from youtube import util

import html
import json
import re
import urllib

# videos (all of type str):

# id
# title
# url
# author
# author_url
# thumbnail
# description
# published
# duration
# likes
# dislikes
# views
# playlist_index

# playlists:

# id
# title
# url
# author
# author_url
# thumbnail
# description
# updated
# size
# first_video_id





def get_plain_text(node):
    try:
        return node['simpleText']
    except KeyError:
        return ''.join(text_run['text'] for text_run in node['runs'])

def format_text_runs(runs):
    if isinstance(runs, str):
        return runs
    result = ''
    for text_run in runs:
        if text_run.get("bold", False):
            result += "<b>" + html.escape(text_run["text"]) + "</b>"
        elif text_run.get('italics', False):
            result += "<i>" + html.escape(text_run["text"]) + "</i>"
        else:
            result += html.escape(text_run["text"])
    return result








def get_url(node):
    try:
        return node['runs'][0]['navigationEndpoint']['commandMetadata']['webCommandMetadata']['url']
    except KeyError:
        return node['navigationEndpoint']['commandMetadata']['webCommandMetadata']['url']


def get_text(node):
    if node == {}:
        return ''
    try:
        return node['simpleText']
    except KeyError:
        pass
    try:
        return node['runs'][0]['text']
    except IndexError: # empty text runs
        return ''
    except KeyError:
        print(node)
        raise

def get_formatted_text(node):
    try:
        return node['runs']
    except KeyError:
        return node['simpleText']

def get_badges(node):
    badges = []
    for badge_node in node:
        badge = badge_node['metadataBadgeRenderer']['label']
        badges.append(badge)
    return badges

def get_thumbnail(node):
    try:
        return node['thumbnails'][0]['url']     # polymer format
    except KeyError:
        return node['url']     # ajax format

dispatch = {

# polymer format    
    'title':                ('title',       get_text),
    'publishedTimeText':    ('published',   get_text),
    'videoId':              ('id',          lambda node: node),
    'descriptionSnippet':   ('description', get_formatted_text),
    'lengthText':           ('duration',    get_text),
    'thumbnail':            ('thumbnail',   get_thumbnail),
    'thumbnails':           ('thumbnail',   lambda node: node[0]['thumbnails'][0]['url']),

    'viewCountText':        ('views',       get_text),
    'numVideosText':        ('size',        lambda node: get_text(node).split(' ')[0]),     # the format is "324 videos"
    'videoCountText':       ('size',        get_text),
    'playlistId':           ('id',          lambda node: node),
    'descriptionText':      ('description', get_formatted_text),

    'subscriberCountText':  ('subscriber_count',    get_text),
    'channelId':            ('id',          lambda node: node),
    'badges':               ('badges',      get_badges),

# ajax format
    'view_count_text':  ('views',       get_text),
    'num_videos_text':  ('size',        lambda node: get_text(node).split(' ')[0]),
    'owner_text':       ('author',      get_text),
    'owner_endpoint':   ('author_url',  lambda node: node['url']),
    'description':      ('description', get_formatted_text),
    'index':            ('playlist_index', get_text),
    'short_byline':     ('author',      get_text),
    'length':           ('duration',    get_text),
    'video_id':         ('id',          lambda node: node),

}

def ajax_info(item_json):
    try:
        info = {}          
        for key, node in item_json.items():
            try:
                simple_key, function = dispatch[key]
            except KeyError:
                continue
            info[simple_key] = function(node)
        return info
    except KeyError:
        print(item_json)
        raise


youtube_url_re = re.compile(r'^(?:(?:(?:https?:)?//)?(?:www\.)?youtube\.com)?(/.*)$')
def normalize_url(url):
    match = youtube_url_re.fullmatch(url)
    if match is None:
        raise Exception()

    return 'https://www.youtube.com' + match.group(1)

def prefix_urls(item):
    try:
        item['thumbnail'] = util.prefix_url(item['thumbnail'])
    except KeyError:
        pass

    try:
        item['author_url'] = util.prefix_url(item['author_url'])
    except KeyError:
        pass

