from __future__ import unicode_literals

import re

from .common import InfoExtractor
from .wistia import WistiaIE
from ..utils import (
    clean_html,
    ExtractorError,
    int_or_none,
    get_element_by_class,
    strip_or_none,
    urlencode_postdata,
    urljoin,
)


class TeachableBaseIE(InfoExtractor):
    _NETRC_MACHINE = "teachable"
    _URL_PREFIX = "teachable:"

    _SITES = {
        # Only notable ones here
        "v1.upskillcourses.com": "upskill",
        "gns3.teachable.com": "gns3",
        "academyhacker.com": "academyhacker",
        "stackskills.com": "stackskills",
        "market.saleshacker.com": "saleshacker",
        "learnability.org": "learnability",
        "edurila.com": "edurila",
        "courses.workitdaily.com": "workitdaily",
    }

    _VALID_URL_SUB_TUPLE = (
        _URL_PREFIX,
        "|".join(re.escape(site) for site in _SITES.keys()),
    )

    def _real_initialize(self):
        self._logged_in = False

    def _login(self, site):
        if self._logged_in:
            return

        username, password = self._get_login_info(
            netrc_machine=self._SITES.get(site, site)
        )
        if username is None:
            return

        login_page, urlh = self._download_webpage_handle(
            "https://%s/sign_in" % site, None, "Downloading %s login page" % site
        )

        def is_logged(webpage):
            return any(
                re.search(p, webpage)
                for p in (
                    r'class=["\']user-signout',
                    r'<a[^>]+\bhref=["\']/sign_out',
                    r"Log\s+[Oo]ut\s*<",
                )
            )

        if is_logged(login_page):
            self._logged_in = True
            return

        login_url = urlh.geturl()

        login_form = self._hidden_inputs(login_page)

        login_form.update(
            {
                "user[email]": username,
                "user[password]": password,
            }
        )

        post_url = self._search_regex(
            r'<form[^>]+action=(["\'])(?P<url>(?:(?!\1).)+)\1',
            login_page,
            "post url",
            default=login_url,
            group="url",
        )

        if not post_url.startswith("http"):
            post_url = urljoin(login_url, post_url)

        response = self._download_webpage(
            post_url,
            None,
            "Logging in to %s" % site,
            data=urlencode_postdata(login_form),
            headers={
                "Content-Type": "application/x-www-form-urlencoded",
                "Referer": login_url,
            },
        )

        if ">I accept the new Privacy Policy<" in response:
            raise ExtractorError(
                "Unable to login: %s asks you to accept new Privacy Policy. "
                "Go to https://%s/ and accept." % (site, site),
                expected=True,
            )

        # Successful login
        if is_logged(response):
            self._logged_in = True
            return

        message = get_element_by_class("alert", response)
        if message is not None:
            raise ExtractorError(
                "Unable to login: %s" % clean_html(message), expected=True
            )

        raise ExtractorError("Unable to log in")


class TeachableIE(TeachableBaseIE):
    _VALID_URL = (
        r"""(?x)
                    (?:
                        %shttps?://(?P<site_t>[^/]+)|
                        https?://(?:www\.)?(?P<site>%s)
                    )
                    /courses/[^/]+/lectures/(?P<id>\d+)
                    """
        % TeachableBaseIE._VALID_URL_SUB_TUPLE
    )

    _TESTS = [
        {
            "url": "https://gns3.teachable.com/courses/gns3-certified-associate/lectures/6842364",
            "info_dict": {
                "id": "untlgzk1v7",
                "ext": "bin",
                "title": "Overview",
                "description": "md5:071463ff08b86c208811130ea1c2464c",
                "duration": 736.4,
                "timestamp": 1542315762,
                "upload_date": "20181115",
                "chapter": "Welcome",
                "chapter_number": 1,
            },
            "params": {
                "skip_download": True,
            },
        },
        {
            "url": "http://v1.upskillcourses.com/courses/119763/lectures/1747100",
            "only_matching": True,
        },
        {
            "url": "https://gns3.teachable.com/courses/423415/lectures/6885939",
            "only_matching": True,
        },
        {
            "url": "teachable:https://v1.upskillcourses.com/courses/essential-web-developer-course/lectures/1747100",
            "only_matching": True,
        },
    ]

    @staticmethod
    def _is_teachable(webpage):
        return "teachableTracker.linker:autoLink" in webpage and re.search(
            r'<link[^>]+href=["\']https?://(?:process\.fs|assets)\.teachablecdn\.com',
            webpage,
        )

