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

import aiohttp

from bot.utils.proxy import get_proxy_connector

DOWNLOAD_DIR = Path("bot/data/downloads")
DOWNLOAD_DIR.mkdir(parents=True, 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_file(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)
    connector = get_proxy_connector()

    try:
        async with aiohttp.ClientSession(timeout=timeout, connector=connector) as session:
            async with session.get(final_url) as response:
                response.raise_for_status()
                payload = await response.json()
                download_url = payload["href"]

            async with session.get(download_url) 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=str(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
    finally:
        if connector:
            await connector.close()