from __future__ import annotations

from datetime import datetime, timezone
from pathlib import Path

import oss2

from app.settings import settings


class OSSUploader:
    def __init__(self) -> None:
        self.enabled = bool(settings.oss_enabled)
        if not self.enabled:
            self.bucket = None
            return

        if not all([
            settings.oss_endpoint,
            settings.oss_bucket,
            settings.oss_access_key_id,
            settings.oss_access_key_secret,
        ]):
            raise RuntimeError("OSS is enabled but endpoint/bucket/ak/sk is not fully configured")

        auth = oss2.Auth(settings.oss_access_key_id, settings.oss_access_key_secret)
        self.bucket = oss2.Bucket(auth, settings.oss_endpoint, settings.oss_bucket)

    @staticmethod
    def _safe_name(name: str) -> str:
        return name.replace("\\", "_").replace("/", "_")

    def _key(self, dispatch_id: str, filename: str) -> str:
        date_part = datetime.now(timezone.utc).strftime("%Y%m%d")
        safe_file = self._safe_name(Path(filename).name)
        return f"{settings.oss_prefix.strip('/')}/{date_part}/{dispatch_id}/{safe_file}"

    def _public_url(self, key: str) -> str:
        if settings.oss_public_base_url:
            return f"{settings.oss_public_base_url.rstrip('/')}/{key}"

        endpoint = settings.oss_endpoint.rstrip("/")
        if endpoint.startswith("http://") or endpoint.startswith("https://"):
            return f"{endpoint}/{key}"
        return f"https://{endpoint}/{key}"

    def upload_fileobj(self, dispatch_id: str, filename: str, fileobj) -> dict[str, str]:
        if not self.enabled or self.bucket is None:
            raise RuntimeError("OSS uploader is not enabled")

        key = self._key(dispatch_id, filename)
        fileobj.seek(0)
        self.bucket.put_object(key, fileobj)
        return {
            "filename": Path(filename).name,
            "object_key": key,
            "url": self._public_url(key),
        }


oss_uploader = OSSUploader()