InfoExtractor):
	"""Information extractor for youtube.com."""

	_LOGIN_URL = 'http://www.youtube.com/login?next=/'
	_AGE_URL = 'http://www.youtube.com/verify_age?next_url=/'
	_NETRC_MACHINE = 'youtube'

	def _real_initialize(self):
		if self._downloader is None:
			return

		username = None
		password = None
		downloader_params = self._downloader.get_params()

		# Attempt to use provided username and password or .netrc data
		if downloader_params.get('username', None) is not None:
			username = downloader_params['username']
			password = downloader_params['password']
		elif downloader_params.get('usenetrc', False):
			try:
				info = netrc.netrc().authenticators(self._NETRC_MACHINE)
				if info is not None:
					username = info[0]
					password = info[2]
				else:
					raise netrc.NetrcParseError('No authenticators for %s' % self._NETRC_MACHINE)
			except (IOError, netrc.NetrcParseError), err:
				self.to_stderr('WARNING: parsing .netrc: %s' % str(err))
				return

		if username is None:
			return

		# Log in
		login_form = {
				'current_form': 'loginForm',
				'next':		'/',
				'action_login':	'Log In',
				'username':	username,
				'password':	password,
				}
		request = urllib2.Request(self._LOGIN_URL, urllib.urlencode(login_form), std_headers)
		try:
			self.to_stdout('[youtube] Logging in')
			login_results = urllib2.urlopen(request).read()
			if re.search(r'(?i)<form[^>]* name="loginForm"', login_results) is not None:
				self.to_stderr('WARNING: Unable to log in: bad username or password')
				return
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self.to_stderr('WARNING: Unable to log in: %s' % str(err))
			return
	
		# Confirm age
		age_form = {
				'next_url':		'/',
				'action_confirm':	'Confirm',
				}
		request = urllib2.Request(self._AGE_URL, urllib.urlencode(age_form), std_headers)
		try:
			self.to_stdout('[youtube] Confirming age')
			age_results = urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			sys.exit('ERROR: Unable to confirm age: %s' % str(err))

	def _real_extract(self, url):
		# Extract video id from URL
		mobj = re.match(r'^((?:http://)?(?:\w+\.)?youtube\.com/(?:(?:v/)|(?:(?:watch(?:\.php)?)?\?(?:.+&)?v=)))?([0-9A-Za-z_-]+)(?(1).+)?$', url)
		if mobj is None:
			self.to_stderr('ERROR: Invalid URL: %s' % url)
			return [None]
		video_id = mobj.group(2)

		# Downloader parameters
		format_param = None
		if self._downloader is not None:
			params = self._downloader.get_params()
			format_param = params.get('format', None)

		# Extension
		video_extension = {18: 'mp4'}.get(format_param, 'flv')

		# Normalize URL, including format
		normalized_url = 'http://www.youtube.com/watch?v=%s' % video_id
		if format_param is not None:
			normalized_url = '%s&fmt=%s' % (normalized_url, format_param)
		request = urllib2.Request(normalized_url, None, std_headers)
		try:
			self.to_stdout('[youtube] %s: Downloading video webpage' % video_id)
			video_webpage = urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			sys.exit('ERROR: Unable to download video: %s' % str(err))
		self.to_stdout('[youtube] %s: Extracting video information' % video_id)
		
		# "t" param
		mobj = re.search(r', "t": "([^"]+)"', video_webpage)
		if mobj is None:
			self.to_stderr('ERROR: Unable to extract "t" parameter')
			return [None]
		video_real_url = 'http://www.youtube.com/get_video?video_id=%s&t=%s' % (video_id, mobj.group(1))
		if format_param is not None:
			video_real_url = '%s&fmt=%s' % (video_real_url, format_param)
		self.to_stdout('[youtube] %s: URL: %s' % (video_id, video_real_url))

		# uploader
		mobj = re.search(r'More From: ([^<]*)<', video_webpage)
		if mobj is None:
			self.to_stderr('ERROR: Unable to extract uploader nickname')
			return [None]
		video_uploader = mobj.group(1)

		# title
		mobj = re.search(r'(?im)<title>YouTube - ([^<]*)</title>', video_webpage)
		if mobj is None:
			self.to_stderr('ERROR: Unable to extract video title')
			return [None]
		video_title = mobj.group(1).decode('utf-8')
		video_title = re.sub(u'&(.+?);', lambda x: unichr(htmlentitydefs.name2codepoint[x.group(1)]), video_title)

		# simplified title
		simple_title = re.sub(u'([^%s]+)' % simple_title_chars, u'_', video_title)
		simple_title = simple_title.strip(u'_')

		# Return information
		return [{
			'id':		video_id,
			'url':		video_real_url,
			'uploader':	video_uploader,
			'title':	video_title,
			'stitle':	simple_title,
			'ext':		video_extension,
			}]

if __name__ == '__main__':
	try:
		# General configuration
		urllib2.install_opener(urllib2.build_opener(urllib2.ProxyHandler()))
		urllib2.install_opener(urllib2.build_opener(urllib2.HTTPCookieProcessor()))

		# Information extractors
		youtube_ie = YoutubeIE()

		# File downloader
		fd = FileDownloader({
			'usenetrc': False,
			'username': None,
			'password': None,
			'quiet': False,
			'simulate': True,
			'format': None,
			'outtmpl': '%(id)s.%(ext)s'
			})
		fd.add_info_extractor(youtube_ie)
		fd.download([
			'http://www.youtube.com/watch?v=t7qdwI7TVe8',
			'http://www.youtube.com/watch?v=IJyn3pRcy_Q',
			'http://www.youtube.com/watch?v=DZRXe1wtC-M',
			])

	except KeyboardInterrupt:
		sys.exit('\nERROR: Interrupted by user')