"""Azure Blob Storage 업로드.

SAS 토큰을 붙인 URL로 PUT 한 번. 경로 규칙은 부르는 쪽이 정한다.
클라이언트를 모듈에서 공유해 커넥션 풀을 재사용한다.
"""
import mimetypes
from pathlib import Path

import httpx

from settings import settings

BLOB_TYPE_HEADER = {"x-ms-blob-type": "BlockBlob"}
DEFAULT_CONTENT_TYPE = "application/octet-stream"
UPLOAD_TIMEOUT = httpx.Timeout(180.0, connect=10.0)
POOL_LIMITS = httpx.Limits(max_keepalive_connections=10, max_connections=20)

_client: httpx.AsyncClient | None = None


def get_client() -> httpx.AsyncClient:
    global _client
    if _client is None or _client.is_closed:
        _client = httpx.AsyncClient(timeout=UPLOAD_TIMEOUT, limits=POOL_LIMITS)
    return _client


async def close_client() -> None:
    global _client
    if _client is not None and not _client.is_closed:
        await _client.aclose()
        _client = None


def guess_content_type(path: str) -> str:
    return mimetypes.guess_type(path)[0] or DEFAULT_CONTENT_TYPE


def public_url(path: str) -> str:
    return f"{settings.azure_blob_base_url.rstrip('/')}/{path.lstrip('/')}"


def upload_url(path: str) -> str:
    # SAS 토큰이 따옴표나 ? 로 감싸여 오는 경우가 있다
    token = settings.azure_blob_sas_token.strip("?'\"")
    return f"{public_url(path)}?{token}"


async def upload_bytes(data: bytes, path: str, content_type: str | None = None) -> str:
    """path 예: playreel/nol_26007416/clip.mp4. 공개 URL을 돌려준다."""
    if not settings.azure_blob_base_url or not settings.azure_blob_sas_token:
        raise RuntimeError("AZURE_BLOB_BASE_URL / AZURE_BLOB_SAS_TOKEN 없음")

    headers = {"Content-Type": content_type or guess_content_type(path), **BLOB_TYPE_HEADER}
    response = await get_client().put(upload_url(path), content=data, headers=headers)
    if response.status_code not in (200, 201):
        raise RuntimeError(f"blob 업로드 실패 {response.status_code}: {response.text[:300]}")
    return public_url(path)


async def upload_file(file_path: Path, path: str, content_type: str | None = None) -> str:
    return await upload_bytes(file_path.read_bytes(), path,
                              content_type or guess_content_type(file_path.name))