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

'''dvdinfo.py [--title n] [dvd device]
dvdinfo.py --help | -h

Displays information on the longest title on the DVD. If the dvd
device is not specified, /dev/dvd is used. You can also use a DVD
image as the device.

The title with the largest number of titles is considered the 'longest
title'. This is the feature film on the majority of the DVDs.

If you want to display the information on a specific title, pass the
title number with the --title option.
'''

# Changes:
#
# Version 1.1, 2006-08-13 13:00
#
#    - Only consider a title the main movie if it has an audio track.
#      This ensures that picture-titles with one chapter per picture
#      aren't considered the main movie, even though such titles can
#      have a lot of chapters.
#
#    - Added the ability to specify which title to read.
#
#    - Display 1/? instead of 1/1 if the total number of titles is
#      unknown.
#
# Version 1.0, released 2006-06-12 23:05
#
#    - Initial release

# COPYING: this software is released under the GPL licence. For more
# information, see http://www.stuvel.eu/licence

import re
import popen2
import sys
import getopt

__author__ = 'Sybren Stüvel'
__email__ = 'sybren@stuvel.eu'
__revision__ = '1.1'
__url__ = 'http://www.stuvel.eu/dvdinfo'

device = '/dev/dvd'

def banner():
	'''Display the banner'''

	print 50*'='
	print 'dvdinfo.py version %s' % __revision__
	print '%s <%s>' % (__author__, __email__)
	print __url__
	print 50*'='
	print

def title_info(title):
	'''Returns title information about a single title.
	
	Returns a tuple max_titles, chapters, audiotracks, subtitles.
	'''

	mpcmd = 'mplayer dvd://%i -v -v -v -nosound ' \
		'-frames 0 -dvd-device %s 2>&1'

	mplayer = popen2.Popen3(mpcmd % (title, device))
	
	mplayer.tochild.close()

	info = {
		'max_titles': 0,
		'chapters': 0,
		'audiotracks': {},
		'subtitles': []
	}

	def parse_max_titles(match):
		'''Parse the number of titles on this DVD'''
		info['max_titles'] = int(match.group(1))

	def parse_chapters(match):
		'''Parse the number of chapters in this title'''
		info['chapters'] = int(match.group(1))

	def parse_audio(match):
		'''Parse a single audio-channel line'''
		aid = int(match.group(3))
		track = {
			'format': match.group(1),
			'language': match.group(2)
		}
		info['audiotracks'][aid] = track

	def parse_sub(match):
		'''Parse a single subtitle-channel line'''
		sid = int(match.group(1))
		lang = match.group(2)
		info['subtitles'].append((sid, lang))

	tests = [
		['^There are ([0-9]+) titles', parse_max_titles],
		['^There are ([0-9]+) chapters', parse_chapters],
		['audio format: (.+) language: (.+) aid: ([0-9]+)', parse_audio],
		['subtitle \( sid \): ([0-9]+) language: (.*)', parse_sub]

	]
	
	# Compile the regular expressions
	for num, (regexp, func) in enumerate(tests):
		tests[num][0] = re.compile(regexp)

	# Parse incoming lines
	for line in mplayer.fromchild:
		for (regexp, func) in tests:
			match = regexp.search(line)
			if match:
				func(match)
	
	mplayer.fromchild.close()
	mplayer.wait()
	
	return (info['max_titles'], info['chapters'], info['audiotracks'],
			info['subtitles'])

def main():
	'''The main function'''

	global device

	# Set to the real value after the first read.
	max_title = '?'

	# Info of the longest title
	longest_title = 0
	chapters = None
	audiotracks = None
	subtitles = None

	title = 1
	find_longest = True

	banner()

	# Parse options
	opts, args = getopt.gnu_getopt(sys.argv[1:], 'ht:', ('help',
		'title='))
	opts = dict(opts)

	if '-h' in opts or '--help' in opts:
		print __doc__
		return

	if '-t' in opts:
		title = int(opts['-t'])
		find_longest = False
	if '--title' in opts:
		title = int(opts['--title'])
		find_longest = False

	if args:
		device = args[0]

	if find_longest:
		# Walk through all titles
		while max_title == '?' or title <= max_title:
			sys.stdout.write('Reading title %i/%s   \r' % (title, max_title))
			sys.stdout.flush()

			max_title, c, a, s = title_info(title)

			# Remember info about the title with the most chapters,
			# but only if it has audio tracks.
			if a and (chapters is None or c > chapters):
				chapters = c
				audiotracks = a
				subtitles = s
				longest_title = title

			title += 1

		print 'Done reading.            '

		print 'Longest title: %s' % longest_title
	else:
		print 'Reading title: %i' % title
		# Get info about given title
		max_title, chapters, audiotracks, subtitles = title_info(title)
	
	if not max_title:
		raise SystemExit("Unable to find any titles on %s" % device)

	print 'Chapters: %s' % chapters

	print 'Audio tracks:'
	for aid, info in audiotracks.iteritems():
		print '\taid=%3i lang=%s fmt=%s' % (aid, info['language'], info['format'])

	print 'Subtitles:'
	for sid, lang in subtitles:
		print '\tsid=%3i lang=%s' % (sid, lang)

if __name__ == '__main__':
	main()