init: new structure + fix lint errors

cpv3/infrastructure/storage/s3.py

@@ -0,0 +1,107 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+from typing import BinaryIO
+
+import boto3  # type: ignore[import-untyped]
+import boto3.session  # type: ignore[import-untyped]
+from botocore.config import Config  # type: ignore[import-untyped]
+from botocore.exceptions import ClientError  # type: ignore[import-untyped]
+
+
+@dataclass(frozen=True)
+class S3Config:
+    access_key: str
+    secret_key: str
+    bucket_name: str
+    endpoint_url_internal: str | None
+    endpoint_url_public: str | None
+    presign_expires_seconds: int = 3600
+
+
+class S3StorageBackend:
+    def __init__(self, cfg: S3Config) -> None:
+        self._cfg = cfg
+        self._bucket_ready = False
+
+        session = boto3.session.Session()
+        common = {
+            "aws_access_key_id": cfg.access_key,
+            "aws_secret_access_key": cfg.secret_key,
+            "region_name": "us-east-1",
+            "config": Config(signature_version="s3v4", s3={"addressing_style": "path"}),
+        }
+
+        self._client = session.client(
+            "s3", endpoint_url=cfg.endpoint_url_internal, **common
+        )
+
+        presign_endpoint = cfg.endpoint_url_public or cfg.endpoint_url_internal
+        self._presign_client = session.client(
+            "s3", endpoint_url=presign_endpoint, **common
+        )
+
+    def ensure_bucket(self) -> None:
+        if self._bucket_ready:
+            return
+
+        try:
+            self._client.head_bucket(Bucket=self._cfg.bucket_name)
+        except ClientError as e:
+            code = str(e.response.get("Error", {}).get("Code", ""))
+            if code in {"404", "NoSuchBucket"}:
+                self._client.create_bucket(Bucket=self._cfg.bucket_name)
+            else:
+                raise
+
+        self._bucket_ready = True
+
+    def upload_fileobj(
+        self, key: str, fileobj: BinaryIO, *, content_type: str | None
+    ) -> None:
+        self.ensure_bucket()
+        extra_args = {"ContentType": content_type} if content_type else None
+        self._client.upload_fileobj(
+            Fileobj=fileobj,
+            Bucket=self._cfg.bucket_name,
+            Key=key,
+            ExtraArgs=extra_args,
+        )
+
+    def download_fileobj(self, key: str, fileobj: BinaryIO) -> None:
+        self.ensure_bucket()
+        self._client.download_fileobj(self._cfg.bucket_name, key, fileobj)
+
+    def exists(self, key: str) -> bool:
+        self.ensure_bucket()
+        try:
+            self._client.head_object(Bucket=self._cfg.bucket_name, Key=key)
+            return True
+        except ClientError as e:
+            code = str(e.response.get("Error", {}).get("Code", ""))
+            if code in {"404", "NoSuchKey"}:
+                return False
+            raise
+
+    def size(self, key: str) -> int:
+        self.ensure_bucket()
+        resp = self._client.head_object(Bucket=self._cfg.bucket_name, Key=key)
+        return int(resp.get("ContentLength", 0))
+
+    def delete(self, key: str) -> None:
+        self.ensure_bucket()
+        self._client.delete_object(Bucket=self._cfg.bucket_name, Key=key)
+
+    def read(self, key: str) -> bytes:
+        self.ensure_bucket()
+        resp = self._client.get_object(Bucket=self._cfg.bucket_name, Key=key)
+        body = resp["Body"].read()
+        return body
+
+    def generate_url(self, key: str) -> str:
+        self.ensure_bucket()
+        return self._presign_client.generate_presigned_url(
+            ClientMethod="get_object",
+            Params={"Bucket": self._cfg.bucket_name, "Key": key},
+            ExpiresIn=self._cfg.presign_expires_seconds,
+        )