import re

class StyleException(Exception): pass
class EventException(Exception): pass
class ScriptException(Exception): pass

class ScriptInfo:
	def __init__(self, f = None):
		# original case keys used for writing
		self.ock = {}
		self.info = {}
		if f:
			self.read(f)

	def __getitem__(self, key):
		try:
			return self.info[key.lower()]
		except ValueError:
			raise KeyError

	def read(self, f):
		s = f.readline().strip()
		while s:
			if not s.startswith(';'):
				k, v = s.split(': ', 1)
				self.ock[k.lower()] = k
				self.info[k.lower()] = v
			s = f.readline().strip()

	def write(self, f):
			f.write('[Script Info]\n')
			f.writelines(['%s: %s\n' % (self.ock[k], self.info[k]) for k in self.info.keys()])

class Style:
	def __init__(self, format, s = None):
		self.format = format
		if s:
			self.parse(s)

	def __str__(self):
		return 'Style: %s' % ','.join([getattr(self, x.lower()) for x in self.format])

	def parse(self, s):
		s = s.split(': ', 1)
		if s[0] != 'Style':
			raise StyleException('invalid style line')
		s = s[1].split(',')
		for k, v in zip(self.format, s):
			setattr(self, k.lower(), v)

class Styles:
	def __init__(self, f = None):
		self.format, self.styles = [], {}
		if f:
			self.read(f)

	def __getitem__(self, key):
		if self.styles.has_key(key.lower()):
			return self.styles[key]
		else:
			raise KeyError('style "%s" not found' % key)

	def read(self, f):
		s = f.readline().strip()
		s = s.split(': ', 1)
		if s[0] != 'Format':
			raise StyleException('format line not found')
		self.format = s[1].split(', ')

		s = f.readline().strip()
		while s:
			s = Style(self.format, s)
			self.styles[s.name.lower()] = s
			s = f.readline().split()

	def write(self, f):
		f.write('[V4 Styles]\n')
		f.write('Format: %s\n' % ', '.join(self.format))
		f.writelines(['%s\n' % str(s) for s in self.styles.values()])

class Syllable:
	def __init__(self, start, end, text):
		self.start, self.end, self.dur, self.text = start, end, end - start, text

	def __str__(self):
		return '{\\k%d}%s' % (self.dur / 10, self.text)

class Event:
	def __init__(self, format, s = None):
		self.karaoke = []
		self.format = format
		if s:
			self.parse(s)

	def __getitem__(self, key):
		if type(key) is int:
			return self.karaoke[key]
		else:
			raise TypeError('key must be int')

	def __str__(self):
		return '%s: %s' % (self.kind.capitalize(), ','.join([getattr(self, x.lower()) for x in self.format]))

	def parse(self, s):
		s = s.split(': ', 1)
		self.kind = s[0].lower()
		s = s[1].split(',')
		for k, v in zip(self.format, s):
			setattr(self, k.lower(), v)
		if self.kind == 'dialogue' and self.text.find('\\k') > -1:
			self.parse_karaoke()

	def parse_karaoke(self):
		s = self.text
		i = 0
		tot = 0
		while i < len(s):
			i = s.find('\\k', i)
			# break if no more \k's (end-of-line-text is added at the end of the loop)
			if i == -1:
				break
			i += 2
			ms = ''
			while s[i].isdigit():
				ms += s[i]
				i += 1
			ms = int(ms) * 10
			tot += ms
			# unless next is another override, skip one char (past '}')
			if s[i] != '\\':
				i += 1
			n = s.find('\\k', i)
			if n > -1:
				part = s[i:n-1] # get text up to next \k
			else:
				part = s[i:] # end of line

			# go to next if part is empty
			if not part.strip():
				continue

			self.karaoke.append(Syllable(tot - ms, tot, part))

class Events:
	def __init__(self, f = None):
		self.format, self.events = [], []
		if f:
			self.read(f)

	def __getitem__(self, key):
		if type(key) is int:
			return self.events[key]
		else:
			raise TypeError('key must be int')

	def read(self, f):
		s = f.readline().strip()
		s = s.split(': ', 1)
		if s[0] != 'Format':
			raise EventException('format line not found')
		self.format = s[1].split(', ')

		s = f.readline().strip()
		while s:
			self.events.append(Event(self.format, s))
			s = f.readline().strip()

	def write(self, f):
		f.write('[Events]\n')
		f.write('Format: %s\n' % ', '.join(self.format))
		f.writelines(['%s\n' % str(e) for e in self.events])

class Script:
	def __init__(self, f = None):
		if f:
			self.read(f)

	def read(self, f):
		f = open(f, 'r')

		s = f.readline().strip()
		if s.startswith('\xef\xbb\xbf'):
			s = s[3:]
		if s == '[Script Info]':
			self.info = ScriptInfo(f)
		else:
			raise ScriptException('script info not found')

		s = f.readline().strip()
		if re.match('\[V4\+? Styles\]', s):
			self.styles = Styles(f)
		else:
			raise ScriptException('script styles not found')

		s = f.readline().strip()
		if s == '[Events]':
			self.events = Events(f)
		else:
			raise ScriptException('script events not found')

	def write(self, f):
		f = open(f, 'w')
		self.info.write(f)
		f.write('\n')
		self.styles.write(f)
		f.write('\n')
		self.events.write(f)
		f.write('\n')