"""
MinIO storage helper for workers.

Provides upload/download functionality to replace Docker Shared Volume.
Workers download inputs from MinIO to local temp dir, process, then upload results.

Uses boto3 (S3-compatible API) to communicate with MinIO.
"""

import logging
import os
import shutil
from typing import Optional

import boto3
from botocore.config import Config as BotoConfig

logger = logging.getLogger(__name__)


class MinIOStorage:
    """MinIO storage client for job file exchange."""

    def __init__(
        self,
        endpoint_url: str = None,
        bucket: str = None,
        access_key: str = None,
        secret_key: str = None,
        region: str = None,
        lifecycle_days: int = None,
    ):
        self.endpoint_url = endpoint_url or os.environ.get("MINIO_ENDPOINT_URL", "http://192.168.0.130:9000")
        self.bucket = bucket or os.environ.get("MINIO_BUCKET", "convertet-working-space")
        self.access_key = access_key or os.environ.get("MINIO_ACCESS_KEY", "convuser")
        self.secret_key = secret_key or os.environ.get("MINIO_SECRET_KEY", "")
        self.region = region or os.environ.get("MINIO_REGION", "us-east-1")
        self.lifecycle_days = lifecycle_days if lifecycle_days is not None else int(os.environ.get("MINIO_LIFECYCLE_DAYS", "7"))

        self.client = boto3.client(
            "s3",
            endpoint_url=self.endpoint_url,
            aws_access_key_id=self.access_key,
            aws_secret_access_key=self.secret_key,
            region_name=self.region,
            config=BotoConfig(signature_version="s3v4"),
        )
        self._ensure_bucket()
        if self.lifecycle_days > 0:
            self._ensure_lifecycle_rule()

    def _ensure_bucket(self):
        """Verify bucket exists (do not auto-create — bucket is managed externally)."""
        try:
            self.client.head_bucket(Bucket=self.bucket)
            logger.info(f"MinIO bucket verified: {self.bucket}")
        except Exception as e:
            logger.error(f"MinIO bucket '{self.bucket}' is not accessible: {e}")
            raise

    def _ensure_lifecycle_rule(self):
        """Set lifecycle rule to auto-expire objects under jobs/ prefix."""
        rule_id = "auto-cleanup-jobs"
        try:
            self.client.put_bucket_lifecycle_configuration(
                Bucket=self.bucket,
                LifecycleConfiguration={
                    "Rules": [
                        {
                            "ID": rule_id,
                            "Status": "Enabled",
                            "Filter": {"Prefix": "jobs/"},
                            "Expiration": {"Days": self.lifecycle_days},
                        }
                    ]
                },
            )
            logger.info(f"MinIO lifecycle rule set: jobs/* expire after {self.lifecycle_days} days")
        except Exception as e:
            logger.warning(f"Could not set lifecycle rule: {e}")

    def upload_file(self, local_path: str, key: str):
        """Upload a local file to MinIO."""
        self.client.upload_file(local_path, self.bucket, key)
        logger.debug(f"Uploaded {local_path} -> minio://{self.bucket}/{key}")

    def upload_data(self, data: bytes, key: str):
        """Upload raw bytes to MinIO."""
        self.client.put_object(Bucket=self.bucket, Key=key, Body=data)
        logger.debug(f"Uploaded {len(data)} bytes -> minio://{self.bucket}/{key}")

    def download_file(self, key: str, local_path: str):
        """Download a file from MinIO to local path."""
        os.makedirs(os.path.dirname(local_path), exist_ok=True)
        self.client.download_file(self.bucket, key, local_path)
        logger.debug(f"Downloaded minio://{self.bucket}/{key} -> {local_path}")

    def download_to_stream(self, key: str):
        """Get a streaming body for a MinIO object."""
        response = self.client.get_object(Bucket=self.bucket, Key=key)
        return response["Body"]

    def list_keys(self, prefix: str) -> list:
        """List all keys under a prefix."""
        keys = []
        paginator = self.client.get_paginator("list_objects_v2")
        for page in paginator.paginate(Bucket=self.bucket, Prefix=prefix):
            for obj in page.get("Contents", []):
                keys.append(obj["Key"])
        return keys

    def upload_directory(self, local_dir: str, prefix: str):
        """Upload all files in a local directory to MinIO under a prefix."""
        for root, _, files in os.walk(local_dir):
            for fname in files:
                local_path = os.path.join(root, fname)
                rel_path = os.path.relpath(local_path, local_dir)
                key = f"{prefix}/{rel_path}"
                self.upload_file(local_path, key)

    def download_prefix(self, prefix: str, local_dir: str):
        """Download all files under a MinIO prefix to a local directory."""
        keys = self.list_keys(prefix)
        for key in keys:
            rel_path = key[len(prefix):].lstrip("/")
            if not rel_path:
                continue
            local_path = os.path.join(local_dir, rel_path)
            self.download_file(key, local_path)

    def exists(self, key: str) -> bool:
        """Check if a MinIO key exists."""
        try:
            self.client.head_object(Bucket=self.bucket, Key=key)
            return True
        except Exception:
            return False

    def get_size(self, key: str) -> Optional[int]:
        """Get the size of a MinIO object in bytes."""
        try:
            response = self.client.head_object(Bucket=self.bucket, Key=key)
            return response["ContentLength"]
        except Exception:
            return None