text: # coding: utf-8
  from __future__ import unicode_literals
  
  import re
  
  from .common import InfoExtractor
  
  from ..compat import (
      compat_urlparse,
  )
  
  from ..utils import (
      urlencode_postdata,
      urljoin,
      int_or_none,
      clean_html,
      ExtractorError
  )
  
  
  class AluraIE(InfoExtractor):
      _VALID_URL = r'https?://(?:cursos\.)?alura\.com\.br/course/(?P<course_name>[^/]+)/task/(?P<id>\d+)'
      _LOGIN_URL = 'https://cursos.alura.com.br/loginForm?urlAfterLogin=/loginForm'
      _VIDEO_URL = 'https://cursos.alura.com.br/course/%s/task/%s/video'
      _NETRC_MACHINE = 'alura'
      _TESTS = [{
          'url': 'https://cursos.alura.com.br/course/clojure-mutabilidade-com-atoms-e-refs/task/60095',
          'info_dict': {
              'id': '60095',
              'ext': 'mp4',
              'title': 'Referências, ref-set e alter'
          },
          'skip': 'Requires alura account credentials'},
          {
              # URL without video
              'url': 'https://cursos.alura.com.br/course/clojure-mutabilidade-com-atoms-e-refs/task/60098',
              'only_matching': True},
          {
              'url': 'https://cursos.alura.com.br/course/fundamentos-market-digital/task/55219',
              'only_matching': True}
      ]
  
      def _real_extract(self, url):
  
          course, video_id = self._match_valid_url(url)
          video_url = self._VIDEO_URL % (course, video_id)
  
          video_dict = self._download_json(video_url, video_id, 'Searching for videos')
  
          if video_dict:
              webpage = self._download_webpage(url, video_id)
              video_title = clean_html(self._search_regex(
                  r'<span[^>]+class=(["\'])task-body-header-title-text\1[^>]*>(?P<title>[^<]+)',
                  webpage, 'title', group='title'))
  
              formats = []
              for video_obj in video_dict:
                  video_url_m3u8 = video_obj.get('link')
                  video_format = self._extract_m3u8_formats(
                      video_url_m3u8, None, 'mp4', entry_protocol='m3u8_native',
                      m3u8_id='hls', fatal=False)
                  for f in video_format:
                      m = re.search(r'^[\w \W]*-(?P<res>\w*).mp4[\W \w]*', f['url'])
                      if m:
                          if not f.get('height'):
                              f['height'] = int('720' if m.group('res') == 'hd' else '480')
                  formats.extend(video_format)
  
              self._sort_formats(formats)
  
              return {
                  'id': video_id,
                  'title': video_title,
                  "formats": formats
              }
  
      def _perform_login(self, username, password):
  
          login_page = self._download_webpage(
              self._LOGIN_URL, None, 'Downloading login popup')
  
          def is_logged(webpage):
              return any(re.search(p, webpage) for p in (
                  r'href=[\"|\']?/signout[\"|\']',
                  r'>Logout<'))
  
          # already logged in
          if is_logged(login_page):
              return
  
          login_form = self._hidden_inputs(login_page)
  
          login_form.update({
              'username': username,
              'password': password,
          })
  
          post_url = self._search_regex(
              r'<form[^>]+class=["|\']signin-form["|\'] action=["|\'](?P<url>.+?)["|\']', login_page,
              'post url', default=self._LOGIN_URL, group='url')
  
          if not post_url.startswith('http'):
              post_url = compat_urlparse.urljoin(self._LOGIN_URL, post_url)
  
          response = self._download_webpage(
              post_url, None, 'Logging in',
              data=urlencode_postdata(login_form),
              headers={'Content-Type': 'application/x-www-form-urlencoded'})
  
          if not is_logged(response):
              error = self._html_search_regex(
                  r'(?s)<p[^>]+class="alert-message[^"]*">(.+?)</p>',
                  response, 'error message', default=None)
              if error:
                  raise ExtractorError('Unable to login: %s' % error, expected=True)
              raise ExtractorError('Unable to log in')
  
  
  class AluraCourseIE(AluraIE):
  
      _VALID_URL = r'https?://(?:cursos\.)?alura\.com\.br/course/(?P<id>[^/]+)'
      _LOGIN_URL = 'https://cursos.alura.com.br/loginForm?urlAfterLogin=/loginForm'
      _NETRC_MACHINE = 'aluracourse'
      _TESTS = [{
          'url': 'https://cursos.alura.com.br/course/clojure-mutabilidade-com-atoms-e-refs',
          'only_matching': True,
      }]
  
      @classmethod
      def suitable(cls, url):
          return False if AluraIE.suitable(url) else super(AluraCourseIE, cls).suitable(url)
  
      def _real_extract(self, url):
  
          course_path = self._match_id(url)
          webpage = self._download_webpage(url, course_path)
  
          course_title = self._search_regex(
              r'<h1.*?>(.*?)<strong>(?P<course_title>.*?)</strong></h[0-9]>', webpage,
              'course title', default=course_path, group='course_title')
  
          entries = []
          if webpage:
              for path in re.findall(r'<a\b(?=[^>]* class="[^"]*(?<=[" ])courseSectionList-section[" ])(?=[^>]* href="([^"]*))', webpage):
                  page_url = urljoin(url, path)
                  section_path = self._download_webpage(page_url, course_path)
                  for path_video in re.findall(r'<a\b(?=[^>]* class="[^"]*(?<=[" ])task-menu-nav-item-link-VIDEO[" ])(?=[^>]* href="([^"]*))', section_path):
                      chapter = clean_html(
                          self._search_regex(
                              r'<h3[^>]+class=(["\'])task-menu-section-title-text\1[^>]*>(?P<chapter>[^<]+)',
                              section_path,
                              'chapter',
                              group='chapter'))
  
                      chapter_number = int_or_none(
                          self._search_regex(
                              r'<span[^>]+class=(["\'])task-menu-section-title-number[^>]*>(.*?)<strong>(?P<chapter_number>[^<]+)</strong>',
                              section_path,
                              'chapter number',
                              group='chapter_number'))
                      video_url = urljoin(url, path_video)
  
                      entry = {
                          '_type': 'url_transparent',
                          'id': self._match_id(video_url),
                          'url': video_url,
                          'id_key': self.ie_key(),
                          'chapter': chapter,
                          'chapter_number': chapter_number
                      }
                      entries.append(entry)
          return self.playlist_result(entries, course_path, course_title)
  