import base64
from . import pyproto

def proto(d, padding=False):
    return base64.urlsafe_b64encode(pyproto.ProtoBuf(d).toBuf()) \
            .decode('ascii').replace("=", "%3D" if padding else "")

def continuation(subject, params, query=None):
    return proto({
        80226972: {
            2: subject,
            3: proto(params, padding=True),
            11: query,
        }
    }, padding=True)

def make_sp(sort=None, date=None, type=None, len=None, features=[], extras=[]):
    sortorder  = dict(relevance=0, rating=1, date=2, views=3)
    datefilter = dict(hour=1, day=2, week=3, month=4, year=5)
    typefilter = dict(video=1, channel=2, playlist=3, movie=4, show=5)
    lenfilter  = dict(short=1, long=2, medium=3) # short=0-4min, long=20+min, medium=4-20min
    extraflags = dict(verbatim=1)
    featureflags = dict(is_hd=4, subtitles=5, ccommons=6, is_3d=7, live=8,
                    purchased=9, is_4k=14, is_360=15, location=23, is_hdr=25)

    return proto({
        1: sortorder.get(sort),
        2: {
            1: datefilter.get(date),
            2: typefilter.get(type),
            3: lenfilter.get(len),
            **{featureflags[k]:True for k in features if k in featureflags}
        } if date or type or len or features else None,
        8: { extraflags[k]:True for k in extras if k in extraflags } or None
    }, padding=True)

def make_channel_params(subject, typ="videos", sort=None, query=None):
    if typ in ("playlists",):
        sortorder = dict(newest=3, modified=4)
        return continuation(subject, {
            2: "playlists", #type_s
            4: 1, #type_i
            3: sortorder.get(sort),#sort optional
            7: 1, #unknown_const1
            23: 0, #unknown_const2
            6: 2, #list_or_grid (2=list, None/1=grid)
            61: proto({1: proto({1: 0})}) #offset
        })
    elif typ in ("search",):
        return continuation(subject, {
            2: "search",#type_s
            7: 1, #unknown_const1
            23: 0, #unknown_const2
            6: 2, #list_or_grid (2=list, None/1=grid)
        }, query)
    elif typ in ("videos", "streams", "shorts"):
        sortorder = dict(newest=1, popular=2)
        typekey = dict(videos=15, streams=14, shorts=10)
        return continuation(subject, { 110: { 3: {
            typekey[typ]: {
                2: { 1: "00000000-0000-0000-0000-000000000000" },
                3: sortorder.get(sort,1)
            }
        }}})
    else:
        raise NotImplementedError

def make_playlist_params(playlist_id, offset):
    # mix takes video id instead of offset. an id not in the playlist requests the beginning.
    mix_playlist = playlist_id.startswith("RD")
    return continuation("VL" + playlist_id, {
        15: "PT:" + proto(
            { 2: '___________' } if mix_playlist else { 1: offset }
        )
    })