# -*- coding: future_fstrings -*-
# mautrix-telegram - A Matrix-Telegram puppeting bridge
# Copyright (C) 2018 Tulir Asokan
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
from io import BytesIO
import time
import logging

import magic
from PIL import Image
from sqlalchemy.exc import IntegrityError

from telethon_aio.tl.types import (Document, FileLocation, InputFileLocation,
                               InputDocumentFileLocation)
from telethon_aio.errors import LocationInvalidError

from ..db import TelegramFile as DBTelegramFile

log = logging.getLogger("mau.util")


def _convert_webp(file, to="png"):
    try:
        image = Image.open(BytesIO(file)).convert("RGBA")
        new_file = BytesIO()
        image.save(new_file, to)
        return f"image/{to}", new_file.getvalue()
    except Exception:
        log.exception(f"Failed to convert webp to {to}")
        return "image/webp", file


async def transfer_file_to_matrix(db, client, intent, location):
    if isinstance(location, (Document, InputDocumentFileLocation)):
        id = f"{location.id}-{location.version}"
    elif isinstance(location, (FileLocation, InputFileLocation)):
        id = f"{location.volume_id}-{location.local_id}"
    else:
        return None

    db_file = DBTelegramFile.query.get(id)
    if db_file:
        return db_file

    try:
        file = await client.download_file_bytes(location)
    except LocationInvalidError:
        return None
    mime_type = magic.from_buffer(file, mime=True)

    image_converted = False
    if mime_type == "image/webp":
        mime_type, file = _convert_webp(file, to="png")
        image_converted = True

    uploaded = await intent.upload_file(file, mime_type)

    db_file = DBTelegramFile(id=id, mxc=uploaded["content_uri"],
                             mime_type=mime_type, was_converted=image_converted,
                             timestamp=int(time.time()))
    try:
        db.add(db_file)
        db.commit()
    except IntegrityError:
        db.rollback()
        log.exception("Integrity error while saving transferred file data. "
                      "This was probably caused by two simultaneous transfers of the same file, "
                      "and should not cause any problems.")

    return db_file