import re
import time
import sqlite3
import requests
from urllib.parse import urlparse
#from flask_login import current_user, login_required
from flask_login import LoginManager, UserMixin, current_user, login_user, logout_user, login_required
from flask import Blueprint, render_template, request, redirect, flash, url_for, jsonify, g, current_app
from werkzeug.exceptions import NotFound, BadGateway

from ..common.common import *
from ..common.anticaptcha import submit_captcha
from .lib import *

frontend = Blueprint('youtube', __name__,
    template_folder='templates',
    static_folder='static',
    static_url_path='/static/yt')

@frontend.route('/')
def index():
    return redirect(url_for('.feed'), code=302)

@frontend.route('/feed/subscriptions')
# disabled for guest user: @login_required
def feed():
    if current_user.is_anonymous:
        token = 'guest'
        if 'welcome_message' in cf['frontend']:
            flash(cf['frontend']['welcome_message'], "welcome")
    else:
        token = current_user.token
    page = int(request.args.get('page', 0))
    with sqlite3.connect(cf['global']['database']) as conn:
        c = conn.cursor()
        c.execute("""
	   SELECT videos.id, channel_id, name, title, length, livestream, published, playlist_videos.playlist_id, display
	     FROM videos
	     JOIN channels ON videos.channel_id = channels.id
    LEFT JOIN playlist_videos ON (videos.id = playlist_videos.video_id)
	LEFT JOIN flags ON (videos.id = flags.video_id) AND (flags.user = ?)
        WHERE (channel_id IN (SELECT channel_id FROM subscriptions WHERE user=? AND type = 'channel')
               OR playlist_videos.playlist_id IN (SELECT channel_id FROM subscriptions WHERE user=? AND type = 'playlist')
	           OR flags.display = 'pinned')
	          AND flags.display IS NOT 'hidden'
	 ORDER BY (display = 'pinned') DESC, crawled DESC
	    LIMIT 36
	   OFFSET 36*?""", (token, token, token, page))
        rows = [{
            'video_id': video_id,
            'channel_id': channel_id,
            'author': author,
            'title': title,
            'length': length,
            'livestream': livestream,
            'published': published,
            'playlist': playlist,
            'pinned': display == 'pinned',
        } for (video_id, channel_id, author, title, length, livestream, published, playlist, display) in c.fetchall()]
    return render_template('index.html.j2', rows=rows, page=page)

@frontend.route('/watch')
def watch():
    if current_user.is_anonymous:
        token = 'guest'
    else:
        token = current_user.token

    if not 'v' in request.args:
        return "missing video id", 400

    plaintextheaders = {
        'content-type': 'text/plain',
        'Link': "<data:text/css,body%7Bcolor:%23eee;background:%23333%7D>; rel=stylesheet;"
    }

    video_id = request.args.get('v')
    sts, algo = get_cipher()
    video_url, stream_map, metadata, error, errdetails = get_video_info(video_id, sts, algo)

    extra = {'geolocked':'local=1', 'livestream':'raw=0'}.get(error,'')
    invidious_url = f"https://invidious.snopyta.org/watch?v={video_id}&{extra}"
    errdetails = {
        'banned':     "Instance is being rate limited.",
        'malformed':  "Video ID is invalid.",
        'geolocked':  "This video is geolocked.",
        'livestream': "Livestreams not supported on this instance.",
        'agegated':   "Unable to bypass age-restriction.",
        'exhausted':  errdetails or "Couldn't extract video URLs.",
        'player':     errdetails,
    }.get(error)

    # if the video is geolocked, and the proxy is enabled, we can still play
    # it, if the video is available in the instance server's region:
    if error == 'geolocked' and video_url and 'proxy' in current_app.blueprints.keys():
        videoplayback = url_for('proxy.videoplayback')
        query = urlparse(video_url).query
        video_url = f"{videoplayback}?{query}"
        for s in stream_map['adaptive']:
            query = urlparse(s['url']).query
            s['url'] = f"{videoplayback}?{query}"
        for s in stream_map['muxed']:
            query = urlparse(s['url']).query
            s['url'] = f"{videoplayback}?{query}"
        error = None

    # if the proxy is enabled, we can also play livestreams:
    if error == 'livestream' and 'proxy' in current_app.blueprints.keys():
        # Note: hlsManifestUrl's hostname will be replaced client-side
        video_url = stream_map['hlsManifestUrl']
        error = None