def add_extra_html_info(item):
    if item['type'] == 'video':
        item['url'] = util.URL_ORIGIN + '/watch?v=' + item['id']

        video_info = {}
        for key in ('id', 'title', 'author', 'duration'):
            try:
                video_info[key] = item[key]
            except KeyError:
                video_info[key] = ''

        item['video_info'] = json.dumps(video_info)

    elif item['type'] == 'playlist':
        item['url'] = util.URL_ORIGIN + '/playlist?list=' + item['id']
    elif item['type'] == 'channel':
        item['url'] = util.URL_ORIGIN + "/channel/" + item['id']


def renderer_info(renderer, additional_info={}):
    type = list(renderer.keys())[0]
    renderer = renderer[type]
    info = {}
    if type == 'itemSectionRenderer':
        return renderer_info(renderer['contents'][0], additional_info)
    
    if type in ('movieRenderer', 'clarificationRenderer'):
        info['type'] = 'unsupported'
        return info

    info.update(additional_info)


    if type in ('compactVideoRenderer', 'videoRenderer', 'playlistVideoRenderer', 'gridVideoRenderer'):
        info['type'] = 'video'
    elif type in ('playlistRenderer', 'compactPlaylistRenderer', 'gridPlaylistRenderer',
                  'radioRenderer', 'compactRadioRenderer', 'gridRadioRenderer',
                  'showRenderer', 'compactShowRenderer', 'gridShowRenderer'):
        info['type'] = 'playlist'
    elif type == 'channelRenderer':
        info['type'] = 'channel'
    elif type == 'playlistHeaderRenderer':
        info['type'] = 'playlist_metadata'
    else:
        info['type'] = 'unsupported'
        return info

    try:
        if 'viewCountText' in renderer:     # prefer this one as it contains all the digits
            info['views'] = get_text(renderer['viewCountText'])
        elif 'shortViewCountText' in renderer:
            info['views'] = get_text(renderer['shortViewCountText'])

        if 'ownerText' in renderer:
            info['author'] = renderer['ownerText']['runs'][0]['text']
            info['author_url'] = normalize_url(renderer['ownerText']['runs'][0]['navigationEndpoint']['commandMetadata']['webCommandMetadata']['url'])
        try:
            overlays = renderer['thumbnailOverlays']
        except KeyError:
            pass
        else:
            for overlay in overlays:
                if 'thumbnailOverlayTimeStatusRenderer' in overlay:
                    info['duration'] = get_text(overlay['thumbnailOverlayTimeStatusRenderer']['text'])
                # show renderers don't have videoCountText
                elif 'thumbnailOverlayBottomPanelRenderer' in overlay:
                    info['size'] = get_text(overlay['thumbnailOverlayBottomPanelRenderer']['text'])

        # show renderers don't have playlistId, have to dig into the url to get it
        try:
            info['id'] = renderer['navigationEndpoint']['watchEndpoint']['playlistId']
        except KeyError:
            pass
        for key, node in renderer.items():
            if key in ('longBylineText', 'shortBylineText'):
                info['author'] = get_text(node)
                try:
                    info['author_url'] = normalize_url(get_url(node))
                except KeyError:
                    pass

            # show renderers don't have thumbnail key at top level, dig into thumbnailRenderer
            elif key == 'thumbnailRenderer' and 'showCustomThumbnailRenderer' in node:
                info['thumbnail'] = node['showCustomThumbnailRenderer']['thumbnail']['thumbnails'][0]['url']
            else:
                try:
                    simple_key, function = dispatch[key]
                except KeyError:
                    continue
                info[simple_key] = function(node)
        if info['type'] == 'video' and 'duration' not in info:
            info['duration'] = 'Live'

        return info
    except KeyError:
        print(renderer)
        raise


def parse_info_prepare_for_html(renderer, additional_info={}):
    item = renderer_info(renderer, additional_info)
    prefix_urls(item)
    add_extra_html_info(item)

    return item


def extract_channel_info(polymer_json, tab):
    info = {'errors': []}
    response = polymer_json[1]['response']
    try:
        microformat = response['microformat']['microformatDataRenderer']

