"""
Object Storage Service for FTC Team Website
Handles persistent file uploads using Google Cloud Storage (Replit Object Storage)
"""

from google.cloud import storage
import os
from uuid import uuid4
from werkzeug.utils import secure_filename

REPLIT_SIDECAR_ENDPOINT = "http://127.0.0.1:1106"


class ObjectStorageService:
    def __init__(self):
        """Initialize the object storage client with Replit credentials"""
        self.client = storage.Client(
            credentials={
                "audience": "replit",
                "subject_token_type": "access_token",
                "token_url": f"{REPLIT_SIDECAR_ENDPOINT}/token",
                "type": "external_account",
                "credential_source": {
                    "url": f"{REPLIT_SIDECAR_ENDPOINT}/credential",
                    "format": {
                        "type": "json",
                        "subject_token_field_name": "access_token",
                    },
                },
                "universe_domain": "googleapis.com",
            },
            project="",
        )
        
        # Get bucket name from environment variable
        self.bucket_name = os.environ.get('OBJECT_STORAGE_BUCKET')
        if not self.bucket_name:
            raise ValueError(
                "OBJECT_STORAGE_BUCKET environment variable not set. "
                "Please create a bucket in the Object Storage pane and set this variable."
            )
        
        self.bucket = self.client.bucket(self.bucket_name)
    
    def upload_file(self, file, folder='uploads'):
        """
        Upload a file to object storage
        
        Args:
            file: Werkzeug FileStorage object
            folder: Folder name in the bucket (default: 'uploads')
        
        Returns:
            str: Public URL of the uploaded file
        """
        if not file or not file.filename:
            return None
        
        # Generate unique filename
        original_filename = secure_filename(file.filename)
        file_extension = os.path.splitext(original_filename)[1]
        unique_filename = f"{uuid4()}{file_extension}"
        object_name = f"{folder}/{unique_filename}"
        
        # Upload to bucket
        blob = self.bucket.blob(object_name)
        blob.upload_from_file(
            file.stream,
            content_type=file.content_type or 'application/octet-stream'
        )
        
        # Make the blob publicly accessible
        blob.make_public()
        
        # Return the public URL
        return blob.public_url
    
    def get_blob(self, url):
        """Get a blob object from a URL"""
        if not url or not url.startswith('https://storage.googleapis.com/'):
            return None
        
        # Extract blob name from URL
        parts = url.replace(f'https://storage.googleapis.com/{self.bucket_name}/', '')
        return self.bucket.blob(parts)
    
    def delete_file(self, url):
        """Delete a file from object storage"""
        blob = self.get_blob(url)
        if blob and blob.exists():
            blob.delete()
            return True
        return False