    @staticmethod
    def _extract_url(webpage, source_url):
        if not TeachableIE._is_teachable(webpage):
            return
        if re.match(r"https?://[^/]+/(?:courses|p)", source_url):
            return "%s%s" % (TeachableBaseIE._URL_PREFIX, source_url)

    def _real_extract(self, url):
        mobj = re.match(self._VALID_URL, url)
        site = mobj.group("site") or mobj.group("site_t")
        video_id = mobj.group("id")

        self._login(site)

        prefixed = url.startswith(self._URL_PREFIX)
        if prefixed:
            url = url[len(self._URL_PREFIX) :]

        webpage = self._download_webpage(url, video_id)

        wistia_urls = WistiaIE._extract_urls(webpage)
        if not wistia_urls:
            if any(
                re.search(p, webpage)
                for p in (
                    r'class=["\']lecture-contents-locked',
                    r">\s*Lecture contents locked",
                    r'id=["\']lecture-locked',
                    # https://academy.tailoredtutors.co.uk/courses/108779/lectures/1955313
                    r'class=["\'](?:inner-)?lesson-locked',
                    r">LESSON LOCKED<",
                )
            ):
                self.raise_login_required("Lecture contents locked")
            raise ExtractorError("Unable to find video URL")

        title = self._og_search_title(webpage, default=None)

        chapter = None
        chapter_number = None
        section_item = self._search_regex(
            r'(?s)(?P<li><li[^>]+\bdata-lecture-id=["\']%s[^>]+>.+?</li>)' % video_id,
            webpage,
            "section item",
            default=None,
            group="li",
        )
        if section_item:
            chapter_number = int_or_none(
                self._search_regex(
                    r'data-ss-position=["\'](\d+)',
                    section_item,
                    "section id",
                    default=None,
                )
            )
            if chapter_number is not None:
                sections = []
                for s in re.findall(
                    r'(?s)<div[^>]+\bclass=["\']section-title[^>]+>(.+?)</div>', webpage
                ):
                    section = strip_or_none(clean_html(s))
                    if not section:
                        sections = []
                        break
                    sections.append(section)
                if chapter_number <= len(sections):
                    chapter = sections[chapter_number - 1]

        entries = [
            {
                "_type": "url_transparent",
                "url": wistia_url,
                "ie_key": WistiaIE.ie_key(),
                "title": title,
                "chapter": chapter,
                "chapter_number": chapter_number,
            }
            for wistia_url in wistia_urls
        ]

        return self.playlist_result(entries, video_id, title)


class TeachableCourseIE(TeachableBaseIE):
    _VALID_URL = (
        r"""(?x)
                        (?:
                            %shttps?://(?P<site_t>[^/]+)|
                            https?://(?:www\.)?(?P<site>%s)
                        )
                        /(?:courses|p)/(?:enrolled/)?(?P<id>[^/?#&]+)
                    """
        % TeachableBaseIE._VALID_URL_SUB_TUPLE
    )
    _TESTS = [
        {
            "url": "http://v1.upskillcourses.com/courses/essential-web-developer-course/",
            "info_dict": {
                "id": "essential-web-developer-course",
                "title": "The Essential Web Developer Course (Free)",
            },
            "playlist_count": 192,
        },
        {
            "url": "http://v1.upskillcourses.com/courses/119763/",
            "only_matching": True,
        },
        {
            "url": "http://v1.upskillcourses.com/courses/enrolled/119763",
            "only_matching": True,
        },
        {
            "url": "https://gns3.teachable.com/courses/enrolled/423415",
            "only_matching": True,
        },
        {
            "url": "teachable:https://learn.vrdev.school/p/gear-vr-developer-mini",
            "only_matching": True,
        },
        {
            "url": "teachable:https://filmsimplified.com/p/davinci-resolve-15-crash-course",
            "only_matching": True,
        },
    ]

    @classmethod
    def suitable(cls, url):
        return (
            False
            if TeachableIE.suitable(url)
            else super(TeachableCourseIE, cls).suitable(url)
        )

    def _real_extract(self, url):
        mobj = re.match(self._VALID_URL, url)
        site = mobj.group("site") or mobj.group("site_t")
        course_id = mobj.group("id")

        self._login(site)

        prefixed = url.startswith(self._URL_PREFIX)
        if prefixed:
            prefix = self._URL_PREFIX
            url = url[len(prefix) :]

        webpage = self._download_webpage(url, course_id)

        url_base = "https://%s/" % site

        entries = []

        for mobj in re.finditer(
            r'(?s)(?P<li><li[^>]+class=(["\'])(?:(?!\2).)*?section-item[^>]+>.+?</li>)',
            webpage,
        ):
            li = mobj.group("li")
            if "fa-youtube-play" not in li and not re.search(r"\d{1,2}:\d{2}", li):
                continue
            lecture_url = self._search_regex(
                r'<a[^>]+href=(["\'])(?P<url>(?:(?!\1).)+)\1',
                li,
                "lecture url",
                default=None,
                group="url",
            )
            if not lecture_url:
                continue
            lecture_id = self._search_regex(
                r"/lectures/(\d+)", lecture_url, "lecture id", default=None
            )
            title = self._html_search_regex(
                r'<span[^>]+class=["\']lecture-name[^>]+>([^<]+)',
                li,
                "title",
                default=None,
            )
            entry_url = urljoin(url_base, lecture_url)
            if prefixed:
                entry_url = self._URL_PREFIX + entry_url
            entries.append(
                self.url_result(
                    entry_url,
                    ie=TeachableIE.ie_key(),
                    video_id=lecture_id,
                    video_title=clean_html(title),
                )
            )

        course_title = self._html_search_regex(
            (
                r'(?s)<img[^>]+class=["\']course-image[^>]+>\s*<h\d>(.+?)</h',
                r'(?s)<h\d[^>]+class=["\']course-title[^>]+>(.+?)</h',
            ),
            webpage,
            "course title",
            fatal=False,
        )

        return self.playlist_result(entries, course_id, course_title)
