from datetime import datetime
from io import BytesIO
from typing import Optional

from aiogram import Bot
from aiogram.enums import ContentType
from aiogram.types import User, PhotoSize, Message, BufferedInputFile

import ai
import utils


async def get_user_name_for_ai(user: Optional[User]) -> str:
    if user is None:
        return "Неизвестный пользователь"
    elif user.first_name and user.last_name:
        return "{} {}".format(user.first_name, user.last_name)
    elif user.first_name:
        return user.first_name
    elif user.username:
        return user.username
    else:
        return str(user.id)


async def download_photo(photo: PhotoSize, bot: Bot) -> bytes:
    # noinspection PyTypeChecker
    photo_bytes: BytesIO = await bot.download(photo.file_id)
    return photo_bytes.getvalue()


def get_message_text(message: Message) -> Optional[str]:
    if message.content_type == ContentType.TEXT:
        return message.text
    elif message.content_type == ContentType.PHOTO:
        return message.caption
    else:
        return None


async def create_ai_message(message: Message, bot: Bot) -> ai.Message:
    ai_message = ai.Message()
    ai_message.message_id = message.message_id
    ai_message.user_name = await get_user_name_for_ai(message.from_user) if message.from_user else "Неизвестный"
    if message.text is not None:
        ai_message.text = message.text
    elif message.photo is not None:
        if message.media_group_id is None:
            ai_message.text = message.caption
            ai_message.image = await download_photo(message.photo[-1], bot)
        else:
            raise utils.UnsupportedContentType()
    else:
        raise utils.UnsupportedContentType()
    return ai_message


def wrap_photo(image: bytes) -> BufferedInputFile:
    return BufferedInputFile(image, 'image.jpg')


def wrap_document(document: bytes, name_prefix: str, extension: str) -> BufferedInputFile:
    name = "{}_{}.{}".format(name_prefix, datetime.now().strftime("%Y%m%d_%H%M%S"), extension)
    return BufferedInputFile(document, name)


def trim_caption(caption: Optional[str]) -> Optional[str]:
    if caption is not None:
        return caption[:1024]
    else:
        return None


__all__ = [
    "create_ai_message",
    "get_message_text",
    "get_user_name_for_ai",
    "trim_caption",
    "wrap_photo",
    "wrap_document",
    "wrap_document"
]