# encoding: utf-8
#
# Copyright (C) 2013 Mesar Hameed <mhameed@src.gnome.org>
# This file is covered by the GNU General Public License.

import os
import re
import sys
import threading
from time import sleep
from random import randint
import logging
log = logging.getLogger("translator")
import urllib2

# Each group has to be a class of possible breaking points for the writing script.
# Usually this is the major syntax marks, such as:
# full stop, comma, exclaim, question, etc.
arabicBreaks = u'[،؛؟]'
# Thanks to Talori in the NVDA irc room:
# U+3000 to U+303F, U+FE10 to U+FE1F, U+FE30 to U+FE6F, U+FF01 to U+FF60
chineseBreaks = u'[　-〿︐-︟︰-﹯！-｠]'
latinBreaks = r'[.,!?;:\n]'
splitReg = re.compile(u"{arabic}|{chinese}|{latin}".format(arabic=arabicBreaks, chinese=chineseBreaks, latin=latinBreaks))

def translate(text, source="auto", target="en"):
	if source == "": source = "auto"
	t = Translator(lang_from=source, lang_to=target, text=text)
	t.start()
	while t.isAlive():
		sleep(0.1)
	t.join()
	return t.translation

def splitChunks(text, chunksize):
	pos = 0
	potentialPos = 0
	for splitMark in splitReg.finditer(text):
		if (splitMark.start() - pos +1) < chunksize:
			potentialPos = splitMark.start()
			continue
		else:
			yield text[pos:potentialPos+1]
			pos = potentialPos + 1
			potentialPos = splitMark.start()
	yield text[pos:]

class Translator(threading.Thread):

	def __init__(self, lang_from, lang_to, text, lang_swap=None, chunksize=350, *args, **kwargs):
		super(Translator, self).__init__(*args, **kwargs)
		self._stop = threading.Event()
		self.text = text
		self.chunksize = chunksize
		self.lang_to = lang_to
		self.lang_from = lang_from
		self.lang_swap = lang_swap
		self.translation = ''
		self.lang_translated = ''
		self.firstChunk = True

	def stop(self):
		self._stop.set()

	def run(self):
		for chunk in splitChunks(self.text, self.chunksize):
			# Make sure we don't send requests to google too often.
			# Try to simulate a human.
			if not self.firstChunk:
				sleep(randint(1, 10))
			req = self.buildRequest(chunk, self.lang_from, self.lang_to)
			try:
				response = urllib2.urlopen(req)
				translation, lang_translated = self.parseData(response)
				if self.firstChunk and self.lang_from == "auto" and  lang_translated == self.lang_to and self.lang_swap is not None:
					self.lang_to = self.lang_swap
					self.firstChunk = False
					req = self.buildRequest(chunk.encode('utf-8'), self.lang_from, self.lang_to)
					response = urllib2.urlopen(req)
					translation, lang_translated = self.parseData(response)
			except Exception as e:
				log.exception("Can not translate text '%s'" %chunk)
				# We have probably been blocked, so stop trying to translate.
				raise e
			self.translation += translation
		# some adjustment, better to do on full text
		self.translation = self.fixNewlines(self.translation)
		self.lang_translated = lang_translated

	def buildRequest(self, text, lang_from, lang_to):
		"""Build POST request which will be sent to Google."""
		urlTemplate = 'http://translate.google.com/translate_a/single?client=t&sl={lang_from}&tl={lang_to}&ie=utf-8&oe=utf-8&dt=t&dt=bd&tk='
		url = urlTemplate.format(lang_from=lang_from, lang_to=lang_to)
		header = {'User-agent': 'Mozilla/5.0', 'Content-Type': 'application/x-www-form-urlencoded'}
		data = 'text=%s' %urllib2.quote(text)
		req = urllib2.Request(url, data, header)
		return req

	def parseData(self, response):
		"""Parse unstructured response."""
		data = response.readlines()[0]
		# get segments with couples ["translation","original text"]
		l1, l2 = data.split(']],', 1)
		translation = l1[3:]
		if l2.startswith('[[\"'):
			# get list of synonyms
			syn = l2[l2.find(',[')+1:l2.find(']')].split(',')
			temp = ', '.join([x.replace('\"', '') for x in syn])
		else:
			# get a list with each couple as item
			sentences = translation.split('],[')
			temp = ''
			# get translation, removing first char (quote symbol)
			for item in sentences:
				item = item.split('\",\"', 1)[0][1:]
				# join all translations
				temp = ' '.join([temp, item])
		translation = temp.decode('string-escape').decode('utf-8')
		translation = self.fixPunctuation(translation)
		# get the language of original text
		tempLang = data.partition(']],,\"')[2]
		lang = tempLang[:tempLang.find('\"')]
		if lang == '':
			lang = _("unavailable")
		return translation, lang

