from minio import Minio
from django.conf import settings
import uuid
import os
import json
import logging

logger = logging.getLogger(__name__)

class MinioClient:
    def __init__(self):
        self._client = None
        self.bucket_name = getattr(settings, 'MINIO_BUCKET_NAME', 'opc-assets')
        self._initialized = False

    @property
    def client(self):
        if self._client is None:
            self._client = Minio(
                endpoint=getattr(settings, 'MINIO_ENDPOINT', 'localhost:9000'),
                access_key=getattr(settings, 'MINIO_ACCESS_KEY', 'minioadmin'),
                secret_key=getattr(settings, 'MINIO_SECRET_KEY', 'minioadmin'),
                secure=getattr(settings, 'MINIO_SECURE', False)
            )
        if not self._initialized:
            try:
                self._ensure_bucket()
                self._initialized = True
            except Exception as e:
                logger.warning(f'MinIO bucket init failed (will retry on next call): {e}')
        return self._client

    def _ensure_bucket(self):
        if not self._client.bucket_exists(self.bucket_name):
            self._client.make_bucket(self.bucket_name)
        
        # Always update policy to ensure public access
        policy = {
            "Version": "2012-10-17",
            "Statement": [
                {
                    "Effect": "Allow",
                    "Principal": {"AWS": ["*"]},
                    "Action": ["s3:GetBucketLocation", "s3:ListBucket"],
                    "Resource": [f"arn:aws:s3:::{self.bucket_name}"],
                },
                {
                    "Effect": "Allow",
                    "Principal": {"AWS": ["*"]},
                    "Action": ["s3:GetObject"],
                    "Resource": [f"arn:aws:s3:::{self.bucket_name}/*"],
                },
            ],
        }
        self._client.set_bucket_policy(self.bucket_name, json.dumps(policy))

    def upload_file(self, file_obj, folder='general'):
        # Generate a unique name
        ext = os.path.splitext(file_obj.name)[1]
        file_name = f"{folder}/{uuid.uuid4()}{ext}"
        
        # Upload (this will trigger lazy init of the client)
        self.client.put_object(
            self.bucket_name,
            file_name,
            file_obj,
            length=file_obj.size,
            content_type=file_obj.content_type
        )
        
        # Return the public URL
        base_url = getattr(settings, 'MINIO_PUBLIC_URL', 'http://127.0.0.1:9000')
        return f"{base_url}/{self.bucket_name}/{file_name}"


# Lazy singleton — does NOT connect at import time
minio_client = MinioClient()