    # if the instance is blocked, try submitting a job to the anti captcha service:
    if error == 'banned' and cf['captcha']['api_key']:
        r2 = requests.get(f'https://www.youtube.com/watch?v={video_id}&hl=en&gl=US')
        status = submit_captcha(r2)
        if status is False:
            raise Exception("we are banned, but captcha wasn't triggered!")
        else:
            message = "right now" if status is True else f"{int(status)} seconds ago"
            raise BadGateway(f"""
                {errdetails} An attempt at getting unblocked has been made {message}.
                Please try again in 30 seconds.
            """)

    show = request.args.get("show")
    if show == "raw":
        if error:
            msg = errdetails if error=='player' else f"{error.upper()}: {errdetails}"
            return f"{msg}\n\nRedirecting to Invidious.", 502, {
                'Refresh': f'2; URL={invidious_url}&raw=1',
                **plaintextheaders}
        return redirect(video_url, code=307)
    elif show == "json":
        if error and not metadata:
            return {'error': True, error: errdetails}, 400 # TODO: better (test _CpR4o81XQc)
        return jsonify(metadata)
    elif show == "audio":
        # sorting: we want to prioritize mp4a over opus, and sort by highest quality first
        # todo: geolocking; prefer open format?
        if error and not metadata:
            msg = errdetails if error=='player' else f"{error.upper()}: {errdetails}"
            return msg, 400, plaintextheaders # TODO: nicer
        stream = next(iter(sorted([
                    stream for stream in stream_map['adaptive']
                    if stream['mimeType'].startswith('audio/')],
                key=lambda stream: ('opus' not in stream['mimeType'],
                    stream['bitrate']), reverse=True)
            ),{}).get('url')
        return redirect(stream)
    else:
        if error and not metadata: # e.g. malformed, private/deleted video, ...
            return render_template('video-error.html.j2', video_id=video_id,
                video_error=error, errdetails=errdetails, invidious_url=invidious_url)
        meta = prepare_metadata(metadata)
        with sqlite3.connect(cf['global']['database']) as conn:
            c = conn.cursor()
            c.execute("""
            SELECT COUNT((
                SELECT 1 FROM subscriptions WHERE channel_id = ? AND user = ?
            )), COUNT((
                SELECT 1 FROM flags WHERE video_id = ? AND display = 'pinned' AND user = ?
            ))""", (meta['channel_id'], token, video_id, token))
            (is_subscribed, is_pinned) = c.fetchone()
            return render_template('watch.html.j2',
                video_id=video_id, video_url=video_url, stream_map=stream_map,
                video_error=error, errdetails=errdetails, invidious_url=invidious_url,
                is_pinned=is_pinned, is_subscribed=is_subscribed,
                **meta)

@frontend.route('/embed/videoseries')
def embed_videoseries():
    return redirect(url_for('.playlist', list=request.args.get('list')))
@frontend.route('/embed/<video_id>', strict_slashes=False)
def embed(video_id):
    if video_id == "videoseries":
        return redirect(url_for('.playlist', list=request.args.get('list')))

    return redirect(url_for('.watch', v=video_id, t=request.args.get('start')))

@frontend.route('/<something>', strict_slashes=False)
def plain_user_or_video(something):
    # yt.com interprets this as a username, but we also want to catch youtu.be
    # short-urls. so we check if it's a channel by querying the RSS feed (this
    # shoudn't be rate-limited); if that fails, check if it looks like a video
    # id; or finally give up.
    if '.' not in something and channel_exists(something):
        # periods are not valid in usernames, vanity urls or ucids, but common
        # in urls that get crawled by bots (e.g. index.php). failing early
        # reduces the amount of invalid channel names getting looked up.
        return redirect(url_for('.channel', channel_id=something))
    elif re.match(r"^[-_0-9A-Za-z]{11}$", something): # looks like a video id
        return redirect(url_for('.watch', v=something, t=request.args.get('t')))
    else: # ¯\_(ツ)_/¯
        # XXX: something == 'thethoughtemporium' -> 404s
        raise NotFound("Note: some usernames not recognized; try searching it")

