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

import aiohttp
from aiohttp_socks import ProxyConnector, ProxyType

from config import PROXY_URL, PROXY_ENABLED

DOWNLOAD_DIR = Path("bot/data/downloads")
DOWNLOAD_DIR.mkdir(parents=True, exist_ok=True)

def _get_connector():
    if PROXY_ENABLED and PROXY_URL:
        parsed = PROXY_URL.replace("socks5://", "").replace("socks5h://", "")
        if "@" in parsed:
            auth, host_port = parsed.split("@", 1)
            username, password = auth.split(":", 1)
        else:
            username = None
            password = None
            host_port = parsed

        host, port = host_port.rsplit(":", 1)
        port = int(port)

        return ProxyConnector(
            proxy_type=ProxyType.SOCKS5,
            host=host,
            port=port,
            username=username,
            password=password,
        )
    return None

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_connector()

    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