from __future__ import unicode_literals

import re

from .common import InfoExtractor


class AcademicEarthCourseIE(InfoExtractor):
    _VALID_URL = r"^https?://(?:www\.)?academicearth\.org/playlists/(?P<id>[^?#/]+)"
    IE_NAME = "AcademicEarth:Course"
    _TEST = {
        "url": "http://academicearth.org/playlists/laws-of-nature/",
        "info_dict": {
            "id": "laws-of-nature",
            "title": "Laws of Nature",
            "description": "Introduce yourself to the laws of nature with these free online college lectures from Yale, Harvard, and MIT.",
        },
        "playlist_count": 3,
    }

    def _real_extract(self, url):
        playlist_id = self._match_id(url)

        webpage = self._download_webpage(url, playlist_id)
        title = self._html_search_regex(
            r'<h1 class="playlist-name"[^>]*?>(.*?)</h1>', webpage, "title"
        )
        description = self._html_search_regex(
            r'<p class="excerpt"[^>]*?>(.*?)</p>', webpage, "description", fatal=False
        )
        urls = re.findall(
            r'<li class="lecture-preview">\s*?<a target="_blank" href="([^"]+)">',
            webpage,
        )
        entries = [self.url_result(u) for u in urls]

        return {
            "_type": "playlist",
            "id": playlist_id,
            "title": title,
            "description": description,
            "entries": entries,
        }