@frontend.route('/channel/<channel_id>/<subpage>')
@frontend.route('/user/<channel_id>/<subpage>')
@frontend.route('/c/<channel_id>/<subpage>')
@frontend.route('/channel/<channel_id>/')
@frontend.route('/user/<channel_id>/')
@frontend.route('/c/<channel_id>/')
def channel(channel_id, _=None):
    token = getattr(current_user, 'token', 'guest')

    if re.match(r"(UC[A-Za-z0-9_-]{22})", channel_id):
        xmlfeed = fetch_xml("channel_id", channel_id)
    else:
        xmlfeed = fetch_xml("user", channel_id)

    if not xmlfeed:
        return "not found or something", 404 # XXX
    title, author, videos, channel_id, _ = parse_xml(xmlfeed)

    with sqlite3.connect(cf['global']['database']) as conn:
        c = conn.cursor()
        c.execute("""
            SELECT COUNT(*)
              FROM subscriptions
             WHERE channel_id = ? AND user = ?
        """, (channel_id, token))
        (is_subscribed,) = c.fetchone()

    return render_template('xmlfeed.html.j2', title=author, rows=videos,
        is_subscribed=is_subscribed, channel_id=channel_id)

@frontend.route('/playlist')
def playlist():
    playlist_id = request.args.get('list')
    if not playlist_id:
        return "bad list id", 400 # todo

    xmlfeed = fetch_xml("playlist_id", playlist_id)
    if not xmlfeed:
        return "not found or something", 404 # XXX
    title, author, videos, _, _ = parse_xml(xmlfeed)
    return render_template('xmlfeed.html.j2', title=f"{title} by {author}", rows=videos)

@frontend.route('/api/timedtext')
def timedtext():
    r = requests.get("https://www.youtube.com/api/timedtext", request.args.to_dict())
    # Note: in srv1 format, xmlentities are double-encoded m( a smart quote is
    # even worse: it's '&amp;39;<smartquote>' wtf!? (at least vvt seems ok)
    if not r.ok:
        return "error: {r.text}", 400 # TODO: better
    retval = r.text
    if request.args.get('fmt') == 'vtt' and request.args.get('kind') == 'asr':
        # autocaptions are extremely confusing, and stuck in the lower-left corner. fix it up a bit
        retval = re.sub(r"<.+?>", "", retval) # remove inline html-like markup that times each word/adds styles
        retval = retval.replace("align:start position:0%", "") # let browser position the text itself
        # each subtitle-line is repeated twice (first on the lower line, then
        # on the next "frame" on the upper line). we want to remove the
        # repetition, as that's confusing without word and line animations:
        lines = retval.split('\n')
        retval = '\n'.join([line for line, prev in zip(lines, ['']+lines) if not " --> " in prev])
    return retval, {'Content-Type': r.headers.get("Content-Type")}

@frontend.route('/manage/subscriptions')
# disabled for guest user: @login_required
def subscription_manager():
    if current_user.is_anonymous:
        token = 'guest'
    else:
        token = current_user.token
    with sqlite3.connect(cf['global']['database']) as conn:
        #with conn.cursor() as c:
            c = conn.cursor()
            c.execute("""
		  SELECT subscriptions.channel_id, name, type,
		         (subscribed_until < datetime('now')) AS obsolete
		    FROM subscriptions
		    LEFT JOIN (SELECT name, id FROM channels
                       UNION
                       SELECT name, id FROM playlists
                      ) AS channels ON channels.id = subscriptions.channel_id
		    left JOIN websub ON channels.id = websub.channel_id
		   WHERE user = ?
		     AND subscriptions.type IN ('channel', 'playlist')
		ORDER BY obsolete=0, name COLLATE NOCASE ASC""", (token,))
            rows = [{
                'channel_id': channel_id,
                'author': author or channel_id,
                'type': type,
                'subscribed_until': subscribed_until
            } for (channel_id, author, type, subscribed_until) in c.fetchall()]
    return render_template('subscription_manager.html.j2', rows=rows)

@frontend.route('/feed/subscriptions', methods=['POST'])
@login_required
def feed_post():
    token = current_user.token
    action = next(request.form.keys(), None)
    if action in ['pin', 'unpin', 'hide', 'unhide']:
        video_id = request.form.get(action)
        display = {
            'pin': 'pinned',
            'unpin': None,
            'hide': 'hidden',
            'unhide': None,
        }[action]
        with sqlite3.connect(cf['global']['database']) as conn:
            c = conn.cursor()
            store_video_metadata(video_id) # only needed for pinning
            c.execute("""
                INSERT OR REPLACE INTO flags (user, video_id, display)
                VALUES (?, ?, ?)
            """, (token, video_id, display))
        undo_flash(video_id, action)
    else:
        flash("unsupported action", "error")
    return redirect(request.url, code=303)

