import os
import re
import tempfile
from pathlib import Path
from urllib.parse import urlencode, unquote

import aiohttp

from config import create_aiohttp_session, get_aiohttp_request_kwargs

DOWNLOAD_DIR = Path("downloads")
DOWNLOAD_DIR.mkdir(exist_ok=True)


def sanitize_filename(filename: str) -> str:
    filename = os.path.basename(filename).strip()
    filename = re.sub(r"[\\/:*?\"<>|]+", "_", filename)
    return filename or "downloaded_file"


async def download_yandex_files(public_url: str, progress_callback=None) -> str:
    base_url = "https://cloud-api.yandex.net/v1/disk/public/resources/download?"
    final_url = base_url + urlencode({"public_key": public_url})

    timeout = aiohttp.ClientTimeout(total=None, sock_connect=30, sock_read=300)

    async with create_aiohttp_session(timeout=timeout) as session:
        request_kwargs = get_aiohttp_request_kwargs()

        async with session.get(final_url, **request_kwargs) as response:
            response.raise_for_status()
            payload = await response.json()
            download_url = payload["href"]

        async with session.get(download_url, **request_kwargs) as response:
            response.raise_for_status()

            content_disposition = response.headers.get("Content-Disposition", "")
            filename = download_url.split("/")[-1]

            if "filename*" in content_disposition:
                try:
                    encoded = content_disposition.split("filename*=")[1].strip()
                    parts = encoded.split("''", 1)
                    if len(parts) == 2:
                        filename = unquote(parts[1], encoding=parts[0] or "utf-8")
                except Exception:
                    pass

            filename = sanitize_filename(filename)
            suffix = Path(filename).suffix or ".bin"

            with tempfile.NamedTemporaryFile(delete=False, suffix=suffix, dir=DOWNLOAD_DIR) as tmp_file:
                total_size = int(response.headers.get("Content-Length", 0))
                downloaded_size = 0

                async for chunk in response.content.iter_chunked(1024 * 64):
                    tmp_file.write(chunk)
                    downloaded_size += len(chunk)
                    if progress_callback:
                        await progress_callback(downloaded_size, total_size)

                return tmp_file.name