import logging
import re
from pathlib import Path

import httpx

from common.utils import get_env

logger = logging.getLogger(__name__)

_DEFAULT_CONTENT_TYPE = "application/octet-stream"
_CONTENT_TYPES = {
    ".jpg": "image/jpeg",
    ".jpeg": "image/jpeg",
    ".png": "image/png",
    ".gif": "image/gif",
    ".webp": "image/webp",
    ".bmp": "image/bmp",
    ".mp3": "audio/mpeg",
    ".mp4": "video/mp4",
    ".mov": "video/quicktime",
    ".pdf": "application/pdf",
    ".txt": "text/plain",
    ".json": "application/json",
    ".csv": "text/csv",
}

_shared_client: httpx.AsyncClient | None = None


async def _get_client() -> httpx.AsyncClient:
    global _shared_client
    if _shared_client is None or _shared_client.is_closed:
        _shared_client = httpx.AsyncClient(
            timeout=httpx.Timeout(180.0, connect=10.0),
            limits=httpx.Limits(max_keepalive_connections=10, max_connections=20),
        )
    return _shared_client


def _sanitize_filename(file_name: str) -> str:
    stem = Path(file_name).stem
    suffix = Path(file_name).suffix
    sanitized = re.sub(r"[^가-힣a-zA-Z0-9]", "", stem) or "file"
    return f"{sanitized}{suffix}"


def _guess_content_type(file_name: str) -> str:
    return _CONTENT_TYPES.get(Path(file_name).suffix.lower(), _DEFAULT_CONTENT_TYPE)


class AzureBlobUploader:
    def __init__(self, group: str, category: str = "file"):
        self._group = group
        self._category = category
        self._base_url = get_env("AZURE_BLOB_BASE_URL")
        self._sas_token = get_env("AZURE_BLOB_SAS_TOKEN").strip("?'\"")

    def _public_url(self, file_name: str) -> str:
        return f"{self._base_url}/{self._group}/{self._category}/{file_name}"

    def _upload_url(self, file_name: str) -> str:
        return f"{self._public_url(file_name)}?{self._sas_token}"

    async def upload_bytes(self, content: bytes, file_name: str, content_type: str | None = None) -> str:
        file_name = _sanitize_filename(file_name)
        ct = content_type or _guess_content_type(file_name)
        url = self._upload_url(file_name)
        headers = {"Content-Type": ct, "x-ms-blob-type": "BlockBlob"}

        client = await _get_client()
        resp = await client.put(url, content=content, headers=headers)
        if resp.status_code not in (200, 201):
            logger.error("Azure Blob upload failed status=%s body=%s", resp.status_code, resp.text[:500])
            raise RuntimeError(f"Azure Blob upload failed: {resp.status_code}")

        public_url = self._public_url(file_name)
        logger.info("Azure Blob uploaded url=%s size=%s", public_url, len(content))
        return public_url