@frontend.route('/manage/subscriptions', methods=['POST'])
@login_required
def manage_subscriptions():
    token = current_user.token
    if 'subscribe' in request.form:
        some_id = request.form.get("subscribe")
        match = re.search(r"(UC[A-Za-z0-9_-]{22})", some_id)
        if match:
            some_id = match.group(1)
            id_type = "channel"
        else:
            match = re.search(r"((?:PL|LL|EC|UU|FL|UL|OL)[A-Za-z0-9_-]{10,})", some_id)
            if match:  # NOTE: PL-playlists are 32chars, others differ in length.
                some_id = match.group(1)
                id_type = "playlist"
            else:
                flash("not a valid/subscribable URI", "error")
                return redirect(request.url, code=303)
        with sqlite3.connect(cf['global']['database']) as conn:
            #with conn.cursor() as c:
                c = conn.cursor()
                c.execute("""
			INSERT OR IGNORE INTO subscriptions (user, channel_id, type)
			VALUES (?, ?, ?)
                """, (token, some_id, id_type))
                # TODO: sql-error-handling, asynchronically calling update-subs.pl
        undo_flash(some_id, 'subscribe')

    elif 'unsubscribe' in request.form:
        some_id = request.form.get("unsubscribe")
        with sqlite3.connect(cf['global']['database']) as conn:
            #with conn.cursor() as c:
                c = conn.cursor()
                c.execute("""
			DELETE FROM subscriptions
			WHERE user = ? AND channel_id = ?
                """, (token, some_id))
                # TODO: sql-error-handling, report success
        undo_flash(some_id, 'unsubscribe')

    else:
        flash("unsupported action", "error")

    return redirect(request.url, code=303)

def get_cipher():
    # reload cipher from database every 1 hour
    if 'cipher' not in g or time.time() - g.get('cipher_updated', 0) > 1 * 60 * 60:
        with sqlite3.connect(cf['global']['database']) as conn:
            c = conn.cursor()
            c.execute("SELECT sts, algorithm FROM cipher")
            g.cipher = c.fetchone()
            g.cipher_updated = time.time()

    return g.cipher

#@frontend.teardown_appcontext
#def teardown_db():
#    db = g.pop('db', None)
#
#    if db is not None:
#        db.close()

def undo_flash(thing_id, action):
    undo_action, past_action = {
        'pin': ('unpin', 'pinned'),
        'unpin': ('pin', 'unpinned'),
        'hide': ('unhide', 'hidden'),
        'unhide': ('hide', 'unhidden'),
        'subscribe': ('unsubscribe', 'subscribed'),
        'unsubscribe': ('subscribe', 'unsubscribed'),
    }.get(action)
    if 'subscribe' in action and thing_id.startswith('UC'):
        thing = "channel"
        thing_url = url_for('.channel', channel_id=thing_id)
    elif 'subscribe' in action:
        thing = "playlist"
        thing_url = url_for('.playlist', playlist_id=thing_id)
    else:
        thing = "video"
        thing_url = url_for('.watch', v=thing_id)
    flash(f'''
        <form method=post><input type=hidden name="{undo_action}" value="{thing_id}">
        <a href="{thing_url}">{thing}</a> {past_action}.
        <label><input type="submit" hidden>
        <span style="text-decoration:underline;cursor:pointer">undo</span>.
        </label></form>''', "info")

@frontend.app_template_filter('format_date')
def format_date(s):
    import datetime # can't import at top level, because it is inherited from common
    (y,m,d) = (int(n) for n in s.split('T')[0].split(' ')[0].split('-'))  # iso-dates can seperate date from time with space or 'T'
    M = '_ Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec'.split()
    if y == datetime.datetime.now().year:
        return f"{d} {M[m]}"
    else:
        return f"{M[m]} '{y%100}"

@frontend.app_template_filter('format_time')
def format_time(i):
    if i is None:
        return None
    h = i // (60*60)
    m = i // 60 % 60
    s = i % 60
    return '%d:%02d:%02d' % (h,m,s) if h else '%02d:%02d' % (m,s)

@frontend.app_template_filter('timeoffset')
def timeoffset(s):
    if s is None:
        return None
    match = re.match(r"^(\d+)s?$", s)  # e.g. 2040s
    if match:
        return match.group(1)
    match = re.match(r"^(?:(\d+)h)?(?:(\d+)m)?(?:(\d+)s)?$", s)  # e.g. 34m, 1h23s
    if match:
        return ":".join([n.zfill(2) for n in match.groups('0')])
    return None