from __future__ import annotations

from dataclasses import dataclass
from datetime import datetime, timezone
from pathlib import Path
from typing import Any, Mapping

import boto3


@dataclass(frozen=True)
class S3Config:
    bucket_name: str
    region_name: str | None = None
    endpoint_url: str | None = None
    aws_access_key_id: str | None = None
    aws_secret_access_key: str | None = None
    aws_session_token: str | None = None


class S3VideoStorage:
    def __init__(self, s3_config: S3Config | Mapping[str, Any]) -> None:
        self.config = self._normalize_config(s3_config)

        client_kwargs: dict[str, Any] = {
            "region_name": self.config.region_name,
            "endpoint_url": self.config.endpoint_url,
            "aws_access_key_id": self.config.aws_access_key_id,
            "aws_secret_access_key": self.config.aws_secret_access_key,
            "aws_session_token": self.config.aws_session_token,
        }
        filtered_kwargs = {k: v for k, v in client_kwargs.items() if v is not None}
        self._s3_client = boto3.client("s3", **filtered_kwargs)

    def store_file(self, file_path: str | Path) -> str:
        path = Path(file_path)
        if not path.exists():
            raise FileNotFoundError(f"File does not exist: {path}")
        if not path.is_file():
            raise ValueError(f"Path is not a file: {path}")

        now = datetime.now(timezone.utc)
        key = f"video_content/{now.year:04d}/{now.month:02d}/{now.day:02d}/{path.name}"

        self._s3_client.upload_file(str(path), self.config.bucket_name, key)
        return f"s3://{self.config.bucket_name}/{key}"

    @staticmethod
    def _normalize_config(s3_config: S3Config | Mapping[str, Any]) -> S3Config:
        if isinstance(s3_config, S3Config):
            return s3_config

        bucket_name = s3_config.get("bucket_name")
        if not bucket_name:
            raise ValueError("s3_config must contain non-empty 'bucket_name'")

        return S3Config(
            bucket_name=str(bucket_name),
            region_name=_optional_str(s3_config, "region_name"),
            endpoint_url=_optional_str(s3_config, "endpoint_url"),
            aws_access_key_id=_optional_str(s3_config, "aws_access_key_id"),
            aws_secret_access_key=_optional_str(s3_config, "aws_secret_access_key"),
            aws_session_token=_optional_str(s3_config, "aws_session_token"),
        )


def _optional_str(config: Mapping[str, Any], key: str) -> str | None:
    value = config.get(key)
    if value is None:
        return None
    return str(value)