from __future__ import unicode_literals

import re
import json

from .common import InfoExtractor
from .youtube import YoutubeIE
from ..utils import (
    clean_html,
    ExtractorError,
    get_element_by_id,
)


class TechTVMITIE(InfoExtractor):
    IE_NAME = "techtv.mit.edu"
    _VALID_URL = r"https?://techtv\.mit\.edu/(?:videos|embeds)/(?P<id>\d+)"

    _TEST = {
        "url": "http://techtv.mit.edu/videos/25418-mit-dna-learning-center-set",
        "md5": "00a3a27ee20d44bcaa0933ccec4a2cf7",
        "info_dict": {
            "id": "25418",
            "ext": "mp4",
            "title": "MIT DNA and Protein Sets",
            "description": "md5:46f5c69ce434f0a97e7c628cc142802d",
        },
    }

    def _real_extract(self, url):
        video_id = self._match_id(url)
        raw_page = self._download_webpage(
            "http://techtv.mit.edu/videos/%s" % video_id, video_id
        )
        clean_page = re.compile(r"<!--.*?-->", re.S).sub("", raw_page)

        base_url = self._proto_relative_url(
            self._search_regex(
                r"ipadUrl: \'(.+?cloudfront.net/)", raw_page, "base url"
            ),
            "http:",
        )
        formats_json = self._search_regex(
            r"bitrates: (\[.+?\])", raw_page, "video formats"
        )
        formats_mit = json.loads(formats_json)
        formats = [
            {
                "format_id": f["label"],
                "url": base_url + f["url"].partition(":")[2],
                "ext": f["url"].partition(":")[0],
                "format": f["label"],
                "width": f["width"],
                "vbr": f["bitrate"],
            }
            for f in formats_mit
        ]

        title = get_element_by_id("edit-title", clean_page)
        description = clean_html(get_element_by_id("edit-description", clean_page))
        thumbnail = self._search_regex(
            r"playlist:.*?url: \'(.+?)\'", raw_page, "thumbnail", flags=re.DOTALL
        )

        return {
            "id": video_id,
            "title": title,
            "formats": formats,
            "description": description,
            "thumbnail": thumbnail,
        }


class OCWMITIE(InfoExtractor):
    IE_NAME = "ocw.mit.edu"
    _VALID_URL = r"^https?://ocw\.mit\.edu/courses/(?P<topic>[a-z0-9\-]+)"
    _BASE_URL = "http://ocw.mit.edu/"

    _TESTS = [
        {
            "url": "http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-041-probabilistic-systems-analysis-and-applied-probability-fall-2010/video-lectures/lecture-7-multiple-variables-expectations-independence/",
            "info_dict": {
                "id": "EObHWIEKGjA",
                "ext": "webm",
                "title": "Lecture 7: Multiple Discrete Random Variables: Expectations, Conditioning, Independence",
                "description": "In this lecture, the professor discussed multiple random variables, expectations, and binomial distribution.",
                "upload_date": "20121109",
                "uploader_id": "MIT",
                "uploader": "MIT OpenCourseWare",
            },
        },
        {
            "url": "http://ocw.mit.edu/courses/mathematics/18-01sc-single-variable-calculus-fall-2010/1.-differentiation/part-a-definition-and-basic-rules/session-1-introduction-to-derivatives/",
            "info_dict": {
                "id": "7K1sB05pE0A",
                "ext": "mp4",
                "title": "Session 1: Introduction to Derivatives",
                "upload_date": "20090818",
                "uploader_id": "MIT",
                "uploader": "MIT OpenCourseWare",
                "description": "This section contains lecture video excerpts, lecture notes, an interactive mathlet with supporting documents, and problem solving videos.",
            },
        },
    ]

    def _real_extract(self, url):
        mobj = re.match(self._VALID_URL, url)
        topic = mobj.group("topic")

        webpage = self._download_webpage(url, topic)
        title = self._html_search_meta("WT.cg_s", webpage)
        description = self._html_search_meta("Description", webpage)

        # search for call to ocw_embed_chapter_media(container_id, media_url, provider, page_url, image_url, start, stop, captions_file)
        embed_chapter_media = re.search(r"ocw_embed_chapter_media\((.+?)\)", webpage)
        if embed_chapter_media:
            metadata = re.sub(r'[\'"]', "", embed_chapter_media.group(1))
            metadata = re.split(r", ?", metadata)
            yt = metadata[1]
        else:
            # search for call to ocw_embed_chapter_media(container_id, media_url, provider, page_url, image_url, captions_file)
            embed_media = re.search(r"ocw_embed_media\((.+?)\)", webpage)
            if embed_media:
                metadata = re.sub(r'[\'"]', "", embed_media.group(1))
                metadata = re.split(r", ?", metadata)
                yt = metadata[1]
            else:
                raise ExtractorError("Unable to find embedded YouTube video.")
        video_id = YoutubeIE.extract_id(yt)

        return {
            "_type": "url_transparent",
            "id": video_id,
            "title": title,
            "description": description,
            "url": yt,
            "ie_key": "Youtube",
        }