	def fixPunctuation(self, translation):
		"""Clean text from space before punctuation symbol."""
		# list of potentially positions of spaces to remove
		spacePos = []
		for puncMark in splitReg.finditer(translation):
			spacePos.append(puncMark.start()-1)
		if len(spacePos) == 0:
			return translation
		fixedTranslation = ''
		for n in xrange(0,len(translation)):
			temp = translation[n]
			if n in spacePos and temp == ' ':
				continue
			else:
				fixedTranslation += temp
		return fixedTranslation

	def fixNewlines(self, translation):
		"""Adjust newlines and (subsequent or double) spaces."""
		fixes = [('\r\n ', '\r\n'), ('\n ', '\r\n'), ('  ', ' ')]
		for fix in fixes:
			translation = translation.replace(fix[0], fix[1])
		# first char is a space, so...
		return translation[1:]

languages = {
  "af": _(u"Afrikaans"),
  "sq": _(u"Albanian"),
  "am": _(u"Amharic"),
  "ar": _(u"Arabic"),
  "hy": _(u"Armenian"),
  "az": _(u"Azerbaijani"),
  "eu": _(u"Basque"),
  "be": _(u"Belarusian"),
  "bn": _(u"Bengali"),
  "bh": _(u"Bihari"),
  "bg": _(u"Bulgarian"),
  "my": _(u"Burmese"),
  "ca": _(u"Catalan"),
  "chr": _(u"Cherokee"),
  "zh": _(u"Chinese"),
  "zh-CN": _(u"Chinese_simplified"),
  "zh-TW": _(u"Chinese_traditional"),
  "hr": _(u"Croatian"),
  "cs": _(u"Czech"),
  "da": _(u"Danish"),
  "dv": _(u"Dhivehi"),
  "nl": _(u"Dutch"),
  "en": _(u"English"),
  "eo": _(u"Esperanto"),
  "et": _(u"Estonian"),
  "tl": _(u"Filipino"),
  "fi": _(u"Finnish"),
  "fr": _(u"French"),
  "gl": _(u"Galician"),
  "ka": _(u"Georgian"),
  "de": _(u"German"),
  "el": _(u"Greek"),
  "gn": _(u"Guarani"),
  "gu": _(u"Gujarati"),
  "iw": _(u"Hebrew"),
  "hi": _(u"Hindi"),
  "hu": _(u"Hungarian"),
  "is": _(u"Icelandic"),
  "id": _(u"Indonesian"),
  "iu": _(u"Inuktitut"),
  "ga": _(u"Irish"),
  "it": _(u"Italian"),
  "ja": _(u"Japanese"),
  "kn": _(u"Kannada"),
  "kk": _(u"Kazakh"),
  "km": _(u"Khmer"),
  "ko": _(u"Korean"),
  "ku": _(u"Kurdish"),
  "ky": _(u"Kyrgyz"),
  "lo": _(u"Laothian"),
  "lv": _(u"Latvian"),
  "lt": _(u"Lithuanian"),
  "mk": _(u"Macedonian"),
  "ms": _(u"Malay"),
  "ml": _(u"Malayalam"),
  "mt": _(u"Maltese"),
  "mr": _(u"Marathi"),
  "mn": _(u"Mongolian"),
  "ne": _(u"Nepali"),
  "no": _(u"Norwegian"),
  "or": _(u"Oriya"),
  "ps": _(u"Pashto"),
  "fa": _(u"Persian"),
  "pl": _(u"Polish"),
  "pt-PT": _(u"Portuguese"),
  "pa": _(u"Punjabi"),
  "ro": _(u"Romanian"),
  "ru": _(u"Russian"),
  "sa": _(u"Sanskrit"),
  "sr": _(u"Serbian"),
  "sd": _(u"Sindhi"),
  "si": _(u"Sinhalese"),
  "sk": _(u"Slovak"),
  "sl": _(u"Slovenian"),
  "es": _(u"Spanish"),
  "sw": _(u"Swahili"),
  "sv": _(u"Swedish"),
  "tg": _(u"Tajik"),
  "ta": _(u"Tamil"),
  "tl": _(u"Tagalog"),
  "te": _(u"Telugu"),
  "th": _(u"Thai"),
  "bo": _(u"Tibetan"),
  "tr": _(u"Turkish"),
  "uk": _(u"Ukrainian"),
  "ur": _(u"Urdu"),
  "uz": _(u"Uzbek"),
  "ug": _(u"Uighur"),
  "vi": _(u"Vietnamese"),
  "cy": _(u"Welsh"),
  "yi": _(u"Yiddish")
}

def available_languages():
    l = languages.keys()
    d = languages.values()
    l.insert(0, '')
    d.insert(0, _(u"autodetect"))
    return sorted(zip(l, d))