# Translates entries of RSS 2.0 (or ATOM) feed into different locale.
#
# Requires Python 3.10+.
#
# Make sure to have all dependencies installed:
#   pip3 install googletrans-py lxml bs4 httpx httpcore asyncio --upgrade
#
# You must provide raw RSS 2.0 (or ATOM) UTF-8 feed XML data as input, for example with curl:
#   curl 'https://phys.org/rss-feed/' | python ./translate-feed.py "en" "pt_BR" "true"
#
# You must provide three command line arguments:
#   translate-feed.py [FROM-LANGUAGE] [TO-LANGUAGE] [RUN-PARALLEL] [FEED-ENCODING (optional)]

import io
import sys
import time
import setuptools._distutils.util
import xml.etree.ElementTree as ET
import itertools as IT
from googletrans import Translator
from bs4 import BeautifulSoup

lang_from = sys.argv[1]
lang_to = sys.argv[2]
parallel = bool(setuptools._distutils.util.strtobool(sys.argv[3]))

if (len(sys.argv) >= 5):
  src_enc = sys.argv[4]
else:
  src_enc = "utf-8"

if parallel:
  import asyncio
  from concurrent.futures import ThreadPoolExecutor

sys.stdin.reconfigure(encoding = src_enc)
rss_data = sys.stdin.read()

try:
  rss_document = ET.fromstring(rss_data)
except ET.ParseError as err:
  lineno, column = err.position
  line = next(IT.islice(io.StringIO(rss_data), lineno))
  caret = '{:=>{}}'.format('^', column)
  err.msg = '{}\n{}\n{}'.format(err, line, caret)
  raise 

translator = Translator()

atom_ns = {"ns": "http://www.w3.org/2005/Atom"}

def translate_string(to_translate):
  try:
    if to_translate is None:
      return to_translate

    translated_text = translator.translate(to_translate, src = lang_from, dest = lang_to)

    if not parallel:
      time.sleep(0.2)

    return translated_text.text
  except:
    return to_translate

def process_article(article):
  title = article.find("title")

  if title is None:
    title = article.find("ns:title", atom_ns)

  if title is not None:
    title.text = translate_string(title.text)

  # RSS.
  contents = article.find("description")

  if contents is None:
    # ATOM.
    contents = article.find("ns:content", atom_ns)

  if contents is not None:
    htmll = "<div>{}</div>".format(contents.text)

    soup = BeautifulSoup(htmll, features = "lxml")
    contents.text = translate_string(soup.get_text())
    contents.text = contents.text.replace("\n", "<br/>")

# Translate title.
# RSS.
channel = rss_document.find("channel")

if channel is not None:
  title = channel.find("title")

if (channel is None) or (title is None):
  # ATOM.
  title = rss_document.find("ns:title", atom_ns)

if title is not None:
  title.text = translate_string(title.text)

# Translate articles.
if parallel:
  with ThreadPoolExecutor(max_workers = 2) as executor:
    futures = []
    for article in rss_document.findall(".//item"):
      futures.append(executor.submit(process_article, article))
    for article in rss_document.findall(".//ns:entry", atom_ns):
      futures.append(executor.submit(process_article, article))
    for future in futures:
      future.result()
else:
  for article in rss_document.findall(".//item"):
    process_article(article)
  for article in rss_document.findall(".//ns:entry", atom_ns):
    process_article(article)

out_xml = ET.tostring(rss_document)
out_decoded_xml = out_xml.decode()

print(out_decoded_xml)