    # channel doesn't exist or was terminated
    # example terminated channel: https://www.youtube.com/channel/UCnKJeK_r90jDdIuzHXC0Org
    except KeyError:
        if 'alerts' in response and len(response['alerts']) > 0:
            for alert in response['alerts']:
                info['errors'].append(alert['alertRenderer']['text']['simpleText'])
            return info
        elif 'errors' in response['responseContext']:
            for error in response['responseContext']['errors']['error']:
                if error['code'] == 'INVALID_VALUE' and error['location'] == 'browse_id':
                    info['errors'].append('This channel does not exist')
                    return info
        info['errors'].append('Failure getting microformat')
        return info


    info['current_tab'] = tab


    # stuff from microformat (info given by youtube for every page on channel)
    info['short_description'] = microformat['description']
    info['channel_name'] = microformat['title']
    info['avatar'] = microformat['thumbnail']['thumbnails'][0]['url']
    channel_url = microformat['urlCanonical'].rstrip('/')
    channel_id = channel_url[channel_url.rfind('/')+1:]
    info['channel_id'] = channel_id
    info['channel_url'] = 'https://www.youtube.com/channel/' + channel_id

    info['items'] = []

    # empty channel
    if 'contents' not in response and 'continuationContents' not in response:
        return info


    # find the tab with content
    # example channel where tabs do not have definite index: https://www.youtube.com/channel/UC4gQ8i3FD7YbhOgqUkeQEJg
    # TODO: maybe use the 'selected' attribute for this?
    if 'continuationContents' not in response:
        tab_renderer = None
        tab_content = None
        for tab_json in response['contents']['twoColumnBrowseResultsRenderer']['tabs']:
            try:
                tab_renderer = tab_json['tabRenderer']
            except KeyError:
                tab_renderer = tab_json['expandableTabRenderer']
            try:
                tab_content = tab_renderer['content']
                break
            except KeyError:
                pass
        else:   # didn't break
            raise Exception("No tabs found with content")
        assert tab == tab_renderer['title'].lower()


    # extract tab-specific info
    if tab in ('videos', 'playlists', 'search'):    # find the list of items
        if 'continuationContents' in response:
            try:
                items = response['continuationContents']['gridContinuation']['items']
            except KeyError:
                items = response['continuationContents']['sectionListContinuation']['contents']     # for search
        else:
            contents = tab_content['sectionListRenderer']['contents']
            if 'itemSectionRenderer' in contents[0]:
                item_section = contents[0]['itemSectionRenderer']['contents'][0]
                try:
                    items = item_section['gridRenderer']['items']
                except KeyError:
                    if "messageRenderer" in item_section:
                        items = []
                    else:
                        raise Exception('gridRenderer missing but messageRenderer not found')
            else:
                items = contents    # for search

        additional_info = {'author': info['channel_name'], 'author_url': 'https://www.youtube.com/channel/' + channel_id}
        info['items'] = [renderer_info(renderer, additional_info) for renderer in items]

    elif tab == 'about':
        channel_metadata = tab_content['sectionListRenderer']['contents'][0]['itemSectionRenderer']['contents'][0]['channelAboutFullMetadataRenderer']


        info['links'] = []
        for link_json in channel_metadata.get('primaryLinks', ()):
            url = link_json['navigationEndpoint']['urlEndpoint']['url']
            if url.startswith('/redirect'):     # youtube puts these on external links to do tracking
                query_string = url[url.find('?')+1: ]
                url = urllib.parse.parse_qs(query_string)['q'][0]

            text = get_plain_text(link_json['title'])

            info['links'].append( (text, url) )


        info['stats'] = []
        for stat_name in ('subscriberCountText', 'joinedDateText', 'viewCountText', 'country'):
            try:
                stat = channel_metadata[stat_name]
            except KeyError:
                continue
            info['stats'].append(get_plain_text(stat))

        if 'description' in channel_metadata:
            info['description'] = get_text(channel_metadata['description'])
        else:
            info['description'] = ''

    else:
        raise NotImplementedError('Unknown or unsupported channel tab: ' + tab)

    return info