#!/usr/bin/env python3
import yaml
from telethon import TelegramClient, events, sync
import logging
from telethon import functions, types, errors
from pathlib import Path

mimes={
    "image/webp": "webp",
    "application/x-tgsticker": "tgs",
    "video/webm": "webm"
    }
w = Path(".")
wn = w / "env"
wn.mkdir(exist_ok=True)
wd = wn/"download"
wd.mkdir(exist_ok=True)
wdi = wd/"inline"
wdi.mkdir(exist_ok=True)
logging.basicConfig(filename=str(wn/"bot.log"),level=logging.DEBUG)
log = logging.getLogger("gentoobot")
dllog=logging.getLogger("gentoobot.download")

def download_sticker(client, document):
    stickerdir, setid = get_sticker_setid(document)
    if stickerdir is None:
        return
    dldir = wd / stickerdir
    dldir.mkdir(exist_ok=True)
    dlpath = dldir / (str(document.id)+"."+mimes.get(document.mime_type, "")) 
    if not  dlpath.exists() or dlpath.stat().st_size != document.size:
        dllog.info("downloading %s to %s", document.id, str(dlpath))
        client.download_file(document, dlpath)
    else:
        dllog.info("document %s already downloaded at %s", document.id, str(dlpath))

def get_sticker_setid(document):
    stickerset = None
    for a in document.attributes:
        if hasattr(a, "stickerset"):
            stickerset = a.stickerset
    if stickerset is None:
        dllog.debug("document %s is not a sticker", document.id)
        return None, None
    if isinstance(stickerset, types.InputStickerSetID):
        log.debug("document %s is a normal sticker", document.id)
        return str(stickerset.id), stickerset
    if isinstance(stickerset, types.InputStickerSetEmpty):
        dllog.debug("document %s is an inline sticker", document.id)
        return "inline", stickerset

def fetch_dialogs(client):
    sticker_archives=list()
    for dialog in client.iter_dialogs():
        log.debug(dialog)
        if dialog.entity.id in cfg["stickers"]["sources"]["dialogs"]:
            log.info(dialog.stringify())
            yield dialog

def process_archive(archive, stickerset_seen=set()):
    for msg in client.iter_messages(sticker_archive, limit=None):
        log.debug(msg)
        if not hasattr(msg, "media"):
            log.debug("message %i has no media", msg.id)
            continue
        if not hasattr(msg.media, "document"):
            log.debug("message %i has no documents", msg.id)
            continue
        try:
            dldir, setid = get_sticker_setid(msg.media.document)
            if dldir == "inline":
                download_sticker(client, msg.media.document)
            elif dldir is not None:
                download_sticker(client, msg.media.document)
                if setid.id not in stickerset_seen:
                    log.info("preparing to download whole stickerset %s as %s", setid, dldir)
                    stickerset_seen.add(setid.id)
                    try:
                        for doc in client(functions.messages.GetStickerSetRequest(stickerset=setid,hash=0)).documents:
                            try: 
                                download_sticker(client, doc)
                            except Exception as e:
                                log.critical("oops: %s", exc_info=e)
                    except errors.rpcerrorlist.StickersetInvalidError:
                        log.warning("sadly, stickerset %s no longer exists", setid.id)
        except Exception as e:
            log.error("somethin wrong happened during checking message: %s", msg.stringify(), exc_info=e)



####################


if __name__ == "__main__":
    log.debug("opening %s", repr("config/bot.yaml"))
    with open("config/bot.yaml") as cfgstream:
        cfg = yaml.safe_load(cfgstream)
        log.debug(cfg)
        app = cfg["apps"][0]
    log.debug("starting client with id %s and hash %s", app['id'], app['hash'])
    client = TelegramClient('env/gentoo_session', app['id'], app['hash'])
    client.start()
    log.debug(client.get_me().stringify())
    try:
        for sticker_archive in fetch_dialogs(client):
            process_archive(sticker_archive)
    except KeyboardInterrupt:
        pass
    client.disconnect()