from __future__ import unicode_literals

import re
import json

from .subtitles import SubtitlesInfoExtractor
from .common import InfoExtractor
from ..utils import (
    compat_urllib_parse,
    compat_urllib_request,
    ExtractorError
)


class LyndaIE(SubtitlesInfoExtractor):
    IE_NAME = 'lynda'
    IE_DESC = 'lynda.com videos'
    _VALID_URL = r'https?://www\.lynda\.com/[^/]+/[^/]+/\d+/(\d+)-\d\.html'
    _LOGIN_URL = 'https://www.lynda.com/login/login.aspx'
    _NETRC_MACHINE = 'lynda'

    _SUCCESSFUL_LOGIN_REGEX = r'<a href="https://www.lynda.com/home/userAccount/ChangeContactInfo.aspx" data-qa="eyebrow_account_menu">My account'
    _TIMECODE_REGEX = r'\[(?P<timecode>\d+:\d+:\d+[\.,]\d+)\]'

    ACCOUNT_CREDENTIALS_HINT = 'Use --username and --password options to provide lynda.com account credentials.'

    _TEST = {
        'url': 'http://www.lynda.com/Bootstrap-tutorials/Using-exercise-files/110885/114408-4.html',
        'file': '114408.mp4',
        'md5': 'ecfc6862da89489161fb9cd5f5a6fac1',
        'info_dict': {
            'title': 'Using the exercise files',
            'duration': 68
        }
    }

    def _real_initialize(self):
        self._login()

    def _real_extract(self, url):
        mobj = re.match(self._VALID_URL, url)
        video_id = mobj.group(1)

        page = self._download_webpage('http://www.lynda.com/ajax/player?videoId=%s&type=video' % video_id,
                                      video_id, 'Downloading video JSON')
        video_json = json.loads(page)

        if 'Status' in video_json:
            raise ExtractorError('lynda returned error: %s' % video_json['Message'], expected=True)

        if video_json['HasAccess'] is False:
            raise ExtractorError('Video %s is only available for members. ' % video_id + self.ACCOUNT_CREDENTIALS_HINT, expected=True)

        video_id = video_json['ID']
        duration = video_json['DurationInSeconds']
        title = video_json['Title']

        formats = [{'url': fmt['Url'],
                    'ext': fmt['Extension'],
                    'width': fmt['Width'],
                    'height': fmt['Height'],
                    'filesize': fmt['FileSize'],
                    'format_id': str(fmt['Resolution'])
                    } for fmt in video_json['Formats']]

        self._sort_formats(formats)

        if self._downloader.params.get('listsubtitles', False):
            self._list_available_subtitles(video_id, page)
            return

        subtitles = self._fix_subtitles(self.extract_subtitles(video_id, page))

        return {
            'id': video_id,
            'title': title,
            'duration': duration,
            'subtitles': subtitles,
            'formats': formats
        }

    def _login(self):
        (username, password) = self._get_login_info()
        if username is None:
            return

        login_form = {
            'username': username,
            'password': password,
            'remember': 'false',
            'stayPut': 'false'
        }        
        request = compat_urllib_request.Request(self._LOGIN_URL, compat_urllib_parse.urlencode(login_form))
        login_page = self._download_webpage(request, None, note='Logging in as %s' % username)

        # Not (yet) logged in
        m = re.search(r'loginResultJson = \'(?P<json>[^\']+)\';', login_page)
        if m is not None:
            response = m.group('json')
            response_json = json.loads(response)            
            state = response_json['state']

            if state == 'notlogged':
                raise ExtractorError('Unable to login, incorrect username and/or password', expected=True)

            # This is when we get popup:
            # > You're already logged in to lynda.com on two devices.
            # > If you log in here, we'll log you out of another device.
            # So, we need to confirm this.
            if state == 'conflicted':
                confirm_form = {
                    'username': '',
                    'password': '',
                    'resolve': 'true',
                    'remember': 'false',
                    'stayPut': 'false',
                }
                request = compat_urllib_request.Request(self._LOGIN_URL, compat_urllib_parse.urlencode(confirm_form))
                login_page = self._download_webpage(request, None, note='Confirming log in and log out from another device')

        if re.search(self._SUCCESSFUL_LOGIN_REGEX, login_page) is None:
            raise ExtractorError('Unable to log in')

    def _fix_subtitles(self, subtitles):
        if subtitles is None:
            return subtitles  # subtitles not requested

        fixed_subtitles = {}
        for k, v in subtitles.items():
            subs = json.loads(v)
            if len(subs) == 0:
                continue
            srt = ''
            for pos in range(0, len(subs) - 1):
                seq_current = subs[pos]
                m_current = re.match(self._TIMECODE_REGEX, seq_current['Timecode'])
                if m_current is None:
                    continue
                seq_next = subs[pos + 1]
                m_next = re.match(self._TIMECODE_REGEX, seq_next['Timecode'])
                if m_next is None:
                    continue
                appear_time = m_current.group('timecode')
                disappear_time = m_next.group('timecode')
                text = seq_current['Caption']
                srt += '%s\r\n%s --> %s\r\n%s' % (str(pos), appear_time, disappear_time, text)
            if srt:
                fixed_subtitles[k] = srt
        return fixed_subtitles

    def _get_available_subtitles(self, video_id, webpage):
        url = 'http://www.lynda.com/ajax/player?videoId=%s&type=transcript' % video_id
        sub = self._download_webpage(url, None, note=False)
        sub_json = json.loads(sub)
        return {'en': url} if len(sub_json) > 0 else {}


class LyndaCourseIE(InfoExtractor):
    IE_NAME = 'lynda:course'
    IE_DESC = 'lynda.com online courses'

    # Course link equals to welcome/introduction video link of same course
    # We will recognize it as course link
    _VALID_URL = r'https?://(?:www|m)\.lynda\.com/(?P<coursepath>[^/]+/[^/]+/(?P<courseid>\d+))-\d\.html'

    def _real_extract(self, url):
        mobj = re.match(self._VALID_URL, url)
        course_path = mobj.group('coursepath')
        course_id = mobj.group('courseid')
        
        page = self._download_webpage('http://www.lynda.com/ajax/player?courseId=%s&type=course' % course_id,
                                      course_id, 'Downloading course JSON')
        course_json = json.loads(page)

        if 'Status' in course_json and course_json['Status'] == 'NotFound':
            raise ExtractorError('Course %s does not exist' % course_id, expected=True)

        unaccessible_videos = 0
        videos = []
        (username, _) = self._get_login_info()

        for chapter in course_json['Chapters']:
            for video in chapter['Videos']:
                if username is None and video['HasAccess'] is False:
                    unaccessible_videos += 1
                    continue
                videos.append(video['ID'])

        if unaccessible_videos > 0:
            self._downloader.report_warning('%s videos are only available for members and will not be downloaded. '
                                            % unaccessible_videos + LyndaIE.ACCOUNT_CREDENTIALS_HINT)

        entries = [
            self.url_result('http://www.lynda.com/%s/%s-4.html' %
                            (course_path, video_id),
                            'Lynda')
            for video_id in videos]

        course_title = course_json['Title']

        return self.playlist_result(entries, course_id, course_title)